Two Rings

Now have a look at this object (and its enlargement on the right):

double einstein rings

What is it? It’s a double Einstein ring! An Einstein ring is formed by gravitational lensing – the bending of light from one object by the gravity of another object – and is typically formed when a distant galaxy lines up with another, closer galaxy. The result is a rather nice ring shape.

To find a double Einstein ring is rare! In fact, this is the first one that’s been announced. Not only is it novel, it can also use used to do a good deal of science, such […] Click to continue reading this post

Categorically Not! – Beginnings

Bob Miller at Categorically Not!The next Categorically Not! is on Sunday December 16th (upcoming). The Categorically Not! series of events that are held at the Santa Monica Art Studios, (with occasional exceptions). It’s a series – started and run by science writer K. C. Cole – of fun and informative conversations deliberately ignoring the traditional boundaries between art, science, humanities, and other subjects. I strongly encourage you to come to them if you’re in the area.

Here is the website that describes past ones, and upcoming ones. See also the links at the end of the post for some announcements and descriptions (and even video) of previous events. (Above right: The artist Bob Miller speaking at the event entitled “Really?” on 23rd April, 2006. He died recently on Oct. 28th 2007, and this week’s event is dedicated to him.)

The theme this month is Beginnings. Here’s the description from K C Cole:

Every thing (and every body) began sometime. Even matter, space and time have a history. So do music, religion and galaxies (and along with them, musicians, religious scholars and astronomers.) Of course, how things begin determines to a large extent how they evolve and go on to influence both human culture and the universe at large. So for this month’s Categorically Not, we’ll look at beginnings from three widely (and somewhat wildly) diverse perspectives.

categorically not! Beginnings Speakers

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The Universe Tomorrow

Over on Correlations, I talked a bit about the History Channel’s science show “The Universe” (as I have here), and pointed out that the new season (season two) has already begun being broadcast. Here’s hoping that it’s a good series of programmes that will be enjoyable and informative. The show’s website is here.

Well, I’ve learned that the second episode, tomorrow’s (showing at 9:00pm), is one of those that i did some shooting for over the last two months at a number of places around LA. Rather than repeat, here’s what I said:

The next one, to air on Tuesday the 4th December, is called “Cosmic Holes” (yeah, I know), and the subject matter will be right on the edge of the known and the unknown, talking about black holes, white holes, and wormholes. While we know that the first are out there, the second two, while also solutions of Einstein’s General Relativity, are still theoretical constructs (and not without problems). The show explores some of the ideas and the prospects for the ideas surrounding

[…] Click to continue reading this post

The Flat Universe

chuck steidelkc coleWhile searching through their site to find something else, I noticed that there was a conversation on KPCC’s Zocalo between science writer K C Cole and Astrophysicist Chuck Steidel not long ago. Have a look at their listing of past conversations here – there’s a lot of good stuff about various topics and people in the Los Angeles area. I listened to it, and it’s very interesting indeed.

It is not quite your usual light touch conversation that you hear on public radio – it is a little more involved, taking you a bit further (without losing you) and gives you more insights into the work, the puzzles, the discoveries and the hopes for future ones. As a journalist, and the guest host of the program, K C Cole knows her material, and so is able to steer things rather well, while inserting useful remarks to help the listener keep up. This might be perfect listening if you want to get a sense of what it’s like to work in Chuck’s area of expertise (finding and characterizing the youngest galaxies and understanding their cosmological implications), either out of general curiosity or if you’re planning a career in that area. Take out some time and have a listen. Here’s the blurb from the site:
[…] Click to continue reading this post

A Return

I’m in Lexington, Kentucky, for a couple of days to give three presentations at the University of Kentucky (or “UK” as everyone refers to it here – I hope that explains the previous post). I should be preparing two of them instead of blogging, but… you know how it is. Here’s how I got here:

lexington visit On Wednesday afternoon, after a class on magnetostatics, and an attendance of a lunchtime event where four of our faculty (Biology, Geology, Cosmology (our very own Elena Pierpaoli!), Biology) presented their research, I dashed for a plane. Some hours later, at 10:45pm local time, I touched down in Chicago, and 15 minutes later was on the highway in the company (and car) of Nick Halmagyi.

Our mission? To hang out for a few hours in an excellent bar or two of his acquaintance and catch up on what’s been going on with each other, workwise and otherwise. The Charleston was indeed excellent, and (after chortling a bit about the memory of my annoyance at being charged $29 for a serving of a single malt scotch in a bar in Aspen during the Summer) proceeded to order the same here (he the Macallan, me the Talisker). At about 1:00am, the music stops and a guy with a face full of character sits down at the upright piano, is introduced to a scattering of applause, and proceeds to play some Chopin. Everybody shuts up and turns to listen. Appropriately, the piano sounds like all upright pianos in all bars all around the world sound (the tuning is just a bit wobbly), and the guy is good – really good. He stops playing the piece, and there’s some more scattered applause; someone (jokingly?) offers his a dollar as he walks away which he waves away enthusiastically; the music comes back up, and everybody turns back to their conversations. Nick and I continue to chat about various aspects of life, and order a couple more whiskeys.

At 1:25am or so we wander over to another bar. Nick seems a bit surprised by my suggestion to do this (‘cos I’m supposed to be going to sleep), but I’m just enjoying walking for a bit in the cold, wearing a cozy hat and coat that normally get no use these days, and there’s something nice about a proper bar hop in a neighbourhood with good bars and in the company of someone who appreciates it. This bar has an […] Click to continue reading this post

Tales From The Industry XIII – Magnetic Moments

[Post reconstructed after 25.10.07 hack]:

magnetism shoot

The strange object pictured above is a rather nice demonstration of the “field lines” around a bar magnet. It is not a great photo (all my fault), but the demo is great. The designers suspended the tiny bits of iron in oil, inside a sealed chamber, forming a block. There’s a little cylindrical hole through the centre of the block (but still outside the chamber) that allows you to put a bar magnet in. This makes for a demo far more exciting than any shake-it-up snow scene: You shake block and the iron filings are all over the oil in three dimensions, randomly arranged. You then insert the magnet. They slowly but determinedly arrange themselves into the familiar pattern, in three dimensions. It’s great. (Why didn’t they have these when I was growing up?! I might have gone into science… Oh, wait…)

I was looking around one of our demo labs last week for things to use to demonstrate some of the principal effects of magnetism. The above demonstration was one of the […] Click to continue reading this post

More Than A Hint Of The Old Days, II

A strange but satisfying aspect of my time here (I’m at the Aspen Center for Physics, recall) has been the fact that due to some odd serendipity, there’s a ton of people from the “old days”. Which ones? My Princeton years, in the early 90s, as a postdoc at the Institute for Advanced Study (and later at Princeton University). These are not all people doing what I do, but in a wide range of fields such as high energy physics, astrophysics, condensed matter physics. Several of us were postdocs together. I’ve been chatting with people I’ve not seen for a while, sometimes not since those days, or they are people I met back then, and with whom I have a pool of shared memories from those days. So it has put me in mind of those times somewhat.

A quick example. Soon after I arrived last week, I was walking along, chatting with Petr Horava (Berkeley) about various things, and we got on to reminiscing a bit about our time together as postdocs in Princeton. And then minutes later, as though conjured from the very substance of our conversation, who should walk by but one of the Gods/Legends of the field (then and now), Princeton’s Alexander Polyakov. He walked by in exactly the same sort of way he would back then, either coming from or going to a walk along the river or canal, perhaps to give us a lecture. Petr and I looked at each other, and continued our walk and talk.

The great news for me last week was that Polyakov then gave a talk. I’ll admit to being a big fan of his physics. When he gives a talk nearby, I show up, no matter how confused I might end up at the end. There’s going to be good stuff in there – it’s only a matter of time before it sorts itself out in your head. Often years. Decades. Several of us sat in on his graduate class back in Princeton in the early 90s just to try to catch the pearls of wisdom which we’d pick up as he lectured on….. Well, I’ve no idea to this day what the class was really about. He would show up (probably fresh from a walk), with no notes or anything, and just pick up a piece of chalk, stare out the window for a few seconds, and then start writing stuff. Essentially, he was randomly jumping around the subject matter in his widely under-read book “Gauge Fields and Strings”. He was all over the book. It was not always a simple and coherent path through the subject matter, and it seemed that he was largely exploring whatever took his mood in the moment, but I suspect that was largely my ignorant young mind’s impression.

Polyakov in Aspen
A. M. Polyakov in the middle of giving what for me was an excellent and intriguing seminar at the Aspen Center for Physics. Click for larger view.

Sadly, it is the type of course that these days would score close to zero in most […] Click to continue reading this post

TASI@Home

This year’s month-long Theoretical Advanced Study Institute -TASI- looks especially good, from my point of view, with a great combination of topics and lecturers. As usual, it is held in Boulder, Colorado. It’s all about current ideas and experiments and observations in particle physics and cosmology. Three USC students are there and I’ve heard from them that things have been great so far.

raphael bousso at TASIWell, the great news is that the TASI people are making the lectures available online a fairly short time after their delivery. The link is here. So even though not there, you can schedule some time to take these lecture courses if you like. I glanced for a while at Raphael Bousso’s first lecture in the series “Cosmology and the Landscape”, and it was clear and very well presented. (This is not entirely surprising – Raph is always an excellent lecturer.) […] Click to continue reading this post

Through a Lens Darkly

Richard Massey

Well, yesterday’s colloquium by Caltech’s Richard Massey was a lot of fun, and really excellent. When faculty, postdocs and students are all chatting about it afterwards, you know it went well. This is what a departmental colloquium is supposed to do, and it happens when subject, level of delivery and speaker all come together in just the right way.

When the news about that lovely dark matter result broke some months ago, I got in […] Click to continue reading this post

Dark Matter in 3D

Have a look at this:

hubble 3d dark matter

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

Really Old Stars?

One sees them a lot around here, given the town I’m in, but that’s not what I’m talking about.

There’s a Spitzer telescope press release about the possible discovery of the most early stars detected to date. These would be the very first stars to have formed in the universe. Remembering that the universe is 13.7 billion years old, pause for a moment to be impressed by the claim of Kashlinsky, Arendt, Mather and Moseley that these stars appeared less than a billion years after the big bang. You should also read some discussion in John Baez’ recent post. [Update: See remarks from Ned Wright at the end of this post.]

The new milestone on the timeline of the universe’s history, if this is correct, would look roughly as in this image (from the press release):

timeline of the universe from spitzer

Extraordinary claims (like this one) require extraordinary evidence, and so there’ll no […] Click to continue reading this post