## Friday, October 7, 2011

### Total Perspective Vortex

[I apologise to all readers of the blog who also take the time to read the comments because you have probably already have seen the following videos. For those who don't read the comments, you're missing out on half of the purpose of the blog.]

Michelle asked in this post what role cinema plays in science. I think this is an interesting question and a smart choice of post from Michelle. Opening a dialogue between science and art isn't easy. We speak very different languages. We sometimes tackle similar questions, but we do the tackling in very different ways. Moving images though are something that exist in both worlds. They may be used very differently, but that's the interesting thing; how are they used differently? How are they used similarly? There are tools such as sculpture and advanced mathematics that probably aren't used in both worlds, but moving images are.

So moving images are a great example for this blog because they give us that first piece of common ground from which to begin a conversation.

My first contributions to Michelle's questions were the following two films. They are the best examples I know of that properly show how insignificant the Earth is. Watch them in high definition.

The first film, above, is a film of the dark matter particles in the Millenium Simulation. This is what we expect the universe should look like if we could see the dark matter in it. As stated in the wikipedia link, each individual particle in this simulation (i.e. pinprick of light in the film) has a mass one billion times the mass of the sun. Not only that, but the total volume of the simulation is much less than the total volume of the observed universe. Keep that in perspective when watching... this video shows only a small fraction of the total volume of the universe and each dot in the video is much bigger than an entire galaxy! (don't forget that one galaxy will itself be 100,000 light years wide - this is so big that in one human lifetime light could only travel 0.1% of its width - and that is just one galaxy, something just big enough [edited from the original - "not big enough"] to be seen in this video.)

The film above is the real world equivalent. This film shows the locations of individual galaxies in the observed universe as seen by the Sloan Digital Sky Survey. SDSS has only mapped a fraction of the sky and can only see galaxies that are within a certain distance of us. So you see less of the universe, but at a finer resolution. In each galaxy in this video there will be billions and billions of stars just like our sun. This website helps if you find it hard to visualise what the number one billion actually means.

As the conversation develops I will hopefully find time to explain the scientific gains from both SDSS and the Millenium Simulation as well as what a scientist gains from watching the films themselves. But for now, let's just treat these as eye candy for the weekend as we wait for James' next proper post, due to arrive on Monday.

1. "You are here."

2. It is a shame blogger won't let me "+1" your comment.

3. As a non-scientist, when confronted with images like these, demonstrating the vastness of the known universe, my feelings are mixed. It's staggeringly difficult to comprehend; simply amazing seeing simulations (and the SDSS real-world view); but also more than a little scary...

4. Hi John, I think with videos like this the reaction is universal for scientist or non-scientist. It *is* scary. This is perhaps a very good example for a use of the word terrific.

In fact, the title of the post was an allusion to the Hitch-Hiker's Guide to the Galaxy where the Total Perspective Vortex (a device that gives a human being a true sense of perspective regarding their importance in relation to the whole universe) was actually a form of extreme torture.

Even though the answer may be nothing, you just can't help but wonder what the point of all that matter and space is.

Why is it there?

But then, how lucky are we that we can observe it? And what if we are the only ones in all of that space who can?

5. What if we are the only ones? Given the incomprehensible vastness, and countless numbers of galaxies, each with countless stars, my old brain tells me that the odds that we are alone in all this must be miniscule.

I could say a million to 1, but as we know from Discworld, when the odds are a million to 1, then the event always happens. So, more than a million to 1...

6. Fair enough. On a side note... I received an email tipoff that you have actually already visited NZ back in August, so I feel a bit silly about thinking it was November. Nevermind.

Have you ever read the Science of the Discworld books? Maybe this is a silly, question and the answer is "Of course!" I really liked the way Pratchett and the other authors used the internal logic of the Discworld to help explain (and as a contrast to) the science of the real world. The Discworld works very much how our stories work and how we secretly expect the world to work, whereas the real world often, stubbornly, does things differently (like having 99.9999999999% of the universe just, empty - what is the point of that?). It is amusing "watching" as the Discworld characters try to understand our world's logic where nothing obeys common sense and everything is just so pointless.

7. John, it's great to have your contributions. I'm glad Shaun used the wonder tag for this post because I think that the terror or lump-in-your-throat reaction to understanding something about the *scale* of these visualizations is where art and the aesthetic gets into the science. Perhaps a subject for a future post.