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!

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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.