I’m not supposed to be blogging, since I’ve got to go and set up and introduce the visiting speaker, but I thought I’d point you to an LA Times (front page!) article by John Johnson, talking about some new material about Einstein and his more “human” side, as opposed to … Click to continue reading this post
Gosh, where do I begin? It’s going to be a hugely busy day on Monday. I’m excited about Monday first and foremost because of the colloquium. Charles (Chuck) Stevens from the Salk Institute generously accepted my invitation to come and visit USC and give a special colloquium to an audience … Click to continue reading this post
On Wednesday night, accompanied by Tameem, a student of mine, I wandered across campus to attend the “Mathematics in Music” event. I blogged about it earlier. I don’t really want to talk about the event itself in this post. It was a nice enough recital of three pieces. I don’t know why, but the promised “mathematics” was disappointingly virtually non-existent. I’m not exaggerating, I’m afraid.
Keep in mind that it may simply just be my misunderstanding of the intent of the event, but there’s simply next to nothing to report in the way of what was said about mathematical aspects of music. There were plenty of opportunities, but (almost) none were taken. I got out my notebook and pen, all excited at what the presenters might say at various points… and the mathematics never showed up. There were a few extremely elementary remarks about tonal ratios in chords, about scales, keys, and time, and that was it, more or less. This was a bit of a shame, since I suspect that Elaine Chew could have talked at length and with some authority on the matter (given the projects she’s involved in see e.g. here), but mathematics was almost completely missing in the event – despite the title. I imagine there were what seemed like good reasons for this. I was not party to decisions made behind the scenes, so cannot comment further.
More interestingly on that front was what took place in the minutes leading up to the delayed start of the event. First, although it was a free event, they pointed us to the box office where an attendant printed us two tickets from the computer so that we can show them to someone at the door who wasn’t really looking anyway. Fine. We got into the recital hall, but rather than sitting at the obvious available seats, I suggested that we move to the other side of the room where one can get a better view of the piano keyboard. I’m less than happy when I can’t see what a musician is doing, you see, so I always try to sit with the pianist’s view of the piano. So we did that, and found two seats. While we chatted and looked around us at the growing assembly, I spotted a friend and colleague of mine, the composer Veronika Krausas. She was in the company of someone who she introduced as Brian Head, who is a composer, performer (guitar) and music theorist (a “triple threat”, Veronika joked), also in USC’s Thornton school of music. They were looking for seats and there was one on either side of the two we were sitting in, and so they joined us and we chatted some more.
When the event start was about ten or fifteen minutes late -they were trying to get the reassuringly large crown all seated, they announced- Veronika idly looked at her ticket, pointed out that they were numbered, and wondered if we should have been […] Click to continue reading this post
I love teaching undergraduate electromagnetism. It has such an elegance, logic, and completeness about it. It introduces such a host of powerful techniques and ideas to the student, taking them across the threshold into maturity in their physics studies: Once you’ve done electromagnetism, you don’t usually think about large chunks … Click to continue reading this post
The Solar and Heliospheric Observatory (SOHO), a spacecraft that studies the sun, has been taking rather spectacular photos of comet McNaught. See here, for example. But the recent news that’s been exciting everyone are the comet pictures from the newer twin-spacecraft Solar Terrestrial Relations Observatories (STEREO), such as this one … Click to continue reading this post
The BBC1 are calling her the proud “mum and dad”. I’m talking about Flora, who is the parent of five baby Komodo dragons so far. Read the story at the link above. You’ll recall my earlier post about her, back when she featured in the “virgin birth” story leading up … Click to continue reading this post
’m watching my email for an invitation to fly suddenly to the Southern Hemisphere. Perhaps the Latin American Summer School (being held in Argentina this year) needs an emergency strings lecturer? I’ll be happy to reprise my lectures from the one I taught at in Mexico city in 2000…
Why do I want to go South with such urgency? This is largely because Comet McNaught continues to put on a wonderful show in the Southern Hemisphere. Amara Graps has kindly put several links for us to look at in the comment stream of my Look Up Down South post. Have a look here, here, here, here, and here. I did, and I found this lovely shot (by Mary Fanner – click for larger) of the comet over the beautiful city of Cape Town, which I miss a lot from the days when I helped run the ASTI science education program in 2004:
There are several more to be found on […] Click to continue reading this post
On the comment stream of my Light Cone post, commenter Neil pointed out something you may find amusing. I quote: At this website, you can generate an RSS feed of your personal light cone (starting from your date of birth), which notifies you when it passes a stellar object. Quite … Click to continue reading this post
I don’t know why this possibility did not occur to me before. So let me give you a heads up if you do demos in your lectures. In Physics 100 (which I taught last semester) and in Astro 100 especially, we do a lot of demos to demonstrate various physics concepts. I did a post on the Newton’s third law jet propulsion demo some time ago (linked photo right). My colleague Ed Rhodes did this same demo in his Astro 100 class.
He received an email from one of the students in the class recently saying “Congratulations, you’ve been YouTubed…”.
Apparently, one of the students in the class used his or her mobile phone camera to […] Click to continue reading this post
So imagine that you’re standing at some spot, holding a big round bulb that can shine in all directions. At a particular time, you switch on the bulb and it shines out brightly. Who has a chance to see the light from your bulb? Let’s not worry about things like buildings, cars, etc., getting in the way of the light, but just imagine it can shine free in all directions. You’ll realize that there is a whole ball of light expanding away from the bulb – light going away from you in all directions. (The edge of that ball describes what is called a sphere, a two-sphere to be precise, denoted [tex]S^2[/tex] in the trade.) The sphere expands at the speed of light. You might imagine that eventually every point in space around you would be reached by your expanding sphere (let’s stay local and not worry about the expanding universe and so forth), and you’d be right. But when? When does it get to some particular point that you might care about? As soon as it takes the light the time it takes to get there, of course. It can’t get there any sooner than that.
Let me put it another way. Your sending out the light is a particular “event”. It took […] Click to continue reading this post
I’ve been meaning to post this for a couple of weeks and forgot. From the New Yorker two weeks ago (I can’t decipher the artist’s name) [Update: Lee Lorenz, I think.]):
I’m pleased to see this for lots of reasons. It reminds me that it was in the New Yorker […] Click to continue reading this post
EDGE here stands for “Evolutionarily Distinct and Globally Endangered” and is a term that was coined to refer specifically to certain threatened species of animal around the world. They’re not always your big marquee animals (Lions and Tigers and Bears! Oh My!), and a great deal of them will be unfamiliar to you. (I’d never encountered the Golden-Rumped Elephant Shrew before, and I’ll admit that my life has been all the poorer for not having known about it before. It’s so cute! Furthermore, it has a golden rump. What’s not to like? Apparently, it is related to an elephant, somewhat distantly. Yes, it has a trunk, but it takes more than that to detemine its relationship to elephants! Update: – Here’s a Wikipedia article on elephant shrews, which could be a starting point for finding out more. The EDGE site has a lot of information too: here.
That unfamiliarity – blissful ignorance on our part – is part of the motivation. There’s a campaign to highlight them more, and raise both funds and awareness to enable […] Click to continue reading this post
We’re more or less all done with comet McNaught up here in the North. We’ve handed it over to the Southern hemisphere viewers. That lucky lot are getting quite a show, since the comet seems to be outgassing more and producing a longer tail of debris. It is spectacular. Here … Click to continue reading this post
An American Physics Student in England has a nice post about physics resources online in the form of video. In addition to the resource list provided by Serkan Cabi, which he discusses, he provides some favourites of his own. Check out his list. I am pleased to see the ASTI … Click to continue reading this post
What’s a calorie? Well, it is a unit of energy. If you take a gram of water and put some energy into it, you’ll raise its temperature (assuming it is away from its boiling point). If you succeed in raising the gram of water’s temperature by 1oC, you’ve put one calorie of energy into it.
But that’s not the calorie you probably have used in your everyday conversation. You’ve probably been talking about the Calorie. (Note the upper case C.) The Calorie, or the kilocalorie. It is 1000 times larger than the calorie of the previous paragraph. It’s the energy needed to raise the temperature of one kilogram of water by 1oC (assuming it’s not at its boiling point). That’s the Calorie you find discussed in the context of nutrition – the energy content of the food you eat.
Without further ado, let me show you what the Calories “look like”. Let’s take a reasonable number of them – 200. Each of the pictures below represents 200 Calories of a food, which you’d get from eating it. Mini peppers, gummy bears, and kiwi fruit: […] Click to continue reading this post
