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Contents 30 CSOTVOERRY
New evidence of DNA in
dinosaur babies has brought new
hope for the dream of reviving
dinosaurs. But some scientists
remain sceptical. New sterile
bone hunts and research
into the artificial creation
of fossils aim to provide
ISSUE #79 38 46
AUSTRALIAN SCIENCE ILLUSTRATED MYSTERY OF A TWO-SPEED UNIVERSE SUMMER BLOODSUCKERS
PUBLISHED 19 NOVEMBER 2020
The universe is expanding, but when scientists try to We love the summer – but so do mosquitoes, ticks and
calculate how fast it’s happening, they get two different other creatures that have learned the nutritional value
answers. It means we’re missing something fundamental. of human blood. Find out how they get under your skin...
52 REGULARS EDITORIAL
AND OTHER Editor: Jez Ford
GOOD HAIR DAY! FEATURES [email protected]
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follicular challenges. 10 SCIENCE UPDATE
Scientists are finding [email protected]
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including hair grown Mars, help for the Barrier
in a laboratory. Reef, and organic wine ducks. Production Manager: Peter Ryman
Associate Publisher: Daniel Findlay
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THE SCIENCE ILLUSTRATED CREDO
We share with our readers a fascination
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scienceillustrated.com.au | 5
6 | SCIENCE ILLUSTRATED
Metre-long ‘King Ragworm’
feeds on rotting whales
The ‘King Ragworm’ (Alitta virens) can
grow to more than a metre in length; a
Russian photographer captured this example in
the Russian White Sea. Despite its name, the worm’s
life is not very regal. It resides in the darkness of the
deep sea, in burrows lined with its own mucus, or
feeding on the bones of dead whales and fish that
have sunk to the bottom. Although called the ‘King’,
it is not the biggest of its kind. The bristle-worm
Eunice aphroditois can grow up to three metres long.
Photo // Alexander Semenov
scienceillustrated.com.au | 7
Science meets art in ‘Quantum
Memories 2020’ artwork
The gigantic, ever-changing immersive multimedia
artwork envisaged on the right will be a centre-
piece for the National Gallery of Victoria’s ‘NGV Triennial
2020’, which opens free to the public on December 19.
Turkish-born L.A.-based artist Refik Anadol has worked
with Google’s AI Quantum research division to harness
data from more than 200 million nature-related images
from publicly-available internet resources, composing
his visuals and accompanying audio using a generative
algorithm (second inset) enabled by artificial intelligence.
Images // Refik Anadol
8 | SCIENCE ILLUSTRATED
scienceillustrated.com.au | 9
THE LATEST FINDINGS AND DISCOVERIES
Best home identified for
first Martian colonists
Astronauts inhabiting a permanent Mars base will need to be protected against cosmic radiation
more than 10 times the levels they would experience on Earth. The solution may be to live in
volcanic lava tunnels, and scientists have now identified the ideal location to look for them.
S P A C E Scientists and science-fiction writers have long suggested the great plain of Hellas Planitia in the southern
suggested that the safest place to build a base on Mars might hemisphere, one of the lowest-lying areas on the planet, so that
be in lava tunnels created by volcanoes that are now extinct. radiation must pass through more of Mars’ atmosphere before it
strikes the surface, reducing radiation levels by 50%. That’s still
Unlike Earth, Mars does not have a magnetic field that too high – 25% more than levels encountered by astronauts on
protects against radiation. So anyone going to live on Mars will the International Space Station during stays which typically last
require some other protection, and according to scientists from only a few months. But a tunnel location would
the Center for Planetary Science in the US, the solution could be reduce the radiation still further. The scientists
to go underground. Lava tunnels are a possibility – as depicted in have used similar tunnels on Earth to find out
Ron Howard’s 2016 sci-fi/doc series ‘Mars’. Scientists have how well they protect against radiation, and
scrutinised close-up images of Mars and have the analyses indicate that the radiation in a
found evidence that partly collapsed tunnels
exist near several extinct volcanoes. tunnel would be only 18% of the level on
the surface of Hellas Planitia. If a tunnel
But the very best location would be in could be identified in this area, it would
areas of the Red Planet already less affected be the optimum place to build a base.
by radiation. In this regard scientists have
50 m NASA A Mars base would be most
efficiently protected against
Scientists are searching for holes in cosmic radiation if it were built
the surface of Mars that indicate the existence of
underground lava tunnels. The best place to look is the in underground caves.
Hellas Planitia plain in the southern hemisphere.
10 | SCIENCE ILLUSTRATED
Editor: Jens E Matthiesen
Lava tunnels are
500+ million years old
The underground tunnels on Mars were
created by processes in the planet’s
past, when it still had active volcanoes.
Bleached coral reefs are evidence that coral polyps are dying. When the water gets too warm,
the polyps lose the algae that supply vital energy via photosynthesis.
ERUPTION DRILLS THE TUNNEL Mutant algae may help Barrier Reef
1 When the original volcanic cone is The great reefs of the world’s oceans are threatened by global warming,
clogged with hardened lava, a but help may be on its way in the form of new Australian-developed algae.
new eruption can force the lava to take
other routes through the ground. The
result is a horizontal tunnel. B I O L O G Y Ocean temperatures are Scientists from the University of
rising, and coral reefs are early victims. Melbourne have developed algae
TUNNEL DRAINED OF LAVA The reefs host the greatest variety of mutants that tolerate higher temper-
animal species in the oceans, with our atures. From one single alga, the
2 After the eruption, the pressure Great Barrier Reef supporting 1625 scientists spent four years breeding
on the lava flow decreases. species of fish, and more than 3000 100 generations and acclimatising
species of mollusc. Scientists now hope them to water temperature of 31˚C,
Instead of being pushed out into open to make the corals more robust by means the ocean temperature during a typical
of an organism developed in the lab. heat wave at the Barrier Reef. In
air, the liquid lava remaining in the subsequent aquarium tests, the best
Corals coexist with algae in a algae variants showed promising results,
tunnel seeps away into the ground. symbiosis that is vulnerable to even with coral polyps absorbing the algae and
minor temperature change. The algae retaining them even when scientists
are protected in the skin cells of the coral increased the temperature to 31˚C.
polyps, supplying energy for the polyps
via photosynthesis. But when ocean The scientists explain that the heat-
temperatures rise, the algae become tolerant algae developed an ability to
overheated, causing the polyps to spit curb photosynthesis, so releasing less
them out of their cells. The result is coral toxic waste. The scientists will now study
bleaching, in which the corals turn white the genetic change in more detail to see
– and can die of starvation. if the algae can manage in the wild.
Light well Test yourself Answers to p82. No peeking!
TREMOR CREATES ENTRANCES 4: 19. The three numbers at the 1: Sol. The equation: A + B + C = 84.
centre of the 3 cubes are 7, 9 and 3, Replace A + C with 2B. 3B = 84 or B = 28.
3 Over time, the hollow tunnel will be totalling 19. In the same equation, replace B + C
subjected to tremors – such as with A. 2A = 84 or A = 42. So Luna
5: C. See page 15. 6: D. See page 72. has 42 books, Sol 28, and Sirius 14.
during a meteor strike. This makes the 7: C. See page 45. 8: B. See page 64.
2: 14. In every box, the total of the
cave collapse in some places, creating diagonal numbers is the same.
9 + 8 = 3 + 14 = 17
light wells and entrances from the outside.
3: Pierre. Aside from the
SEFRINA ARIFIN shape-fitting, you may
have recognised Marie and
Pierre as the Curies, one of
science’s most famous
couples. Marie Curie’s story is
told in a new movie, Radioactive,
just released in Australia.
scienceillustrated.com.au | 11
Bats and ducks are keeping
South Australian wine organic
S U S T A I N A B I L I T Y ‘Wildlife managers. Organic produce done ANGOVE ORGANIC / INSET: HILLS AND FLEURIEU LANDSCAPE BOARD
for Wine’ is an initiative of the Hills properly requires a sustainable
and Fleurieu Landscape Board in eco-system in which natural Ducks eat around 400kg of slugs and snails per season at Angove Organic,
South Australia, and it aims to processes do the jobs for which while boxes for microbats (inset) help reduce flying pests.
highlight environmental impacts chemicals may more commonly be
to those in the winemaking used to increase efficiency and
business. Started in 2018 in yields. Here the bat population
McLaren Vale and since expanded keeps insects at bay, which avoids
to the Barossa, the initiative pesticide spraying so that natural
includes planting native vegetation enzymes, bacteria and compounds
to encourage beneficial insects, can thrive and flourish. The ducks,
and the installation of boxes to meanwhile, eat their way through
host microbats in vineyards. around 400kg of slugs and snails
per season, while also fertilising
Fifth-generation McLaren Vale the soil. Angove further employs
winery Angove (famous, aside from bee-hive hosting, along with more
its wines, for inventing the wine modern tech including drones and
cask in 1965) maintains its Angove imaging from space to obtain a
Organic vineyards with the fully-informed appraisal of the
assistance of both microbats and health of their vines.
Indian runner ducks as pest
BEAUCHAMP ET AL./CELL Electrodes in the brain can
make blind people ‘see’ letters
Blind people can make out letters drawn with electrodes
directly on the surface of the brain’s centre of vision.
Electrodes on the surface of the brain’s centre of vision draw simple M E D I C I N E A new method our field of vision. The scientists
shapes for blind people, which they can reproduce on a computer screen. that stimulates the brain’s have tested the method on
centre of vision can allow blind blind people and others,
Blind people can ‘see’ a letter when the electrodes are activated people to see letters and other implanting electrodes at the
dynamically – as if the letter had been drawn in the palm of a hand (right). simple shapes. It is the first step centre of vison in connection
towards hooking a video camera with epilepsy treatment. Both
up to the centre of vision. groups could decode the figures
formed by the electrodes and
The method, developed by draw them on a computer
scientists from the Baylor display. The test subjects
College of Medicine in the US, is described the experience as
most comparable to our sense seeing shining points or lines
of touch. If a letter N was simply that shaped the figure.
pressed into the palm of your
hand, you almost certainly So far, the resolution is
couldn’t identify it. But when it limited by the number of
is drawn across the palm of your electrodes. The surface of the
hand, it is obviously an N. brain’s centre of vision includes
some 0.5 billion nerve cells, and
Similarly, a set of electrodes the experiment stimulated only
implanted on the centre of a fraction of those. According to
vision can create recognisable the scientists, the resolution
figures if they are activated in a will improve as better implants
dynamic sequence. The surface are developed with thousands
of the centre of vision is a kind of small electrodes located
of map, where each small area closer together.
corresponds to a specific area of
12 | SCIENCE ILLUSTRATED
SHUTTERSTOCK Once solar panels in deserts are heated
above 25˚C, their energy generation
begins to decrease.
Sweaty solar panels
Solar power plants in deserts are easily overheated, but water-absorbing gel
can cool them back down – and increase their energy generation by up to 19%.
T E C H N O L O G Y Engineers across the solar power stations, desert temperatures air humidity relatively high. During the
world are searching for ways to improve can be a problem, with the panels heating day, when temperatures rise and air
the efficiency of solar panels. As new to more than 40˚C, when their energy humidity falls, the water then evaporates
materials and designs are tested, any generation is already affected at just 25˚C. from the gel again.
efficiency improvement – even a few
percent – is announced as a breakthrough. Scientists from the Hong Kong The scientists added a layer of the gel to
Polytechnic University have now solar panels to test if the evaporation of
Most solar panels convert only around introduced an ingenious idea that can help water could cool them. The effect was
20% of solar energy into power, and that’s the solar cells get rid of the heat – they surprising. The sweating gel cooled the
measuring them in laboratory conditions. have taught solar panels how to sweat. solar panels by up to 10˚C, while energy
The vast majority of solar energy turns generation increased by 15%. When the
into heat, and solar panels function less The main element of the invention is a scientists tested the set-up outdoors, the
efficiently when they are overheated. So gel made of carbon nanotubes mixed with gain proved to be even higher at 19%,
while desert regions might otherwise seem polymers that are linked with calcium because the cooling was still more efficient
obvious locations for the construction of chloride. The gel absorbs water vapour at in the presence of wind.
night, when temperatures are low and the
New method protects solar panels against heat stroke
A new gel collects water at night and cools solar panels during the day, making them more efficient.
Water molecule Vapour
GEL ABSORBS LIQUID AT NIGHT SOLAR PANELS SWEAT IN THE DAYTIME
1 During the night, when temperatures are low and air 2 During the day, when solar panel temperatures get too high,
humidity is high, the solar panel gel absorbs water molecules. the heat migrates to the gel, which emits the water as vapour.
scienceillustrated.com.au | 13
Mars was once a ringed planet –
and its rings will return
New computer models show that the Red Planet’s two moons have a dramatic past. Phobos,
the innermost moon, probably formed from the dust of a ring only 200 million years ago.
A S T R O N O M Y An effort to explain the path of one of the towards the Martian surface, making the bigger moon migrate
moons of Mars has led to a surprising conclusion: Mars has a inwards again until the planet’s gravity ripped it apart to form a
past in which various moons formed and disintegrated. During new ring, which subsequently collected into a new moon. So
some period, the Red Planet must have had rings like Saturn – Mars has switched between rings and moons several times
and it probably will develop rings again in the future. before Phobos, the present innermost moon, formed. This is now
migrating inwards, expected to disintegrate in 30-50 million
Scientists from Purdue University and the SETI Institute in the years, when Mars would become a ringed planet again.
US have created separate computer models to find out why the
outermost moon, Deimos, has a path that slants two degrees The scientists’ theory could be confirmed in 2024
away from Mars’ equatorial plane. The most likely explanation is when the Japanese MMX space probe arrives at
that at some point, the moon was influenced by the gravity of a Phobos, aiming to take samples of the surface
bigger moon, around 20 times heavier than Phobos, which which could accurately indicate the age of
slowly migrated outwards. And that could only happen if the the moon. The ring-planet-ring theory
bigger moon itself was influenced by a ring system. predicts that Phobos formed only 200
million years ago, at the time when
So scientists believe that Mars had rings until some three dinosaurs ruled the Earth.
billion years ago, until the material of the rings was drawn
Mars moons have a dramatic past
The innermost Mars moon, Phobos, is the last of a series of moons
that have been crushed by gravity to form a ring around the planet.
RINGS FORCE MOONS OUT RINGS DISINTEGRATE INNER MOON IS CRUSHED
1 Three billion years ago, Mars had 2 The rings later disintegrated 3 As the large inner moon
rings that influenced two moons as the matter in them was migrated inwards, it was
– a large inner moon and an outer one: drawn to the planet’s surface by increasingly influenced by gravity.
Deimos. The influence provided Deimos gravity. The two moons both began Finally, the moon was torn apart, and
with the slanting path it still has today. to migrate towards the planet. the remains of it formed a new ring.
14 | SCIENCE ILLUSTRATED
Editor: Jens E. Matthiesen
In 2024, a Japanese probe will GE RENEWABLE ENERGY/LAFARGEHOLCIM/COBOD
arrive at the Martian moon of Phobos.
Samples should establish its precise age.
A new 3D-printed concrete structure can double the height of wind turbines. The method
was tested on a 10-metre-high prototype printed in Copenhagen, Denmark, in 2019.
Wind turbines grow by 3D printing
New concrete foundations will be printed directly at the site of the wind
turbine, solving transport issues and paving the way for far higher turbines.
T E C H N O L O G Y American energy mounted to reach a combined height of
company GE Renewable Energy will use 200 metres. Engineers from the company
3D printing to build wind turbines 100 COBOD tested the method in October
metres higher than existing ones. 2019, printing a 10-metre-high prototype
in Copenhagen. The tubular concrete
One problem with land-based wind structure consists of interior and exterior
turbines is the difficulty in carrying huge shells linked by wave-shaped structures.
parts to the often remote locations in Both the shells and the links between
which mills may be erected. The lower them are 3D-printed.
part of the turbine is made of concrete,
and turbine bases are generally Higher wind turbines can access the
restricted to a width of 4.5 metres, stronger winds of higher altitudes, which
simply because the parts must be carried are also more stable, as turbulence
on roads to the site. This limits existing caused by buildings and trees is reduced.
turbines to heights below 100 metres. This means that a 5-megawatt turbine
able to generate some 15GWh of power a
‘Printing’ the lower sections on site year at 80 metres could increase its
means that bases can be wider, and so generation to more than 20GWh when
completed turbines can be much higher. raised to 160 metres high.
The company plans to build turbines in
which the lower concrete part reaches The highest land-based turbine is in
80 metres into the air, on top of which Gaildorf, Germany, built on top of a water
the actual turbine, made of steel, will be tower to reach a height of 178 metres.
RINGS COLLECT INTO MOON
4 The material of the ring collected NASA/SHUTTERSTOCK/KEN IKEDA MADSEN
into a new moon. The process
repeated itself, forming the current
inner moon of Phobos after several is the likely increase in
generations of rings and new moons. power generation when wind turbines
can be built twice as high.
scienceillustrated.com.au | 15
On long space missions,
hibernating astronauts could
save energy, avoid being
bored, and live longer.
Teaching humans to hibernate
New experiments have manipulated mice and rats into hibernation, even though they do not
do so naturally. It’s a step towards allowing astronauts to sleep away the tedium of space flight.
M E D I C I N E The idea of making their bodies consume a minimum amount scientists think that this indicates it should
astronauts hibernate on long space of energy. The Japanese scientists made be possible to make all mammals
missions often appears in science fiction, mice do the same thing by activating hibernate, including humans. In the long
but now it is one step closer to reality. specific cells, known as Q neurons, in the term, it might be possible for astronauts
Scientists from the University of Tsukuba in hypothalamus brain centre which controls to hibernate on space missions of several
Japan have made mice and rats hibernate, a series of basic bodily functions. The body years, which would serve three purposes –
even though they do not do so naturally. temperature of the mice fell 10 degrees, they will not get bored, they will need
with cardiac rhythm and breathing also fewer supplies, and they will live longer,
Several mammals can reduce their reduced. The state lasted for 48 hours as hibernation is easier on their organs.
bodily functions during months in which with the mice suffering no apparent harm.
food is scarce – bears, hedgehogs, and But there is also medical potential
bats all do so, as do a few primates such In nature, mice can hibernate for a few down here on Earth. Patients with breathing
as lemurs. They all lower their body hours, so the scientists repeated the difficulties could be saved by hibernation
temperature and cardiac rhythm so that experiment with rats, which can’t. The temporarily reducing their oxygen demand.
HKoibret rtnegantiinnggmruicberik HIBERNATION BEGINS
TAecgtinviantgiomnaonf Q neurons in the brain can 2 When the Q neurons
make mice hibernate, according to are activated, the
new ground-breaking research.
mice become dull. They
move less, with their pulse
rate, metabolic rate and
oxygen uptake all reduced.
ACTIVE MICE HAVE TEMPERATURE
HIGH METABOLISM SHOWS DIFFERENCE
UNIVERSITY OF TSUKUBA/SHUTTERSTOCK 1 Without stimulation of 3 Measurements of
the brain’s Q neurons, infrared heat radiation
mice are physically active from the mice shows that
and have a high pulse rate, their body temperature falls
a high metabolic rate, and a by about 10 degrees.
high oxygen uptake.
16 | SCIENCE ILLUSTRATED
Artificial sloth could be left GEORGIA TECH
alone to monitor rainforests
An ultra-slow robot could and keep an eye on the ecosystem’s The SlothBot was designed to mimic a sloth. It requires so little
provide new knowledge about populations, such as the interaction energy that it is able to manage on its own for months.
endangered animals and plants. between predators and prey, or
plants and pollinators.
T E C H N O L O G Y Scientists from
the Georgia Institute of Technology The SlothBot can hang around
have developed an ultra-slow robot for months or even years, and so
that is just as energy-efficient as its could provide biologists with
model: the sloth. The 0.9-metre- important extended knowledge
long SlothBot moves along a steel about the delicate balance of the
wire extended between two trees – rainforest ecosystem.
but only when necessary. It is
powered by solar cells and The robot is tested in the Atlanta
automatically seeks out sunlight Botanical Garden, where it moves
when it needs a recharge. Other- along a 30-metre-long wire. The
wise it saves energy for its real next step will be to install one in a
purpose: measurement. Equipped South American rainforest, where it
with a thermometer, hygrometer, will monitor primarily orchids and
CO2 detector, and cameras, it is to endangered frogs. As this may
monitor the rainforest environment require it to cover a large area,
scientists are working on a way for
it to move from one wire to another.
KYUNG SOO KIM ET AL./NATURE/ R. ANTHONY ROMILIO Prehistoric croc was faster
on two legs, despite flat feet
Scientists have found evidence that crocodile ancestors
walked on their hind legs – like a Tyrannosaurus rex.
These 120-million-year-old footprints reveal that a prehistoric P A L A E O N T O L O G Y Modern on their flat feet, putting their
crocodile roamed the Earth without using its forelegs. crocodiles crawl forwards with heels down, as do we. In one of
four legs all to the sides, but the prints, scientists can see a
The distance between footprints and their size indicate that the walking 120 million years ago, a impression of the skin of the
croc’s hind legs were a similar length to those of a modern human. crocodile was walking upright heel, and the texture is much
on two legs in what is now like the skin under the feet of
South Korea, according to modern crocodiles.
footprints that used to present
a puzzle for scientists. Scientists have no fossils,
but have used the size and
The best previous theory distance of the footprints to
was that these were made by estimate that the crocodile,
pterosaurs, but now scientists named Batrachopus grandis,
from South Korea, the US and was about 3 metres long, with
the University of Queensland hind legs the same length as
have ruled out this possibility, those of adult humans.
because there are only rear
footprints. Pterosaurs also used The crocodile put its feet in
their wings to take off, and front of each other in an almost
there is no evidence of that. straight line, below its own
centre of gravity, which is the
Instead, the scientists most energy-efficient way of
conclude that the prints were carrying one’s own weight.
made by a prehistoric crocodile Together with the long legs, it
which walked on its hind legs indicates that the prehistoric
like two-legged dinosaurs. But crocodile was able to move
unlike dinosaurs, which tiptoed longer and faster on dry land
around, the crocodiles walked than can modern crocodiles.
scienceillustrated.com.au | 17
SCIENTISTS ANSWER QUESTIONS FROM OUR READERS
Could CRISPR kill cancer cells?
With the CRISPR-Cas9 genetic scissors, doctors can make
small and accurate changes to cell DNA. Does this mean that
the method could be used in the struggle against cancer?
G E N E T E C H N O L O G Y Yes it could: indeed the University of Pennsylvania entered the
DNA editing using CRISPR-Cas9 ‘gene scissors’ game in 2019, and earlier this year, their
is already used in cancer treatment. But the experiments completed phase 1, in which
most promising editing is not aimed directly scientists focus on the safety of the treatment,
at cancer cells, instead employing immune such as ensuring that it does not have any
therapy to improve the body’s own defences. negative effects. This was completed by the
American scientists in February 2020, and
Scientists extract white blood cells known they are now ready to continue.
as T lymphocytes from patients with incurable
cancer that cannot be removed by surgery and CRISPR-Cas9 is the cheapest and
does not react to ordinary treatment such as most efficient way of editing DNA,
chemotherapy. The DNA of these cells is edited equipping cells with new
using CRISPR-Cas9 so that they stand a better abilities or deactivating
chance of finding and combating the cancer. unwanted genes. Animal
The upgraded cells are then inserted into the tests indicate that the
body. The scientists expect that this method method can alleviate
will be efficient against human blood cancer, several disorders and
leukaemia, and lymph node cancer. achieve remarkable results.
In 2016, a group of blind rats
Chinese scientists began to experiment got part of their vision back
with the method in 2016, but its effects have by means of this method.
not yet been fully documented. Scientists from
Scientists fortify the body’s own defence
Scientists reprogram DNA in a group of white blood cells known as
T lymphocytes using CRISPR-Cas9 gene scissors. The reprogrammed cells
function as specially-equipped ‘soldiers’ that seek out and eliminate cancer.
1 Scientists extract a 2 The T lymphocytes have receptors
type of white blood that are the keys to specific
cells known as T lymphocytes proteins. The scientists deactivate genes
from the patient. that code for the TCR and PD-1 receptors.
Cell membrane TCR gene
line TCR receptor
5 The upgraded cells are inserted
into the patient’s body, where
they are more efficient at seeking
out and combating cancer cells.
18 | SCIENCE ILLUSTRATED
Editor: Esben Schouboe
Blood cells (pink) are ? INSIDE THE BODY
recoded by scientists to
combat cancer (yellow).
Which human bone STIRRUP
is the lightest?
WHERE: In the
The body’s lightest bone is in interior middle
the middle ear. The stirrup is ear, closely linked
only 3.4mm long and in adults with the hammer
weighs around 2.6 thousandths and the anvil.
of a gram. The bone is the last of
a chain that translates sound WHAT: The
into vibrations in the ear fluid. stirrup uses
sound to produce
the ear fluid.
3 Scientists insert DNA from a
virus into the cells and thereby
code for another version of TCR,
but not for PD-1. Is Rudolph’s nose really red?
Virus B I O L O G Y Reindeer do have red
New TCR gene noses, due to a high concentration of
red blood cells. The four-legged animals
4 The T lymphocytes develop new have at least 25% more blood cells in 35°C
TCR receptors with the new DNA their noses than humans. While this 30°C
may have the side effect that Rudolph 25°C
as the template. The receptors can can light up Santa’s path, the nose has 20°C
developed in this way to protect the 15°C
reindeer against extreme cold. The 10°C
increased blood circulation in the nose
prevents freezing mucosa and helps In an experiment with reindeer on a treadmill,
regulate the brain’s temperature. It can infrared camera data showed the nose as
be difficult to see the red nose because red and at around 24 degrees Celsius.
many reindeer are greyish brown with
dark skin on their noses. In white
reindeer, the nose becomes red after
physical exercise – just as people get
rosy cheeks due to blood circulation.
recognise proteins on cancer cells. INCE ET AL.
STEVE GSCHMEISSNER/SPL & KEN IKEDA MADSEN
New TCR receptors
scienceillustrated.com.au | 19
Why does snow creak?
C H E M I S T R Y The creaking sound so the points of the crystals have SHUTTERSTOCK
of winter boots on snow has never had time to merge into a substantial
been scientifically studied. Scientists network that is crushed like glass, Snow probably creaks because the weight of your steps crushes links
believe that the sound comes from and hence emits the creaking sound between snow crystals. The colder the snow, the creakier it gets.
the pressure caused by our body when you step on it.
weight breaking down the small
delicate links between individual The creakiest snow is cold –
snow crystals. This corresponds well preferably colder than -5°C. If it is
with the observation that snow warmer, the pressure from boots
creaks the most when it has been on makes the tiny links melt instead of
the ground for at least a few hours, break, and the sound is not loud
enough for you to hear it.
IN THE GROUND · How small can tectonic plates be?
Tectonic plates are sections of Earth’s crust and uppermost mantle, and their
size varies greatly. The largest is the Pacific Plate of some 100 million square
kilometres, while the smallest known by geologists is the North Galápagos
Microplate which is 1559km2 – a little smaller than Fraser Island in Queensland.
North Galápagos Microplate
THE WORLD’S SMALLEST MICROPLATES BETWEEN MAJOR PLATES MAKE THE
PLATE IS IN THE PACIFIC THREE MAJOR PLATES SMALL ONES ROTATE SHUTTERSTOCK & KEN IKEDA MADSEN
1 The North Galápagos Microplate is 2 Together with the slightly 3 The microplates originated to fill
a small section of ocean floor in the bigger Galápagos Microplate to the gaps between the three big
Pacific some 2000km west of Ecuador the south, the plate is between the ones, whose motions make the small
and 2000km south of Acapulco, Mexico. Pacific, Nazca and Cocos plates. plates rotate in opposite directions.
WORLD RECORDS Why do Christmas Island
How small is the world’s crabs swarm every year?
The beaches of Christmas Island are crowded with red crabs between
The tiniest functional cogwheel October and December. Why do they migrate to the ocean at this time?
was developed in 2016 and can
only be observed through a N A T U R E Once a year on Christmas Island, to coincide with the turning of the tide,
microscope. The six-toothed wheel Australia’s distant territory in the Indian the female releasing their eggs when the
is powered by ‘Janus’ particles, Ocean, some 120 million terrestrial crabs difference between ebb and flow is the least.
tiny particles with two sides that migrate from the jungle to the water to breed.
have different properties. These The crabs swarm during the rainy season, The eggs hatch immediately they come
particles are covered in platinum between October and December. When the into contact with water, the small crabs
on one side, causing them to move air is moist, the crabs are able to complete the developing in the ocean over a period of
in a particular direction through 5-7 day trip without dying from dehydration. about one month, until they are 5mm wide.
hydrogen peroxide. As they They then move back onto shore and begin a
become captured in the teeth, The crabs mate on the beach in small holes nine-day march back towards the rainforest.
they make the cogwheel rotate. in the sand, then the males return to the
rainforest while the females produce eggs. As the crabs migrate across several of the
1/10Tcohgewmhiecerol siscoopnilcy The eggs are then carried to the water’s edge island’s roads, traffic is halted so that cars
of hthuemwaindhthaiorf. a don’t crush too many of the red crabs.
ALAMY/IMAGESELECT & JURGEN FREUND/INGO ARNDT/NATURE PL
C. MAGGI ET AL./SMALL JOURNAL3In December-January, 4 The crab larvae live in
when the tide is the ocean for about a
on the turn, the females month, and then by the
enter the water and water’s edge for 3-5 days.
release the eggs,
which then hatch.
2 The females lay
eggs in holes
in the beach sand –
some 100,000 per
crab – holding the
eggs in a brood ‘pouch’. 5 Once their shells have
hardened, the small
crabs migrate back to
1 The rainy season
runs through October-
December, and the crabs
migrate to the water to mate.
Italy 6 At the age of four, the crabs are
sexually mature and ready to mate.
WHO: Scientists from Italy,
Germany and Spain, sponsored by
the European Research Council.
WHY: The cogwheel is the first
step on the way towards building
scienceillustrated.com.au | 21
What are antioxidants?
B I O L O G Y An antioxidant is reactive, capable of damaging SHUTTERSTOCK
simply a chemical compound body cells, proteins and even
that prevents oxidisation. In DNA, causing early ageing,
the body, oxidative stress can inflammation, and at worst
occur if the balance is disturbed diseases such as cancer.
between antioxidants and free
radicals, which are molecules Antioxidant molecules are
with an unpaired electron. stable enough to donate an
These free radicals are highly electron to neutralise a free
radical. They have become a
SEVERAL VARIANTS OF familiar concept in the field
ANTIOXIDANTS EXIST: of nutrition, as some foods –
such as blueberries and
Selenium from fish, meat, etc. cranberries – carry them in high
Carotenoids from carrots, concentrations, with these
dried apricots, and spinach ‘superfoods’ considered to have
Polyphenols from blue- a positive effect on our health.
berries, green tea, wine, etc.
Vitamin E from nuts, etc. Antioxidants are substances that
Vitamin C from citrus fruit, etc. neutralise free radicals that
could otherwise cause
inflammation and disease.
WHAT IS THIS? · Nanothreads made of zinc oxide
Scientists can PEIDONG YANG/UC BERKELEY/SPL
as zinc oxide.
> of zinc oxide are
measuring a few
nanometres – so tiny that
they can only be observed
in an electron microscope.
> filaments can be
grown via thermal
evaporation. The method
converts zinc oxide into a
gas that subsequently
crystallises as ‘threads’ on
> are semiconductors
and can be used in
transistors that act as
biosensors along with
organic sensory material.
They can, for example,
measure glucose content in
the blood for diabetics.
22 | SCIENCE ILLUSTRATED
IS IT REALLY TRUE THAT...
... bacteria can feed on oil pollution?
Oil spills are lethal to the environment, as evidenced by the BP Deepwater Horizon explosion in
2010. But where does uncollected pollution go? Is it eventually broken down in the ocean?
C H E M I S T R Y Scientists know of more than 500 organisms that nutrients to ocean water which will improve conditions for the
can consume different types of hydrocarbons, including oil. The bacteria to break down as much oil as possible.
most specialised is a genus of bacteria known as Alcanivorax,
which survives almost solely from breaking down crude oil. The The bacteria use the oil as an energy source and break it down
species that usually contributes most to the natural clean-up is by oxidising the carbohydrates. The waste products are carbon
Alcanivorax borkumensis. The rod-shaped bacterium thrives in dioxide and water. Oil-consuming bacteria were active after the
warm oxygen-rich salt water. However the nutrients of nitrogen Deepwater Horizon spill in 2010. Scientists from the University of
and phosphorus must be available – otherwise the oil breakdown Rochester in New York calculated that Alcanivorax borkumensis
process comes to a halt. In cases of pollution, biologists can add and other bacteria together consumed some 200,000 tonnes of
carbohydrates, primarily crude oil and natural gas.
Floating slick-cleaner encourages
bacteria while scaring off animals
Oil-degrading bacteria exist naturally in most environments, but only in low
quantities. So it takes time before they reproduce sufficiently to counteract
an oil spill. Technology such as the BIO-Cleaner can accelerate the process.
Oil and ocean water are CO2 3 The oil is broken down
sucked into the BIO-Cleaner, into carbon dioxide and
water, which is released to
where a filter isolates the oil. the surroundings.
2 Oil and oxygen are
pumped into the
H2O Sound waves scare LÜNSDORF/HZI & SHUTTERSTOCK & KEN IKEDA MADSEN
marine animals away
4 The Alcanivorax borkumensis bacterium
feeds almost exclusively on crude oil,
from the oil pollution. which it breaks down via oxidisation.
scienceillustrated.com.au | 23
Why do silverfish
live in bathrooms?
“I have silverfish in my bathroom, and I am puzzling over two things:
where do they come from, and why do they seem to exist only in bathrooms?”
Z O O L O G Y If you have silverfish in your bathroom, laundry in a study, then there can be
room or basement boiler room, it is primarily a symptom of high greater consequences.
air humidity, usually in combination with high temperatures. In kitchens the small
silvery creatures eat
It’s often said that silverfish will be more likely to invade a sugar, and if they infest
bathroom if it is dirty. This is true to the extent that silverfish bookshelves they may
consume anything with starch in it – such as skin scales – so a eat the glue that
dirty bathroom will offer more food for the insects. holds books together. They can damage art and stamp
collections, or family photo albums.
But silverfish rarely cause much trouble in bathrooms.
They can neither bite nor sting nor transmit diseases. The best way to get rid of silverfish is to air out the rooms
However, if they move into kitchen cupboards or behind books of your home often, so the air
humidity is reduced.
Silverfish depend Silverfish belong to one of the
on humans most primitive groups of insects, and
can be recognised easily by their
Silverfish often live in silvery colour, long antennas, and
moist soil, but a few the three long bristles on their
species, such as the ordinary abdomens. The insect has existed for
silverfish and the firebrat (which some 400 million years almost
prefers warm environments), unchanged, and was probably one of
live so successfully in close the first creatures to leave the oceans
proximity to people and their to live on dry land. Silverfish
homes that they now hardly originated at a time when insects
exist in the wild. hadn’t yet developed wings, and
silverfish remain wingless today.
What happens in the A lisp can be caused by an
mouth to cause a lisp? unusually short frenum
P H Y S I O L O G Y Lisping occurs when the air from the which redirects air flow from
vocal chords flows out in places other than the normal the ‘normal’ locations.
ones, such as between the lateral edge of the tongue
and the molars. It is often observed in young children as Short frenum
they learn how to speak, as incorrect tooth positions
can cause a lisp. But it can also be a permanent SCIENCE PICTURE LIBRARY
condition, the primary cause being a frenum that is
too short, so the person does not produce normal ‘s’
sounds. Children’s lisping typically stops after the age
of five, and speech specialists can often train lispers to
reduce or eradicate the effect. But it’s not always an
impediment. People from Catalonia speak with a lisp-
like ‘s’ deliberately, as the language uses a specific
phoneme which differs from most Spanish usage.
24 | SCIENCE ILLUSTRATED
Editor: Esben Schouboe
Silverfish take three years to grow up
After extensive courtship, the male leaves a packet of sperm cells
on the floor for the female to absorb, eggs are laid in cracks and
crevices, then the offspring faces a long road towards adulthood.
FEMALE LAYS EGGS EGGS HATCH YOUNG CHANGE SILVERFISH BECOME SHUTTERSTOCK & STEVE GSCHMEISSNER/SPL
AFTER MATING PALE OFFSPRING SKIN AND COLOUR FULLY GROWN
1 After mating, the 2 After 2-8 weeks, 3 Silverfish offspring 4 After three years, the
female lays her the eggs hatch. The cast off their skin, offspring are fully
eggs, typically 50-60, in offspring resemble small, growing a little each time grown. They can live up to
small cracks and crevices. pale copies of the adults. and gaining colour. eight years.
SCALE · Are there more sand grains than water molecules on Earth?
Water SHUTTERSTOCK 6000Awsaitnegrlceolnittraeinosf SandSHUTTERSTOCK
A water molecule mtthoismleaeonncboenuudsneamlamgEelclrsbahoatrethreithrensheaos.nf Sand is considered to
consists of 2 hydrogen be mineral grains,
mainly quartz, of up
atoms and 1 oxygen to 2mm that form as
atom. Water can be rock such as granite
solid (ice), liquid, or is broken down. The
number of sand
gaseous (steam). grains on Earth’s
One litre of water beaches is estima-
includes 33 septillion ted to be some 5.6
(24 zeros) molecules, sextillion (21 zeros).
and the oceans contain
1.3 sextillion (21 zeros) Sand grains measure
litres of water.
5.6 × 1021 sand grains
1 litre of water includes exist on Earth's beaches.
33 × 1024 water molecules.
scienceillustrated.com.au | 25
Earth’s oceans contain
1.3 × 1021 litres of water.
Does the Moon influence The Moon The Moon
things other than the oceans? makes Earth's
The Sun crust rise by
can pull up to 14.4cm.
A S T R O N O M Y The Moon’s gravity Earth crust waves travel across the up by 6.6cm.
affects all water on Earth, whether in planet: one facing the Moon and one
oceans, lakes, streams, even in your facing in the opposite direction — the Sun
bathtub. But only seas and oceans are phenomenon is known as crustal tides.
big enough for the effect to cause a Crustal tides caused by the Moon have Note: The illustration is not to scale. The rises SHUTTERSTOCK
wave, and hence tides. And it’s not only a maximum ‘bulge’ height of 14.4cm. are very small compared to the whole planet.
water — the Moon influences Earth’s The Sun also influences the crust,
crust as well. Just like global tides, two causing a deformation up to 6.6cm.
HOW THINGS WORK · How does an electric toothbrush charge wirelessly?
Wireless charging works according to the same principle
as a transformer. An alternating current is directed through
a copper coil, producing a magnetic field, and that field
makes an alternating current flow in another copper coil.
The toothbrush charges even though it is sealed in plastic.
3 The alternating
current of the
Battery secondary coil is converted
into a direct current
which charges the
FROM WALL TO COIL
1 An alternating
current from a socket
outlet produces a magnetic
field in the primary coil
located in the charger.
Direct current transformer Iron core
Secondary coil Primary coil
2 The magnetic field is
amplified by an iron core,
making an alternating current
flow in the secondary coil inside
CLAUS LUNAU the toothbrush.
26 | SCIENCE ILLUSTRATED
Which tree is the
tallest in the world, and
where is it located?
In a park on the American west
coast, one tree towers above all
others in the world: the 115-metre-
high Hyperion, named after one of
the Titans of Greek mythology.
Hyperion is a type of redwood
which does not live in any other
place of the world, as it requires a
special combination of moderate
coastal climate and fog.
115mweootfrrHeldsy'sipsettarhiloleenhs,tettihgreehet. High sugar concentration
contributes to honey having
CALIFORNIA an extremely long shelf-life.
Huge American tree Does honey really
never go off?
WHERE: Redwood National and
State Parks, a few kilometres from “I heard that honey has no expiry date. Is that true?”
the US west coast.
WHAT: The world's tallest conife- C H E M I S T R Y If honey is eliminate both bacteria and When archaeologists excavated SHUTTERSTOCK & THE NEW YORK TIMES/SCANPIX
rous tree, Hyperion – a redwood of kept in a jar with a tight- fungi. The honey’s Tutankhamun’s tomb in the
the species Sequoia sempervirens. fitting lid so that no moisture concentration of sugar is 1920s, they found honey that
can enter, it should last another important cause was still edible.
effectively forever. The of long durability. Honey
lack of an expiry date is contains approximately
due to a combination of 80% sugar, which binds
very high sugar content, the liquid. But the sugar
special enzymes, and low also sucks liquid out of
water content. bacteria, thereby causing
them to dry up and die.
When bees suck nectar
from plants, they add Moreover, honey is
enzymes that change the relatively acidic, with a pH
types of sugar found in the value of some 3 to 4.5 (7 is
nectar. Some of the sugar is neutral). Most bacteria and
split into glucose acid and fungi cannot survive in such
hydrogen peroxide, which an acidic environment.
scienceillustrated.com.au | 27
Can a brain injury give
you amazing new abilities?
N E U R O L O G Y In rare cases, a ordinary gifts in others, such as REBA MCCONNELL
brain injury can either cause or music, maths or art. In the
activate new abilities, in a acquired syndrome these abilities
condition known as “acquired only find expression after an
savant syndrome”. Savants are accident, or in connection with,
people who may lack skills in say, Alzheimer’s. According to
some areas yet have extra- theories, the syndrome can
originate in two ways — either
NEW CAPACITIES by the brain injury impeding
rational brain activity that
Music: Following head injury, would normally curb creative
Derek Amato could suddenly expression, or the injured brain
play seven instruments. cells stimulate growth and
activity in brain centres that
Maths: Jason Padgett provide the new gifts.
geometry after a concussion. Derek Amato hit his head against a
swimming pool floor. After the
Art: After suffering brain accident, he suddenly began to
injury as a child, Alonzo
Clemons became a capable compose music and play the piano.
WHAT IS THIS? · Gooseneck barnacle
These red-lipped MINDEN/RITZAU SCANPIX
stalks lined with
barnacles, a type
> known as Pollicipes
polymerus is related
to balinidae and typically
lives on stones or other
hard surfaces to which they
attach by means of stalks up
to 15cm long.
> barnacles often
pigment that protects them
against sunlight. However,
the Nakwakto species
shown in this photo lives in
deeper waters and does not
have the same pigment, so
that the brighter red colour
The white shells
> protect the animal’s
body, which can
grow up to 4.5cm long.
The stalk includes edible
meat that is said to taste a
little like lobster.
28 | SCIENCE ILLUSTRATED
IS IT REALLY TRUE THAT ...
Venus and Jupiter in 2 BC, or Jupiter
and Saturn in 7 BC – could these
have caused a phenomenon in the
sky for three ‘wise men’ to follow?
THEORY 2 Jupiter
Another candidate for the bright star
above Bethlehem is the conjunction
between Jupiter and Venus in June of
the year 2 BC. Observed from Earth, the
two bright planets would have merged.
... a bright star shone THEORY1
above Bethlehem? 29 MAY 29 SEPTEMBER 5 DECEMBER
According to the Bible, a star shone very brightly before
and when Jesus of Nazareth was born. Could this be true?
A S T R O N O M Y The shining star According to modern astronomers, Jupiter
that heralded the birth of Jesus is the last of these is the most likely
mentioned only in the Gospel of explanation. Particularly notable in Saturn
Matthew, and the text is not very this regard is a triple conjunction that
scientifically informative, making it occurred between the Solar System’s Earth
difficult to identify the star as a two biggest planets, Jupiter and
celestial event. The uncertainty of an Saturn, in 7 BC. Three times within The Bethlehem star
accurate date for the birth of Jesus seven months the two planets passed could have been a rare
further complicates an identification. closely by each other, an event which triple cosmic conjunction
happens only once every 900 years.
That hasn’t stopped scientists The two bright planets merging in the Three times in the year 7 BC, Jupiter
offering a wealth of explanations over sky might well have made such an and Saturn were very close when
the years for what led the three wise impression that the light could have observed from Earth, so emitting very
men to Bethlehem: suggestions have been considered a sign from God. powerful light. The first conjunction
included a comet, a nova, a took place in May, the last in December.
supernova, the planet of Venus, The timing of the celestial events
a powerful shooting star, and a is consistent with historical estimates GETTY IMAGES
constellation of bright planets of the year in which Jesus was born,
combining to emit bright light. placing this between 4 BC and 8 BC.
scienceillustrated.com.au | 29
THE PAST DINOSAURS
In the film Jurassic Park,
DNA and revive the
SHUTTERSTOCK & CLAUS LUNAU
30 | SCIENCE ILLUSTRATED
By Antje Gerd Poulsen
New evidence of DNA in
dinosaur babies has breathed
new life into the hope of reviving
dinosaurs. But some scientists
remain sceptical. Artificial fossil
creation and sterile dinosaur
hunts are providing answers.
scienceillustrated.com.au | 31
THE PAST DINOSAURS
The tools to revive
ancient dinosaur DNA
Drilling machines, DNA printers, and artificial eggs –
we have the tools, and if the claims of DNA discovery
in dinosaur bones are correct, these techniques might
be used by scientists to bring dinosaurs back to life.
REBOR STUDIO, LONDON, UK
MAX PLANCK INSTITUTE FOR Bone powder Extract DNA
EVOLUTIONARY ANTHROPOLOGY (MPI) is drilled out from bone powder
Scientists pulverise some of
1 the bone and dissolve the
powder into a liquid.
Subsequently they can extract the
DNA and read its sequence. Any holes
in the sequence could be filled by
computer with similar sequences from
modern dinosaur relatives: birds.
SHUTTERSTOCK DNA base Make genetic material
The patched-up genome is
2 printed from the computer.
This happens by combining
small chains of DNA bases,
subsequently gluing the sections
together into larger units. Scientists
have previously used this method to
build bacterium genomes from scratch.
SHUTTERSTOCK Bird genome Transfer DNA
extracted to a bird cell
Dinosaur- The scientists take a fertilised
inserted 3 egg cell from a bird and
carefully remove the DNA of
the cell nucleus without harming the
cell. Then they insert their new
dinosaur genome into the cell.
A similar method was used in 1996
when scientists cloned a sheep.
32 | SCIENCE ILLUSTRATED
aPrltaicfiecciaellleigng W earing a face mask, blue stakes are high for Saitta and potentially for
rubber gloves and a cap all of us, because if it turns out that the
4 tOhveeergagfecewlldays, with a wide brim, the bones really can harbour million-year-old
US palaeontologist Evan DNA from dinosaurs, it will resurrect a
ctviahhdttinaiieiccnsbakahsylneare.etnmTdimdfheieiincenbviwnoreadayslaliiohovatyepeiuiidgasnnriegsn’mbass,tdaiooieconnbvugaetyewglostdi.uhnaatriceoh Saitta looks more like a dream on which scientists had long since
man going shopping during the pandemic given up — reviving dinosaurs.
than a scientist doing field work. But he is in
Canada’s Dinosaur Provincial Park, famous Mosquito blood turned into dinos
for its dinosaur fossils – and that’s why Sait-
ta is wearing protective gear. In the film Jurassic Park, a scientist drills a
hole in a piece of amber to reach a mosquito
He is not afraid of being infected with a that had been captured in the amber
disease. Rather the equipment is there to millions of years ago. Out of the insect’s
protect the fossils from him. He is trying to stomach he carefully sucks its last meal –
avoid any of his own DNA ending up on the dinosaur blood full of DNA. The DNA
bones, because he is looking for any DNA has missing sequences, so these are
that the bones themselves might contain. patched with frog DNA, and when the
completed genome is transferred into an
Saitta’s mission is to settle an ongoing egg, it develops into a real, living dinosaur.
and heated scientific debate. In recent years,
several scientists have claimed sensational When Spielberg’s film opened in 1993,
discoveries of dinosaur bones with evidence the sensational scenario seemed like a real
of soft tissue: blood vessels, cells, proteins, possibility not only to filmgoers, but to
scientists as well. DNA had indeed been
and even DNA. Other scientists say that discovered in insects from amber, and a new
these amazing discoveries have not been genome sequencing method based on tiny
sufficiently tested by independent scien- fractions of DNA had been invented.
tists – and they consider it unlikely that
But since then, the amber discoveries
such delicate molecules could survive have been criticised for being polluted with
millions of years in the ground. modern DNA – and the methods behind the
discovery were criticised as well. Since then,
Evan Saitta is an expert on how tissue several studies have raised questions over
is broken down during the creation of whether DNA could possibly survive for
fossils, and he even creates new fossils millions of years. In 2013, English scientists
from scratch, based on dead lizards studied insects in copal – an intermediate
and birds, to learn more about what state between resin and amber. The insects
happens in the process. He agrees were 60-10,600 years old, and the scientists
with the scientists who think further found no preserved DNA there at all. Nor
testing of the DNA claims is required, have fossilised bones yielded any evidence
but rather than merely expressing of truly ancient DNA. The oldest recovered
doubt, he has gone DNA hunting in an complete genome is from a 700,000-year-old
effort to settle the matter. Back in the horse bone discovered in permafrost.
lab he will subject his discoveries to
everything that modern science has to In 2012, Danish and Australian scientists
offer in the form of electron micro- tried to define an accurate ‘expiry date’ for
scopes and gene sequencing. The
Discovery: Collagen protein. Discovery: Blood vessels
Where: Montana, USA. with blood cells.
Age: 80 million years Where: Montana, USA.
Maximum length: 9 metres. Age: 68 million years.
Maximum length: 13 metres.
scienceillustrated.com.au | 33
THE PAST DINOSAURS
DNA. They studied the condition of DNA KENTARO CHIBA have the characteristic that they can bind
in bones of different ages from extinct moa only – or almost only – to a specific type of
birds and calculated how the hereditary ma- Palaeontologist Evan Saitta wears rubber gloves protein. Hence they can be used in research
terial became broken down over time. They and a mask in his search for fossils. to find out whether a specific protein is
found that bones would be devoid of DNA present in a specimen. And in Mary
fractions sufficiently large for sequencing dinosaur fossils from Montana, they claim Schweitzer’s experiment, the antibodies
after only 1.5 million years. Since dinosaurs to have found collagen protein in something showed that both the emu and the fossils
– except for birds – disappeared 66 million that resembles cartilage. They have also dis- included evidence of a specific type of col-
years ago, their DNA’s expiry date should be covered tiny cell-like structures, some of lagen which exists in cartilage.
long passed. which may be dividing, while others include
oblong objects that are apparently cell nu- The scientists think that cartilage had
As we detailed in a recent issue, it is also clei – full of DNA. covered parts of the backs of the babies’
possible to retrieve genetic data from pro- heads where bone plates were gradually
teins, because their structure reflects the The discoveries were made in skulls growing together. If the cartilage has been
code of the DNA that led to their creation. from two duckbilled dinosaur babies that preserved, the chances of DNA conservation
The proteins can survive longer than DNA, lived in Montana 75 million years ago. Jack are good. Cartilage is not as porous as bone,
but the oldest proteins that scientists have Horner made his contribution to their dis- so it might offer a more robust container
yet discovered are 2.4 million years old – so covery back in 1979 when he discovered an where DNA could be preserved.
they don’t solve the problem either. entire nesting site known as the “egg moun-
tain of Montana”. The skulls were cut into The scientists also examined whether
Still, the search for ancient DNA and thin discs and conserved, and now scien- the emu’s cells and the cell-like structures
proteins, or other evidence of soft tissue from tists have made new discoveries in the an- from the fossils included DNA. The test to
dinosaurs, has intensified over the past few cient finds. They compared the fossils to determine this involves adding a pigment to
decades, and the epicentre of molecular pal- the skull of a young emu, with both old and the samples which binds to DNA – and in
aeontology is Montana, in north-western new skulls subjected to a series of tests. this case the substance stuck to both emu
USA. It was there that palaeontologist Jack First they were placed in an acid bath to and fossils. The result indicates that DNA –
Horner, a scientific consultant on the Juras- dissolve all inorganic material, then the sci- or at least DNA fragments – might survive in
sic Park films, used to work in his lab at the entists added antibodies that normally bones for some 75 million years.
Museum of the Rockies. Today several of his form in the immune system against bacte-
former students are central figures in the ria and viruses. A near-infinite number of Schweitzer and her colleagues are not
scientific battle over how long DNA and pro- different antibodies exist, each of which the only ones who think they have con-
teins can survive wear and tear. firmed this theory. English scientists claim
to have found evidence of cartilage fibres
Dinosaur babies include DNA and blood cells in a series of dinosaur bones.
And unlike other scientists’ finds, their dis-
Molecular palaeontologist Mary Schweitzer coveries were based on bones that were not
is one of Jack Horner’s former students. particularly well-preserved, so that the Eng-
Together with other scientists, she has pub- lish scientists not only believe that soft tis-
lished several debated discoveries in recent sue can be preserved, they think it happens
years indicating that soft tissue can be more often that anybody dared hope.
found in well-preserved bones. She is also
involved in a new discovery this year (2020) And that was the particular claim that
together with another one of Jack Horner’s led Evan Saitta to don his safety gear and set
former students, Alida Bailleul. In two out in search of DNA and proteins in the
Dinosaur Provincial Park in Canada.
Discovery: Collagen protein.
Where: Yunnan province, China.
Age: 195 million years.
Maximum length: 9 metres.
Discovery: Collagen protein, cells, DNA.
Where: Montana, USA.
Age: 68 million years.
Maximum length: 9 metres.
34 | SCIENCE ILLUSTRATED
Scientists disagree about DNA
Debated discoveries of DNA, proteins, and cells from dinosaurs in million-year-old
fossils have caused controversy in the world of science. New research reveals that
the discoveries are probably not what they were first believed to be.
Bones are full ALIDA M. BAILLEUL ET AL./NRS PROTEINS Test provides
of protein Antibody wrong answers
Antibodies The antibody
aimed at method is
proteins bind to the because the anti-
dinosaur bone. And as bodies can also bind to
bacteria do not produce minerals such as calcium
collagen, the proteins phosphate. Evidence of
must come from the collagen could also be
dinosaur itself. from tiny fungi.
Blood cells BLOOD VESSELS AND CELLS Vacuum leads
have survived to false cells
Several resembling a Structures
independent red blood cell. resembling
electron blood vessels
microscope examinations UNIVERSITY OF BRISTOL can be formed by
reveal that the fossils bacteria. Small,
include structures cell-like lumps could
which resemble blood be side effects of
vessels, red blood the vacuum in the
cells, and bone cells. electron microscope.
Bones ALIDA M. BAILLEUL ET AL./NRS Cell-like DNA is from
conserve DNA structure microbes
Pigment Pigment Analyses of
that binds DNA in other
to DNA fossils show
collects in cell-like that DNA is broken
structures in the bone. down in a few million
The discovery is years. The evidence of
extraordinary, but DNA dinosaur DNA is either
research has produced incorrect – or the DNA
surprises before. comes from microbes.
scienceillustrated.com.au | 35
THE PAST DINOSAURS
Bones deliver a surprise “This project shows that bones are not peratures.This process is what Saitta is trying
very fit to protect soft tissue”, says Evan to recreate in the lab. Previous experiments
Saitta first collected fossils following carefully Saitta. “They are like a time capsule – they consisted in subjecting different organic ma-
sterile procedures to avoid polluting the are porous and open systems that allow terial to heat and pressure in a sealed con-
bones during the excavation itself.The bones organic material to escape to the soil and tainer. But this process would trap substances
were 75 million years old and from a relative microbes to invade them.” that in a natural environment would evapo-
of the three-horned Triceratops. They were rate or otherwise escape. Here they remained
sent to university labs in Princeton, USA, and Saitta now believes that the evidence of as a sticky substance in the container.
Bristol and York in the UK, to be analysed DNA discovered by other scientists has
using several different methods, to avoid come from microbes, and that the colla- So Saitta and his colleagueTom Kaye devel-
errors and misinterpretations. One method gen-like proteins could have been produced oped a new method.They placed parts of dead
not used was the antibody method used on by fungi. The structures similar to cells, cell lizards or chickens in clay inside a steel piston
Mary Schweitzer’s fossils, to guard against the nuclei and blood vessels were probably also that is subjected to several tonnes of pressure
danger of false positives. formed by the invading microbes. by means of a hydraulic press. The result is a
1.25-metre-high plate that is subsequently
All analyses produced the same results. Pressure cooker produces fossils placed in an oven at a temperature of 200+ de-
The samples had not been contaminated, grees for 24 hours. The porous clay
and there was no evidence of collagen. The fossil search in the Canadian wilderness is allows unstable molecules to escape during the
But they delivered another surprise – the only a small part of Saitta’s work. He also uses process, and the artificial fossils end up being
bones were full of DNA, but not from dino- completely different – and more creative – very much like the real thing.
saurs. The DNA came from large quantities methods to examine whether ancient fossils
of microbes that had settled in the bones. might still include their original molecules. So far, Saitta’s experiments indicate that
Saitta and his colleagues found a total of 46 only skeleton remains and the melanin pig-
species of bacteria and other microbes, in- For an animal to become a fossil when it ment are conserved during fossilisation.
cluding several unknown species. And some dies, it must first be buried in sand or some Just about everything else, including collagen,
of the microbes in the bone were able to other enclosing substance, buried so deeply is lost. The experiments do confirm that
break down collagen. over millions of years that its remains are pigments are among the few biomolecules
subjected to extreme pressure and high tem-
that can be preserved for millions of years. SCIENCE/AAAS
Still, the discussion of DNA and proteins in
fossils is not yet over, and Mary Schweitzer’s Palaeontologists have found well-preserved dinosaur feathers in amber several times.
most recent discovery from Montana has New research indicates that some of the feathers’ original amino acids – the building
revived it. However, Saitta now intends to blocks of proteins – have also been preserved.
look for more stable biomolecules – such as
the amino acids that are the tiniest building
blocks of proteins. They may not promise
cloned dinosaurs, but on the other hand
they last longer than proteins and DNA, and
could provide us with new knowledge about
the animals’ biology.
Research indicates that – as in Jurassic
Park – amber can conserve some molecules
for millions of years. But Saitta has begun to
focus on something else: dinosaur eggs.
“Egg shells are interesting because,
unlike bones, they can function like closed
systems,” he says. “They might include
mechanisms for conserving short sequences
of amino acids for millions of years.”
And his theory has now been confirmed.
During 2020, Saitta found evidence of
ancient amino acids in a 80-million-year-old
egg from a long-necked dinosaur.
Reverse evolution to turn Chicken embryo SHUTTERSTOCK
chicken into dinosaur
Birds trace their origins to dinosaurs, and
1 so they still carry genetic remains of their
ancestors. Palaeontologist Jack Horner
had the idea of using the remains to turn back the
evolution of birds. By means of the CRISPR gene
tool, he has tried to alter the DNA of chickens so
they will develop more like their ancestors. But the
project hasn’t come close to achieving its goals.
Robots move like ALESSANDRO CRESPI/
prehistoric animals EPFL LAUSANNE
Several museums and theme parks exhibit Extinct reptile
2 artificial robotic dinosaurs – but they are
often clumsy and rarely scientifically
correct. New robot technology can now make
robotic motions more fluid, and in recent years
palaeontologists have produced robots with
appearance and motion more accurately based
on actual bones and footprints.
Holograms make Hologram EIMONTAS JANKAUSKIS/UNIVERSITY OF SUSSEX
creatures fly of flying
A dinosaur in full motion projected as a
scienceillustrated.com.au | 37
3 huge, 3D figure – hologram technology is
still at an early stage, but scientists are
making rapid progress. In one experiment, a small
illuminated plastic pearl was blown about rapidly
with its motion carefully controlled by air waves,
so that it drew a 3D flying butterfly in the air.
SPACE UNIVERSE EXPANSION
displays two results:
WHY DO WE
LIVE IN A
How fast is the universe
expanding? It’s a simple question
to which scientists have no simple
single answer – they have two.
Accurate measurements indicate
two different results, and the only
logical explanation is that there’s
something fundamental about the
universe which we don’t understand.
38 | SCIENCE ILLUSTRATED
By Henrik Bendix
The universe has been
expanding since the Big Bang,
but scientists disagree about the
speed at which it is expanding.
SPACE UNIVERSE EXPANSION
PLANCK Data from Planck 74.0
has led to the most km/s
TYPE: Space telescope accurate yet measurement is the speed at
of the Hubble constant.
OPERATION: 2009-2013 which the universe
AIES MEDIALAB/ESA is expanding,
WAVELENGTH: From microwaves based on
to the infrared spectrum
temperature differences of 67.4
cosmic background radiation km/s
is the speed at
Y ou are driving in a car between expansion. This hasn’t happened. In recent which the
two cities, trying to measure years, more accurate methods have indeed universe is
your speed. The car’s speedo- been developed, but the answers haven’t
meter says you are travelling come closer to each other, instead settling expanding, based
at a constant 74, but when you around two separate values – 67.4 and 74 on background
measure the distance on a map and divide kilometres per second. Many astronomers radiation data.
by the final time spent travelling, the result now believe that the explanation must be
is 67.4. Where is the error? Is the speedo that our understanding of the universe’s
badly calibrated, did you make an incorrect content and forces requires revision.
measurement – or is it something else?
Star death reveals galaxy speeds
The world’s astronomers are facing a
similar problem, except that they are trying For more than 20 years, American Nobel
to measure not the distance between two Prize laureate and Johns Hopkins University
cities, rather the speed at which the uni- professor Adam Riess has worked on meas-
verse is expanding. Just like the car journey, uring the Hubble constant using the super-
they have reached two different results. The nova method. When particular types of big
measurements behind each result have stars end their lives as supernovas, they
been carefully checked for errors – without shine at a very specific intensity, making it
any being found. But if the leading theories possible to measure the distance to remote
about the content and development of the galaxies and the speed at which they are
universe are correct, they can’t both be right. moving away from us. In 2019, Riess and his
team of scientists arrived at a Hubble con-
All astronomers agree that the universe stant of 74.0km/s for every megaparsec by
is expanding, making galaxies move away which two galaxies are separated. (A mega-
from each other. The chief question is the parsec – Mpc – is a measure of length that
speed at which the galaxies are spreading astronomers use for extremely long distanc-
apart. The speed is known as the Hubble es: one megaparsec corresponds to some 31
constant, and astronomers can’t agree on it. billion billion kilometres.)
And this disagreement over the Hubble con-
stant also affects other calculations, so that The measurement is not 100% accurate,
the same uncertainty also casts doubt on but Riess and his colleagues are confident in
the age of the universe. claiming that the Hubble constant must be
somewhere between 72.6 and 75.4km/s per
The Hubble constant is difficult to measure Mpc. And their result is supported by anoth-
accurately or directly. Different ways of er team of astronomers. headed by Sherry
measuring it have always produced slightly Suyu from the Max Planck Institute of Astro-
different results, but scientists expected physics in Germany. Instead of supernovas,
that as measuring methods improved they they used quasars – bright galaxy centres
would move ever closer to the real speed of
40 | SCIENCE ILLUSTRATED
Measurements produce two results
The Hubble constant is a measure of how fast the universe is expanding.
The speed can be measured based on either supernovas or background
radiation variation, but the two methods deliver different results.
Starting Moving Moving faster Speed Incline =
point away away Hubble
Star explosions Expansion shifts the colours Distance
provide reference points of light towards red
Speed / distance =
Supernovas light up with a known light When a supernova is travelling away Hubble constant
1 intensity. A doubling of the distance 2 from us, the wavelength of light is By dividing the supernova’s speed as it
results in a quartering of light intensity, lengthened, so the light becomes
as it is distributed across a larger area. So the shifted towards red. By measuring the red shift, 3 travels away from us by the distance to
light intensity shows how far away the star is. scientists calculate the speed of the supernova. it, astronomers can calculate the Hubble
constant. The more supernovas used as reference
points, the more accurate the calculations.
For billions of years, the entire everywhere – there were slight variations in Bang very accurately. Today, the
universe was showered in heat the density and temperature of matter. temperature of the universe is minus
radiation that dates back from the Since then the universe has been expanding 270.42°C – only 2.73°C above absolute zero
early childhood of the universe – cosmic and cooling, but radiation from the time – but still with slight variations. The
background radiation. Back then, the when the universe was only 380,000 years variation of the background radiation
universe was a hot soup of matter and old still remains. The Planck telescope has corresponds to different matter density in
radiation, but the soup was not equally hot measured this residual heat from the Big
the young universe, based on which
Background radiation astronomers can calculate
how fast the universe
The expansion of the PLANCK COLL./ESA
universe can be
calculated based on
the sizes and
distribution of hot
and cold regions.
scienceillustrated.com.au | 41
SPACE UNIVERSE EXPANSION
Matter and dark energy
pull in opposite directions
The universe has been expanding since the Big Bang, but the expansion
is slowed by ordinary and dark matter. Dark energy, however, accelerates
the expansion, functioning as a kind of spring that expands space itself.
SHUTTERSTOCK & KEN IKEDA
Dark energy expands.
Ordinary matter pulls FUTURE
Stars, planets, and elementary particles
that we can observe, are ordinary matter.
All matter attracts other matter – and the
attraction is recorded as gravity. Gravity contracts
the universe, or counteracts its expansion.
Dark matter pulls even more PRESENT
Like ordinary matter, dark matter attracts all
other matter, and it slows down the universe’s
expansion even more. Because dark matter neither
emits nor absorbs any kind of radiation, it can only
be observed through its gravitational effects.
Dark energy accelerates PAST
Gravity is counteracted by dark energy, which Big Bang
functions as negative pressure. The quantity of
dark energy per volume remains the same, but as dark
energy produces more space, the quantity constantly
increases, accelerating the universe’s expansion.
68.3 26.8 4.9 Most of the universe is dark
per cent per cent per cent
dark energy dark matter ordinary
According to the standard model The different measurements of
of cosmology, the universe the universe’s expansion may
consists of three main be due to something about the
ingredients: dark energy, dark invisible universe – the dark
matter, and ordinary matter. The energy or the dark matter –
ordinary matter that we can that physicists do not yet
observe makes up only 4.9%. understand sufficiently well.
42 | SCIENCE ILLUSTRATED
– to arrive at their value of approximately Astronomers have made every effort to
73.3km/s per Mpc. Other measurements
have been made, with higher levels of un- account for anything that might have intro-
certainty but still producing similar results
from 72 to 75km/s per Mpc. duced errors, but all the calculations seem ADAM RIESS
rock-solid – both the ones that indicate a ASTRONOMY PROFESSOR
But another highly accurate method of
measurement arrived at a much lower num- Hubble constant close to 67km/s per Mpc
ber. It was calculated based on data from the
European Planck space telescope, active and the ones of around 74km/s per Mpc. The
from 2009 to 2013. The telescope measured Nobody can identify any errors in the anal- disparity
cosmic background radiation, the afterglow yses. In other words, cosmology is in a crisis.
of the Big Bang, released when the universe
was only 380,000 years old. By analysing the Yet scientists are often happy about such has now reached a level
radiation, astronomers can calculate how crises, because the way out of them can lead that is totally impossible
the universe has expanded ever since. In to new and sometimes fundamental realisa- to refer to as coincidence.
2018, the team behind the mission reported tions. Adam Riess calls the difference of the
that, according to their calculations, the
Hubble constant is 67.4km/s per Mpc, with Hubble measurements the most exciting
an uncertainty of only ±0.5km/s Mpc, the
lowest margin of error any calculation has development in cosmology for decades,
concluding that “the disparity has
And this result is backed by other meas-
urements in which astronomers calculate increased and has now reached a
the Hubble constant by looking at galaxy
locations in the universe. In the early uni- level that is totally impossible
verse, matter wasn’t evenly distributed, so
that the galaxies are not quite evenly dis- to refer to as coincidence.”
tributed today, and scientists can use this
pattern to calculate the Hubble constant. So if all measurements
If astronomers use the two last measure- are correct, but still the
ments to turn back time to the Big Bang,
the universe’s age is the 13.8 billion years answers are different,
that most scientists have estimated so far.
But if the universe is expanding faster, as there must be something in
Adam Riess’ measurements of supernovas
indicate, then it could be hundreds of mil- the ground rules of the uni-
lions of years younger.
verse that we don’t under-
This uncertainty over the Hubble constant
also affects the shape of the universe. Most stand correctly. As Sherlock
astronomers agree that the universe is al-
most flat, but they don’t know whether it is Holmes said: “When you
infinite or not. In a November 2019 scientific
article in the journal Nature Astronomy, have eliminated the impos-
three physicists argued that the measure-
ments from the Planck telescope indicate sible, whatever remains,
the existence of a closed universe, where
the universe bends inwards like a sphere, however improbable, must be
and has a finite extent. The theory hardly
solves the Hubble problem, however, since a the truth.”
curved, closed universe would require a
Hubble constant even lower than the team So, astronomers may have to
behind the Planck telescope calculated.
correct the model of the universe
Universe model requires revision
that has been developed over dec-
When scientists measure a specific physical
value such as the speed of the universe’s ades, and proposals for the solu-
expansion, the result should, of course, be
the same every time – it should not depend tion of the Hubble problem have
on the method of measurement. If scientists
arrive at different results, either the meas- already materialised. They have one
urements are at fault, or some of the basic
ideas of physics are incorrect. thing in common: they describe a
universe that is more complex than
the currently accepted model.
Astronomers’ cosmological standard
model – LCDM, short for Lambda Cold
Dark Matter – has so far explained why our
universe looks the way it does, and this
model forms the basis of all measurements
of the universe’s expansion. Dark matter
was given its name because it does not emit
any kind of radiation. By cold, physicists
mean that it travels much more slowly than
light. ‘Lambda’ signifies dark energy – a type
of energy that exists everywhere in the uni-
verse, causing it to grow ever bigger. And the
proposal that has attracted the most atten-
tion has to do with this dark energy.
In the simplest model of the universe,
astronomers assume that dark energy has
always been the same – that every cubic me-
tre of space has always included a specific
quantity of dark energy. Dark energy
makes the universe expand ever
faster, because there is ever Astronomer Adam Riess
more space and so also has calculated the Hubble
more dark energy. constant by measuring supernovas.
SPACE UNIVERSE EXPANSION
The Euclid satellite will 13.8 of ghost particle that pass right through
try to find ascertain everything – and so are very difficult to
whether dark energy has billion years is the estimated measure. Hence physicists don’t know much
changed over time. age of the universe. But it about neutrinos, and they might involve se-
may be rather younger.
ATG MEDIALAB/ESA crets that explain the different measure-
Neutrino makes results match ments of the Hubble constant.
EUCLID Physicists know about three differ-
If a new force of nature is not the solution, it ent types of neutrinos, but it is possible
TYPE: Space telescope might be an enigmatic particle. Astronomers there is a fourth that has not yet been
LAUNCH: 2022 from Fermilab in the US and elsewhere have identified. If this fourth neutrino was
WAVELENGTHS: pointed at a possible explanation involving at play in the young universe, it
Visible to near-infrared light tiny elementary particles known as neutri- would influence both the cosmic
MISSION: Exploration of dark nos. Although they exist everywhere and are background radiation and the way in
energy and dark matter via measure- produced in great numbers inside the Sun,
ment of the universe’s expansion they often go ‘under the radar’. Neutrinos which galaxies are distributed. If so, data
interact with hardly any other matter, a kind that forms the basis of the low value of
But if the dark energy becomes stronger in the Hubble constant must be analysed in a
itself, the expansion will accelerate even new way — and that could result in a value
more. That could explain why different closer to the one that is based on super-
measurement methods produce different novas and quasars.
results. The lower value of the Hubble con-
stant, calculated by means of background The new Hyper-Kamiokande neutrino
radiation, is based on the assumption that observatory may come up with the answer.
dark energy is a constant. The measure- The observatory, built in Japan, consists of a
ments that produce the higher value are water tank with 260 million litres of ultra-
based on the speed of galaxies moving away pure water and 40,000 extremely sensitive
from us and do not depend on assumptions photo detectors to capture any evidence of
about dark energy. If dark energy is not con- neutrinos when, on rare occasions, they col-
stant, different results might be produced. lide with a water molecule – and perhaps
But then physicists need to better explain reveal that unknown fourth neutrino.
what dark energy is and what mysterious
force of nature might change it over time. Or, if the supernovas are the problem,
the large Vera C. Rubin Observarory tele-
There has also been a suggestion that an scope in Chile could provide more accurate
explanation of the Hubble disagreement measurements. The telescope will be com-
might come from another enigmatic type of pleted in 2023 and will be able to detect
energy, one which operated only during the many more supernovas than has been pos-
first 100,000 years of the universe’s history, sible so far. The more supernovas available
and subsequently disappeared. Or perhaps for which to calculate distances and speeds,
a new fundamental force of nature is re- the more accurately the Hubble constant
quired to explain why the universe behaves can be derived.
in a way that astronomers did not expect.
In 2022, the European Euclid space tele-
scope will be launched to find out how the
universe expanded over the past 10 billion
years. The telescope will allow astronomers
to see not only how the universe is expand-
ing now, but how the expansion proceeded
throughout the history of the universe.
Astronomers should be able to see whether
the observations fit with their theories of
the universe’s expansion over time.
Only future measurements will reveal
which of the above theories will prevail — or
whether a third one is required. Only once
the right model for the universe and its
constants has been found will scientists be
able to say anything definitive about the
universe’s speed of expansion, and its age.
New observations of neutrinos, dark en-
ergy and supernovas will hopefully lead to a
more accurate description of the universe,
so that when we’re driving our hypothetical
car between two cities, the speedometer
and map measurements will at last provide
the same unequivocal result.
44 | SCIENCE ILLUSTRATED
A flat universe – or a closed ball?
The distribution of matter and energy provides the universe with a specific shape.
It can be closed, open, or flat. Most astronomers think that the universe is almost flat,
but one group of scientists recently proposed that the universe may be closed.
CLOSED UNIVERSE OPEN UNIVERSE FLAT UNIVERSE
High density makes Low density makes Definite density makes
the universe closed the universe open the universe flat
If the average quantity of matter If the density is low, the universe If the density has a definite
1 and energy – the density – of the 2 bends outwards like a saddle. 3 value, the universe will not bend
universe is high, it bends inwards This is known as an ‘open’ at all on the largest of scales. It
like a ball. Scientists call such a universe universe, because two light beams that is flat as a pancake – though in 3D. Two
‘closed’, because two light beams that are are sent off on parallel paths will move parallel light beams will remain parallel
sent off on parallel paths will eventually ever away from each other. In the open indefinitely, and the total of the angles of
approach each other. In a closed universe, universe, the total of the angles of a a triangle will always be 180 degrees.
the total of the angles of a triangle is more triangle is less than 180 degrees.
than 180 degrees.
With his ordinary relativity theory,
Albert Einstein proved that any
mass, such as that of Earth, bends
space. This means that the entire
universe could also be curved.
WMAP SCIENCE TEAM/NASA & SCIENCE PHOTO LIBRARY
scienceillustrated.com.au | 45
needles into your skin
Each time you swat a bloodthirsty mosquito,
you’re destroying a perfect little machine.
When a female mosquito is ready to develop eggs,
she needs blood. For this purpose the mosquito
has developed a proboscis that consists of a sheath
surrounding a collection of needles. The mosquito presses
on the needles and vibrates its head, helping them to
penetrate the skin. The suction of the blood takes place by
means of muscle pumps that cause underpressure so the
blood rises up through the proboscis and into the digestive
system, where it nourishes the eggs.
SUMMER IS THE
They cut into your skin, inject
you with chemicals and potentially
infect you with diseases, all to get
a drink of one of the world’s most
nutritious liquids: your blood.
Look forward to the summer –
it’s the bloody season of vampires.
46 | SCIENCE ILLUSTRATED
By Lise Tønner, Lars Thomas & Henrik Vinther Nielsen CLAUS LUNAU
pokes the way to blood
The mosquito’s proboscis consists
of a sheath around a bundle of hollow
needles used to extract your blood.
1 Sensory cells at the points
of the needles register
when a blood vessel is struck. Proboscis
Needle bundle 2 The mosquito’s
hides the pointed
needles, but yields as
they enter the skin.
Underpressure Blood vessel
causes blood flow
3 The mosquito sucks up
the blood from the blood vessels
via muscle pumps in its head and throat.
Over millions of years
the mosquito has developed
a sophisticated system that
allows it easy access to your blood.
Ticks inject saliva
to mask their attack
You rarely feel a tick bite – which is one of the reasons these
little blood-suckers can cause such serious problems.
There are 17 human-biting ticks in In spite of their size, these small spider-
Australia, according to research like mites pose an outsized threat to both
published in 2019 by an international animals and people, and their plan of attack
team including scientists from the University is pretty unpleasant as well – the ticks stab
of Sydney and Macquarie University. you with mouth parts like barbed straws and
Ornithodoros gurneyi can cause severe local then squirt saliva into you. The saliva
and systemic reactions in humans, while contains chemicals which reduce pain
others deliver bacterial pathogens causing Q so you don't notice the bite, as well as
fever, Queensland tick typhus (QTT), Flinders anti-coagulants and immune-restraining
Island spotted fever (FISF) or Australian chemicals. If you notice a tick, don’t
spotted fever (ASF). The bite of Ixodes squeeze it or try to pull it off, as it will
holocyclus (the East Coast paralysis tick) just increase its injections. Use fine-
rarely causes serious paralysis in humans tipped forcep tweezers (without twisting
but affects some 10,000 dogs each year, or squeezing), or freeze it with an ether-
5% of them fatally, with many of the rest containing spray, which will kill the tick in
requiring significant vet bills to save them. five minutes or so; it will then drop off.
The tick poisons you
SPECIAL CHEMICALS HIDE THE BITE 1
1 Tick saliva includes special chemicals that are Toxin
injected into the victim to reduce itching and
pain around the bite, so the victim does not notice
the attack, and the tick remains undetected.
SALIVA PREVENTS HEALING
2 The tick saliva also includes many anticoagulants,
which prevent the blood from closing the
wound as it otherwise would, giving the tick
more time to suck the victim’s blood.
THE IMMUNE SYSTEM IS WEAKENED
3 Immune-restraining chemicals in the tick’s
saliva impede the victim’s defences. The
chemicals prevent the immune system’s soldiers
and waste collectors from becoming alerted.
This makes it easier for the bacteria to survive. Red blood cells 3
SALIVA KEEPS THE WOUND OPEN
4 Chemicals in the tick’s saliva – vasodilators –
expand the blood vessels and counteract their
contraction as would occur in normal healing. The
wound remains open for the transfer of bacteria.
48 | SCIENCE ILLUSTRATED
To extract your blood, the tick Herbivore has
injects a chemical cocktail to soothe become bloodthirsty
your immune system so you don’t
notice the bite – until it is too late. The vampire moth was once interested only in fruit.
But it has developed a taste for blood.
NICOLAI AARØE, SCIEPRO/SCIENCE PHOTO LIBRARY
A small genus of moth, vampire DE AGOSTINI/GETTY IMAGES
4 moths, has evolved into
occasional bloodsuckers. Their The vampire moth originated in warm regions of
proboscis is short, powerful and South-East Asia, but in recent years has been
divided in two. By rocking the two observed as far north as areas of Scandinavia.
parts back and forth in relation to
each other, the moths can drill the
proboscis into prey and suck blood.
Normally they attack small creatures,
but a few species are able to penetrate
human skin. Originally, the moths
used their proboscis to penetrate the
peel of fruit to get to the nectar and
juice. It seems they have accidentally
discovered that blood is also an
Among other insects, it is usually
the female that sucks blood to get
extra nutrition for her eggs. But
among vampire moths it is only the
males which go for the blood.
The good news is that, although
species of the vampire moth originated
in Malaysia and have spread as far as
Scandinavia, those found in Australia
seem relatively happy to stick to fruit.
Swarms of midges attack
IMAGESELECT One single midge can be annoying, but worst summer nuisances. When female
doesn’t make a big impact: the small, midges search for nutrition for their eggs,
mosquito-like insect rarely grows to be more the air can become thick with bloodseeking
than 3mm long. But for people who happen midge swarms. And although a midge is
to be near its breeding places – lakes, barely visible, its bite can be rather painful.
streams, and other moist areas – when the Unlike insects that access blood
mating takes place, the midge is one of the surreptitiously with thin needles and
painkillers, the midge bites with a pair of
When the midge is alone, it is fairly harmless, but in jagged nippers that penetrate the skin.
breeding season the air can become thick with the
small bloodsuckers as the females seek nutrition. These nippers are strong enough to
penetrate the skin of most animals, and once
there is a hole the midge sends saliva into the
wound to avoid coagulation. Subsequently, it
sucks only a small quantity of blood, rarely
any more than a microlitre, which it stores in
its stomach and carries back to its eggs.
It is the mating that causes midge
swarms. The females secrete a hormone
that attracts local males, and they begin
to dance around the female as she chooses
with which she wants to mate. When the
female has been fertilised, she lays her eggs
– and the search for blood begins.
scienceillustrated.com.au | 49
MICHAEL D. KERN/NATUREPL ANIMALS BLOODSUCKERS
The world is crawling
Let’s take a trip around the world and be thankful for
the bloodthirsty creatures that live somewhere else...
feast on blood
Centipedes in Thailand
and elsewhere in SE Asia
can capture animals as big as
bats. They kill the prey with
fangs, then drink their blood.
The sandfly of New
Zealand uses its saliva
to make the victim’s blood
vessels expand. The attack is
so violent that the blood
squirts up into the fly.
The North American
lamprey sticks to
its prey with a mouth full
of opposing teeth while
it feasts on the
GETTY IMAGES Unlike many
is very painful.
MAITLAN/WILD WONDERS OF EUROPE/NATURE PICTURE LIBRARY