Tag Archives: Physics

Revision is pretty much the worst thing ever.

I really, really dislike revision. It’s not so bad when it’s something that’s reasonably interesting, like Quantum Mechanics or something, but trying to bludgeon my brain into learning Thermodynamics in this kind of heat is frankly just horrific and painful, and I want it to go away and leave me alone.

My exams are:

  • Thermodynamics & Statistical Physics
  • Quantum Mechanics
  • Applications of Quantum Mechanics & Electrons in Solids
  • Fourier Methods, Differential Equations, & Statistics of Meausurement
  • Mathematical Methods
  • Electromagnetism & Optics

I’ve done one past paper each for the first two, and overall I’m fairly confident, although there are some pretty major gaps in my Thermodynamic knowledge (how do you work out entropy change again?!), which I’m desperately trying to plug. I’ve done some revision in the other areas too, so I’m feeling fairly alright with differential equations, and statistics is just a retread of A Level stats anyway, for the most part.

First exam is on the 28th, so things are moving on.

Went camping last weekend, may or may not do a writeup on that at some point, possibly when I run out of ways to continue procrastinating. Should have struck while the iron was hot.

Wow. Sometimes work really is worth doing.

So today I sat down with the intention of figuring out how to solve ∇²u = 0, otherwise known as the Laplace equation, in spherical polar co-ordinates. Because it’s part of my course.

It may sound as a task somewhat obscure, but it’s really not. It governs any kind of potential, like gravitational, or fluid, or electrical, whatever.

Solving the equation in spherical polar co-ordinates gives insight into any problems in which potentials are important in a spherical environment, like the hydrogen atom. As it turns out, the various solutions to this equation are what create the energy levels in atoms, what makes a metal like copper behave differently from a gas like argon. It’s kinda fascinating that you are just going in solving this equation, and this kind of really fundamental stuff just leaps out of the mathematics.

Like the basis of energy levels is that a component of this differential equation has a series solution, a long chain of terms. If this chain of terms is allowed to go off to infinity, it’ll be unbounded – the sum of the series will itself be infinite. So you have to impose an artificial cut-off to the sequence for the solution to exist. The series of terms has to be finite. The really odd part is then this cut-off number, known as L, actually is something physical.

If you ever studied chemistry, you’ll know about s, p, d, and f orbitals, and how different numbers of electrons can fit in each. Well, if an electron is in the p orbital, then the L number I mentioned is 1. d, the L number is 2. You can probably guess what f is!

The reason that chemistry is the way it is all falls out of the solutions to this kind of equations. That really boggles my mind that the way the world is seems to be an inevitable result of the equations that govern it. Amazing.

Concious of a vast, numbing stupidity

I was earlier reading about the NUS conference on the excellent Live! website, and it basically looks like a complete cluster-fuck. Once again, the conference has been hijacked by the far-left, more obsessed with idealism and political activism than with making the NUS an organisation which acts in the best interests of students.

I advise you to take a look at Live! to see the full disaster of the thing. but it more or less boils down to a defeat for reform, policies calling for a disastrous national bursary scheme, and the like.

For those of you who aren’t Imperial students, we only (re)joined the NUS last year after a narrowly fought referendum. It was sold by the “Yes” campaign on a promise that the dysfunctional NUS would reform, and would give Imperial a national voice. This rather emphatically hasn’t happened; the reform has failed, and most of the motions went against Imperial’s interest. It gets worse – the delegates to the conference were elected on the basis that they were mandated to represent the position of the Union, and by extension, the students. One of the Imperial delegates, Camilla Royle, broke mandate three times to vote with the Student Respect faction. Absolutely disgraceful behaviour.

The NUS is mess – even the most clear-cut benefit, that of discounts, is debatable. You have to buy their NUS extra card, and then the NUS lobbies for discounts to be restricted to only card holders, rather than being for all students; a despicable policy.

Anyways, if you’re an Imperial student, the campaign for disaffliation has already begun. Join this Facebook group and sign the petition, 500 signatures will trigger a referendum on leaving the NUS. If you’re not an Imperial student, I would suggest seeing if such a thing can be done with your Union.

On another tack of stupidity, I saw this on the Bad Science Blog:

Luckily, it also had the antidote, a Feynman chaser.

FYI, You’re All Gonna Die Screaming

So lots of stuff happened that I pretty much forgot to blog about. Whoops. So I’ll have to perform some kinda compressed info dump, which is not necessarily in the right order:

Went to RCSU RAG ball. Nice venue, alright food, alright company from everyone not called Sarah (ah, I jest), drama, a DJ mashing up “By The Way” (FOR THE LOVE OF GOD WHY!?!), freezing cold winds on the way home… it had it all.

Drank some Fairtrade wine at a wine tasting. Nice.

Handed lab report in a whole 24 hours (!!!) early. Double nice.

Had cheese and wine party at Rowan’s. Lots of wine consumed, with predictable results. Then someone produced a bottle of port, and one of sambuca. More predictable results.

Installed IE8 beta. Buggy. Do not recommend yet.

Bought tickets to aforementioned gig, and which acted as a catalyst to get me listening to JoCo’s music. Which is awesome, so you should all do it.

Continued staying off MSN for unknown reasons even to myself. Probably should go back on before everyone thinks I’m dead!

Thought the Hawking thing that was on tonight was actually kinda lame. They used the same clip of a sphere exploding over, then the same clip of some points of light on these funny planes over and over, and they had to keep saying “Other people got to it first…” because Hawking’s famous, but hasn’t exactly done anything ground-breakingly interesting for ages. I guess saying physics is a big collaborative effort isn’t as sexy as a race to be first to create the theory of everything.

No wonder people think that physics is an impenetrable subject practiced only by geniuses in their ivory towers if this is face being presented to the public at large.

Oh, and they kept presenting string theory and supersymmetry as basically facts, which they’re not. There isn’t a single shred of evidence to support either. If the LHC doesn’t detect any of the predicted supersymmetric partners of fundamental particles (like the electron should have a partner known as a selectron) then it’s going to put a massive nail into the coffin of these theories. Or hypotheses? Theory is surely a term reserved for something that’s actually supported by data and not a theoretician’s appeal to mathematical beauty.

Hmm. That wasn’t compressed.

Bought a Stanley Kubrick box set, which includes: Full Metal Jacket, 2001, Clockwork Orange, Eyes Wide Shut, & The Shining. Personally, I’m none too keen to ever see a movie with Tom Cruise in ever again, but hell, the others are worth seeing. Also part of me wants to play a GlaDOS / Hal duet

PLRW, and the ASUSEEE

The second probably being more recognisable than the first, so I’ll just start with that.

So my major gripe with it so far is getting it to connect to Imperial’s wireless, otherwise I’ve got a laptop I can only ever use when it’s tethered to a network cable. Somehow, this feels slightly like missing the point to my mind. The problem is that the EEE only supports the kind of wireless security used by home connections, WEP (which is dreadful, and nobody should ever use ever. It is less security, and more like a deterrent. Think of it as a waist-high fence) and WPA-Personal (or WPA-PSK, for the TLA minded) and the Imperial network uses WPA-Enterprise.

There were two real solutions before me, blow away the default Xandros install and go with Xubuntu (which would work) or try and hack WPA-Enterprise support into Xandros through the agency of bizarre text commands (none of which, sadly, were sudo make me a sandwich, although I did a lot of sudo nano) and a bucket-load of patience.

The first option I discarded because Xubuntu looked even harder to use than Xandros, and I was getting quite attached to the cute default tabs interface. And the second required more patience than even I possess.

As luck would have it, Imperial have an insecure network, through which one can use something called VPN (or Virtual Private Networking) to create a tunnel through to the real network. To start with, I though this would have been even more horrific than getting WPA to work so I didn’t even consider it, but as it turns out, it actually works out of the box using the default installed software. So it works! Hooray!

PLRW is Professor Lord Robert Winston, who today did a talk at Imperial to help launch the annual RCSU Science Challenge. The top prize is £2500, a MacBook (which I would immediately sell or install Windows on. Probably both.) and A TRIP TO CERN. Honestly, there was an actual audible gasp at that one. The guy organising the event is a physicist, so he took the opportunity to ask any medics to let him have the tickets if they happened to win. It’s one hell of a prize, never mind the free trip to the French-Swiss border, the chance to have a look around CERN is pretty much once in a lifetime for anyone who isn’t a high-energy physicist by trade.

My thoughts about the lecture itself will probably have to wait until sometime tomorrow.

Until we meet again.

BBC NEWS | Technology | Holographic displays step closer

I think some of this is really funny

Holographs are created by mixing reflected laser light with a second laser beam to lay down a static image – typically a lengthy, complicated and delicate process.

Actually, an undergrad physicist can do it pretty easily. I know, because I’ve made holograms in lab this year. About 3-4 weeks ago, as a matter of fact. I feel that this is probably another science story where they’ve oversimplified it to the point of pointlessness. If that makes sense. I might see if I can dig out the original article from Nature later.

BBC NEWS | Technology | Holographic displays step closer