Dark Puzzles
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This lovely composite image of Abell 520 that includes an inferred distribution of dark […] Click to continue reading this post
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Category Archives: galaxies
The Scary Universe?
Ok, there’s “The Elegant Universe”, and “The Ambidextrous Universe”…. even “Stephen Hawking’s Universe”… and so on for these titles. But how about “The Scary Universe” or “The Dangerous Universe”? (Personally, I wish we’d just stop with the whole “The fill-in-the-blank Universe” stuff, so I probably should have not written this first paragraph.)
Well, I myself don’t think of the Universe that way, but tonight (at 9:00pm) the History Channel will be presenting the next show in their series (called “The Universe”), which is about (they say) the Most Dangerous Place In The Universe”. It looks as though it will be a survey of various places where a lot of very energetic activity is taking place, powering some of the most powerful phenomena we’ve ever seen, such as quasars, magnetars, and so forth. So black holes will feature quite a bit, I imagine, and although I probably should not really be telling you about it before I’ve had a chance to see it (recall my remarks about the windy shooting conditions here), I think (I’m not sure) that I’ll be making an appearance as one of the contributors. (I did not get caught off guard this time.)
The whole “dangerous” motif is a sort of deliberately sensational way of presenting […] Click to continue reading this post
The Walk Up Mount Wilson
[A friend of mine in LA told me today that she was planning to go with a group of friends to do some observing up at the big telescope on Mount Wilson. This put me in mind of a post that I did on CV two years ago (how time … Click to continue reading this post
Andromeda Now Makes Sense
The Andromeda Galaxy is bigger than previously thought. Perhaps as much as five times bigger. I know that you’re thinking – “Oh, that’s because most of it is dark matter, right?” No, this is not another dark matter story. In fact, there are many newly discovered stars from a recent study! The suburbs of the galaxy are much more extensive than previously identified. It’s rather good news, since the galaxy makes more sense than it did before, in the context of our understanding of how galaxies form and evolve. (Image above is of Andromeda in the infra-red, from NASA.)
The point here is that current theories of evolution for galaxies have the oldest stars Click to continue reading this post
Dark Matter in 3D
Have a look at this:
What is it? It is an image of part of the three dimensional (see below) distribution of clumps of dark matter in our universe, produced by an extensive survey using the Hubble telescope. How did they produce it, given that dark matter is -by definition- not visible? They deduced the presence of the chunks of dark matter by looking at the gravitational […] Click to continue reading this post
Some Observations at Griffith Observatory
So I must apologize. I went to the preview of the Griffith Observatory so long ago now and did promise to blog about it with more than just one nice picture, but it did not happen. Partly because I had to go back across the Atlantic to do some work, and then got ill over the weekend I was planning to do it, and then…
Anyway, here are some of my thoughts. First note that my two week delay means that this is no longer a scoop, since even the LA Times had a spread on the whole thing on Thursday. A rather nice one as well. I urge you to consult it for a lovely pull-out graphic of the whole site. There is also a special website with picture tours, nifty 360 degree interactive shots of the spaces, and other information. The Griffith opened yesterday.
What they’ve done over the last four or five years is simply shut down the entire building and rethink and redo a great deal of it. How to preserve the lovely 70 year old landmark, while making it even better? Simple question – simple answer: Get $93 million for your project (I find this number, the earth-sun distance in miles, suspicious), and then go underneath the existing building and hollow out about the same amount of space that is has, but underground. Fill it with lots of goodies. And I mean lots and lots. What goodies? We’ll see. […] Click to continue reading this post
The Lives Of The Stars
Well, I’m back from the visit to the preview of the Griffith Observatory that I mentioned to you I was going to. It was a rather good visit. They organised it well, and -boy!- have they done a great job on the restorations! I’ll try and assemble the several pictures that I took into some sort of narrative for you, and report soon. While you wait, here’s one of my favourites:
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This is particularly poignant, in my opinion. The children are looking at the lovely […]
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Explaining Cosmic Rays
Well, before disappearing into a long session of thinking about some funny behaviour my strings are up to (more later) I’d like to do a quick report on the departmental colloquium that I went to just now. We had Gary Zank, the Director of the Institute for Geophysics and Planetary Physics of the UC system (he’s based out of UCR) give us a talk entitled: “Particle Acceleration in Cosmic Plasmas”, and it was quite fascinating (and very well presented).
It is all about the physics of cosmic rays […] Click to continue reading this post
From Dwarf Planets to Hobbit Galaxies
I learned from an article in New Scientist by David Shiga that there have been recently found four more small satellite galaxies of our Milky Way galaxy. The satellites are dwarf galaxies a few hundred to a few thousand light years across. The tiny galaxies are thought to be the … Click to continue reading this post
