I went to another night of the film festival, this evening. Tonight was shorts, and they varied from ok to very good indeed. They are all worth seeing once, if you get the chance, and you can check out the list over here at the Boston Scifi web site.

There were also shorts last night, which I missed because of a music rehersal and more shorts tomorrow night, which I will almost certainly miss because of my astronomy class.

It is supposed to snow for the next two days and we’re supposed to get significant accumulation, but that means nothing here in New England.

Now, back in my hometown, they’ve been shut down for a few days already because of snow. I have always been a little bitter that everyone here expects one to simply go on with life in spite of the snow. On the other hand, my mid-Atlantic friends are getting a little stir-crazy.

Since nothing gets canceled here, I will almost certainly be at my astronomy class tomorrow night. We will be learning how telescopes work, and looking at pretty pictures. Tragically, if the weather forecast comes to pass, we will not be looking at pretty pictures *through* telescopes. This makes me sad, as the opportunity to look at things through telescopes is at least 20 percent of why I wanted to take the class in the first place. Though the Hubble pictures the prof uses in his slides are very nice.

It’s just the science is more fun when you can look at the stars in person, even through a telescope in the freezing cold.

Of course, meterology is its own science. Perhaps tonight, I will consider what’s happening in the sky that I can not see that will keep me from seeing beyond the stratosphere tomorrow.

The universe is speeding up.

Some days, it really seems that way, but it is actually true. Or, at least, there’s evidence that it’s true, thanks, in part, to X-Ray astronomy.

That evidence is one of many things that has come out of the Chandra X-Ray observatory program in the ten years of its existence. I got to hear about a few of them tonight at a public lecture at the Harvard-Smithsonian Center for Astrophysics.

A video of the lecture will be available here, though it is not, yet, as I write this. It’s worth taking a look at, as Andrea Prestwich, who gave the lecture, actually works in x-ray astronomy. Plus, there are some very pretty pictures of things in space.

X-ray astronomy isn’t that different from other forms of astronomy. All astronomy examines wavelengths from the heavens. For most of the history of the science, all the wavelengths being examined were in the part of the electromagnetic spectrum that humans can see. At this point, observational astronomers are working in every part of the electromagnetic spectrum. Chandra’s work in X-Ray astronomy are part of that puzzle.

The Chandra telescope is in orbit around the Earth, like the Hubble. Unlike astronomy done in the visual wavelengths, though, x-ray astronomy must be done outside the Earth’s atmosphere. The atmosphere is very good at keeping out x-rays which is good for we humans, but bad for x-ray astronomy.

Chandra is also much farther out than the Hubble – 139,000km to the Hubble’s mere 569km.

Chandra has much better resolution than any x-ray telescope that came before it. This helped solved one of the mysteries of x-ray astronomy – that of the bright x-ray background. On previous generations of telescopes, the entire sky looked bright with x-rays. Chandra’s resolution made it obvious that the bright background was the result of “unresolved point sources”. That is, there were lots of individual x-ray emitting objects — super-massive black holes, in fact — that could not be discerned in images taken by previous telescopes (such as the Röntgen Satellite), because they simply were not fine enough grained.

Chandra’s high resolution detection of x-rays has also made it possible to look at matter that is in the process of being swallowed by black holes. As the matter stretches out and is sucked into a black hole, it gives off more x-rays than usual and becomes a bright spot for Chandra.

Some of these black holes actually form a small binary system with the normal star they’re swallowing, called an x-ray binary. These binaries can also contain a different compact, massive object, such as a neutron star or white dwarf, instead of a black hole.

But I began all this by talking about the universe speeding up. This is not something that was initially detected by the folks at the Chandra observatory. It was detected first (if I am understanding and remembering the lecture correctly) by scientists looking at supernovae. I’m not going to go into the supernova stuff, here and now, but if you’re interested to know, check out this article (warning, it’s a pdf) that’s linked off the Supernova Cosmology Project at Berkeley Lab.

The upshot of the supernova research is that astronomers found something unexpected. They knew that the objects in the universe are moving away from each other. The assumption was that this movement was slowing down – that it was being counteracted by gravity. What they found was that the objects in the universe appear to be speeding up. The explanation for this is dark energy which, like dark matter, is something scientists don’t know much about, except that it exists and it has an effect on the physics that rule our universe.

The Chandra x-ray project was able to verify the findings of the supernovae folks from a different angle. Instead of looking at the speed and red-shift of objects, they looked at the formation of galactic clusters. If objects in space are really all speeding up (so my understanding goes) then galactic clusters can’t be growing at the same rate. Whatever is speeding things up is also keeping matter from sticking together and arresting the growth of galactic clusters.

Which is, indeed what the Chandra folks found. It’s independent verification that dark energy exists and has a significant effect on the universe.

I love that we learn more and more all the time but there is still more to find out. I think there always will be. And that’s not just in space. Over 40 new species were discovered in one tiny place on Earth just last month.

There’s always something left that we don’t know and it’s worth working to find it out!