Category: musings

Fire

As Australian readers will know, Victoria has been devastated by bushfire over the last week, with nearly two hundred lives lost and whole towns destroyed. If you’re looking for a place to help, the Australian Red Cross is a good place to start; use their web site for donations of money, as the call centre is overrun, and if you want to donate blood that’s great but you can afford to leave it for a month or two (they have enough for immediate use and more donors than they can currently schedule).

If you don’t have much money to spare, there are other ways to donate; Australian companies are donating all or some profits from sales on a particular day, from Coles (Friday 13th) to smaller local businesses like Trampoline (Friday 13th) and The Book Grocer (Saturday 14th). Closer to home for me, the Australian comedy and arts communities are holding benefit gigs left, right and centre. This Sunday is the Anarchist Guild Social Committee’s meeting #9, and we’ll be donating some of the ticket income to the appeal; a larger scale fundraiser gig, Out of the Ashes, will be held on February 22 at Trades Hall. I’d encourage you to get along to one or both of these, or to any other events in your local area.

The Time Lord at 45

November 23, 1963: a television programme like no other premiered in the United Kingdom. So today, Doctor Who is 45, and it’s an exciting time to be a fan, as David Tennant finishes up his run in the title role over the next year, ushering in both a new Doctor (who at the moment would seem to be all but confirmed as Paterson Joseph) and a new show runner, perennial best-episode-of-the-season author Stephen Moffat.

This is a science-themed blog, though, so it’s worth me taking a moment to reflect on the sometimes rocky history between two of my great loves: science and Doctor Who. Things started out well: the first episode, An Unearthlty Child – justly lauded as one of the series’ greatest – includes a couple of brief classroom scenes in which the Doctor’s granddaughter shows her vastly superior science knowledge. Over the years the Doctor has generally championed science; during John Pertwee’s tenure in the seventies, and despite the fairly blatant Buddhist overtones of that era and various seemingly supernatural foes, he always insisted that magic was merely advanced science not understood by humans. This stretched a bit, including such unobserved phenomena as psychic abilities and so on, but by and large it was clear that the Doctor is a scientist.

Mind you, it was also John Pertwee who famously called on a suffering UNIT technician to “reverse the polarity of the neutron flow” and perpetuated the myth that “classical aerondynamics” suggests bumblebees can’t fly… And these were signs of the trend to follow. In the late seventies, scientific concepts and terms were tossed into scripts where they bore no resemblance to their re-world counterparts; during the eighties a tendency to mix real world science with nonsense escalated to the insane psuedo-science of Time and the Rani.

These days, science and the good Doctor might seem estranged. The show has become a member of that quite specific genre of science fantasy: fantasy with the trappings of science (a niche occupied also by Star Wars). Since Russell T. Davies took over, the only real-world grounding for Doctor Who has been a social one: the famliy and context of the current companion, which during his series has always been contemporary (though, as sharp readers will know, set one year in the future).

It’s easy to get caught up in arguments about this sort of thing; time “paradoxes” (they usually aren’t, and if they are…well, they’re paradoxes, and by definition cannot exist) and black holes are particular bugbears, with the former almost unknown in the series until recently (surprisingly, for a show about a Time Lord!) and the latter ascribed any and all peculiar abilities. But really it’s the Doctor’s attitude that makes the show still one of science’s greatest allies.

He’s not a two-fisted adventurer or a soldier or even a policeman; the sonic screwdriver might be a magic wand and is occasionally wielded as if it were a gun, but even so the Doctor’s main weapon continues to be his mind. He’s a thinking hero, a man of action whose first action is always to analyse his foe, to outwit rather than outgun. It’s true these days this sometimes gets lost in the emotional drama, which Davies rightly put first when reestablishing the show, and sometimes the Doctor’s solution relies almost entirely on information never established in advance (the void matter being attracted to the void in Doomsday, for example), but the Doctor is still the thinking man’s hero. Science is about asking questions, examining the observed facts, establishing patterns…

There are few finer examples of a science hero than Eccleston’s Doctor, trapped in 10 Downing Street, marshalling the facts about the Slitheen in order to discover their identity and weaknesses.

Happy LHC Day!

What better way to celebrate than by checking out the Large Hadron Rap? It’s the best way to learn about the various programmes at the LHC – after all, the stuff I wrote about yesterday was just one of the many experiments for which the LHC will be used.

Thanks to Kate McAlpine for that one, though I might also mention that she was inspired by one of my personal favourites in the growing world of science/entertainment, MC Hawking.

And if anyone is worried about the end of the world, be sure to remind them that today is just a test-firing; no collisions are happening until at least October 21st, so they’ve more than a month to get the absurd panicking out of their systems. For my money, though, October 21st will be the real day for celebration.

The Great On-Turning

Tomorrow is the Day of the Great On-Turning – not of Deep Thought, but the Large Hadron Collider (LHC). It’s the sort of thing Stephen Hawking – who I can only hope will be there – once lamented not having in A Brief History of Time; twenty years ago he never dreamed the money would ever be available to build a machine this big and powerful. But here it is!

No doubt you’ve heard of this device from many other sources, not least Andrew Denton’s interview with Brian Cox on last night’s Enough Rope. Like most discussions of the Collider, that interview featured heavily the claims that the LHC will destroy the world, mostly fuelled by the ridiculous law suit still pending in the District Court of Hawaii (filed by a group of “concerned citizens”, at least one of whom has previously tried to stop other large particle collider projects). Well, we’ll have none of that here; if you’re still concerned by the warnings of crackpots, let CERN reassure you with their latest press release on the matter.

Instead, here’s a primer for those of you who are still unsure what it’s all about. First, let’s break down the name:

  • Large – the Large Hadron Collider is a “large collider of hadrons”, not a “collider of large hadrons” (hadrons do come in different types – see below – but not significantly different sizes). Some sources claim it’s the largest machine ever built by humans, and it’s certainly the largest science experiment – it’s a 27 kilometre long loop, buried underground near CERN in Geneva, and it crossed the border between Switzerland and France. It took 10 years to build with another 10 years of design work before that.
  • Hadron – a hadron is a particle made up of quarks, one of the fundamental particles that make up all matter. The most famous hadrons are baryons, which consist of three quarks, one of each “colour” – red, green and blue – that are held together by the strong nuclear force. Baryons include neutrons and protons, which make up the nuclei of atoms. The difference in charge between positively charged protons and neutrally charged neutrons is down to basic maths – different “flavours” of quark have different charges (it’s a little more complex than that, but we’re only interested in the quarks that make up “normal” baryons). In a neutron, the positive charge of one up quark (+2/3) is exactly balanced by the negative charge of two down quarks (2 x -1/3); in a proton, there are two up quarks (2 x 2/3) and one down quark (-1/3), resulting in a total charge of +1.
  • Collider – the LHC is a particle accelerator – it accelerates particles to very high velocities, giving them enormous energies. It’s also an “atom-smasher” (though it’s only smashing bits of atoms, not whole ones) – its purpose is to accelerate particles in two directions, colliding them together. It was collisions like this that allowed us to observe the existence of quarks, since normally they can’t exist on their own; smash some hadrons together, though, and their component bits go flying all around the place like bits of plastic bumper in a car crash.

The specific purpose of the LHC is to accelerate hadrons to speeds which will give them enough energy to simulate the state of matter only a few billionths of a second after the Big Bang, when things were very different to how they are now. This is hugely exciting because so little is known about the origins and initial formation of matter, or as Brian Cox put it, “what makes stuff stuff”.

One big question is to do with photons and W and Z bosons. A great success in particle physics was a combined theory explaining both the electromagnetic force and the weak nuclear force; it basically says they are two different aspects of the same force, which at high energies – like in the Big Bang – would manifest as a single “electroweak” force. The particles that carry these forces – photons and W and Z bosons, respectively – are different forms or states of the same particle, and at suitably high energies the combined force is carried by the Higgs boson. One of the big mysteries is why photons have no mass, while the W and Z bosons are massive (meaning they have mass, not that they’re huge!); hopefully observing the Higgs boson will shed some light on this!

It’ll be more than a month before the first collision is made – tomorrow’s “Great On-Turning” will involve only a single beam, not colliding with anything. But it’s an exciting time to be a scientist, or even a scientician – some big questions are going to get some kind of answer very soon. Of course, once the “answer” is determined, the real fun begins: trying to interpret what it all means… Perhaps it’s not so far from Deep Thought, after all.

That sensation you’re feeling is the Quickening

Man in the Lab Coat reader and friend Dan posed a great question in the comments of my last post: assuming an astronaut was immortal, would they experience an infinite amount of time while falling into a black hole?

The tricky part about this is time dilation. To an outside observer, once the astronaut passes beyond the event horizon she can no longer be observed, and theoretically takes an infinite amount of time to fall in – we’ll never hear from her again. But for the astronaut herself, time proceeds as normal – and it takes her a finite amount of time to fall into the black hole, or at least, to fall far enough past the event horizon that she is spaghettified. I also pointed out that no form of immortality save being unaffected by gravity could save you from this fate – and if you were unaffected by gravity, you wouldn’t be falling in in the first place! So the answer is no.

Note, too, that this whole scenario is only feasible if it’s a supermassive black hole – for smaller black holes, an astronaut would be spaghettified long before crossing the event horizon.

While checking my facts, I came across a fascinating idea – that it’s possible to find a “sweet spot” of acceleration that maximises that finite time before you are destroyed. This study can be found in a paper from last year titled “No Way Back: Maximizing survival time below the Schwarzschild event horizon“, written by two Australian physicists, Geraint F. Lewis and Juliana Kwan from the University of Sydney. A great summary of the article can be found in the Universe Today blog.