Bose-Einstein condensates in space!
To create a Bose-Einstein condensate normally requires equipment that takes up a whole room. But a couple of years ago, NASA’s Cold Atom Lab managed to blast the whole setup up to the International Space Station - and they’re now starting to get exciting experiments underway. Phil Sansom heard from Rob Thompson, the project scientist in question...
Rob - We have built an apparatus that will allow scientists to study ultra cold matter in the microgravity environment of the International Space Station. So we're making Bose-Einstein condensates in space.
Phil - That sounds, on the face of it, super cool.
Rob - Both literally and figuratively, I think, yes.
Phil - Why? What's the point?
Rob - What's the point? Gravity affects these types of experiments. People are doing these on the ground, but almost every terrestrial experiment has at least some sort of effect of gravity that limits how long you can look at the atoms. For experiments that really are trying to reach the ultimates in sensitivity and so on, those types of experiments will benefit by going into microgravity.
Phil - Can you make it concrete for me? How much longer, for example, can you get a Bose-Einstein condensate to last in space compared to on Earth?
Rob - Sure. Ultimately the limits are simply how cold you can get them. The colder the cloud is, the slower a gas will expand, and the longer we'll have to look at it. In our experiment, we're aiming for about five seconds. As far as I know the record on Earth is about two seconds.
Phil - Does the fact that space itself is so cold help with the fact that you need to cool this stuff super cold?
Rob - No, it doesn't. Space while it's super cold, is a couple of degrees Kelvin above absolute zero. And the temperatures that we're trying to achieve are below a billionth of a degree above absolute zero. So while space is relatively cold for most of us, in the context of this experiment, it's actually really, really hot.
Phil - Is it the astronauts up in the ISS that are controlling this and doing the experiments?
Rob - Oh, so we run the experiment entirely from Earth. Basically we can connect up to it as if we're connecting up to a machine over the internet.
Phil - What are you hoping to achieve with your sci-fi space Bose-Einstein condensate lab?
Rob - I really would like us to achieve the goals that our science teams are looking at, because I find them just amazing. Several of the teams are focused on atom interferometry, this ability to use the wave-like nature of atoms to make these incredibly sensitive quantum sensors. And one of those teams is going to test Einstein's theory of general relativity, and also to search for certain candidates for what is dark energy.
Phil - Why should anyone who's not a physicist care about this?
Rob - These are questions, I think that ultimately, are important for humanity to think about and have answers to, but there's also a lot of more practical, potential applications. We can use these atom interferometers as navigation, for spacecraft navigation and exploration and so on. We can potentially use them to help monitor the effects of climate change. As you have things like ice sheets melting, those change the local gravity of Earth in that area. I think there's always this thing that you learn from basic science, basic physics; it always kind of surprises you that it ends up being profoundly important.