Monday, 21 November 2016

Pluto got tipped over by its ice cap

Pluto is an extremely cold planet with quite a lot of ice. So much so that New Horizons discovered that it even tilted Pluto to its side.

That’s a whole lot of ice
A few months ago, space probe New Horizons flew past Pluto. The advanced equipment it has on board includes a device that detects solarwinds, an ultraviolet detector, and a multitude of cameras and telescopes. These cameras have already taken extremely detailed pictures of Pluto, revealing things about the dwarf planet that we had no idea about previously. For example, we now know that our previous information about Pluto’s size was inaccurate; it is a bit bigger than we thought, but unfortunately still not big enough to be classified as a planet. New Horizons also discovered that a large part of Pluto is covered by a tear-shaped ice cap which is so big and so heavy that scientists think that it has actually caused the dwarf planet’s tilt.

There goes your frisbee
Pluto’s rotational axis is tilted about 60 degrees. Previously, scientists had no idea what the reason was. Now, James Keane and his team think it has something to do with the enormous ice cap, Sputnik Planitia. They think that the ice cap is so heavy that it has actually tipped over the dwarf planet a little. Imagine Pluto as a frisbee and the ice cap as a small weight stuck to one side of the frisbee. If you throw the frisbee, it will tilt to the side because of the weight; the same thing has happened to Pluto.

The imaginary bar is shown in re

Hey moon!
But there’s something else that’s a bit odd about the icecap that has to do with Pluto’s moon. Pluto and its biggest moon, Charon, are always facing each other with the same side. So a Plutonian would only ever see one side of Charon and a creature living on Charon would only see one side of Pluto. Pluto and Charon seem to be connected to each other by an imaginary bar. The ice cap however, is located exactly opposite to the side that’s facing Charon. So our Charon-creature would never see the icecap. And this is exactly one of the places where a heavy weight like the ice cap could be located without tilting the dwarf planet further. If you imagine the frisbee with the weight again, but now, you stick the weight exactly in the center of the frisbee. Then it won’t tilt to the side anymore when you throw it. The same is true for the location of the ice cap on Pluto, because Charon keeps the dwarf planet in check.

Satellites are expensive
But the problem is, we can only guess how heavy the icecap is. And how it actually influences Pluto’s gravity. To study this more closely, we need a satellite orbiting around Pluto. This satellite could then study closely how Pluto’s gravity field behaves, and if the ice cap actually has any effect on it. This won’t happen anytime soon however, since it’s incredibly difficult and expensive to get a satellite in orbit around such a distant dwarf planet. But for now, it’s a good explanation for Pluto’s tipped axis and the location of Sputnik Planitia.

Click here to read more about astronomy.


Saturday, 12 November 2016

Zombie mice and fish?

When you’re dead, you’re dead, right?  Which means nothing is going on in your body anymore. But recent studies have proven that that may not be so true after all.

It’s alive!
Alexander Pozhitkov and his team have published a study in which they discovered that some genes keep being active for up to a few days after an organism died. Or after mice and zebrafish died, at least, because that are the two species Pozhitkov and his team studied. They found out that the cells in those animals keep producing proteins, because that’s what genes do, up to four days after the zebrafish died. The genes in the mouse survived a little shorter; up to a day. This is really weird, because this essentially means that the cells of the mouse are still alive after the mouse died. From this, Pozhitkov and his team concluded that these cells must also still have enough energy to create these proteins. This is something scientists thought was impossible. Because when an organism, like a mouse, is dead, its heart stops. This means now blood flows through the mouse’s body anymore, and its cells don’t get enough oxygen and can’t produce any energy anymore. But it appears that some energy is still around in the cell.

Nah, not really.
But does this mean that zebrafish and mice are essentially zombies for up to four days? Of course not. All active genes are related to stress, immunity and inflammation. So those genes are only creating proteins that were useful in the few moments before the mouse or zebrafish died. And since a mouse or zebrafish can’t live with only those proteins. Because mice and fish, like all other organisms, also need other proteins to grow, digest their food, move and generally live. And since the mice and fish lack those when they die, they just stay dead. That’s also we don’t see zombie mice or zebrafish in our daily lives, because they need way more proteins to become alive or a zombie.

Better transplantations
But this can help us greatly when it comes to learning more about transplantation. Since mouse-genes live after the mouse died, it is quite likely that human genes do the same. Pozhitkov and his team are thinking about new transplantation methods that can make use of these still-active genes. We could use this knowledge to keep transplantation organs ‘fresh’ for a longer period of time, and we also could learn how to ‘revive’ organs that would otherwise be useless for transplantation. This can be a great advantage for the medical world in general, and especially for the people waiting for an organ transplant.

Click here to read more about biology.


Not only a new president; also new solar panels!

Solar cells will probably be one of the cornerstones of our civilisation in the near future. So scientists are continuously trying to improve the solar cells we have today. Their newest innovation are perovskite solar cells.

That’s way easier!
These new solar cells use inexpensive, commonly available materials. Which means that they are on their way to be used everywhere! On top of that, these new solar cells are just as good, or maybe even better than the solar cells we use today. Their secret is that they’re made of perovskite. Perovskite is a material that is mostly made of calcium-titanium crystals. And it is relatively easy to find calcium and titanium in the earth’s crust. Furthermore, Giles Eperon, Tomas Leijtens and Kevin Bush, the scientists that developed these new solar panels, could build the solar panels quite easily in their laboratorium. Something that is unthinkable with the solar panels we currently use, since they can only be manufactured at extremely high temperatures.
The alternating layers or perovskite
Combining the best traits
But the advantages don’t stop here yet. Perovskite solar panels are also thinner, more flexible, cheaper and better at capturing energy than the solar panels we currently use. Which are made of silicium, or basically just sand. Eperon and his team managed to achieve most of these advantages with just one trick. Instead of just using one layer of perovskite for their solar cell, they used two. And two layers with totally different abilities to be precise. The first layer can only absorb some specific types of light, but can then turn that into a super high electrical energy output. The second layer isn’t that picky and can absorb almost every type of light, but only puts out little electrical energy. By combining those two, the scientists got one super efficient solar cell.

There are some clouds...
But it’s not all sunshine with these new solar cells. Perovskite is known to degrade more quickly than silicon when exposed to moisture or light. But this problem mostly arises when the solar panels contain tin. And scientists have already found a way to work around this. They’ve designed perovskite solar panels that don’t contain any tin at all. So the only thing that the researchers have to do is perfect their design so that the solar panels can generate a maximum amount of electrical energy, and the solar panels are ready to roll.

Click here to read more about physics.


Sunday, 2 October 2016

It’s raining meteorites!

The dinosaurs went extinct when the earth was struck by a meteorite 65 million years ago. Recent research suggests that another meteor may have hit 10 million years later.

Some species of foraminifera
Spheres, but no micro-organisms
Megan Fung and her team were looking for Foraminifera. Foraminifera are the fossils of single celled microorganisms, often used for determining how old a particular layer in the soil is. They have calcium carbonate shells, which can reveal things such as the climate in particular time period. Fung and her team discovered something strange; they didn’t find any Foraminifera, or forams for short, when they were studying the soil by the coast of New Jersey. Instead, they found a whole bunch of small, black orbs.

Microtektites in all kinds of shapes
Can’t believe we missed that!
The spheres appeared to be a bit like glass, and the team quickly discovered that they had found microtektites. This is the debris that forms from the extreme heat and force of the impact of a meteorite on earth. What really surprised them though, were two things. First, the soil in which they discovered the spheres was extremely well-studied. Why hadn’t other scientists found the orbs yet? The answer is quite simple. Foraminifera are usually white, thus they are gathered in black trays and scientists can easily see them stand out. Nobody noticed the microtektites because spheres are black, the same color as the tray. Second, Fung and her team found the microtektites in a layer that is only 56 million years old. It’s almost impossible that the spheres were formed by the meteorite that killed off the dinosaurs, since that event happened millennia ago. Another asteroid must have hit the earth 10 million years later.

Boom! The climate changed
Conveniently, the impact also accounts for something scientists couldn’t explain, a change in climate that happened around the same time. Around 56 million years ago, the earth suddenly became extremely warm, warmer than it is now. Scientists were puzzled by this climate change for a long time. Now there finally seems to be an answer; it was a meteorite.

Maybe not…
Not everybody in the world of geology has accepted this explanation. One man, Jerry Dickens from the university of Houston has his doubts. “They have completely misinterpreted the data and missed the correct, and more cool, story.” he told Science. He believes that the microtektites were around throughout the whole warmer time period. He says the spheres disappeared in some layers of the soil because they got broken down by microorganisms that flourished in the warmer climate. This would mean the meteorite hit the Earth way earlier than Fung and her team proposed, and the meteorite and the hotter climate have nothing to do with each other. Either way, it’s an interesting discovery that will tell us more about the time period between us humans and the dinosaurs.

Click here to read more about geography. 


Friday, 30 September 2016

If you can’t find you limbs

We all know our five senses. But, we have many more senses than just those five. We have the sense of proprioception, for example, that helps you keep track of where your body parts are. But, what if you lack that?

Where’s my nose?
Proprioception is, the sense that allows you to touch your nose with your eyes closed, or type without looking at your hands. The reason for this is that your brain knows where your hands and nose are without necessarily having to look at them. And that’s what proprioception does. But what if you don’t have that sense? What if you’re blind, but instead of lacking sight, your proprioception did not work.

Hard to find that sense
Well, it’s quite hard to study that. Because the symptoms of lacking proprioception aren’t as clear as, say, lacking hearing. Another things is that the sense isn’t located at one point in your body, unlike, for example, your eyes. Eyes have a specific place and you know exactly what they do; they see. But with proprioception, the location isn’t really clear. The sense is working all over your body. So you know where all your body parts are hanging out. But this makes it really hard to study this sense.

9 and 19
Fortunately, Carsten Bönnemann and his team have found two people; a nine-year-old girl and a nineteen-year-old woman who totally lack proprioception. With their eyes closed, they can’t tell where they limbs are, or in which way their joints are being moved. With their eyes open, they can tell, but they can only do so if they actually see what’s happening. The researchers considered the situation of the woman and the girl to be so weird that they did a genetic test on both of them. The scientists discovered that both of them have an extreme mutation in a gene called PIEZO2. Scientists already linked this gene to our sense of touch earlier, which made Carsten Bönnemann and his team think that PIEZO2 plays an important role in proprioception.

Whoops, I didn’t mean to…
The discovery of this gene also has another advantage, especially when you’re a bit clumsy. Clumsiness has already been linked to your sense of proprioception not working perfectly. Since proprioception is linked to the PIEZO2 gene, this means that, if you’re clumsy, you may have a mutation in that gene. It doesn’t have to be extreme to the point that you totally lack the sense. But if it malfunctions a bit, this could also be reason enough for you to tip over glasses of water a little more often. So don’t worry, it’s not your fault, it’s just your genetics.


Sunday, 18 September 2016

Gaia is mapping the stars

Spacecraft Gaia is going to map our entire galaxy. And with all that data, NASA scientists hope to compose a five-dimensional map of our galaxy, and discover the Milky Way’s past.

spacecraft Gaia
Where are the stars?
Three years ago, spacecraft Gaia was launched. Then the spacecraft, which basically is a giant telescope floating in space, needed the past three years to put together a draft of a map of our galaxy. The reason it took Gaia so long to only turn out a draft is that the spacecraft has already catalogued more than a billion stars for this draft. This is of course an incredible amount, but Gaia isn’t done yet. Our galaxy consists of over 200 billion stars, so the telescope has only catalogued half a percent of all stars. Gaia is going to further map our galaxy for at least another two years. In these five years, Gaia isn’t going to be able to map the other 199 billion stars, instead Gaia is going to focus on refining the data about the billion stars that the spacecraft already mapped.

Gaia's map so far
A look into the future and the past
Gaia has already mapped the position and brightness of over a billion stars, and also the distance and speed of the two million brightest stars. In the next two years, NASA scientists, who control the spacecraft, want to find the distance and speed of way more stars. They’re hoping for a billion. But that’s not all, they also want to map the speeds of the 100 million brightest stars in 3D. While the speeds of the other, dimmer stars are only in 2D, so only sideways. These data will enable scientists to create a five-dimensional model of our galaxy, and essentially predict the Milky Way’s past and future. This could teach us a whole lot about the Milky Way’s possibly violent past, as there are indications that the Milky Way has absorbed quite a lot of smaller galaxies in the past. Which would have caused violent collisions of which we still can see traces today.

Better than the ocean floors
This galaxy-map will also help scientists understand the birth of stars better. Because with the data that will be gathered by Gaia, scientists can calculate the size and also the age of stars, which are essential for finding out how stars actually form. Another thing is that our own Milky Way is a bit like the earth’s ocean floor compared to the moon. We’ve got a better grasp of what’s happening on the moon than on what’s happening on the ocean floor. In a similar way, we know more about some other galaxies than about our own home. That is mainly because the Milky Way is so big, and we’re right in it so we can’t really take overview pictures of it. This makes getting a good, complete view of the Milky Way really hard, but Gaia is changing that. Within a few years, we’ll have the most detailed map of our galaxy yet. And we will, no doubt, have learned all new kinds of cool and interesting things about our own galaxy, thanks to Gaia.

Click here to read more about astronomy.


Wednesday, 14 September 2016

Ants don’t just smell and count, they also look around

Ants are amazing navigators, they can find their homes even when their quite far away from their nests. This is really impressive, considering the small size of the ants. Scientists have finally found out how the ants can pull it off.

Counting and smelling
A desert ant

Scientists thought they knew all of the tricks ants use to find their way back home. Ants count their steps away from their nests, so they know exactly how far away they are from their home. Ants also have excellent smell, so they can smell other ants and follow them home in the case they accidentally lose count of their steps. This is also the reason ants like to move around in ‘trains’. By moving in trains, they can easily follow each other through their olfactory navigation. Though this method seems flawless, if you were to separate the front and back half of an ant train using a piece of cardboard, for example, the ants in the back half would get utterly disorientated. This would happen because they can’t smell their fellow ants anymore. If you remove the piece of cardboard, the ants will be able to smell their friends again and they can continue their journey back to their nest without any problems. However, a special species of ants called Cataglyphis desert ants are exceptionally good at navigating, better than these two methods can explain. This has left scientists puzzled over the mystery for ages, until now.

How flies see the world
Just use your eyes!
The answer isn’t really weird, or even surprising, desert ants simply look around to estimate distances and find out where they are. It’s the same principle as when you’re driving a car, trying to find your cousin’s new home in a labyrinth-like neighbourhood. Although this seems like a rather obvious answer for humans, it’s somewhat strange for insects like ants since insects have notoriously low vision. The reason for this is that they have so-called facet-eyes made from numerous smaller eyes. These work together to create one big picture. The problem is, insects’ brains aren’t that efficient at putting together all the information from the small eyes. This means that insects see the world in a distorted and pixelated way, which is why you can easily swat a fly with a fly swatter. Due to the holes in the swatter, the fly simply cannot see what’s coming for it. On the other hand, the desert ants can apparently see well enough to find their way back to their nest, even when their step counting and smelling methods fail.

Can the others see too?
Since Cataglyphis desert ants have three different methods of navigating; counting, smelling and looking around, they are some of the best navigators in the realm of insects. This is also due to the fact that they can find their way using each of those methods separately. Scientists already knew that flying insects such as flies, wasps or bees, use their eyes to navigate, but they didn’t know that walking insects, like ants could do the same. This opens all kinds of new, interesting research about the sight of all other kinds of walking insects, for example beetles.

Sunday, 11 September 2016

New giraffe species are endangered

When you think of giraffes, you imagine the long-necked, spotted animal we all know. But German scientists have discovered that there are actually four species of giraffes.

Nubian giraffes
Not nine but four
We used to think that there were nine subspecies of giraffes. The difference tween the different subspecies of giraffes was mostly based on their coat pattern. The Nubian giraffe, for example, has very dark spots on its body, while the Kordofan giraffe has pale spots. These different coat patterns don’t mean that the giraffes are different species. Instead they are different subspecies of an umbrella species of giraffes. This means that, when a giraffe of one subspecies, for example a Kordofan giraffe mates with a Nubian giraffe and they get a baby, that baby giraffe is also fertile. In other words, both giraffes belong to the same species.

That’s a whole different species!
But now, a team of German, American and South-African scientists have discovered that giraffes can be split into nine subspecies, but into four actual species. The scientists have split the old giraffe species into Northern Giraffes, Southern Giraffes, Masai Giraffes and Reticulated Giraffes. This doesn’t mean, however, that two giraffes from different species can’t have fertile offspring. They still can, but to the scientists’ surprise, they don’t interbreed that often in the wild. This is quite odd since giraffes can move big distances and could easily reach other groups of giraffes. And since different giraffe species don’t interbreed, this means that the four different species of giraffes are still getting more diverse. To define the different species, the team of scientists analysed the DNA of different giraffes and compared the results. They found out that some giraffes’ DNA differ even more from each other than a brown bear’s and a polar bear’s do. Those bears belong to two different species, so those two giraffes most likely belong to different species as well. After a detailed study of the DNA of a large group of giraffes in Africa, they discovered a total of four different species of giraffes. And this discovery has some important consequences for animal protection.

Last chance to see; West African Giraffes
Save the giraffes!
The original giraffe species was already somewhat endangered; there are only 100,000 left, where there used to be 150,000 thirty years ago. This means that giraffes aren’t as endangered as rhinos or elephants. But since giraffes can be split into four species, three of those four species are seriously threatened with extinction. Only the Southern Giraffes seem relatively safe, while the Northern Giraffes, of which there are only 4500 left, and the West African Giraffes, of which there are only 400 left are classified as endangered. This new discovery now asks for better protection of and more attention to giraffes, otherwise one or more of these newly discovered species may be gone for good soon.

Click here to read more about biology.


Wednesday, 7 September 2016

Dawn on almost three dwarf-planets

In 2007, space probe Dawn was launched. And now, nine years later the probe has reached its final destination; Ceres. It has already discovered some strange, exciting things.

Is it salt or water?
When Dawn started orbiting Ceres in 2015, it found strange, white spots on the dwarf-planet’s surface. Unfortunately, Ceres’ cameras couldn’t take pictures that were detailed enough for us to see what those white spots were. The NASA scientists that control the space probe then managed to get Dawn into a lower orbit around dwarf-planet Ceres. In this lower orbit, Dawn can observe the white spots more closely. Scientists discovered that the white spots are all the bottoms of craters. This made them think that the spots are either made of salt or ice. The space probe couldn't get close enough to the dwarf-planet to find out which one it is. If the white spots are ice, this means that the dwarf-planet has at least one requirement for life; water. However it’s unlikely that we’ll find aliens there, since the big rock is way too cold. And on top of that, the dwarf-planet doesn’t have an atmosphere. But Ceres isn’t the only dwarf planet space probe Dawn visited.

Two for one!
Space probe Dawn already orbited another dwarf planet called Vesta between in 2011 and 2012. This makes Dawn the only space probe that has orbited a celestial body, studied it and travelled further to orbit and study a second celestial object. The two Voyager space probes also studied multiple celestial bodies; the gas giants of our solar system, but they never orbited them. On Vesta there were dark spots that sparked the interest of scientists. Fortunately, Dawn could zoom in enough onto those dark spots to tell what they are; craters. Craters may not sound as interesting as water and possible - though highly unlikely - alien life. Those craters can tells us something else though; we can discover a lot about what happened during Vesta’s life, and what it was like in our solar system billions of years ago. Dwarf-planets are a bit like time-capsules in this way.

Philae on its comet
Orbiting forever
If we want to learn more about the history of our solar system, the main thing we have to do is study asteroids better. This is also the reason that space probe Rosetta and comet lander Philae were launched. Those probes closely studied comet 67P/Churyumov-Gerasimenko, and even discovered the building blocks of life there. Space probe Dawn, however, isn’t going to orbit another asteroid. NASA scientists had proposed plans about sending Dawn to another asteroid, but this was cancelled. The scientists leading Dawn’s mission think that staying in orbit around Vesta can give us way more scientific data than a quick visit to another asteroid. So it was decided that Dawn will stay in Vesta’s orbit forever, and gather data until at least 2017.

Click here to read more about astronomy.


Saturday, 3 September 2016

Tasmanian devils got rid of their cancer

Since 1996, the population of tasmanian devils have been decimated by a contagious cancer. Recently, it has been discovered that the tasmanian devils have developed a resistance to this cancer.

Devil Facial Tumour Disease

The contagious cancer affects tasmanian devils and gives them facial tumours. These tumours begin as lumps around the mouth area and can spread to the rest of the body. They can affect the devils by preventing them from eating, giving them infections or causing their organs to fail. All of these usually lead to the death of the animal within about 6 months.
Tasmanian Devil with tumors

Lots of biting
The disease spreads when the devils bite each other. Since the disease is spread this way, it is easily propagated through a colony since they bite each other very frequently. A lot of Tasmanian devils’ social interactions are based on biting, for example when they fight.  As well as this, the tasmanian devils are thought to have a very low genetic diversity which lowers their chances of resistance to disease. This means that the devils aren’t very different from each other, so if the cancer can harm one Tasmanian devil, it can harm the other devils too. This gave the disease a very easy way to make it around nearly all the colonies.

Image result for tasmanian devil biting
Fighting Tasmanian Devils

But now, because of an accidental change in the Tasmanian Devils’ DNA, their genetic code, they’re now immune to the contagious cancer. They can’t get the disease anymore. And the best thing is, when they begin to reproduce, the next generation of tasmanian devils will have the immunity as well. Over time, maybe all Tasmanian Devils will have be immune and the cancer will go extinct.

That’s odd...
Scientists discovered this by comparing the genome of the immune tasmanian devils with that of a past tasmanian devil which existed before the tumor had begun. They realized that there was a difference in the actual genetic makeup of the tasmanian devils. This genetic change happened in seven different genes. Five of those are related to immune response against cancer in other mammals such as ourselves. But, the most amazing part of this discovery is that this immune response has happened very quickly. This entire immunity was evolved over just about five generations, which is around twenty years. This evolution can be compared to rabbits when a disease called myxomatosis began to affect Australia. The only difference is that the rabbits took much longer to become immune.

Looking into the future
This exciting new discovery could affect the future of cancer treatment. With the new technological advances which are being made in the realm of genetics, we might soon be able to use this discovery as a cure for cancer. This could be possible since these genetics are similar in other mammals.

Click here to read more about Biology

Di Giallonardo, F. & Holmes, E. C. Viral biocontrol: grand experiments in disease emergence and evolution. Trends Microbiol. 23, 83–90 (2015)
Epstein, B. et al. Rapid evolutionary response to a transmissible cancer in Tasmanian devils. Nat. Commun. 7:12684 doi: 10.1038/ncomms12684 (2016)

Thursday, 1 September 2016

Dragonfly 44: the darkest galaxy yet

Astronomers have found a really small galaxy, which has one weird trait. It spins a lot faster than it should. Pieter van Dokkum and his team think dark matter is the explanation.

A dark dragon
The yellow smudge in the middle is Dragonfly 44

The galaxy measures around 60 000 light-years across, and is about 300 million light years away. It weighs almost the same as the Milky Way, but has nowhere near the amount of stars. Dragonfly 44 consist of about two billion stars, while our galaxy has over two-hundred billion stars. What is really strange is that the Milky Way and Dragonfly 44 appear to have roughly the same mass; both the Milky Way and Dragonfly weigh about as much as a trillion suns. This means 99 percent of the Dragonfly galaxy must consist of matter we can’t observe. A team of American and Canadian scientists think that a lot of dark matter is hiding in Dragonfly 44. It was discovered last year in the Coma galaxy cluster along with other similar galaxies, which the team combined and named Ultra Diffuse Galaxies (UDGs). Dragonfly 44 is the largest out of all of them.

What dark matter would look like if we could see it
We can’t see it, so it’s dark
What exactly is dark matter? Well, the truth is that we don’t really know. What we do know is that more than a quarter of the mass of the whole universe is dark matter. Overall, dark matter leaves scientists completely puzzled. The reason that it’s such a mystery is that dark matter doesn’t interact with light. That’s why it’s called dark matter - we can’t see it. We can only say it exists at all through the effects it has on its surroundings. One way we notice dark matter is in galaxies that appear to have more mass than their amount of stars can explain. An extreme case is Dragonfly 44, but our own galaxy also has quite a big mass-star misalignment. Scientists think that around 90 percent of all the matter in our galaxy is dark matter. This also means that everything you can see, your house; your food; the sun; and everything else is just a tenth of all the matter in our galaxy.

You’re spinning too fast!
If the hypothesis that Dragonfly 44 is made almost completely out of dark matter, it would explain some mysterious things about the galaxy. First of all, it spins way faster than it should. The general rule is the bigger the mass, the faster a galaxy spins. This is because more mass creates more gravitational force, which speeds up the spinning of the galaxy. If all the mass of Dragonfly 44 consisted of normal matter, stars that we can actually see, the galaxy would never reach such a fast spin. On top of that, even if it would, the galaxy would most likely tear itself apart. If the mass is low, the gravitational forces would be too weak to keep such a fast spinning galaxy together if there weren’t any dark matter around. Scientists also consider this discovery to be particularly interesting since galaxies that are almost completely made of dark matter have already been predicted by some theories, and this new discovery only helps those theories to become even more likely. 

Click here to read more about astronomy.


Monday, 29 August 2016

Bacteria on monkey bars

Lyme disease is caused by a bacteria that can spread through the body at a high rate. The method by which it does so has recently been discovered by a team of Canadian scientists.

What is Lyme disease?
The red spot caused by a tick
When you get bitten by a tick that carries Lyme disease, you develop a big red spot around the place you’ve been bitten. Shortly after that, the disease cause all kinds of symptoms all over your body; headaches, stomach aches, muscles soreness and other undesirable things. Because the symptoms appear quite soon after you’ve been bitten by a tick, usually a couple of weeks, the disease spreads incredibly fast through your body. The disease can do that because the Lyme bacteria, that cause the disease, can travel through your bloodstream. But how those bacteria could actually do so, remained a mystery for quite a while. But now, Rhodaba Ebady and Tara Moriarty have found out, after closely studying the bacteria moves.

Which way to go?
The weird thing is, the bacteria doesn’t just float away in a blood vessel in the direction blood is flowing in that vessel. The bacteria can also be quite stubborn and actually climb up, against the direction of the blood flow in that blood vessel. Because of this, the Lyme bacteria can spread through your body twice as fast as when the bacteria would just float around. And this also explains how the bacteria, which is called B. burgorferi can affect your whole body so quickly.

The green and orange stripes are Lyme bacteria,
the colour us in which stage in
their monkey bar jumping they are.
Bacterial monkey bars…?
To study the odd nature of the spread of B. burgdorferi, researchers built an artificial blood vessel which matched the workings of a normal human blood vessel. A B. burgdorferi was placed into the fake vessel,  and then the scientists observed the interactions of the bacteria and the vessel. The way this bacteria works is by attaching itself onto the wall of the vessel. It forms bonds with the wall and undergoes a cycle of breaking and making bonds. By doing so, it acts somewhat like a child swinging on monkey bars. They hold on using two bonds for a period of time. When they let go of one bond, they slingshot themselves forwards and attach themselves to the wall with another bond. By doing this continuously, they can creep through the vessels. This technique is also used by certain human immune cells called leukocytes.

Further use of this technique
Thanks to this study, we are learning more and more about different bacteria. This could help us learn how to cure diseases caused by these bacteria and it could even be mimicked in robotics to move against the flow of blood vessels with little to no problems.

Click here to read more about biology.