5 mind-bending facts about the universe

Let me tell you a secret. Every biologist secretly wishes they had studied physics instead. I certainly do. As a science writer I also love to write about physics. Why? Because physics is sexy. And also images from NASA are free.

Physics is slowly becoming the new rock n’ roll – with celebrity popularizers of science like Brian Cox and Michio Kaku and historic scientific efforts such as the Large Hadron Collider becoming more and more popular every day. Everyone loves a bit of physics. It is a fascinating subject, after all.

Anyways, to round up the series of physics-heavy articles I give you a collection of five mind-bending physics facts about our happy little universe. Feel free to use them to impress people, get dates or satisfy your curiosity.  

1.All the matter that makes up the human race could fit in a sugar cube.

Don’t look at me like that. It will probably surprise you to know that 99.9999999999999% of matter is actually empty space. We most likely all learned about the structure of matter in school: all matter is made up of atoms which are made up of neutrons, protons and electrons. The protons have a positive charge and they group together with the uncharged neutrons to make a positively charged nucleus. This nucleus is kinda like the sun in the centre of our solar system and around the nucleus orbits the tiny, negatively charged electrons – kind of like the planets orbiting the sun. 

You can just about make me out - I'm about three billion atoms in © picsfive - Fotolia.com

If we were to somehow step inside an atom we would realise that the nucleus is like the head of a pin and the space in which the electrons zip around is like a football stadium and the electrons themselves would be the size of a bumblebee. If all this empty space wasn’t there, all of us would fit inside a single sugar lump. Considering the fact that all atoms are by far mostly empty space, why does all matter have mass? This is because of the Higgs field. The Higgs field is an invisible net of energy which exists through the universe associated with its own particle called a Higgs boson – famously discovered by the LHC supercollider in Switzerland last year. The Higgs field acts like a swamp – particles which travel through it are given the property of mass, just like a runner would be slowed down by running through a swamp. Different particles are slowed by the field to differing extents, which gives objects differing mass.

Of course, the sugar cube would still have mass so it would weight something like 5 billion tons – good luck putting that in your hot beverage of choice.

2.If the sun were to suddenly blink out of existence we wouldn't notice for eight minutes.

It's the sun! As far as I know it's still where it's supposed to be. You'll just have to take my word for it for 8 minutes. (Source: NASA)

The speed of light is about 300, 000, 000 meters per second and the sun is 149,600,000 km from planet Earth – that equates to about 8 light minutes. If the sun were to suddenly blink out while you were reading this (let’s say a star-hungry space whale had it for dinner) the light it was radiating at the moment of its disappearance would take 8 minutes to reach your eyes. That’s just long enough to have a sandwich before the world ends!

3. When things move they get heavier.

I discussed this one in my last article, but I thought it warranted a second mention – particularly if anyone hasn’t read the last one. Albert Einstein’s famous equation of relativity E=mc² tells us that energy (E) and mass (m) are simply two different forms of the same thing – meaning that energy has mass. The faster something moves, the more kinetic energy it has (kinetic energy is the energy of movement) and therefore the more mass it has.

Obviously we don’t really notice this in real life, but it does happen – it is just that the percentage of energy which is turned into mass is incredibly tiny at the speeds we experience here on earth. At speeds approaching light speed this becomes much more dramatic, and if it were possible for something with mass to move at the speed of light it would, in theory, become infinitely massive.

4. There is a planet made out of burning ice.

 

Gilese 436b - ideal weather for... a fire breathing yeti? (Source: NASA)

Somewhere out there in space is, you guessed it, a planet completely coated in ice… which is on fire. A confusing place to say the least. The catchily-named Gliese 436 b is a Mercury-sized planet which closely orbits the star Gilese 436 near the constellation of Leo. The planet orbits the star so closely -4.3 million miles (it doesn’t sound close but that is 15 times closer to the star as Mercury is to our sun) – that its surface is constantly at the scorching temperature of 439°C. You might be thinking that it is impossible for frozen water to exist at such an insane temperature – and you would be 100% correct. But as with almost everything in science, there are exceptions to the rules.

In order to understand how 439°C ice can exist, we need to take a look at the difference in structure between ice, water and steam. As we all know, water exists in three states depending on its temperature. This is because the water molecules (made up of a single oxygen atom and two hydrogen atoms) have differing levels of kinetic energy. Ice molecules have very low levels of energy and therefore don’t move around much. This means that they are very ordered and still (but not completely) and very close together which gives ice its solid structure. As temperature increases the molecules become more energetic and move more – this gives rise to water and steam as the particles become more energetic and less ordered. In chemistry this is called entropy, which is a measure of the disorder of the molecules. Steam has higher entropy than water and water has higher entropy than ice.

On Gliese 436 b, most of the planet is made up of water surrounding a small core made of rock. Gravity from the planet core pulls the water molecules on the planet very close together into a more ordered, less entropic state called Ice X (ice ten or hot ice) which remains in a solid state regardless of the 439°C temperature of the entire planet surface. Don't touch it - your arm would be vaporized. So, y'know, wear sunscreen.

5. We really have no idea what is going on.

I think we can all agree that there is a lot of stuff in the universe. All this stuff – planets, stars, life – is made up of matter. Astrophysicists figure that all the matter that exists only accounts for about 4% of the universe. As for the other 96? Nobody knows apparently.

Mysterious, right? (Source: NASA)

Science proposes that 73% of the universe is made up of something called dark energy and the remaining 23% is made up of something called a dark matter. The Big Bang theory states that the universe ‘exploded’ out of an infinitely dense point at the beginning of time and has been expanding in size ever since. According to the laws of physics, the expansion of the universe should be slowing down– but this is not the case. The rate of the expansion of the universe is actually accelerating and nobody is really sure why. The leading theory as to why this happens is down to dark energy acting like an opposite to gravity, pulling matter apart. Dark matter on the other hand is something that science thinks exists but doesn’t really understand.

Basically it’s a fancy way of saying ‘Who knows?’

And that about sums it up. Join us next time for some fascinating critters!

Thanks for reading, remember to check out and Like the Facebook page (https://www.facebook.com/scienceunplugged) to support ScienceUnplugged and to see notifications of new posts, science news and interesting things.

As with every article I post here, this one has been thoroughly researched and a list of sources can be provided for anyone who is curious – just check out the contact page.

The Science of Sci-Fi: Getting around in space.

Now for part two of my epic sci-fi saga: getting around in space (I realise that that isn’t really a good name for a sci-fi movie… well maybe if it was on REALLY late at night). Or on the internet.

Anyway, moving on. 

A spaceship. Yup. Can't really think of a funny caption. Sorry. © innovari - Fotolia.com

Continuing the science of sci-fi series, I’m going to talk about interstellar travel. The ability to travel the vast distances between stars is a staple of most sci-fi universes, but what about our own? The concept of traveling to another solar system brings with it a lot of obstacles which need to be overcome.

The problem with interstellar travel is distance (who’da thunk it?). The distance between Earth and our closest star system, Alpha Centauri is about 25.6 trillion miles away, or 4.3 light years - that is to say it would take a beam of light 4.3 years to travel there from our sun.  So, y’know, It’s a long way. The human race has done some unmanned interplanetary travel within our own solar system and even technically outside its edges, but no human being has ever set foot on another planet – just our moon.

Science has been sending unmanned probes out into space since the launching of the first earth satellite, Sputnik-1, in 1957 which orbited earth for three months, sending radio pulses back to earth. I’m not going to get into the whole cold war space race thing because it’s not relevant here and when science wins, everyone wins (I know you can’t see it, but I just gave a thumbs up with a huge grin and one of my teeth twinkled with a PING). 

The Mariner 10 probe, brought to you by the high-tech 3D redering of the 1970s (source)

Since then there have been numerous probes sent throughout the solar system by various countries.  The Mariner 10 probe was launched by NASA in 1973 with the mission of investigating Venus and Mercury which are 38 million kilometers and 77 kilometers from Earth (at their closest orbits to Earth) respectively. The probe took several thousand photos of the surface of both planets along with collecting data about the atmosphere and magnetic field of both planets. The Mariner 10 finished its mission in 1975 and is thought to be currently orbiting the sun.

The infamous 'accidental' tracks left by the Spirit rover. You might say they made something of a boner

(source)

Perhaps better known are the Spirit and Opportunity rovers that were sent to Mars by NASA in 2003. Landing in 2004, the rovers surveyed the surface of Mars to look for signs of water activities. The Spirit rover became unresponsive in 2010 (maybe it became… SELF AWARE!! …no actually, they just lost contact with it), but the Opportunity rover is still rolling along the surface of Mars, nine years on from the start of the mission – not bad for a piece of equipment designed to last three months. Pros of this mission: it gave us insight into the geological history of mars. Cons: the spirit rover accidentally drew an *ahem* interesting shape on the surface of the red planet shortly after landing in 2004 – probably what it’s most famous for (welcome to the internet).

This blue dot is the first radio transmission from the first man-made object to leave our solar system. Or maybe its just something someone knocked up in Photoshop - who knows? (source)

So, it seems we have become quite adept at shooting robots into space – but what about beyond the limits of the solar system? Well, the closest we have come was when the Voyager 1 probe crossed over the outer limits of the solar system in August 2012 after 36 years in space and 11 billion miles traveled. In February 2013 a radio signal was received from the Voyager from beyond the orbit of our sun – the first signal to be broadcast from interstellar space. The signal was picked up by radio telescopes on earth as a tiny blue dot.

So why haven’t we gone outside our solar system? Traveling at the top speed of Earth’s current space shuttles (about 28,300 km/h) it would take 165,000 years to get to the Alpha Centauri system – several times longer than the written history of the human race - which makes for something of an inconvenient flight (Are we there yet?). And that’s only our closest star. Of course, one way we could go all over our galaxy (and beyond) would be travel very very very fast. Unfortunately this is never going to happen based on conventional jet propulsion systems as it takes 3,000,000 lbs of rocket fuel to send a shuttle just into Eath’s orbit, which is more than 15 times the mass of the shuttle itself, so you can imagine the amount of fuel required to take an interstellar star ship to Alpha Centuri. Engineers and scientists are working on this problem and there are several theoretical and proposed alternatives to conventional methods, but I will talk about those later – first we have to address perhaps the biggest obstacle to deep space travel.

The Speed Limit of the Universe

Much like the motorway/freeway/highway, everything in the universe has a speed limit but, unlike the speed limit on the roads, it is the speed of light and it cannot be broken. Well breaking the speed limit on the road is illegal but it is POSSIBLE – an act that I in no way endorse. Neither do I endorse breaking the laws of physics on the highway – that’s neither funny nor clever. Anyway, you guessed it folks – it’s time for the maths stick once again. In order to explain why nothing in the universe that has mass can travel faster in the speed of light we have to take a look at the most famous mathematical equation in history. You’ve guessed it:

E=mc² 

This is the equation for Albert Einstein’s famous theory of special relativity. In this equation E stands for energy, m stands for mass and c² stands for the speed of light (300, 000, 000 meters per second ) squared. The c in this case stands for constant, as the speed of light in a vacuum which is always the same. Now – if you read my last article you might have guessed that I am not great at mathematics. In fact I suck at it (no – this is not an appropriate place to say ‘that’s what she said’) – so hopefully this explanation is satisfactory. 

Albert Einstein circa 1921, photographed Ferdinand Schmutzer (source)

The equation explains the relationship between mass and energy. I’m not a physicist and trying to explain this in detail would confuse everyone, most of all me, so I will keep it simple. Einstein’s theory states that mass and energy are interchangeable and are just two different forms of the same thing. The faster an object is moving, the more energy it has and therefore more mass. The closer an object gets to the speed of light, the more energy it has pushing it along which equates to more mass. 

So why don’t we notice this in real life? If energy has mass then why don’t we get heavier while we run? Why doesn’t a car get heavier as it gets faster? The answer is that it does happen – we just don’t notice it because it is so small – at the slower speeds we are used to on Earth the percentage of mass increase is tiny. It’s a different story close to the speed of light where the increase in mass would be colossal; in fact if an object moved at the speed of light it would become infinitely massive and have infinite energy. Even if the starting object has tiny mass, like a single electron, the end result would be the same.

So based on Einstein’s equation it would require an infinite amount of energy to travel at the speed of light, making it effectively impossible. So how might we overcome this obstacle if we are ever to travel to other star systems? Both science and fiction have several ideas to get over it.

Cheating Physics – Getting to Other Stars

As I mentioned earlier, our current technologies wouldn’t allow us to make the massive journeys between stars – even if we could get up to a decent speed, the amount of fuel required to power a large star ship would be a *ahem* $@#%load (scientific term). So one way we could approach being able to travel between stars is to develop more efficient propulsion systems.

There are several theoretical and proposed alternatives to current jet propulsion technologies. One such idea is using an antimatter rocket – a rocket engine which generates its thrust with antimatter. Antimatter is basically the ‘evil twin’ of matter particles in our universe – they are particles with the exact opposite properties of matter. For example, the antimatter equivalent of an electron is a positron. Electrons are negatively charged particles which are found in all atoms – their antimatter opposites have the same mass but the opposite charge. When a particle of antimatter meets a particle of matter they annihilate – a reaction which destroys both particles, converting them into the energy equivalent of the mass of both particles. Antimatter annihilation can produce an insane amount of energy from a tiny amount of matter which makes it an ideal rocket engine. Unfortunately antimatter is very hard to make and so far only 38 atoms of anti-hydrogen have been created, lasting only 0.2 seconds before annihilation. Another candidate for getting us close to light speed is nuclear fusion engines, which generate energy and thrust through the process of nuclear fusion – this is when two atoms fuse together to form a heavier element – releasing energy in the process. This is much more efficient than rocket fuel and could take us to (relatively) nearby stars with much smaller rockets.

So assuming we could use one of the many theoretical propulsion systems to get our space ships close to the speed of light and we wanted to travel to a star system a little less than 200 light years away, how would we deal with the problems of making the 200-or-so-year journey there? Again, there are several speculated solutions to this problem. A few of them are actually kinda weird. One proposal is a generation ship – a huge starship where the descendants of the original crew would be the ones arriving at the destination. Of course this would require building a ship capable of sustaining a functioning human society for 200 years, which I don’t think anyone knows how to even begin trying to do. Then we have suspended animation – this would work too for shorter journeys of a few years as well. This one has been in a good few Sci-Fi movies and shows – probably most recently in James Cameron’s 2009 epic, Avatar and the brilliant 2012 prequel to the Alien films, Prometheus by Ridley Scott. This method would involve slowing or pausing the aging process by freezing the passengers of a mission or putting them in deep sleep and waking them up at their destination – again unfortunately no such technology currently exists, but could offer a method of getting people to distant star systems in the future. Another idea is to send frozen fertilised human embryos into space and have them ‘revived’ by a robot (unfortunately not like C3PO) when they are within some years of their objective. Those are probably three of the least weird ideas – there are many more you can look up.

An almost-universally recurring staple of science fiction is faster than light, or FTL, travel. There are also many proposed mechanisms for this one and they are even more theoretical than the stuff I’ve mentioned before. Perhaps one of the more popular ideas found in sci-fi is that of using a wormhole to travel. This is another thing we have to thank Einstein for – working with a student by the name of Rosen he came up with the idea of Einstein-Rosen bridges – what have become known as wormholes. Wormholes are basically shortcuts through the fabric of space and probably the best way to explain it is the analogy which gives it its name. Imagine that the universe is a giant apple and you are at point A and want to get to point B which is on the other side of the apple. You would have to walk from point A to B which would take a few hours (it’s a really big apple) but a worm could get through the apple much more quickly (in less than one hour) by munching its way through the tasty tasty universe – by creating a wormhole. Unfortunately they are just theory at the moment and Einstein speculated that they would be very unstable and collapse almost immediately after coming into existence.  If we could work out a good way to create and stabilize wormholes (like a Stargate?) then we could, in theory, travel to distant stars and even galaxies almost instantaneously.

Well, that about wraps it up for this week. I know what you are thinking: ‘Adam, you should stick to the biological sciences.’ – if you have any complaints about the length, content or nonsensical-ness of this article, please write to our complaints department at 123 Fake Str… oh, sorry – we don’t have one. My mistake.

Thanks for reading, remember to check out and Like the Facebook page (https://www.facebook.com/scienceunplugged) to support ScienceUnplugged and to see notifications of new posts, science news and interesting things.

As with every article I post here, this one has been thoroughly researched and a list of sources can be provided for anyone who is curious – just check out the contact page.

The Science of Sci-Fi: Aliens

It is probably pretty clear from the fact that I run this blog that I am something of a nerd. And what do us nerds love more than anything? No, not energy-drink-fuelled inflammatory rants on message boards, its Sci-Fi! Everyone loves a bit of cheesy, space-battling, laser shooting sci-fi action. Turns out that a lot of the ideas in science fiction have some basis in science fact. If you’ve been reading ScienceUnplugged up until now you know the routine – yup: I’m gonna ramble about a few. In this part I am going to talk about Aliens (YAY!)

Evidence – Europa and Mars

So normally when you see the word ‘Aliens’ on a blog, things go downhill rapidly. There will be none of that sort of thing here. Like how the aliens are abducting everyone and replacing people with hybrid clones… kidding. If you haven’t read my last article about extremophiles you should give it a quick read because a lot of is relevant to the alien conspiracy.

Surprisingly, the concept of alien life isn’t actually a stranger to science. I mentioned in my last article about the theories about extra-terrestrial life involved in microbiology. There are a few signs that suggest that life exists or could exist on other planets in our solar system. 

The ice moon Europa, which turns out is kinda ginger... (source)

One example of this is the ice moon Europa. Europa is one of the moons of Jupiter and is about the same size as Earth’s moon. The entire surface of the planet is covered in ice and scientists believe that a water ocean could exist beneath the ice layer. In my last article I talked a little bit about hydrothermal vents – deep sea chimneys that spout mineral-rich water heated by molten rock in volcanic regions of the sea floor. It is theoretically possible that these vents could exist on Europa and create oases of life on the ocean floor, much the same as they do here. If these places exist on Europa, they would be perfect for critters like giant tubeworms and the ultra-resilient microbe Methanopyrus kandleri.

Another interesting thing about Europa is the red marks visible on its surface. Some have speculated that these could be caused by red-pigmented microorganisms growing in characteristic patterns called blooms, similar to those that can be seen all over planet Earth. As far as theory goes, Europa is probably the most probable candidate for life outside of earth. As for actually proving it… that’s another matter altogether. The European Space Agency is planning to launch a mission to study three of Jupiter’s icy moons called the Jupiter Icy Moon Explorer (JUICE) - so maybe we will find out after 2022 when the mission is planned to take place.

The surface of mars as seen by the Viking Orbiter... do you think martians like to eat MARS-ipan...? Hahaha haha ha ...sorry (source)

Mars has also received much attention as a potential life-supporter. My thesis adviser in my undergraduate degree would always say ‘water is life’. Here on Earth, everything alive requires and is largely made up of water. If water can be identified on a planet it may represent a foundation for life. Several efforts have been made to survey the conditions on mars and several clues about the presence of water on the red planet. Mars has polar ice caps composed mainly of water which also give rise to water vapor clouds. If frozen water can be found on the planet then perhaps liquid water is a possibility also. The conditions on mars can be best described as cold and dry across most of its surface with many volcanoes and the previously mentioned ice caps. On earth, microorganisms have been found which can live in similar temperatures and conditions. 

Science hasn't proved this guy real yet - sorry (source).

I know what you are thinking – bacteria and algae don’t really measure up to the imaginative range of green, blue, purple, orange and grey skinned, tentacled and/or antennae’d creatures that show up in SciFi shows, movies and games. What is particularly interesting about the deep sea vents I mentioned is that they create the conditions for simple life forms to thrive and become the bottom rung of the food chain where they act as the food source for more complex creatures.

Probability – The Drake Equation

Another clue that extra-terrestrial life may exist is the fact that it is technically quite probable. That probably seems like a strange thing to say until you think about it: if you look into the sky on a clear night you will see a lot of stars just like our sun. We live on a single planet out of nine orbiting our sun – the only planet we know of that supports life. If even a very small portion of those stars has just one planet like Earth, then the chances of life existing elsewhere in the galaxy seem quite high.

Okay, now it gets complicated. That’s right – I’m breaking out the maths stick. It may or may not surprise you to learn that astrophysics has come up with an equation to determine the probability of extra-terrestrial life existing in our galaxy. The equation was invented by American astrophysicist Frank Drake in 1961 and goes something like this:

N = N* fp ne fl fi fc fL

Frank Drake - inventor of the euquation - he gets all the ladies now (source)

If you are anything like me, that means absolutely nothing to you. I will try and translate it a little. N is what the calculation was designed to calculate: the number of alien civilizations which could potentially exist in the Milky Way. N* is the number of stars in the Milky Way – which is currently estimated to be around 100 billion. fp is the percentage of stars that have planets around them - currently estimated to be between 20% and 50%. ne is the number of planets which have the necessary conditions to support life – the estimate on this one is between 1 and 5 – because I have only talked about Europa and Mars I’m gonna call it 3. 

The rest of the values in the equation are a little harder to answer and a little more complicated. fl is the percentage of the planets which can support life (ne) where life actually evolves. All we really have to go on for this one is Earth – while there may be some limited evidence and theories about life on other planets, we can’t actually prove whether there is life there or not just yet. It seems that life on Earth started quite early in its history, which leads astrophysicists to believe that life began on Earth as soon as it was ready to support it. Based on this fact, some scientists say that the value for Fl should be at 100%.

A baby hamster inside some kind of fruit and/or vegetable (it was kinda hard to find relevant pictures for this section (source).

That brings me on to fi – the fraction of planets where intelligent life arises. Like many of the terms in this equation, this one is pretty vague and hard to define, as is the trait of intelligence itself. Some might define this as a human-like level of intelligence – the ability to shape the world and develop technology to enhance survival and to communicate with each other. Others might define intelligence as a survival trait which allows animals to adapt to their surroundings and survive life-threatening situations. These definitions give us very different estimates for fi – on Earth only one species out of millions has evolved intelligence by the first definition which would give us an estimate for fi which is very low, whereas intelligence by the second definition is a basic requirement for a species to survive and would give an fi value between 50 and 100%.

fc is the fraction of intelligent life that has the ability and will to communicate through the development of science and technology. Again, this one is hard to define. On Earth, it took one civilisation – the ancient Greeks – to get the ball rolling on science and technology which eventually brought us to the point today where we can look beyond our planet and even beyond our solar system and galaxy. This one is pretty subjective, but it seems to me that such advancements in science and technology are vital to the survival of life on a planet, so I am going to call it 100% - you may disagree though.

On to the final value – fL. This is the fraction of a planet’s lifespan in which intelligent, communicating life lives and is probably the hardest value to answer. The predicted lifespan of Earth is about 10 billion years and we have been communicating wirelessly for less than a century and honestly, things aren’t looking great for human civilization. But let’s say we don’t nuke each other into oblivion or destroy our planet with pollution and survive and prosper for another ten thousand years, that would give us an fL value of 1 millionth.

                                                                                                                                                                                   

If I put all the values into the equation (a lot of it is personal opinion and guesswork unfortunately), I get an N value of 90 thousand estimated communicating civilizations in our galaxy. You can’t really take my word for this though – everyone filling in the equation with their best guesses will get a different answer which can range from tens to billions. 

So I guess the answer to whether there are alien civilisations like those we see on the cinema screen is… 

…probably.

You can make your own estimates and try them out in the equation here.

Stay tuned for the next article in the series – interstellar travel…

Remember to check out and Like the Facebook page (https://www.facebook.com/scienceunplugged) to support ScienceUnplugged and to see notifications of new posts, science news and interesting things.

As with every article I post here, this one has been thoroughly researched and a list of sources can be provided for anyone who is curious – just check out the contact page.

Extremophiles: life in extreme places

Underwater volcanoes, arctic tundra and the reactor at Chernobyl- what do these places have in common? As strange as it might seem, they are the ideal living conditions for several different microorganisms. Think humans are the best at colonising Earth? Think again.

Deadly Radiation Levels: Chernobyl

The exploded reactor at Chernobyl (source)

About 70 miles away from Kiev in Ukraine lies the ruined reactor of the Chernobyl nuclear power plant and the eerie abandoned city of Prypiat.  In April 1986 during a security test at the plant, a huge explosion tore through the nuclear reactor, throwing its 1200 tonne cover high into the air, carrying with it a cloud of radioactive graphite dust and exposing the surrounding areas with lethal levels of radiation. To this day the clean-up of the fallout from this incident continues and a 2,600 exclusion zone has been put in place where no people live except for about 170 samosely – or settlers - who remained behind after the incident. Nobody is quite sure how many people died as a result of the power plant disaster, but estimates go as high as tens of thousands.

Given the catastrophic nature of this incident and the hostility of the area around the plant, it’s pretty surprising that it has been discovered in the last few years that black pigmented fungi grow and actually thrive on the walls of the broken down reactor. Normally gamma radiation (the most harmful form of radiation, the type given off by unshielded nuclear reactors and exploded atom bombs) causes irreparable damage to the DNA of living organisms, rendering them unable to function or reproduce.

The iconic radiation warning at Prypiat (source)

Turns out that the amazing ability these fungi have to thrive in these conditions is down to melanin- the same stuff that gives us moles and freckles. Along with many other organisms, some fungi produce melanin, which gives them a characteristic black colour. Scientists believe that these fungi use melanin to convert the deadly gamma radiation from the crippled reactor to energy they can use to grow. Lab tests with one such fungus, called Cryptococcus neoformans (I’m trying to spare the meaningless unpronounceable Latin names, but apparently us microbiologists are sticklers for it – sorry) showed that it grew three times faster than normal at 500 times the normal radiation found on Earth’s surface.

So, that’s the crazy radiation-munching fungi dealt with – let’s move on to heat, and another awesome environment.

Extreme Temperature and Pressure: Deep Sea Hydrothermal Vent Fields

A black smoker. I'd make a joke but it wouldn't be clever or funny (source)

Hydrothermal vent fields are probably some of the most hostile places on earth and they are freaking awesome. Uhh… that wasn’t very scientific – they are quite interesting. Better? Anyway, hydrothermal vents are holes in the Earth’s crust in volcanic regions which spew mineral rich water heated by molten rock. When this material hits the cold water some of it solidifies creating a chimney through which dissolved minerals issue like white and black smoke. These chimneys, not surprisingly, are called black smokers and white smokers. 

The water in these places can reach temperatures up to 400 degrees and the pressure is several times that of the surface, but amazingly they are some of the most life-filled places in the deep sea.  Discovered in 1970, these vents are relatively new to science, but in spite of this over 300 species have been identified in vent fields – more than 280 of which were completely new to science. The combined biomass (the total mass of living things) in these vent fields is estimated to be the same as the rainforest.

The thriving life in these hydrothermal vent fields is made up of bacteria, tubeworms, crabs, slugs, fish and many more. Like all life on this planet, the smallest lifeforms make it all possible. One of the components of the ‘smoke’ spewing out of the vents is hydrogen sulphide – a gas with a characteristic rotten egg smell which is toxic to most life in high levels. This gas is the primary food source for the microorganisms that live there. These microorganisms make up the bottom rung of the food chain, allowing more complex life to survive by feeding on them. These microbes have to be specially adapted to live in such a place, as high temperature and pressure destroy the structure of cells and damage the proteins that make them work – in fact it is temperature and pressure that are used to sterilise laboratory and medical equipment through a process known as autoclaving.The types of microbes that survive down here are ones whose internal components are highly resistant to such damage.

M. kandleri - fascinating AND pretty (source)

One of these microbes, called Methanopyrus kandleri  (sorry!) is the world record holder for life at high temperatures.  M. kandleri is an archaeon – a member of the archea which are similar to bacteria but are quite different at a genetic level and often to live in extreme and methane gas rich environments – either producing it or using it as an energy source. M. kandleri was discovered on the wall of a black smoker vent and grows happily at 110°C and can survive up to 130°C. Science classifies this awesome little bug as a hyperthermophile, meaning ‘extremely high temperature lover’.

Sub-zero Temperatures: Arctic Permafrost

Whenever people think of inhospitable conditions the Arctic tundra is probably pretty high on the list. I keep thinking of arctic explorers fighting their way through blizzard in huge fur coats with their big bushy beards caked with snow… but maybe that’s just me. One critter that loves to live in the arctic permafrost is the fetchingly-named Planococcus halocryophilus. This one is an extreme survival double-whammy. It is capable of growing at ultra-low temperatures and ultra-high salt concentrations.

P. halocryophilus in the flesh... or whatever they are made of (source)

P. halocryophilus was discovered in 2011 in the Canadian High Arctic where scientists believe they grow in the permafrost – the frozen soil on the surface of the Arctic. These bugs are reported to live in tiny regions of highly salty water in the permafrost, which creates a particularly demanding environment of high salinity (salt content) and sub-zero temperatures. P. halocryophilus has been shown to grow happily at the ambient permafrost temperature of -16°C and survive up to -25°C and has been referred to as a ‘cold temperature champion’.

Normally bacteria are killed by extremely low temperature when water inside the cells freezes or the temperature slows or stops the chemical processes that keep them alive. When water freezes it tends to form crystals which tear through cell walls and render them useless. Cold-loving bacteria (cryophiles) protect themselves by producing their own kind of antifreeze inside and out which prevents them from freezing solid or being killed by ice crystals. P. halocryophilus is able to survive at such low temperatures by doing just that, as well as being highly adapted to be cold-resistant.

So, if you didn’t before, you now know about three of the world champions of survival, and yes, they are all microbes – in microbiology these are called ‘extremophiles’. “That’s all very well” you might be saying, “but so what?” – which is a fair question. Probably the most fascinating thing about these extremophiles is the fact that they provide us with a window to other worlds. I know, right? I made that sound super dramatic. What I am talking about here is xenobiology – the study of extra-terrestrial life. I’m not talking about the E.T., X-files, take-a-deep-breath-here-comes-the-probe type of extra-terrestrial life, I’m talking about microbes. Some of these extreme environments on earth closely mirror what conditions might be like on other planets and studying the life that thrives in them tells us about the possibility of life on other planets. Microbiologists believe in aliens – who knew?  

As with every article I post here, this one has been thoroughly researched and a list of sources can be provided for anyone who is curious – just check out the contact page.