Parthenogenesis, II

bonnethead sharkRemember Flora? The Komodo dragon? I blogged about her here and here. She produced offspring using parthenogenesis while in captivity last year. Well, there was a news story earlier this week about a bonnethead shark in in the Henry Doorly Zoo in Nebraska giving birth to a pup. (Interestingly, zoo-keepers and news reporters seemed uninterested in giving our subject shark a name, as happened for the reptile.)

It was a puzzle for a while as to how she did it (as I learned in a BBC article):

At the time, some theorised that a male tiger shark kept at the zoo could have been the father – but the institution’s three bonnethead females had none of the bite marks that are usually inflicted on their gender during shark sex.

Some even suggested that one of the females could have had sex in the wild and stored the sperm in her body – but the three-year period in captivity made this explanation highly unlikely.

But eventually DNA tests resolved the issue:
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The Burning, II

Well, I’d expected that I’d have got to go to Griffith Park to do a hike and maybe show you some pictures to give you an idea of the changes since the fire (fire posts here and here). This has not happened yet, partly because last I heard they were not allowing people close to those areas… that may have changed by now. It has been over ten days since I checked.

Anyway, Colin Brown of Silver Lake was up there quite soon afterwards, and took many photos. They are not really for the squeamish, since he focused a lot on the animal remains that he found. So don’t look if you are likely to be disturbed by the […] Click to continue reading this post

A Fair Bit of Fun with Science

Yesterday was a full day indeed. The main event? The California State Science Fair. The venue? The California Science Center (just across the road from USC). Here’s a picture of it in case you’ve never been:

california science center
(Click for larger view.) California Science Center (with one of my personal emergency escape crafts cleverly disguised somewhere in the picture – all scientists have emergency escape craft, by the way – along with our plans to take over the world, our lab coat, and so forth…)

science fair briefing of judgingThe time? 7:00am. Yes, we start early, as there is a lot to do for the long morning. The judges all gather in the IMAX theatre for a briefing about the ins and outs of the organization this year, the times at which various things will happen, and a reminder about some of the finer points of judging.

At 8:00am we broke up into groups of judges who will judge various sections. Mine was Applied Mechanics and Structures – Senior. Here, we decided on our collective strategy concerning how we’ll go around the various displays, making sure at least five judges (there were ten of us in total) see each project once in the first round of interviews. We’ll compare notes during the break at 11:00am, agree which ones we should all have seen – in order to focus on deciding which ones get which prizes or honourable mentions. I forgot to take a picture of our group of judges sitting around the table chatting. Most of the judges in my group were people from the aerospace industry, I gathered. About three or four people were new to the whole thing, and so some of us explained a bit about the things that we ought to be looking out for in the judging. This also (given the section were were to judge, and given the makeup of the judging panel – many coming from an industry where the place where the science and engineering are quite thoroughly – and necessarily – mixed together) leads to discussion about making sure to distinguish between a great science project and a great engineering project. It’s also good to be aware, when making comparisons, of the vast differences in resources that some entrants have access to. These two things, to my mind, are very important (and we all agreed). A kid (especially one with access to lots of resources, for example) can dazzle an unwary judge with lots of fancy cool equipment and build something that is truly wonderful and admirable, but that does not necessarily mean that they would have done as much science as the next entrant who has done some very careful scientific experimentation with a innovative way of answering a clearly stated question, but in a less spectacular setting – perhaps mostly using more affordable household items.

science fair students
(Click for larger view.) Overview shot of one of the sections, with poster displays.

Well, with that in mind, we all went off to meet the youngsters! See the project listings here. This is the best part, of course… talking with all those enthusiastic young people […] Click to continue reading this post

Backreacting Asymptotically

(Random title constructed to reply to Bee’s post called Asymptotic Backreaction.)

You know, I’ve made some great online friends here on this blog. It’s all the result of that community I’m trying to keep going (and expand) here with contributions to the conversation from many of you in the comments, and even sometimes in guest posts. I’ve been lucky enough to meet some of these new friends since everyone likes to pass through Los Angeles sooner or later. In the past six months, four familiar Asymptotia contributors have passed through Los Angeles and I’ve been lucky and delighted to meet them: – Amara (November; on her way to a conference, and she gave us a talk – I’m trying to get her to do a guest post on her “Watering the Earth” topic one day), Candace (January; on her way to a conference here -she did a guest post) by the way, Athena (two weeks ago, on the way to a conference), and this week I finally met Bee (also giving a talk, and on her travels -she’s also done a guest post by the way) who turns out to have just that same excellent eye for observation, and quietly sharp sense of humour, as her blog posts. (She’s the main blogger behind the excellent Backreaction, and she’s done a post there which briefly mentions her visit to Disney Concert Hall with me.)

Anyway, in the photo below is Bee (click for larger), at Grand Central Market (inserted into a photo taken near one you saw earlier. See also this post.):

Sabine Hossenfelder at Grand Central Market

Tameem, a student of mine, has teased me a bit about my showing visitors around, […] Click to continue reading this post

JPL the new Disneyland?

If you’re looking for a day (or half day) out today in the greater Los Angeles area, let me suggest a trip up to the Jet Propulsion Laboratories (JPL). (Details here.) Their open house (held today and yesterday) is rather fun…. you get to learn about some of the grand space missions of yesteryear (like the 1977 Voyager missions… both craft are still actively sending data from beyond the solar system now), or of the moment (like Cassini-Huygens, for example sending wonderful pictures of Saturn and Titan back for us to learn from and marvel at – see e.g. here), or to come soon (like WISE (an infra-red telescope which will help broaden and deepen our understanding of planetary systems, galaxies, and the universe at large), or Dawn (a mission to go and orbit and study two large asteroids).

JPL Open House

You can learn lots of things about the science these missions are teaching us about not only far away worlds, but about our own world. There are also missions which are studying earth directly (making observations about our atmosphere, oceans, and so forth), so even if you don’t care about space, there’s something for you.

JPL Open House

JPL Open HouseYou can visit special exhibits for each of the missions, talk to scientists and engineers, and even visit the large warehouses where the spacecraft are made, and where they are assembled. There are the control rooms to visit, JPL Open House a dome with giant robots (I’ve no idea about that one), an extra special exhibit about Mars exploration, and lots of stations with all sorts of entertainment for kids! They’ve done a great job providing a lot of material for everyone to take away, including packets of information for teachers to use in their classes too! […] Click to continue reading this post

Read a Gravity Essay Today

The Gravity Research Foundation announced its awards for the 2007 essay competition. (Hmm: I think we should have more technical science essays, in more categories, to inform each other about what the big questions and answers are…. and maybe even just for fun (because I’m in a silly mood) -and to make an important point about how vital it is to communicate what we’re up to to each other- have a swanky awards ceremony, with speeches, and music, and an MC, and everything. And of course it should be held somewhere in LA… Like the LA Times Book Awards. It could be held at the same time as (another fantasy): awards we give to our peers for the important task of writing essays, books and other efforts in the service of communicating science to the general public.)

But anyway, you can read all about the winners of this year’s awards here. Nicking a bit of text from the site, here are the top prizes: […] Click to continue reading this post

LHC Coverage

CMS at LHC NYTimes

One of the Large Hadron Collider’s detectors, the Compact Muon Solenoid (CMS).

As you gather a lot when there are discussions on the topic here and elsewhere, there’s a lot of excitement and anticipation among high energy physicists about a number of things. I would go as far as to say that we are already in a very rich experimental time for results pertaining to high energy physics (or, if you insist, “fundamental physics” issues (I have in mind, for example, all the wonderful cosmological and astrophysical data that continues to come in, with more to come), and it is set to possibly get much richer – maybe even a new Golden Age with a little bit of luck – when the Large Hadron Collider starts producing results. We are really going into the (relative) unknown with this experiment, and this will be a great time to be working in the field – with a little luck, as I keep repeating.

A number of substantial articles have recently appeared in the general media that give you a good sense of what is going on, more reasons (and more detail) for why there is […] Click to continue reading this post

Taking the Time to Work it out

Itzhak BarsOne of my colleagues here at USC, Itzhak Bars (picture right, by Don Milici), spends a lot of effort trying to understand aspects of time. In fact, in his way of approaching things, the fact that we see a single time dimension (all the others being space dimensions) would be a consequence of certain choices (“gauge choices”, in the more technical language) made, whereas in the underlying formulation, there’s be two times. Yes, two.

You hear about extra dimensions, and you think “string theory”, no doubt. No, this is nothing to do with string theory. He’s developed this idea independently of string theory for years, working first with quantum mechanics, and […] Click to continue reading this post

Tales From The Industry XI – The Universe

The History Channel is diversifying a bit, and doing their first science show. It will be called “The Universe” and will premiere on Tuesday, May 29, 2007 at 9pm ET. It will be a series of 13 episodes. Here’s a blurb I found on the web:

It’s been fifty years since man first ventured into outer space. Now we have robots on Mars, telescopes capturing the birth of the stars and their collapse into black holes, and probes slamming into comets at hyperspeed. What we’ve learned has completely changed our understanding of the universe and our relationship with it – we once thought ourselves to be at the center, now we know we are a small, small spec. This epic series throws light on all the known universe and out to the edge of the unknown – what’s going on out there, what is our place, and is there life outside of Earth?

history channel shootI like the idea of more TV channels (besides the usual suspects like PBS or Discovery) getting involved in making shows that have more science, so given the end that it serves (see the about page) -and because it is interesting and fun work- I was happy to help out when I got a call to do some interviews to camera for use in the show. (The other show I did some segments for last year -see here and here– turns out to be part of a (reportedly somewhat saucy) variety and comedy show, I’ve since heard! It will air on another channel in the Fall, and I’ll tell you more about it then. )

We recorded on Thursday. The original plan was to record in a house in the Hollywood Hills, with access to some Griffith Park backdrop to shoot some b-roll of me doing a bit of hiking, but the fire put a stop to that. Instead, we found another location – a house with a lovely garden overlooking the Topanga wilderness. (Actually, they wondered whether we could use my house and garden, but I decided that the garden was not ready for prime time yet, having just begun to come out of its Winter slump where there was hardly any rainfall… So it remains still just between me and you my dear blog readers, ok? In the end, it would not have worked anyway since on Thursday there was still a lot of activity from helicopters en route to patrolling the Griffith park embers… not good for filming!)

How did it go? Ok, it started well. There were two separate settings, for two separate […] Click to continue reading this post

Assassination Complex

By the way, in case you’re in town here and looking for a good show, I ought to mention Assassins, put on by the Sight Unseen Theatre Group at the Meta Theatre. I saw it with a group of friends on Saturday night and it was excellent. (Friends mostly from a rowing club, go figure. Not a grouping I expected to meet in LA…No, I don’t row, I met them at a party the previous week.) A Stephen Sondheim musical (very clever songs and lyrics therefore), with excellent direction and performances, based on the book by John Weidman. They’re going to be done by the end of the week, so move fast.

assassins
The various assassins and would-be assassins of various US presidents, assembled together, with guns, song and (a bit of) dance. […] Click to continue reading this post

Penguin Opportunity?

So I don’t know whether you’ve noticed or not, but there’s been an awful lot of penguin movies (or movies with a big penguin component) recently. There’s yet another one to come out soon about surfing penguins. I’m slightly annoyed by it already, and I can’t really tell you why. It could turn out to be good, I suppose…

So I got to thinking that this could be theoretical physics’ big break! We can pitch our own penguin movie, since we have up our collective sleeve…

The penguin diagram!

penguin diagram

This is a type of “Feynman diagram” describing how various particles interact with each other in a specific process. (More on Feynman diagrams here, for example.) What does it have to do with Penguins? Well, this picture I got from Wikipedia might help:

penguin diagram

melissa franklinjohn ellisApparently, John Ellis is responsible for their appearance in the literature, pushed along by Melissa Franklin. The usual suspects were involved too (drinks, a pub, darts, etc…) From the Wikipedia article here is the story, in (we’re told) John’s words:
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