I’m guessing that most of you who took pictures during the venus transit on Tuesday (see my modest effort here) did not get something quite as good as the one above. Wow. It is by the JAXA/NASA Hinode craft that is in orbit.
From the site […] Click to continue reading this post
I set up some simple 10×50 binoculars on my tripod, and after a tiny bit of fiddling, out pops the transit in progress from the other end, projected on to the back of an envelope! (The envelope was helpfully held still by a friend so that I could take the photo.) (Click for larger view.) […] Click to continue reading this post
Hot on the heels of the annular eclipse of a few weeks ago, we’ve another giant body passing in front of the sun tomorrow. Venus! This time the giant body (roughly the same size as the earth…just a bit smaller) is much further away from us, and so is dwarfed by the sun. It’ll be a tiny dot on the disc of the sun that takes several hours to pass across. This’ll give you plenty of time to look. (In the US, for example, it’ll start at about 6:06pm EST and about 3:06pm PST…) You won’t get another chance (at least, not from earth…) until 2117, so have a go!
In fact, you’ll be doing something that is vital for modern astronomy right now – observing the effects of a planet on the light of its parent star as seen from afar. This is the principal method for detecting planets moving around distant stars, the “extra-solar” planets you hear so much about in the news from time to time. Here, we’re seeing it happening for a familiar planet around a familiar star. Although both objects are quite familiar, this transit is still worthwhile to study, since it helps planet hunters learn more about how such processes can help deduce things about the planet doing the transit. So study it many will, I’m sure.
You can just look at it for fun, but remember to be careful. Do not look directly at […] Click to continue reading this post
No, not some geometrical artifact of immense power… It is the containment for my next batch of compost. Click for a larger view. I made it last year out of PVC pipes and chicken wire, and it was a huge success (see recent posts with pictures of the produce that has been appearing from that compost batch….) with one design flaw: It was a bit high so that digging in it to turn the forming compost over and so forth was tough on the back – I put my back out for days one time. So I’ve cut it down to a smaller height and now it […] Click to continue reading this post
This was an incredibly busy visit, but worthwhile. We pulled 12+ hour days in getting
everything needed for the film (about the Aspen Center for Physics), with lots of backup, and oodles of great footage. So much that I fear we have so much great material we can make five completely different short films instead of the one that is supposed to be delivered. It is going to be tough. I’m so excited about some of the things that we’ve shot. A number of ideas I had for the arc of the film, the feel and tone, and the opening moments, look to be falling together almost _exactly_ as I envisioned them months ago.
Ouf excellent DP, Dave Gaw, (an accomplished filmmaker in his own right) seems to almost immediately get what I’m trying to do when I explain something I’ve visualized, or when I draw it, and so the shots work out quite nicely, and sometimes he’s gone and filmed some sequences that look very much like ones I’d been imagining, sometimes without us even having had a discussion about it! It has been a great collaboration among the three of us – Dave, Bob Melisso (my co-Producer/Director), and myself – as we exchange ideas about how to best implement something or other to make it tell part of the story…
Anyway, while preparing for getting some nice outdoor shots of physicists doing […] Click to continue reading this post
I’m at the Aspen Center for Physics for some time this week. It is a big week. You will perhaps recall that I’m involved in making a short film for the 50th Anniversary celebrations of the ACP (see some earlier posts) and now we are doing another batch of shooting. Not just interviews, as we have been doing so far, but much of the other footage we need, such as the lovely grounds, the various physicists using the center, in myriad ways, and so forth. We’ve had a super long day today, which[…] Click to continue reading this post
My modest contribution to the photos of the eclipse from Sunday. Modest indeed… […] Click to continue reading this post
Don’t forget the annular solar eclipse on Sunday! You get get all the detail about it at the NASA eclipse site here. According to the site:
“An annular eclipse will be visible from a 240 to 300 kilometre-wide track that traverses eastern Asia, the northern Pacific Ocean and the western United States. A partial eclipse is seen within the much broader path of the Moon’s penumbral shadow, that includes much of Asia, the Pacific and the western 2/3 of North America”…
I’ve put a snap of the graphic they provided on the right for decoration, so you can go to the site for more detail and explanation. This includes precise times for your city, and so on and so forth. Be sure to exercise the usual precautions in viewing (do not look directly at the sun with your eyes, and certainly don’t look at it through any optical instruments… project the eclipse onto something else… there are many sources that can tell you more about that…)
Enjoy!
Here’s a nice article (by Ambrosia Brody) about some of the work the Joint Educational Project (JEP), Women in Science and Engineering (WiSE) and the Dornsife College of Letters, Arts, and Sciences (all here at USC) have been doing to get school students excited about science. It looks like a fun and valuable program, and it is always great to see the look of wonder on the faces of the students as they explore (see film below). (Photo is by Nick Pittarides for USC News.)
A nice aspect of it that caught my eye is that one of the films that got made for the […] Click to continue reading this post
Oh… I forgot to get around to letting you know the result of designing the universe required in a previous post. The result is that it is a radiation (“light”) filled universe with positive cosmological constant [tex]\Lambda[/tex](and so space wants to expand due to negative pressure – much like ours seems to be doing). The radiation density wants the thing to collapse. There’s a balance between the two, and it turns out that it is when the two densities (radiation, and vacuum energy) are equal. This is only possible when there is positive curvature for the universe (so, not like ours), as you can see from the Friedman equation if you were that way inclined. So the universe is a 3-sphere, and if you work it out, the radius of this 3-sphere turns out to be [tex]a=\left(\frac{3}{2\Lambda}\right)^{1/2}[/tex]. The temperature of the radiation is then computed using the usual Stefan-Boltzmann relation.
The equality of densities turns out to result from the fact that the effective potential of the equation is at a maximum, and so this universe turns out to be unstable… It is a radiation-filled version of Einstein’s matter-filled static universe, which is also unstable. It is larger than Einstein’s by a factor of [tex]\sqrt{3/2}[/tex].
Einstein was said to have arrived at his static universe on the grounds of what he thought was observationally clear – the universe was unchanging (on large scales). […]
The equality of densities turns out to result from the fact that the effective potential of the equation is at a maximum, and so this universe turns out to be unstable… It is a radiation-filled version of Einstein’s matter-filled static universe, which is also unstable. It is larger than Einstein’s by a factor of [tex]\sqrt{3/2}[/tex].
Einstein was said to have arrived at his static universe on the grounds of what he thought was observationally clear – the universe was unchanging (on large scales). Hubble […] Click to continue reading this post
This is an extra homework that some students of the General Relativity class did to make up for one that did not count earlier in the semester. While writing it, I realized that this universe is in fact, Heaven! You know, we become beings of light, and live forever, etc…
I thought it would be fun to share its final form:
“You work in the design section of the company that manufactures universes. (This is […] Click to continue reading this post
So last week we had a visit from Kelly Stelle (he’s part of the high energy theory group at Imperial College) who gave us an excellent talk about aspects of supergravity. His work connects to the fascinating ongoing story about finiteness, and the new techniques being used to do the multiloop computations (see a recent Scientific American cover story about some of that – it is misleadingly packaged by the magazine, as usual (preview here) , but the article itself, focusing on the computational issues, is nice).
After his talk, I gave him a tour of the campus, and as we passed through the Doheny Library to view the lovely interior, we stopped by the ongoing construction of the Mosely Snowflake Sponge fractal that I told you about here.
They’re making a lot of progress.
We spent a few minutes folding some business cards to contribute some component cubes to the construction, and I took a snap (see photo on left) of Kelly at work. We made two or three cubes each…
Here’s a shot of one of the completed modules […] Click to continue reading this post
This is rather nicely done*… Stay with it beyond the opening bits, and enjoy the breakdown! Click on the embed after the fold:
[…] Click to continue reading this post
Er… it is National Physics Day today, apparently. National Science Foundation says so, so it must be so.
Bad me for not knowing. In my defence, I try to live every day like it is National Physics Day. International, even.
[…] Click to continue reading this post
It is the 22nd Anniversary of the launch of the Hubble space telescope today! As you know, this instrument has produced a wealth of scientific information over the years, as well as lots of wonderful pictures for everyone that broadened and deepened our sense of wonder about this remarkable universe we find ourselves in. The Hubble site is here.
Phil Plait has re-posted his 2010 post “Ten Things You Don’t Know About Hubble”, […] Click to continue reading this post
