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Space… it’s bigger than my university debt.

January 10, 2011

So how big do you think space is? Large? As big as a football field? Larger? How about the size of TWO football fields? Incredibly, space is even bigger than that. I know, it’s incredible.

So you might think that space is pretty sizeable, but unless you’re an astrophysicist/astronomer (or a colossal nerd who is obsessed with this kind of stuff) it’s hard to really get your head around the vast numbers involved. Afterall, how easy is it to visualise the difference between the numbers 1.9891×1030 and 5.9736 × 1024 ? Not much difference right? It’s just a couple of extra zeros! In fact, that’s the difference in mass between the Sun and the Earth. The Sun is 332,900 times more massive than the Earth. That’s a big difference!

You see, the problem we find is that once numbers get past the couple of thousand mark we can no longer visualise just how many of something there is and we simply see it as LOT. It is easy to see the difference in size between say, an object 2 metres long and something that is 15 metres in length because these are the kind of numbers we deal with on a day to day basis; It’s the difference in size between a person and a bus. However, once the numbers start entering the trillions and even quadrillions of metres (a lightyear is around 9.4 quadrillion metres) our sense of perspective is lost and we lose the ability to imagine what these numbers actually mean.

The Sun is 1989100000000000000000000000000 kg and the Earth is 5973600000000000000000000 kg and yet their comparative masses would be much better demonstrated with a picture.

Suddenly the difference between 1.9891×1030 and 5.9736 × 1024 is much easier to think about isn’t it?  In fact, the reason why pictures make a lot more sense than big numbers is a similar reason to why it is easier to empathise with say, a picture of an orphan rather than a statistic. This happens all the time and it is a phenomenon that affects advertising, charities, politics and the news. Thanks to the way we are hardwired, even if the statistic is big, we often find that an anecdotal story is much more compelling, and don’t the papers know it! If charities simply gave us the numbers, without the accompanying pictures, i’m fairly sure no one would donate (don’t quote me on that).

Anyway, back to space. So we’ve realised that things in space are big right? Like supermarket big. Well the problem of conceptualizing vast numbers gets even harder when we start exploring the how large the distances are in space. Think about the solar system, what is it like? Well we all know that there are nine eight planets, a whole load of moons, a bunch of asteroids and a zoggin big star in the middle. Now when most people think about what this all looks like they imagine a picture like this:

Pretty isn’t it? Unfortunately this picture, and the many images like it are TOTALLY WORTHLESS. Ok maybe not totally worthless but they are certainly not very good at giving the viewer any idea as to the sizes of the planets, (earth, mars, venus, mercury and pluto have all been enlarged) or any clue as to how far away from each other the planets really are. Here’s another egregious offender:

This one is even worse. In fact, it even manages to make me angry. Yes I know, I should have better things to do rather than spend my time getting offended by pictures of planets, but just look at it! If you’re going to make the planets different sizes at least make them the right size, why would you make Mars only “slightly” smaller than Earth and not its correct size? (it’s around half the diameter of the Earth.) If you’re going to go and attempt to scale the planets at least do it correctly. In fact I’m convinced that thanks to this particular picture, generations of children will grow up believing that the planets are all lining up behind each other in some kind of cosmic conga line that leads directly away from the Sun, out of the Solar system and onto a funky cruise ship where all the plutoids and comets are also invited. Oh and Earth is the only planet with a moon for some reason.

Here are the things this picture does right:

a) Look pretty.
b) Give you an idea of the order the planets are in.

That’s it. In fact, I was so enraged by various misleading diagrams of the solar system I decided to set out and create my own, totally useful, beautiful and educational diagram of the solar system. Here is the result of my endeavours:

It’s magnificent isn’t it? You can enjoy clicking on the image and searching for our own blue speck of a planet. Just a warning, it’s about the size of one pixel so it might take you a while to find… (hint: it’s to the left of the text saying “earth”)

Ok, I admit it, maybe my picture suffers from a few problems…

1) It looks like crap.

2) It only shows the Sun and the first three planets. (that’s just me being lazy)

3) Mercury should be less than one pixel in diameter.

3)You can’t see anything.

You see, because I was determined to make my diagram to scale (one pixel equals the diameter of the earth) I quickly ran into the fact that space is really really big. As an educational tool my picture isn’t exactly the best (it’s rubbish)… so instead I found a better way of demonstrating how big space is.

Here is a picture of a football.

Now here is a picture of Trafalgar square.

Now the football represents the Sun and it goes in the middle of the square. The following picture is of a TINY ANT.

See this little ant-thing? That’s how big Venus and Earth are at this scale. Now imagine that Mars is this ant but cut in half (sorry) whilst Mercury is even smaller than that. The following picture is where the planets would lie if the Sun was the size of a football and the planets closest to it the size of ants… or smaller:

That looks about right… the distance between the Sun and Venus is roughly the length of a bus. Now as we travel beyond Mars towards Jupiter the distances get bigger.

Now Jupiter and the gas giants are a lot bigger than the planets in the inner solar system. So instead of an ant imagine that Jupiter, Saturn, Uranus and Neptune are all grapes, ranging from 1.5 cm to something like 2 cm in diameter.

So there you have it. If the Sun was the size of a football then Pluto would be a speck of dust almost a one kilometre away from Trafalgar square. In the Thames. Of course the size of the solar system is peanuts compared to the distance to the nearest star…

That’s Ethiopia by the way.

6 Comments leave one →
  1. Tom permalink
    October 7, 2010 9:35 pm

    Haha! Great post

  2. January 12, 2012 10:43 pm

    coolio. so if sun was empty how many earths could fit in it. try to figure that one out. and ho do they measure something as large as the sun anyway

  3. Erik permalink
    June 15, 2012 5:32 am

    I just stumbled into this page while doing my random googlings, but damn, this was one well written post. Really interesting too.

  4. July 4, 2013 11:12 am

    Really really interesting


  1. Whilst i’m on the subject of awe-inspiring videos. « Suspension of disbelief.

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