I just spotted (a bit late) that Steven Weinberg (one of the giants of my field) has written a piece in the New York Review ofBooks entitled “Physics: What We Do and Don’t Know”. I recommend it. He talks about astronomy, cosmology, particle physics, and by casting his eye over the arc of their recent (intertwined) histories of ideas, experiments and discoveries, tries to put the Standard Models of particle physics and of cosmology into perspective.
The article is […] Click to continue reading this post
Well, the day is here. The Planck collaboration has announced a huge amount of results for the consumption of the scientific community and the media today. The Planck satellite looks with unprecedented precision at the very earliest radiation (“cosmic microwave background radiation”, CMB) from the universe when it was very young (a wee, cute 380,000 years old) and helps us deduce many things about what the universe was like then, and what it is like now. Here’s one of the representations of the universe using the new sky mapping Planck did (image courtesy ESA/Planck):
There’s a ton of data, and a raft of papers with analysis and conclusions. And there’s a very nice press release. I recommend looking at it. It is here, and the papers are here. The title of the press release is “Planck reveals an almost perfect Universe”, and some of the excitement is in the “almost” part. A number of anomalies that were hinted at by the previous explorer of the CMB, WMAP, seem to have been confirmed by Planck, and so there are some important things to be understood in order to figure out the origin of the anomalies (if they ultimately turn out to be real physics and not data artefacts). [Update: Andrew Jaffe has two nice posts I recommend. One on the science, and the other on the PR. Jester also has a nice post on the science from a particle physicist's perspective.]
What is the title of my post referring to? Well, the refined measurements have allowed us to update some of the vital statistics of the universe. First, it is a bit older than previous measurements have indicated. The age is now measured as 13.82 billion years. (I’m already updating pages in the draft of my book…) Second, the proportion of ingredients [...] Click to continue reading this post
You might not know the name Maurice Murphy, but I am certain that you are likely to know – and maybe even be very familiar with – his work. His is the principal trumpet playing the lead themes in very many films with music by John Williams. I have for a long time been very impressed with how so many of those themes trip so easily off the tongue (physical or mental) and seem to fit together so well (just hum the Star Wars theme, and then follow it by the Superman theme, then the Indiana Jones theme, and so on). A lot of this is due to the fact that Williams (like most good composers) is a master at recycling and modifying, creating a cluster of much loved (deservedly) themes that accompany some of our favourite movie-going memories, but I now think that the other reason is that you’re hearing them all played by the same voice! That voice is the playing of Maurice Murphy, the truly wonderful trumpeter who Williams would specifically request to play the lead on recordings of his film music. Murphy died recently, and you can dig a bit more about him and explore what I’ve been telling you further by going to the London Symphony Orchestra’s site devoted to him [...] Click to continue reading this post
You can read a bit about the work of my colleague Elena Pierpaoli and her postdocs and students in this article in one of USC’s in-house publications. It focuses on the Planck observatory (image right from NASA/ESA), which we’ve discussed here before. (Recall the launch?) There’s a lot of exciting physics about the very young universe to be discovered as more data from the mission get gathered and analyzed.
Enjoy the article!
-cvj Click to continue reading this post
My friend, The Universe co-contributor, and colleague Amy Mainzer (JPL) is rubbing gloved hands together in the chilly night air up at Vandenberg. Well, ok, if not this very moment, she probably will be at various points this evening and into the wee hours of the morning. The launch pad for WISE (the mission on which Amy is deputy project scientist) is set, and everything is ready to go! See my earlier post about what [...] Click to continue reading this post
Once again I’m excited about a new piece of machinery. This time it is a space mission again. There have been several remarkable missions launched (many in very recent years), doing all sorts of excellent science, helping us discover all sorts of things about our universe, near and far, young and old. I’ve spoken about (and sometimes followed live) the launches of some of them here on the blog, or spoken about the science results they’ve helped produce. See the graphic on the right for some of them.
Well, very soon (possibly as early as December 9th), there will be the launch of WISE, the Wide-field Infrared Survey Explorer! I learned from my friend, colleague and fellow presenter on History Channel’s The Universe, JPL’s Amy Mainzer, who is a senior scientist and the deputy project scientist on the WISE mission, that they made a series of exciting videos about WISE for you to learn about the science that WISE will do and how it will go about [...] Click to continue reading this post
Friday evening was very enjoyable indeed, with some arts and literature near the start, and live scientific research toward the end. It began with a nice trundle across town on the 920 bus, when it eventually arrived (why are there still so many long gaps in the 720 and 920 schedules at crucial times of the day?) heading over to Westwood to the UCLA campus. I listened to music, read Jonathan Gold’s column in the LA Weekly, and listened to conversations around me. I got to Westwood and Wilshire after half an hour or so and walked up to campus and to Royce Hall, getting coffee on the way and even stopping in to an AT&T store to check on something. The campus was surprisingly quiet at 7:30 or so and I made my way over to Royce Hall, sending a text to a friend about later.
Besides the environmental reason I like to try to take public transport, it is also nice to plan it out and then be 15 minutes early and nice and relaxed before an event, and not be arriving all stressed due to traffic and then worried about parking and so forth. The show started late (as everything does in LA because there is a tacit assumption that everyone will be late due to traffic and parking and so people mostly were late because, of course, they know this assumption is in place. (At the 8:00pm actual official start time only about 20% of the audience that would arrive in the next 15 minutes were actually seated.)
The event, you’ll recall, was all about Margaret Atwood’s new book Year of the Flood. The author and the actors and musicians came onto the nicely decorated set and started with one of the songs specially written for the event. There is a limited set of engagements in 16 or 20 (I’ve forgotten) cities performing this reading and this is one of them. Margaret Atwood was the narrator and there were three actors reading the parts of three characters from the book. A central cult/religion that appears in the book (and the previous book with [...] Click to continue reading this post
Well, ok… Boom is not quite accurate, but the idea is that there will be ten kinds of blasts/explosions/major_energetic_events discussed tonight on the History Channel’s The Universe:
The Universe is full of explosions that both create and destroy. The Chicxulub impact on the Yucatan peninsula, which may have wiped out the dinosaurs 65 million years ago, was two million times more powerful than the largest nuclear bomb ever detonated on Earth. But guess what? That’s only good enough for the very bottom of the Biggest Blasts top ten list. This episode works its way up through supernova explosions and gamma ray bursts all the way to the blast that started it all–the Big Bang.
Sounds good doesn’t it? There’s a lot of good people contributing again, so I know it’ll have some good material and explanations.
In addition, I’m reasonably confident I play a role in this one…This one was a blast (sorry) to film. You saw some posts earlier reporting on some of the filming. Assuming they used the material I did with them, you’ll get to see why I was at the [...] Click to continue reading this post
The fires are racing up the sides of Mount Wilson as I write (19:38). They expect the burn to get to the top sometime in the next few hours, and yes, I imagine it’ll affect the Mount Wilson Observatory in some way.
[Update (20:59): You can get regular updates from the director at this page*. Seems that fire crews will remain on site for when/if the fires sweep through the grounds. ]
All of the working scientific equipment, including the solar telescopes and of course the historic telescopes (the 60 inch is pictured to the right) with which astounding discoveries were made about our universe (such as the fact that it is expanding, and the fact that the universe is vastly more than just our Milky Way Galaxy) are presumably in some danger, as well as support buildings of various kinds. I’ve no idea how much since I do not know what fire-proofing measures are in place up there, although I am sure there are several – such as keeping brush away from the buildings themselves. Here’s a camera up there on one of the solar telescopes where you can see regularly updated pictures that it snaps. I grabbed this one just now (click for larger view):
So keep your fingers crossed for luck for the instruments, and of course for all [...] Click to continue reading this post
I learned from Phil’s blog that (recently launched) Hershel’s official first image has been released:
[...] Click to continue reading this post
Tomorrow is the Big Day. For what? The launch of Planck and Herschel – Major new windows on our universe. Keep your fingers crossed for luck!
They’re on the launch pad right now. See here.
So, what are the missions and objectives of these fine spacecraft, I hear you ask.
Well, from the Planck site: [...] Click to continue reading this post
I had a lot of fun at this year’s Jet Propulsion Laboratory (JPL) open house. I’m happy to report that there were, once again, lots of people wandering around looking at the displays and demonstrations, asking questions, hanging out, and so forth, and an impressive turnout of JPL staff answering questions and being very enthusiastic about the science (something which is easy to do because it’s such an excellent topic!). I’ve made a video for you that is coming up at the end of this post. (Click on stills for larger views.)
There was the usual huge emphasis on planetary exploration with rovers and robots and so forth – this seems to capture the imagination of everyone, so why not? – but I was more than a little surprised to find virtually no showing for the Planck mission. There was one poster somewhere, but no booth, no model, no description of the truly amazing science that it will do in unlocking more about the origins of the entire [...] Click to continue reading this post
Well, the new orbiting instrument, GLAST (Gamma-ray Large Area Space Telescope – launched June 11th this year) has passed all its tests with flying colours, apparently, and is working well. NASA has now renamed the craft the Fermi Gamma-ray Space Telescope, after Enrico Fermi. There’s a press release here.
The craft is a wonderful combination of the fields of particle physics, astrophysics and cosmology, and will teach us so much about the universe (such as the nature of dark matter), and so it is exciting to hear that it all on track.
Excitingly, they’ve also released images of the early results of the observations, and you can read more about them in the press release too. Here’s a sky map made from the observations.
This all-sky view from GLAST reveals bright emission in the plane of the Milky Way (center), bright pulsars and super-massive black holes. Credit: NASA/DOE/International LAT Team.
Some words from the release: [...] Click to continue reading this post
Well, you’ve probably guessed that I’ve been somewhat distracted for several days. In fact, my main focus for the past week has really been on computer issues, frustratingly. I’ll give you the blow by blow later, I hope, but the last couple of days have been the most frustrating of all, and so I’ve not been dealing with much else, including blogging. Part of that is actual logistics – some of the things I wanted to post are on the afflicted computer – and some just the sheer annoyance of not having solved the issues driving me to do something totally non-computer related like going for a hike or seeing a movie.
So tonight i think I have a new theory – well, hypothesis- of what’s wrong, after a good deal of the day spent on detective work. It is a conjecture that is supported only by [...] Click to continue reading this post
The previous post was a farewell to black holes in the class, not here on the blog. (And it was not quite a farewell there either, since the midterm yesterday was all about the properties of the Reissner-Nordstrom black hole, representing a black hole with an electric charge, and a nice computation involving cosmic censorship.)
There have been two rather notable discoveries in the black hole astrophysics world this week. The first is the discovery of what seems to be another case of an intermediate mass black hole (there was only one example known before). Not the supermassive ones that live at the centers of galaxies (tens to hundreds of millions of times the mass of our sun), and not stellar mass ones of a few times the mass of our [...] 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
(Click for larger view.)
This lovely composite image of Abell 520 that includes an inferred distribution of dark [...] Click to continue reading this post
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
[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
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
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
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 thenâ€¦
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 theyâ€™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? Weâ€™ll see. [...] Click to continue reading this post
Well, Iâ€™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! Iâ€™ll try and assemble the several pictures that I took into some sort of narrative for you, and report soon. While you wait, hereâ€™s one of my favourites:
This is particularly poignant, in my opinion. The children are looking at the lovely [...]
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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
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