Monday, March 19, 2007

Hot Fuzz - An Invitation 

Hot Fuzz, the lastest film from Simon Pegg and Edgar Wright (Shaun of the Dead, Spaced) is out in cinemas and I'm going to go and see it, and you're more than welcome to come along!

When: Tomorrow, Tuesday, 20th March
Where: Hoyts Carousel
When: 6:30pm

If you're coming, just leave a note in the forum, so I know to expect you.

Thursday, March 01, 2007

Lightning Strikes Out 

One of the thunderstorms during Monday's unusual weather passed right over my workplace, giving us a fairly impressive light and sound show, and putting all us techies on edge waiting for the seeming inveitable power outage (it didn't happen). We're fairly sure at least on bolt came down in the courtyard outside my window and I'm fairly sure the library got struck as well.

So, it was this recent experience in mind that I settled down to watch the science documentary of the ABC tonight. It was a BBC programme called 'Lightning: Nature Strikes Back'.

From the programme description: 'Lightning: Nature Strikes Back' looks into the cause, effect and current understanding of one of nature's greatest enigmas.

Cause was covered in a single sentence: "Lightning is caused by the friction of ice particles in storm clouds." It was pretty much down hill from there, relying mostly on sensationalism and hyperbole. To give you some idea:

Here's Apollo 12. It got struck by lightning just after launch, causing the primary computer to fail. It it wasn't for the massively redunant systems, people might have died. Lightning is to be feared!

Here's a man who was struck by lightning - he seems normal, but in this MRI test shows that his congnative functions have been remapped to the other side of his brain. Lightning is to be feared!

Here's a research facility in Florida where they fire small rockets attached to long lengths of copper wire into clouds to cause lightning strikes. See how the research assistant runs back from the launch platform. Lightning is to be feared!

Equipment near by registers X-Ray radiation from lightning strikes. That's totally unexpected! (obviously not, or you wouldn't be looking for it) We see gamma rays too! We have a physicist make a statement that the raditation levels are really, really low from 20m away from the impact point, but "we've never measured directly in the lightning channel. Who knows what doses people who get struck are exposed to." (I suggest he goes and reads up on the inverse square law and works it out) Lightning is to be feared!

Lightning causes forest fires! Lightning is to be feared!

There's more lightning than you know. Above the clouds you get huge bolts of lightning in enormous sheets that go more than 15 miles up. Lightning is to be feared!

It was almost over at this point, but I'd had enough and turned it off. For a science documentary, there wasn't much good science. It didn't give a good explaination of how lightning works, and talked about phenomena without talking about why it works. I found the X-ray and gamma radiation fascinating, but had to figure it out for myself - lightning produces light, ie electro-mangnetic radiation in the visible spectrum, and it does seem to have a blue-ish tinge, from the upper end of the spectrum, so it's not too surprising to discover higher-frequency emissions.

I also found the upwards lightning interesting, but no explainations were offered. Lightning is basically a bunch of electrons moving from an area of high charge to an area with a lower charge - what the hell is there to create an electrical potential with more than 24 kilometres up? Wikipedia confirms my thoughts that it could be arcing to the ionosphere, but it's very disappointing no explaination was offered in the programme.

In short - reading the Wikipedia page on lightning was much better use of my time.