I don’t mean that in a bad way. It is what it is. Quite varied and wonderful, our universe is, with unexpected features I don’t think many would have guessed at not long ago (like the fact that we only understand what about 4% of it is!! Crazy, in a […] Click to continue reading this post
Now have a look at this object (and its enlargement on the right):
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
While 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 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.
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
I learned from Often In Error that the paper of Riess et al, reporting on the research that was buzzed in the NASA press release, is out. It is here.
(I must use the term “cosmic jerk†in an everyday sentence one day…. probably not as a term of endearment….)
So the press conference is over. I did not listen to it, but the gist of it, from the press release, seems to be that they’ve observed several more supernovae to pin down even more accurately what the universe’s expansion rate was at very early times (up to nine or ten billion years ago). Image below from their site:
[image]
From the site we learn (for background): Click to continue reading this post
From NASA, tomorrow, at 1:00pm EST: An announcement about Dark Energy. If the pattern of last time is to be followed, there must be new evidence from the space telescope team (represented by Riess and Livio at the press conference) in favour of one interpretation or another. Since they are saying that they will “announce the discovery that dark energy has been an ever-present constituent of space for most of the universe’s historyâ€, I imagine that means that there is stronger evidence than before for Dark Energy being a cosmological constant. […] Click to continue reading this post
