Pluto is not a planet but Neptune is?

Filed under: news,physics @ 16:28

Today’s IAU vote reduced the solar system’s planet count to eight. No, Pluto has not been forcibly removed from orbit for bad behavior, it has merely been demoted; Pluto has been designated a “dwarf planet” since it fails to meet the newly defined criteria for planetary status.

A “planet” is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

It is the third test that Pluto fails; it has not “cleared the neighbourhood around its orbit” (whatever that means) since its orbit and Neptune’s overlap.

Fair enough. Too bad, Pluto.

But just as Pluto’s and Neptune’s respective orbits overlap, so too do Neptune’s and Pluto’s. Neptune, then, has not “cleared the neighbourhood around its orbit” either.

Perhaps I’m missing something in the highly rigorous definitions of “to clear” and “neighbourhood”, but it seems the new rules have been inconsistently applied to yield an ‘eight planet system’.

I should also point out that the new definitions do nothing to define the status of bodies orbiting other stars since all of the language used refers to “the sun” and “the solar system”. Are the IAU resolutions science, then, or just self-important verbiage?

I hope my confusion comes only from my ignorance and that there’s a good answer to all of this.


If I wasn’t from IQI then why would I be wearing this hat?

Filed under: neat!,physics,useless @ 13:32

I received, for “future contributions”, an official IQI hat yesterday at group meeting. Pretty fly. I think it’s going to be my new look. I particularly enjoy the Southwest pointing (in the liturgical sense – that’s 4:30 for all you heathens) ‘gangsta’ style.

In the IQI hood, beeyahtch. Represent. Step off fohz my homes cap y’all whit theyz provably secure implementation of Quantum Key Distribution. Be cracked to front on me, brothah! M’doin some serious QMA-complete sheeyit ovuh heah!

I’m still working on gang signs.


arXiv-fu — 12:23

I just found this. I had no idea: http://arxiv.org/rss/quant-ph.


Now that’s a shockwave

Filed under: a group of folks,neat!,physics @ 11:44

A couple days ago, NASA reported that Voyager 1 has passed through the solar termination shock (and that their graphics people have made some pretty hot little movies). The termination shock is part of the interface between the solar wind exiting our solar system and the intestellar wind blowing about around us.

Suck on that, Jeff. None of this namby pamby kidney nonsense :)


Spatial Quantum Search

Filed under: a group of folks,academe,physics @ 01:03

Following Paul.za’s lead, I’ve decided to write up a brief sketch of some of the background behind my current research: Quantum Spatial Search. Be warned, this is the longest post blogwaffe has ever seen. Skip to the last page of this post and read the last line if you want the short of it. For the long of it, read on.

Use the little page numbers below to navigate this post.


An unexpected perk of being a Caltech grad student

Filed under: academe,neat!,physics @ 18:54

Checking my campus mailbox this morning, I was delightfully surprised by an interesting missive: The January, 1987 edition of The UFO Report. I can only assume some local… is nutjob too strong a word? went through Bridge and put copies in random boxes.

Pretty awesome, though.

The first… article tells the tale of a man and his motorcycle – both driven to seek out extraterrestrials where any reasonable human would most expect to find them: in the woods ripping down the occassional tree and yelling a lot. After passing up the possibility to closely inspect one, nay, two clearly alien spacecraft, he heads to the nearest town for a drink and a chance to interview the locals who had taken advantage of a similar opportunity. Unfortunately, those locals had a dying aunt, or some such, and it wasn’t a good time to discuss the issue. Given, though, the nature of the periodical, you can safely assume he eventually found some aliens (…or did he???). It is particularly remarkable that, in the account, there are literally dozens of witnesses who, one supposes, could verify the presence of our hero near the sighting, yet at the time when he claims to have seen the beast(s?), the author was alone. Naturally, no details about the author are given.

A very entertaining read. Almost as good as the accompanying illustrations.

Read more…


News Flash: Life on Titan!

Filed under: neat!,news,physics @ 13:46

Everyone has no doubt heard of the Cassini Spacecraft launched in 1997 which last year began a series of flybys of Saturn’s moons. Well, on Christmas day, the Hyugens Probe was released from Cassini and began it’s mission: a closer inspection of the moon of Titan. While the Hyugens Mission is primarily an atmospheric one, it was designed to land on the surface (find it liquid or solid), and take some surface measurements and pictures.

January 14th, Hyugens descended into Titan’s atmosphere and it’s four hour data collection spree began. Four hours for two reasons: (1) the batteries wouldn’t last too much longer, and, more importantly (2) because Hyugens transmits to Cassini, not to Earth. And Cassini wasn’t stopping.

Well, as of 2am this morning, a lot of the data have been analyzed. Except for some awesome pictures, though, little has been released; wait until next week, say.

But, I can say that there is quite a high probability that there exitsts life on Titan.

Read more…



Filed under: news,physics,slice @ 01:06

A little bird told me the other day Vroman’s coffee shop stocks hot apple cider. Man, I love the stuff. It’s hard to find out here, even in the fall, and I’ve been jonesin’. So rather than do my field theory in the living room as always, I decided to hit it up last night.

No dice. Last weekend was apparently ridiculously busy, and they’re out of cider. You’d think three days would be enough time to restock, but maybe they were so busy that their cider supply went into the red. Ah well, their Star of India tea was good enough to keep me there taking up half of a big table with various papers and texts.

More interesting than quantizing the Majorana fermion theory was the conversation the two girls (one claiming to be 21, the other 17) were having at the table next door. The conversation was politcal, complete with rightist (the older, fashonista, lush, wannabe socialite) and leftist (the younger, product of divorced parents (whoa there – just stating facts), teetotaler (but only after having a bad experience or two with drugs (and their abusers), outwardly extroverted to compensate for fundamental self-confidence/image issues). Neither was making any real argument, each was just spouting off moral judgements or personal theories without any support (other than, “I have seen a homeless person before”, to paraphrase). I’m sure most of what they said was deeply felt, but none of it was terribly well developed. Well, maybe that’s unfair; at best their ideas were poorly communicated.

It was frustrating to listen to these people trying to string together sentences out of but-grasped-for ideas. I think the amount of information conveyed in their hour long conversation was on the order of bits. Clearly a very noisy channel.

But, hell, at least they were talking about the current administration and what they thought could be better with the country. More power to ’em.

Best Sound bites (all by Rightie): “But we need homeless people. We need 18% unemployment [sic] for this society to function.” “Not everyone needs healthcare.” “I like living in the most powerful country in the world. Having that behind me and being able to tell people that.”



Filed under: neat!,news,physics @ 17:17

About the time I was finally able to get to sleep last night, a certain member of the Caltech faculty was abruptly awakened by the ringing of his telephone. Professor of Theoretical Physics David Politzer must have first awakened in annoyance when he heard the phone, then fear as he subconciously prepared himself for some sort of emergency, and finally elation when he realized what day it was. 10.05.2004: the day the Nobel Prize in Physics is announced.

He lifted the receiver and was connected with Stockholm.

I like to think the King himself was on the phone, but, as far as I know, the Royal Swedish Academy of Sciences, though founded by the Crown, is entirely independent; I do not believe the current King is a member.

Dr. Politzer was awarded the prize for his earlier work in on the concept of asymptotic freedom. The strong nuclear force is responsible for holding together such “everyday” particles as the proton and the neutron (together known as nucleons). These nucleons are in turn comprised of other, more fundamental particles called quarks and gluons. The odd thing (at least in the early 1970’s) is that particle collision experiments suggest that quarks are held together only very weakly inside a nucleon, however they have never been observed on their own outside of a nucleon. How can particles held together so very weakly not be pulled apart and examined individually?

Read more…

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