As you know you can see everyone who's registered for the conference, but I highlight 4-6 participants every day as this may be an easier way for you to digest the list. You can also look at the Program so see who is doing what.

Hope Leman is a Research Information Technologist at Samaritan Health Services. She runs ScanGrants (a free, subscribable (via email or RSS) online listing of grant opportunities, prizes and scholarships in the health and life sciences and community service fields), tweets and blogs on Significant Science. At the conference, Hope will do a demo of ScanGrants.

Ernie Hood is a freelance science writer and he hosts a weekly science radio show - Radio In Vivo - at the local radio station WCOM-FM in Carrboro, NC. Ernie is currently presiding over SCONC - the organization of Science Communicators of North Carolina.

Elle Cayabyab Gitlin writes for Ars Technica, blogs and tweets. And she is always a great help to us at the conference, every year volunteering to help.

Peter Janiszewski is an Obesity Researcher (PhD Candidate) in the Exercise Physiology Lab at Queen's University, Ontario, Canada, a Science/Health Blogger at Obesity Panacea, a freelance writer, a musician, and a Twitterer.

Jayme Corbell, another veteran of our conferences, got her PhD in chemistry at Duke and now works at Catalent.

Jonathan Lifland is the Media and Communications Manager at PNAS (Proceedings of the National Academy of Sciences) and is on Twitter

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Ok, see counselor Troi firing her phaser?

You see this kind of thing all the time on film in scifi. Whether it's Star Trek, Star Wars, or pretty much anything else, energy beams fired from future weapons are visible. Usually someone will point out that in fact laser beams are not visible in this manner. To see light, it has to reach your eyes. This is clearly not possible when all the light is actually traveling down the beam path. You can see this in action with laser pointers - only the spot where the light hits and diffusely reflects is visible. The path is not.

Writers of TV shows usually explain this by saying that the beam is not strictly light, but some stream of particles that slightly emits to the sides along its main path. While this has its own problems, at least it acknowledges the issue.

But what's even more interesting is that in fact there are already automatically particles present along the beam path in the atmosphere. Some of them are sizable particles like dust, others are individual atoms and molecules. Generally they don't scatter much light, but if the light is intense enough then the small amount they do scatter is enough to see. And so you have a visible laser beam. Here's one in my lab:

The beam scatters off the air and you can actually see it as a straight line. Apologies for the terrible camera phone picture, I really need to get a classy camera that can take nice pictures. This is not actually a laser I'm working on, so honestly I'm not sure which variant of frequency-doubled Nd:something laser this is. Probably Nd:YLF.

This is used to pump an infrared ultrashort-pulse laser with a repetition rate of 1 kHz. This can itself be focused to a point in the air, which becomes visible as a little stationary spark as the intense beam ionizes the air. This produces a 1 kHz buzz which can easily be heard by the unassisted ear.

I have to say it's a nice job perk that I can see old science fiction tropes come to life pretty much every day. :)

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It's not often that I regret having a cell phone that is just a phone, but this is one of those occasions-- I stopped by my publisher today to talk about marketing and publicity, and record a video for the web, and got a stack of finished copies of the book, hot off the presses. If I had a cell phone camera, I'd post a picture, but I don't, so you'll have to settle for a plain-text "Woo-hoo!"

On an only vaguely related note, our cultural activities in NYC will include some college hoops, as there's a preseason "tournament" taking place at Madison Square garden tonight. Syracuse vs. Cal, and UNC vs. Ohio State. Not a bad double bill for November basketball.

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Ethan at Starts With A Bang did a nice post the other day on an old chestnut - why you can't touch your toes if you're backed against a wall.

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There are not going to be too many more of these:

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In the comments on one of my posts, someone pointed me towards Stephen Crothers, who gives the following argument (in a nutshell) as to why black holes cannot possibly exist:

1. General Relativity is our theory of gravity, which relates the curvature of space to the gravitational acceleration of objects.
2. This theory only works in certain regimes; it breaks down at the point of singularities.
3. A black hole, as predicted by Schwarzschild, is a singularity.
4. Therefore, since singularities are forbidden by General Relativity, there is no reason to think that black holes exist.

(You can watch his video here, or read his full argument here.) Therefore, he argues, astronomers are wasting their time looking for black holes, since their existence isn't even a physical prediction.

Talk about not seeing a forest for the trees. The "singularity" is not essential for a black hole to exist. Honestly, it isn't important at all whether there's a singularity or not. All that matters, in the real world, is that something is both massive and compact enough so that, within a certain radius, light cannot escape from it. That is the astrophysical definition of a black hole.

So, do they exist? Definitely. Where do you look for incontrovertible proof? The center of the galaxy! There are no two ways around it; there is definitely a black hole there.

How am I so sure? The above image shows the center of our galaxy. There are many, many stars orbiting the central point where the arrows are pointing. We have tracked these orbits over more than a decade, thanks to the UCLA Galactic Center Group. Here's a screenshot of their results.

From the motion of these orbits, we can figure out what the mass of the object they orbit around is. It turns out to be over 2 million times as massive as our Sun. And yet, we don't see any light coming from that point. We don't see a white dwarf, we don't see a neutron star, we don't see any object at all.

For a mass that large, you will have a black hole if that mass is confined to a sphere of a diameter of about ten million kilometers. That isn't hard, considering we have many, many stars that we know of where an entire solar mass is confined to a diameter of about ten kilometers. (These are neutron stars.) If you up the mass, the neutrons at the core will eventually collapse under the tremendous pressures, and collapse farther. There's a well-known upper limit to how massive a neutron star can be, and it's less than three solar masses, much less two million.

So you can argue about whether singularities violate General Relativity or not until you're blue in the face. It doesn't have a damned thing to do with whether any light gets out of your ultra-dense, massive object. And that's what we call a black hole, and it exists. Don't believe it? Then tell me what's going on at the galactic center.

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Do not try this at home unless you are a certified physics teacher. Try not to think about what all the crap is in this guy's microwave. And do wear goggles. The really interesting part is after five minutes. That's where the science starts.

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There's a little bit of buzz burbling around over Al Gore's scientific goof during a Conan O'Brien interview. Discussing geothermal energy, he said the following:

It definitely is, and it's a relatively new one. People think about geothermal energy -- when they think about it at all -- in terms of the hot water bubbling up in some places, but two kilometers or so down in most places there are these incredibly hot rocks, 'cause the interior of the earth is extremely hot, several million degrees, and the crust of the earth is hot ...

Of course the interior of the earth is extremely hot, but not that hot. It's several thousand degrees rather than several million. If the earth were several million degrees it would be a rapidly diffusing cloud of metallic vapor. Even the center of the sun is only perhaps 13 million degrees C.

But I'll let him slide; pretty much everyone blanks out from time to time. And it gives us a chance to do a little thinking about just how much thermal energy is in the earth.

First of all, just because something is hot doesn't mean you can squeeze energy out of it. You can only squeeze energy out of temperature gradients - you need something hot and something cold. This is why we can't just set up a temperature-to-energy machine in the desert and have free energy. In your car, for instance, you need both the heat of the burning gasoline and the much cooler ambient temperature from the outside air via your radiator to turn the hot gasoline vapors into forward progress. Power plants frequently have large cooling towers for that very reason. It's not the energy of the hot substance, it's the process of moving that heat to a cooler place that creates useful work. Think of it in the same way as water flowing downhill can turn a paddlewheel - it won't work unless the water starts off high and ends up low.

But that's not a problem here. The interior of the earth is hot and the exterior is much colder. The difference in temperature is such that the efficiency of heat-to-work conversion could be near 100% in theory, though in practice it would be much lower. And we're not likely to run out of geothermal heat any time soon. As a slightly wild Fermi calculation, assume that the earth is uniformly iron at 3000 C. The specific heat of liquid iron is about 611 J/kg K, so cooling the earth to room temperature this yields about 1.8 million joules of energy per kilogram. Multiply by the mass of the earth, and the total energy content might be in the neighborhood of 10^31 joules. The total energy consumption of the world's human population is in the vicinity of 5e20 joules per year.

Divide out, the earth's geothermal energy could support that consumption rate for about 21 billion years. We're not likely to use it up.

So why isn't it in widespread use? After all, every nation has domestic access to it - all you have to do is drill straight down. The main problem is that the temperature really doesn't start getting ramped up until dozens of miles down. Drilling a hole that deep and pumping water (or whatever) down and up is technically unfeasible. Geothermal is at its best at those places which are close to geological activity that brings the heat closer to the surface. Volcanic and other geologically active locations often do very well with geothermal power. Iceland in particular produces vast quantities of usable energy from the internal heat of the earth. Most other places are much farther from the hot regions of the earth's interior and geothermal is correspondingly much more difficult to get.

Sadly Al Gore's hopes for geothermal as a major clean energy technology are probably futile until deep drilling develops into a much more mature form. It would be nice if that happened; the energy to be tapped is pretty close to inexhaustible.

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The latest news from the USGS/Smithsonian Global Volcanism Program Weekly Volcano Report ...

Highlights (not including Mayon) include:

• Strombolian eruptions and small pyroclastic falls at Arenal in Costa Rica.


• 3 km / 10 000 foot ash plume from Bagana on Bougainville Island in Papua New Guinea.


• Rumbling noises, ~4.5 km / 14 000 foot ash plumes and incandescence were all reported coming from Fuego in Guatemala.


• Steam-and-ash from Popocatepetl near Mexico City reached 7.4 km / 24 300 feet.


• Satellite images of Shiveluch revealed a large thermal anomaly - the new lava dome - along with multiple ash plumes reaching up to 5.5 km / 18 000 feet.
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It has been a slow week for volcano news (and a busy week for me), so I apologize for the abundance of MVPs this week. I've tried to find a good one in the many images submitted to me by Eruptions readers, and #15 is just one of those photos. If you have images you'd like to share with me for MVP or other uses, please email them to me at . (However, I should note that you can't win by identifying your own volcano photo!)

MVP #13 was Lava Butte near Newberry volcano in Oregon. It is a lovely small scoria cone that you can walk/drive to the summit. From there, you get a spectacular view of the central Oregon Cascades and Newberry. I took this photo sometime in 2002 (I think).

MVP #14 was an old photo of the summit cone of Mt. Vesuvius went it last erupted in the 1940's.

Current Standings:
Don Crain - 2
gijs - 2
volcanista - 1
Lockwood - 1
Elizabeth - 1
Ralph - 1
Anne - 1
Cam - 1
gg - 1
The Bobs - 1
Boris Behncke - 1
Damon Hynes - 1

Here's #15, submitted by a reader ... Enjoy!

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Some meteor showers are spectacular, while most are mundane. If you sit around during a typical shower, you might see anywhere from 50 to 100 meteors an hour, if the Moon isn't out.

If you take a time-lapse photograph and look for meteors, you will, sometimes, get a great view of what's going on. Although it isn't immediately clear what's a meteor and what's a passing satellite or airplane, you can tell them apart in this video by looking for the "instant" streaks, which are meteors, versus the ones that streak for many frames, which are satellites or aircrafts.

Well, the Leonids peak tonight, and they are spectacular. Instead of getting one or two meteors a minute, we should get -- on average -- a meteor every five to ten seconds! What's more? The peak, tonight, is at around 3 AM Eastern Standard Time (Midnight Pacific Standard Time).

Even better? The Moon is practically new tonight.

This means that only a tiny crescent will be in the sky, and it'll be gone by an hour or two after sunset. Which means, if you get clear skies, you'll have ideal meteor shower conditions!

So where should you look on the sky? Near the constellation Leo; the meteors will emanate from there. (Ignore Saturn in the image below; it was there in 2006, but isn't in 2009. The stars are still in the same place, though.)

And at its peak, we should get about 500 meteors per hour, which is huge. If you get to see it remember to thank Comet Tempel Tuttle for coming through in 1998 and leaving this beautiful debris trail for us.

All of it makes for a beautiful sight this night! So go out and enjoy it, and know that I'll be jealous here in cloudy Portland!

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As every physics-loving dog knows, the idea that electrons behave like waves was first suggested by Loius Victor Pierre Raymond de Broglie (the 7^th duc de Broglie) in 1923. The proper pronunciation of his surname is a mystery even to human physicists, though. So, how would you say it?

Louis Victor Pierre Raymond de Broglie's surname is pronounced:(polls)

Even though Louis was a quantum pioneer, please choose only one of the available options.

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Sunday night, the Patriots lost a heartbreaker to the Colts 35-34. The talk of the sports world yesterday was Bill Belichick's decision to go for it on fouth-and-two on his own 28 yard line when he was up by six with just over two minutes to play. They didn't get the first down, and turned the ball back over to the Colts, who went on to score a touchdown and win the game.

Yesterday's discussion was a low point even by the standards of sports talk radio, with one idiot after another holding forth about how stupid Belichick's decisions was, and how he "disrespected his defense," and various other dumb sports cliches. In actuality, people who know how to do math know that he was playing the odds, and had a higher probability of winning by going for it than he would've had if they had punted.

Belichick's problem is one that's well known to quantum mechanics. His decision to go for it increased his team's chances of winning, but the actual outcome of the game was still probabilistic-- no matter what he did, the result would come down to chance. And there's no way to get information about probability from a single measurement. The only way to determine probabilities is through many repeated measurements on identically prepared systems, but the rules of football do not allow this, no matter how satisfying it would be to stick it to jackass sports radio yappers.

In quantum terms, what Belichick faced was a superposition of winning and losing states, like so:

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There's been an independent rediscovery of the notion of using dogs to explain physics, as you can see in this YouTube video of Golden Retrievers explaining the structure of atoms:

Emmy thinks she should get royalties, in the form of cheese. But then, she thinks that about everything...

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No, I'm not going to AGU this year. But if you are, AGU has activities for bloggers. From Maria-José Viñas, AGU's public affairs coordinator:

1) We have scheduled a free geobloggers' lunch for Wednesday, from 12:30 to 1:30 PM at the San Francisco Marriott, Pacific H Room. Right now, it's just a socializing event -- no panel discussion has been arranged.

Also, we might have a special guest speaker via videoconference, but we still have to confirm this event.

Please RSVP for this lunch to mjvinas@agu.org by Tues. Dec 1. Feel free to let other geobloggers know about this event, but make sure they also contact me by the deadline if they want to attend, since I have to keep track of the number of lunches needed.

2) We've set up a blog roll for the Fall Meeting (http://www.agu.org/meetings/fm09/newsmedia/blogroll.php)! If you are going to be blogging at the meeting, please sign up here: http://www.agu.org/meetings/fm09/newsmedia/blog_submission.php

I'll make the blogroll publicly available next week, when a few of you have signed up.

3) There will be "Geoblogger" stickers waiting for you at the Press Room (Room 3010, Moscone West Level 3), so that you can attach them to your badges to help you be recognized by fellow bloggers (or to start conversations with other scientists interested in blogging).

4) Unfortunately, this year we won't be able to offer you access to the Press Room, but we'll be glad to discuss at the lunch how AGU might accommodate your needs at future meetings.

5) For the first time, AGU will have an official blog for the Fall Meeting! We'll be using in-house science writers and perhaps some guest contributors, such as AGU officers. I will post the official blog on the blogroll once both are publicly available. Have fun in San Francisco. I'll be checking your blogs while avoiding grading my final exams.

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I thought I should consult you first before I went ahead with my plan to destroy the Moon. -Greg Angelone, via The Straight Dope Last week, scientists from LCROSS announced that they had detected "a buttload" of water on the Moon. Let's go over what happened and what it means.

The Moon is very different from Earth. It has no atmosphere (literally, less than one atom thick), day-and-night lasts for two weeks apiece, and the temperature extremes are horrifically severe. But one of the biggest differences? Whereas the Earth is tilted at 23.5 degrees as it goes around the Sun, the Moon is tilted by less than two degrees.

This is hugely important. On Earth, because of the 23.5 degree tilt, every place on Earth receives a significant amount of sunlight at some point during the year. But with a tilt that tiny on the Moon, the Sun never gets more than 1.54 degrees above the horizon as seen from either the North or South Pole of the Moon!

Or, in other words, if you dug a hole that was 100 meters deep and 100 meters wide, only the top 2.7 meters of your hole would ever get illuminated by the Sunlight, and the bottom 97.3 meters would be permanently shadowed. So if you ever put water in that hole, it should freeze and remain frozen for all eternity.

Well, we don't have holes that have been dug at the poles, but we do have "natural" holes. These appear as humongous craters, like so.

So, what did we do with LCROSS? We crashed it into one of these permanently shadowed craters, and looked at the debris plume that got shot up from the impact. If we find a huge amount of water, then we can infer that pretty much all of these permanently shadowed craters on the Moon are loaded with huge amounts of water, and will be for pretty much the next billion years.

So, the fact that we found "a buttload" of water? That means the Moon's craters at the North and South poles are loaded up with reservoirs of water, and all we have to do is go there and claim it. Hooray for exploration! Hooray for space! And hooray for the Moon!

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This Is A Cool Computer Program - Funny video clips are a click away

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Well, now that Lockwood got #13 on the first try, I will have to reach back into my vault to attempt to find a stumper ...

Current Standings:
Don Crain - 2
gijs - 2
volcanista - 1
Lockwood - 1
Elizabeth - 1
Ralph - 1
Anne - 1
Cam - 1
gg - 1
The Bobs - 1
Boris Behncke - 1

Good luck.

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Busy week leading up to Thanksgiving for me, with a talk to give later in the week and quizzes a plenty!

The Mystery Volcano Photo series has a couple clear frontrunners now, with both Don Crain and Gijs with multiple points.

Current Standings:
Don Crain - 2
gijs - 2
volcanista - 1
Elizabeth - 1
Ralph - 1
Anne - 1
Cam - 1
gg - 1
The Bobs - 1
Boris Behncke - 1

Here's #13 ... good luck!

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NASA's planet hunter mission ought to be announcing something at the American Astronomical Society in january, 2010.
But what?

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