Angels and Demons

Some people get really upset when movies have bad science in them. Despite being a sciencey type myself, I feel the opposite. The more fantastic the concept, the more entertaining I find it. I suppose it's because I take it as a sort of science slapstick comedy rather than the intended movie genre.

Take the movie 2012, for example. Unfortunately it hasn't been ripped to shreds by Insultingly Stupid Movie Physics. Who doesn't want to see a giant tsunami crashing over the Himalayas?

Last night I watched Angels and Demons. It was on TV and I wanted to unwind after a busy day. I'm not a fan of Dan Brown at all. I haven't read his books, but the murder mystery style of the movies is kind of entertaining. For those who haven't seen it, the crux of the movie is that the Illuminati are threatening to destroy the Vatican with some antimatter stolen from CERN.

Now, this antimatter is in a battery powered hand held vial about the size of a water bottle. We are told that the antimatter must be held in a magnetic field or it will just annihilate matter in the container walls. It is true that matter and antimatter annihilate when they come in contact, releasing high energy photons. If you had a milligram, it would be enough for an explosion of the equivalent of 50 tons of TNT. This could potentially be done at CERN with its present capabilities, but it would take 300 billion years to accumulate that much.

There is a nice article at the CERN Courier talking about what it takes to trap antimatter. It takes some very strong magnetic fields, which requires some pretty high currents (since electromagnets are required). So clearly, the hand held antimatter container is highly improbable.

However, this is not what bothered me. What bothers me is that the physicist in the movie says that with their breakthrough in trapping antimatter on a large scale (1 mg), they hope to use it as an energy source to power cities, and not as a weapon. Hold on a second. Their container has a magnetic trap to hold the antimatter. The current for the trap is provided by a battery that lasts up to 24 hours. The magnetic field required to hold antimatter is on the order of several Tesla, generated by superconducting electromagnets. Even if the antimatter is ultracold (like a BEC), you would still need a fairly hefty field. This requires a very high current! Hundreds of amps! Generated by a battery!!

If you have a battery powered device that can trap antimatter, then you probably don't need antimatter as an energy source.

Spider!

The last week has been ridiculously busy, so I haven't had a chance to post! I did make it to the Dunedin Botanical Gardens last weekend for a photo expedition. I was trying to get a particular photo of a flower, but instead, I found a spider:

This one is worth seeing in its original size. You can even make out an eye!

Of Women in Science

A recent post by FSP got me thinking about something. I am well aware that women in male-dominated fields often experience some form of discrimination, but I seriously thought it was an issue well out the door in this day and age. I have never experienced any myself, other than a couple of weird off-hand comments by non-scientists, so I was very shocked to see so many horror stories in the comments of FSP's blog (most of them from the US).

I should also add to this that I didn't know that physics was a male-dominated field until shortly before I started university. I went to an all-girls high school and we had two full physics classes, so one can forgive my preconceptions. As a result, I never expected to be treated differently for being female because I didn't see myself as different from other students.

A pertinent question in physical sciences is why women have not permeated through the ranks as much as in biological sciences. And even then, top academic roles are still dominated by men. So why are their more males in leadership roles anyway? Is a big part of it a generational divide?

In addition to being in a male-dominated field, I also have male-dominated hobbies. I have somehow (unwittingly) ended up in leadership and/or organisational roles in most groups I have been part of (from clubs to academic groups). And you know what? There have always been a disproportionate number of females on these committees. For some reason, they seem more likely to volunteer to organise something or be a club committee member. My experience so far is that most guys prefer to take a back seat and just go with the flow.

So why is it different in the high ranks of academia? Or in business? Do we just have to wait for people like us to grow up and fill those roles?

I would love to hear other people's thoughts on this.

Black and White

There is something I really like about photographing flowers in black and white. In colour photos, there is so much going on that sometimes the subject gets lost in the background, but in black and white it's brought out again. There is something more dramatic about it too!

Of course, I have also taken photos of flower beds in black and white where the petals become indistinguishable from the leaves.

What I really need is a weekend where I am not too busy and the weather cooperates so I can go on a proper photo expedition!

Optical Lattices for Dummies

From the dawn of time, physicists have always been looking for new ways to manipulate atoms. At extremely cold temperatures, it's not quite so straightfoward; one does not simply walk into Mordor contain them in a bowl. When I say "extremely cold", I mean close to absolute zero. Liquid helium is a tropical paradise in comparison. Moreover, usually when atoms are so cold, there are not so many of them. Usually we talk about trapping billions of atoms, and if Bose-Einstein condensates are in question, then a few orders of magnitude less! So solid containers won't work.

Instead, people use magnetic or optical traps, or a combination of both. I'm going to talk about optical traps here. A fun fact about atoms: they can be trapped in laser beams! If you've heard of optical tweezers, this is basically the same thing. The electric field of the light induces a dipole force on the atoms, and they get stuck in the the most intense part of the beam (actually, they can be repelled by the beam as well - it depends on the wavelength of the light).

Now we can get creative! You can do all kinds of stuff with laser light. The nice thing about laser light is that you can make it interfere - peaks and troughs add up or cancel out, and you get something out like water ripples. If you shine two laser beams against each other, they will interfere and produce a periodic structure which we call an optical lattice. If you do this in three dimensions (6 counter-propagating beams, like axes in a 3D plot), you get something that looks like a stack of egg cartons, and in each well you can trap some atoms! If you tune your lattice parameters just right, you can trap a single atom in each well.

There are several awesome things about 3D lattices. One is that they are very much like a crystal structure, so you can simulate a quite different area of physics. Another neat thing about them is that they can be used for quantum computing (at least proof of principle, though perhaps not really for practical purposes - if you've ever seen a cold atoms setup, you'll know why). If you manage to get a single atom in each lattice site, and can somehow manipulate individual atoms, you can make a quantum register with a few hundred qubits!

This brings me to what I actually wanted to talk about: a paper that talks about just this! A group in Germany managed to trap a whole lot of single atoms in a lattice and are able to see the individual atoms (more or less) AND can manipulate single atoms surrounded by other atoms in the lattice! The paper was recently published in Nature (you have to pay to see it, unfortunately, but if you are on a university network, you should be subscribed through your university library). The figures seem to be available, so here is one:

The different patterns demonstrate the level of control they have over the atoms. They can change the spin state of individual atoms and get rid of them if they want to. The result? Pixel art. If it was me, I'd probably draw something inappropriate and see how much I could get away with and still get it published.

Welcome!

I thought it was about time that I make a "proper" blog, something with somewhat themed content devoid of one liners. For some time I have felt the need to contribute to the blogosphere, and this also gives me something to do while I'm waiting for my experiment to run besides facebook and endlessly refreshing news sites.

This blog will include the following:

• Reviews of journal articles I find interesting, fit for the scientifically-minded general public. This has the added personal benefit to myself, because it will force me to actually read more than just the abstract before saving a paper to my massively unread "Papers" folder. I'll endeavor to do one a week.
• Talk about interesting science stuff happening in the world.
• Complain about bad science reporting.
• Occasional nice photos.
• If something interesting actually happens in my lab, you'll hear about that too.
• Whatever else I feel like!

And because I have the word "photos" in the blog title, here is an obligatory cute dog photo: