Learning about the universe

I’m learning about the universe via this tasty Xmas gift:

 

It’s really interesting stuff, but it’s also rather complicated.
Here’s a quick taster:

But the angular power spectrum also had something to say about the nature of the matter comprising our universe. Because it contains charged particles, ordinary matter will have interacted electromagnetically to some degree with the photons in the microwave background. Contrast that with dark matter, which – being dark (and so by definition not interacting electromagnetically) – can have influenced the CMB only through its gravity. These fundamental differences manifest themselves in the power spectrum, through the positions and relative heights of the observed peaks. Reverse-engineering this data showed that 95 per cent of the critical density of the universe does not interact with radiation and so must be composed of something other than ordinary atoms. Primordial nucleosynthesis confirms this too.

I’m on page 114, which coincidentally is also the number of times more powerful my brain would have to be to catch this all first time around without having to flip back a couple of pages every now and again to reinforce knowledge I only gained 60 seconds ago.

I can’t blame author Paul Parsons. He’s doing a great job of spoon-feeding me an extremely complex subject without belittling me in any way. That said, even he is clear that the next bit is going to be:

a quick ramble through the altogether baffling science of quantum mechanics…

I tried once before to understand the basics of quantum mechanics and it didn’t end well. Even seeing the title of Chapter 6 brought back memories of vodka-fuelled late nights in the lab trying to find a quark, and the months of therapy that followed my failure.

Fingers crossed that Paul can help me find my way a little better than last time.

Depressing physics…

It’s not just South Africa. Everything slowly descends into chaos.

Seriously. Whenever atoms are in any given structure or arrangement, they are displaying unnatural organisation. The universe doesn’t like that and it fights back by reducing everything slowly and surely into chaos.
That’s not such a difficult thing to consider when you’re thinking about a radioactive isotope, but then someone goes and makes this (equally valid) observation:

Depressingly, it’s all true.

Snoopy is rapidly disintegrating and so am I.
And before you start feeling all superior, so are you.

Physics Demo

The best branch of science is microbiology. I can say this for certain because I’m a microbiologist, so I should know. There are other sciences that are quite good as well, and then there are some that are OK, and then somewhere deep into the lower half of the list of good sciences is physics. Physicists would probably argue with this, saying that “without physics, there would be no gravity”, but this is plainly untrue. Without microbiology, there would still be bacteria, and it’s not like we’d all go floating off the surface of the planet if physics was suddenly abolished as a science.

Anyway, this isn’t their list.

I did see some physics demonstrated the other day though, and I was impressed. Not impressed enough to move it above anthropology, but impressed nevertheless. And so, I’m going to share the video with you, right here, right now.

What happens in the video isn’t unexpected – physics tells us what to expect and what physics tells us to expect, occurs – but it is still a bit weird and tough to get your head around. Allow me to demonstrate – bring forth The Coxmatron!

The lead in is actually really interesting too, but if you just want to skip to the mentally confusing bit, jump to 2:30.

Galileo hypothesised that falling objects would fall at the same rate regardless of their masses, and so yes, the only reason that a bowling bowl falls more quickly than a bunch of feathers is because of the added air resistance on the latter. And yes, you know that, but because you have never seen a bowling ball and some feathers dropped in the absence of air (until now), it’s properly weird to actually see happening, isn’t it?

PHYSICS!!*

* It’s nowhere near as good as microbiology, but still much better than biochemistry.

Visible wi-fi?

Gizmodo has published a little piece about what we things would look like if we could see wi-fi signals. While it’s quite interesting, for example:

A ‘normal’ field of wi-fi is typically spherical and can extend 65 to 100 feet.

…(i.e. they’re 3d, not simply unidirectional), it’s also not ever so scientific, as if we were able to see wi-fi, we’d surely be able to see all sorts of other (currently invisible) electromagnetic waves as well: infra red, ultraviolet, radio waves etc etc. The picture would surely be far more complex. Your microwave oven would be psychedelic.

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Above is a bit of Washington DC with a depiction of low level wi-fi hanging around the Washington Monument like a colourful mist (or smog, as the hypochondriacs would have you believe). And below, an image showing the decreasing amplitude of the wi-fi waves as they get further from their source. That’s why you can’t get a signal if you’re too far from your router.

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My physics A-level made me wonder if the reflection from the pond would happen. And then I decided that it probably would, since wi-fi is represented as being within our visible spectrum.

But while this is all very pretty, does it really mean anything?

Well no, it doesn’t. But it is very pretty. But I was thinking that it was rather sad that we couldn’t see this sort of stuff with our naked eyes, instead of having to resort to arty depictions. And then I read this comment on the Gizmodo page:

I see things like this, all the time – I see them right now. They’re not as vivid as the photos, they’re more like transparent solids that act as waves and move in specific patterns. There’s more than one pattern though, which I assume would be other noise beyond the visual spectrum. They’re not eye floaties, I’ve researched every visual phenomena that I could find, and though one came close it didn’t really explain everything.

I want some of whatever he’s on.

Knot good

It’s one of those pet hates; when you pop you headphones in your pocket and the tangle elves get to work tying all sorts of knots in them, meaning that listening to music the following day takes 10 minutes longer than you had planned.

Well, it’s not your fault. I’ve recently learned that you can blame PHYSICS!

A duo at the University of California found no elves (durr – they’re invisible!) but they did find some PHYSICS!

It is well known that a jostled string tends to become knotted; yet the factors governing the “spontaneous” formation of various knots are unclear. We performed experiments in which a string was tumbled inside a box and found that complex knots often form within seconds.

From that initial line, maybe the best way to avoid this difficulty is not to jostle your pockets. Some men may find this rather taxing.

We used mathematical knot theory to analyse the knots. Above a critical string length, the probability P of knotting at first increased sharply with length but then saturated below 100%. This behaviour differs from that of mathematical self-avoiding random walks, where P has been proven to approach 100%. Finite agitation time and jamming of the string due to its stiffness result in lower probability, but P approaches 100% with long, flexible strings.

Basically, all other factors (and basically, this means trouser jostling) being equal, the longer your cable, the more likely it is to knot.

There are graphs, photos and a whole raft of other formulae and statistical explanation in the paper. I did my best to work my way through it and, despite falling asleep twice, managed to get to the end.

Imagine my disappointment when I found that they had not even bothered to provide a solution for this horrible phenomenon.

Science is amazing and science can be used to demonstrate amazing things. You only have to look at some Austrian bloke jumping from what appeared to be a large, old-fashioned kettle on the edge of space to see this. But all those amazing things are no use if they can’t be put to practical use. Lest we forget, Felix’s freefall allegedly taught us that we could safely eject from spaceplanes of the future (ok, bit of a stretch there in attempting to justify their expense sheet by the guys at Red Bull perhaps, but still).

But this, for all their efforts:

The experiment was repeated hundreds of times with each string length to collect statistics.

gives us just that. Statistics. And they are statistics that say that if you put your headphones in your pocket and you jostle (or even if you don’t), you are going to end up with knotted cable.

This is no help whatsoever and I feel that I must apologise on behalf of science. In my humble opinion, experiments with no practical application should be banned. Physics should be banned. Raymer and Smith have dragged its name through the mud.

And if those bans leave us with no more skydives from space, well so be it. The likelihood of me ever having to evacuate a spaceplane seems rather small when compared with the likelihood of me having to untie another sodding knot in my Sennheiser CX300II’s every time I take them out of my pocket. And no, I am not a serial jostler.

Science must provide answers and solutions. Otherwise we might as well just all study the arts.