Shadow Dancing
My modest contribution to the photos of the eclipse from Sunday. Modest indeed… […] Click to continue reading this post
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Category Archives: science
Solar Eclipse!
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!
Bringing Science to Schools
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
Heaven’s Parameters
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
Project Heaven
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
Fractal in Progress…
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
Higgs Boson Explanation, by PhD Comics
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
National Physics Day
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
Happy Birthday Hubble!
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
Graphic
This was a fun assignment. I’m giving a talk (“Graphic Adventures in Science Outreach”) on Friday to my colleagues and friends at the Los Angeles Institute for the Humanities, and they asked me to send a graphic to them to use for the poster. So I spent a bit of time digging into my database of drawings for The Project and threw something together pretty quickly. I rather like it. (You will maybe recognize that drawing from an earlier post – I added in an earlier stage, and then a drawing of a hand I’d done for something else…) By the way, it is not an event open to the general public and is by invitation only, so just showing up won’t get you in.
Picasso and Einstein: Face Off?
I just learned from Amy French in a comment on the post on the production of the “Picasso at the Lapin Agile” play that got cancelled) that the short promo film she did for the play is on YouTube. It has two of the principals on screen. It’s short and fun!
Here is is: […] Click to continue reading this post
Inquiries
9:30am, my office. Phone rings. I get it on the first ring.
Hello?
Oh. Is that… Professor… Johnson?
Yes.
Oh! I was not expecting to… Well I’m watching this program, and had some questions…
I see.
Well, when you say…
Well, who am I talking to?
Oh, I’m [name].
Hi.
Hi… So, when you say millions of years, even billions of years in these programs… do you mean earth years? or, um, do you mean space years?
Oh, that’s a good question. I mean the regular years. Earth years, if you like.
Oh. So these things are really that old.
Oh, yes. They are.
I have one more question.
Of course, please go ahead.
Michio Kaku says that the universe is full of many things and all you have to do is ask for something and you’ll get it. How do you go about doing that?
Uh… Well… I’m not sure I understand what that means…
Well, you know we come from supernovae…. and… we’re from space… and there are maybe lots of gods out there that we can ask for things…Kaku says we can just ask the universe. How does one do that?
Well… I am not sure what he had in mind. It might be…. might be best to ask him…. But maybe what he meant is that the universe is a very big place, with lots of things going on, and maybe he meant that there are all sorts of things you could find out there because it is so big and diverse… But perhaps he did not have in mind that a particular person could go out and get any of those things… but you might want to ask him. I can’t say for sure.
Oh, ok.
But I can tell you what I think. I think that while the universe is a big and exciting diverse place, it is still the case that a given individual only has limited access to all those things in it. It is a big place, and so you mostly only have access to what you can get to locally. Travelling around it takes a long time…
Oh, I see. Well, thank you.
And… thank you, by the way, for watching the program. I am glad you enjoyed it.
Yes, I love these programs.
I’m glad to hear that. I hope you continue watching and do tell your friends about them too. All the best.
Goodbye.
Goodbye.
I enjoyed that chat. I love it when people are inspired to step away from their […] Click to continue reading this post
Picasso and Einstein
Tuesday evening was fun. My dear friend Amy French, who was hired to direct a production of Steve Martin’s play “Picasso at the Lapin Agile” had been been rehearsing her cast for a few weeks. She invited two people to come along as guests one evening to talk about Picasso and Einstein – their work discussed in the play (Cubism and Special Relativity), and the impact of their work on the world. Megan Mastroianni from the Art History department (see her in the center of the photo above – you can click it for a larger view) came along to talk about the Picasso aspect, and I talked about Einstein. It was a lot of fun, and verity informative for all concerned.
The cast were all assembled, and Einstein and Picasso were even in costume, as we […] Click to continue reading this post
Downtown Quantum Mechanics
Oddly today I had a meeting in a skyscraper in downtown LA that I’d been studying last year because I was doing a drawing of it for The Project. Funny old world. I really enjoyed being in it because from the meeting room one can view the classic public library building, a favorite of mine, from the 41st floor, and also check out the scene in the Standard rooftop bar (been a while since I’ve hung out there).
But the most unexpected thing of all was when I returned to ground level. I was walking on my way to the subway and slowed to enjoy a view of the public library, only to be faced with Heisenberg’s uncertainty principle in two forms, Schrodinger’s equation, and an atomic spectrum (Rydberg, Bohr, etc) that one can derive from the latter, engraved into the wall! Hurrah!
The thing is, I can’t remember whether I’ve seen this before. I’ve passed there so very […] Click to continue reading this post
Process
A process update, since some of you are curious about The Project.
While hiding in the desert on walkabout recently, I finished writing a story I’d been working on (one of a few I worked on), and started thumbnailing parts of it and refining the pagination of it. Thumbnails are just little sketches of how a page might be laid out, maybe focusing on how the eye might move about the page, how the words and pictures might flow, etc. There were some pages I was immediately interested to try out, and so I did larger versions of them in rough here and there (and for some other stories too)…. For one of them, I have a really exciting exchange (about symmetry and beauty) over a notepad, and I sketched over oatmeal one breakfast time a mannequin construction of the layout. (See earlier for introduction to my mannequin friends.)
Well, on Thursday and Friday I finished the rough pencils for the whole page, featuring those two figures, now given flesh and bone. Today I did the main figures for another page, with a variation on that pose of the mannequin drawing from the desert. (Vellum helps here.) I thought I’d share (click for larger view):
They’ll be refined later on, with things like scaling of various bits and pieces fixed […] Click to continue reading this post
