ScienceBlogs Channel : Physical Science

Some Matter is Strange, but that's okay [Starts With A Bang]

Ethan Siegel none@example.com — Fri, 29 Oct 2010 16:46:33 -0500

"People fear death even more than pain. It's strange that they fear death. Life hurts a lot more than death. At the point of death, the pain is over. Yeah, I guess it is a friend." -Jim Morrison

Yes, Jim Morrison, some people are quite strange, too.

People Are Strange

But that's not what I'm talking about. You see, one of the "doomsday" scenarios people are talking about over at the Large Hadron Collider (LHC) -- in addition to black holes -- are out-of-control strangelets.

Let's talk about what these things are, what people are afraid of, and whether there really is anything worth fearing.

Over at the LHC, they take ultra-high-energy protons and collide them into other ultra-high-energy protons, moving almost (but not quite) at the speed of light. These collisions, when they take place, produce a huge shower of particles -- some stable, some unstable -- and that's why we have the giant detectors that we do!

After all, we are trying to make some new, undiscovered-as-of-yet states of matter, such as the Higgs Boson. We've already discovered all of the quarks (up, down, strange, charm, bottom, and top), but we haven't discovered all of the possible combinations of them. Yet.

Here's something you might not know, though. The LHC, by smashing protons into protons, won't be able to make some of these states!

For some of them, you need many, many more protons than simply one-at-a-time. So we can smash heavy ions together, such as gold or lead nuclei, instead of protons! One accelerator, RHIC, has already been studying this.

And this is great for physics! Not only are we studying high energies, we're also studying high densities at the same time; conditions that aren't around anywhere except at the centers of extreme stars and when the Universe is less than one second old!

Normal matter -- protons and neutrons -- are made up only of up and down quarks. These are the lightest and most stable quarks, but particle accelerators allow us to replace one, two or even all three of these with a strange quark. And when we do this, we get a new, short-lived (a fraction of a microsecond) particle!

But instead of just making a single one (or simply a few) of these particles, if we do something like collide gold into gold, we have around four hundred of these nucleons in one place, and they can form -- instead of Lithium, Beryllium, Boron, Carbon, etc. -- strange versions of them!

In other words, nuclei with a strange quark replacing one of the up or down quarks! Well, one of the new states of matter they hope to create at the LHC, by colliding heavy nuclei at these ultra-high speeds, is a miasma of up, down, and strange quarks, known as a strangelet.

And just like carbon-12 is more stable than three helium-4s, and just like a helium-4 is more stable than a single proton, there's hope that these bound, heavy, strange-quark-carrying particles will live longer than a single, highly unstable one.

This would be neat; we could create them, study them, and perhaps discover a new state of matter that might have been present when the Universe was just a microsecond old, or that might be present today at the core of collapsed stars, like neutron stars!

But that doesn't stop people convinced that the LHC will destroy the world from crying out that maybe "death by strangelet" is what's going to be in our future.

How do they state it could happen?

That if heavier, strange elements are more stable than light ones, it could grow out of control, eating more and more matter until the entire Earth becomes one giant strangelet.

And what I offer to you, in opposition to this point of view, is a little education about how nuclear physics actually works. Yes, heavier elements are more stable; that's why you can fuse lighter elements into heavier ones (like our Sun does) and still release energy.

But you can also split very heavy elements into lighter ones, releasing energy, and that's what nuclear fission is!

In other words, you can only get up to a certain point before you get less stable! For things made up of up and down quarks only, the most stable element is Iron, element 26, with 30 neutrons and 26 protons. Anything with more neutrons or protons in there is less stable!

And guess what? Strange quarks -- or nuclei with strange quarks in them -- are always less stable than ones with only up or down quarks! In other words, things with strange quarks in them will always decay, in a tiny fraction of a second, into something with just up and down quarks.

We see this all the time, and it's the same for charm and bottom quarks too, as this sample decay shows.

So you can either be afraid of strangelets eating the world and destroying it, or you can learn how nuclear physics actually works, and realize that a super-heavy mass of up, down, and strange quarks will be unstable, and decay into things -- like normal elements -- that are stable.

This is great stuff to study, and to discover, and to learn how it works. But to fear it? Save that for my Halloween costume, coming to you this weekend! (Here's last year's, for those who can't wait.) Happy Halloween! Read the comments on this post...

Study Links Fresh Mars Gullies to Carbon Dioxide [Greg Laden's Blog]

Greg Laden none@example.com — Fri, 29 Oct 2010 16:39:28 -0500

View image

The gullies on a Martian sand dune in this trio of images from NASA's Mars Reconnaissance Orbiter deceptively resemble features on Earth that are carved by streams of water. However, these gullies likely owe their existence to entirely different geological processes apparently related to the winter buildup of carbon-dioxide frost.
Scientists at the University of Arizona, Tucson, and at Johns Hopkins University Applied Physics Laboratory, Laurel, Md., compared pairs of images from before and after changes in such dune gullies. They determined that the changes occur in Martian winter, during periods of carbon-dioxide frost, rather than during warmer seasons when frozen water, if present, might somehow melt and flow.

Each of the three images here shows an area about 1.2 kilometers (three-fourths of a mile) across. The dunes lie inside Matara Crater, at 49.4 degrees south latitude, 34.7 degrees east longitude. The images are portions of observations by the High Resolution Imaging Science Experiment (HiRISE) camera on the Mars Reconnaissance Orbiter. HiRISE took the top one on March 14, 2008, which was mid-autumn in Mars' southern hemisphere, the middle one on July 9, 2009, in the first half of the next southern-Mars summer, and the bottom one on October 4, 2010, in the late part of the following (and most recent) winter season.

Illumination is from the upper left. Gullies run leftward downhill from a dune crest in the upper right corner.

Arrows indicate places where changes appeared between observations. Each year, the alcoves at the dune's crest and the channel beds widened during the Martian winter as material moved down slope and lengthened the apron at the bottom. Very new deposits (formed sometime in September 2010) are visible in the bottom image as the darker material extending from the channels and obscuring the pre-existing ripples on the dune's surface. Additionally, on the upper gully, material first filled-in part of the channel (between 2008 and 2009) and then re-incised the channel into the apron (between 2009 and 2010).

The rest of the story is here.

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Stormier Arctic Seas Affects Sea Ice (which was melting anyway, but still...) [Greg Laden's Blog]

Greg Laden none@example.com — Fri, 29 Oct 2010 11:26:47 -0500

Interesting to look back at this now that the Arctic Ice Cap is opening up and disappearing:

A new NASA study shows that the rising frequency and intensity of arctic storms over the last half century, attributed to progressively warmer waters, directly provoked acceleration of the rate of arctic sea ice drift, long considered by scientists as a bellwether of climate change.
NASA researcher Sirpa Hakkinen of Goddard Space Flight Center in Greenbelt, Md., and colleagues from Woods Hole Oceanographic Institution, Woods Hole, Mass., and the Arctic and Antarctic Research Institute, St. Petersburg, Russia, set out to confirm a long-standing theory derived from model results that a warming climate would cause an increase in storminess. Their observational approach enabled them to not only link climate to storminess, but to also connect increasing trends in arctic storminess and the movement of arctic ice -- the frozen ocean water that floats on the Arctic's surface. Results from their study as well as what they could mean for future climate change appeared this month in the American Geophysical Union's Geophysical Research Letters.

"Gradually warming waters have driven storm tracks -- the ocean paths in the Atlantic and Pacific along which most cyclones travel -- northward. We speculate that sea ice serves as the 'middleman' in a scenario where increased storm activity yields increased stirring winds that will speed up the Arctic's transition into a body of turbulently mixing warm and cool layers with greater potential for deep convection that will alter climate further," said Hakkinen. "What I find truly intriguing about confirming the link between the rise in storminess and increased sea ice drift is the possibility that new sinks for carbon dioxide may emerge from this relationship that could function as negative feedback for global warming."

Hakkinen and colleagues analyzed 56 years of storm track data from earlier studies and annual data on atmospheric wind stress, an established indicator of storm activity, that is generated by the National Center for Atmospheric Research in Boulder, Colo. The data confirmed an accelerating trend in storm activity in the Arctic from 1950 to 2006. Acknowledging ice as a harbinger of climate change, they next analyzed ice drift data collected during the same 56-year period from drifting stations and after 1979 from drifting buoys positioned around the Arctic that measured surface air temperature and sea level pressure.

Read the rest here.

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Increased storminess with global warming may follow different patterns in N v S hemispheres [Greg Laden's Blog]

Greg Laden none@example.com — Thu, 28 Oct 2010 22:22:51 -0500

Weather systems in the Southern and Northern hemispheres will respond differently to global warming ... the warming of the planet will affect the availability of energy to fuel extratropical storms, or large-scale weather systems that occur at Earth's middle latitudes. The resulting changes will depend on the hemisphere and season, the study found.
More intense storms will occur in the Southern Hemisphere throughout the year, whereas in the Northern Hemisphere, the change in storminess will depend on the season -- with more intense storms occurring in the winter and weaker storms in the summer. The responses are different because even though the atmosphere will get warmer and more humid due to global warming, not all of the increased energy of the atmosphere will be available to power extratropical storms. It turns out that the changes in available energy depend on the hemisphere and season, according to the study, published in the Proceedings of the National Academy of Sciences.

source

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Spirit Finds Water, Still Stuck [Greg Laden's Blog]

Greg Laden none@example.com — Thu, 28 Oct 2010 14:21:32 -0500

The Mars Rover Spirit got stuck, probably forever, last year, but the little guy has not given up doing science!!!!

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How to Teach Quantum Physics to Your Dog in the Times [Uncertain Principles]

Chad Orzel none@example.com — Thu, 28 Oct 2010 11:28:30 -0500

The Times Higher Education magazine in the UK, that is. They ran a review of my book a couple of weeks ago, which I've only just noticed:

The approach is quite entertaining. The tone of the book is chatty and contains some truly awful puns involving dogs, which, if you can stand them, make it an attractive and lively read. However, don't be fooled - Emmy is no ordinary dog. She can reason with the informed leaps one may expect from a physics undergraduate, despite peppering her conversation with "squirrel", "bunny" and "chase".

If you're in the UK, the edition the review refers to is on sale now, and apparently selling well in W.H. Smith's stores all over, and via the usual Internet sources. If you're in the US, the title is one word shorter, and has also gotten a recent nice review. It's available in hardcover right now, and the paperback version will be out in just over a month (Amazon says December 7th). It makes an excellent holiday gift for whatever holiday may be coming up that you celebrate...

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The Calculus Diaries by Jennifer Ouellette [Uncertain Principles]

Chad Orzel none@example.com — Thu, 28 Oct 2010 10:10:17 -0500

I finished Jennifer Ouellette's new book a few weeks ago, shortly after my trip to Alabama, but it's taken me a long time to get around to reviewing it due to a combination of too much work and being a Bad Person. There's finally a tiny break in the storm of work, though, so here's a slightly belated review.

The Calculus Diaries is not a book that will teach you how to do math. There aren't worked examples, detailed derivations, or homework problems in the main text. It might, however, teach you not to fear math, as it provides a witty and accessible explanation of the key concepts behind calculus, and how those ideas show up in everyday life.

For all its fearsome reputation, calculus is really very simple in concept: it's a mathematical toolbox for dealing with change. Differential calculus (derivatives) is the study of individual small changes-- how mathematical functions change when you change their inputs-- and integral calculus is the study of the cumulative effect of lots of little changes. Those core concepts can get lost in a haze of calculation when you first encounter the subject in school, but in the end, everything flows from those two ideas.

In this book, Ouellette spells those concepts out very clearly, and explains how they apply to a wide range of real-life situations: amusement park rides, games of chance, population biology. OK, that's "real-life" for values of real life that include zombie apocalypses, but the point is, there are lots of engaging examples drawn from everyday experience and pop culture. Each example in the book includes a clear explanation of how it can be understood in terms of individual changes or cumulative effects, setting out the essential relationships in words, not equations, and explaining the important properties of the solution. As a bonus, it also includes some of the many colorful historical anecdotes about the development of key ideas in mathematics.

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Sunspots Redux [Dynamics of Cats]

Thu, 28 Oct 2010 09:32:37 -0500

Same old thing as yesterday...

Seriously, wtf is going on with the Sun?

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The first photograph of human beings ever [Greg Laden's Blog]

Greg Laden none@example.com — Thu, 28 Oct 2010 08:38:21 -0500

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Stormy World [Greg Laden's Blog]

Greg Laden none@example.com — Thu, 28 Oct 2010 08:12:57 -0500

It turns out that the "land hurricane" (technically, a super storm, aka extra tropical cyclone or bomb cyclone) may have been the biggest (most energetic) storm hisorically recorded for the region. Of particular interest is the pressure record (the ultimate measure for a storm) but also, the number of tornadoes and the damage due to winds was also impressive. And, there are interesting tropical things going on in the Atlantic Ocean.

Is this all caused by Global Warming? Yes, probably. Gone are the days when the knee-jerk reaction must be "well, no, no one storm can be attributed to bla bla bla." Instead, we increasingly recognize that the energy balance sheet has shifted (are my metaphors mixing?) and we live in a stormier world now than we did 100 years ago, because of the release of carbon trapped in antiquity into the atmosphere.

Global warming is like your checking account. Your paycheck is automatically deposited every two weeks (that's energy from the sun) and varies only a little from time to time. Several bills are paid every month, and thus the money dissipates from your account like the sun's heat returning to outer space. But then, imagine that the people who bill you delay billing a couple of days each month, until they are a full month out of sync. The same amount of money is going in, the same amount of money is going out, but the money stays in your checking account longer. In this way, instead of the average amount of money in your account hovering around zero (I hope you have overdraft protection!), it hovers around a higher value.

Greenhouse gases retain the energy from the sun longer than usual in the atmosphere. Weather is all about the transfer of the sun's energy, unevenly (at several scales) distributed on delivery, evening out. A hurricane is a blip in the rush of tropical energy (where there is extra) towards the poles (where there is less), for instance.

A certain amount of this energy simply goes away (returns to space) and plays no further part in the weather, but when that energy is retained longer due to greenhouse gasses, the entire system is more energetic.

So this week, Anthropocentric Global Warming gives you the most intense continental storm ever in North America, and three tropical cyclones trying to get borned in the Atlantic ...

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How Big is the Unobservable Universe? [Starts With A Bang]

Ethan Siegel none@example.com — Wed, 27 Oct 2010 20:40:11 -0500

"Really, the fundamental, ultimate mystery -- the only thing you need to know to understand the deepest metaphysical secrets -- is this: that for every outside there is an inside and for every inside there is an outside, and although they are different, they go together." -Alan Watts

We've talked, recently, about the scale of the Universe, and trust me, it's huge.

Filled with hundreds of billions of giant, Milky Way-sized galaxies,

each of which contains nearly a trillion stars,

the whole thing is really, really big. And, after nearly 14 billion years of expansion since the big bang, the part of the Universe we can see -- the observable Universe -- is 93 billion light years across!

But there's more Universe outside of what we see. Based on our best theories of how our Universe got here -- the theory of inflation -- we might be inclined to ask just how big the entire thing is!

After all, inflation takes some initial region of space, and regardless of its initial shape, size, or conditions, stretches it, and causes it to expand at an exponential rate!

This takes any initial Universe and makes it huge! Not just billions of times larger than it was initially, but googols upon googols of times larger! It stretches it flat, it makes it uniform, and even sows the seeds of what will someday grow into the stars and galaxies that fill our Universe today!

Well, let's think about what inflation does. This super-rapid, exponential expansion causes the spacetime of the Universe to stretch flat, but also to expand to a much larger volume than it previously occupied.

(Image credit: Ned Wright's cosmology tutorial.)

That's what inflation is. But how does inflation happen? To the best of our (admittedly limited, and highly theoretical) knowledge, the Universe inflates when it's full of what we call vacuum energy.

But being full of vacuum energy is unstable, and the when the Universe slips down into a more stable state (like sliding down this hill in the picture above), that energy gets transformed into matter, antimatter and radiation, and gives us the hot big bang, and our modern Universe.

But there's something else we need to think about here. The Universe, at a fundamental level, does all the weird things that quantum mechanics lets it do. And one of the most bizarre things about quantum mechanics is that if you take something like, say, an electron, and you put it somewhere (like in an orbit, below), when you look again at a later time, it isn't going to be in the same place!

In physics language, we say that the quantum state spreads out over time! Now, here's where it gets really bizarre. We're going to put all three of these things together.

The Universe is inflating, or expanding exponentially. This means we're making "new space" at an ever-increasing rate. After one unit of time (t), we have one unit of space (V). After 2t, we have 4V. After 3t, we have 16V, and after 4t, we have 256V. In other words, we are making lots and lots of new space very quickly, at an ever increasing rate.
The average vacuum energy is decreasing as we "slide down the hill."
But, the actual vacuum energy in any volume of space, V, has to deal with the fact that the wave-packet is spreading out!

So we've got a race happening: the average energy is trying to slide down the hill, but in some of these areas of space, the spreading of this wave-packet pushes us up the hill instead of down it!

When we put all three of these things together, what we get is the concept known as eternal inflation. The big idea is that what we call "our Universe" is just one place -- which we can only see a part of -- where we've successfully slid down the hill. But the vast majority of the "true" Universe, outside of our little pocket, is still inflating, and still expanding exponentially!

Based on what we currently think about inflation, this means that the Universe is at least 10^(10³⁰) times the size of our observable Universe! And good luck living long enough to even write that number down. Thanks to Rob Knop for making me think about this, and isn't that a mind-blowing thing to think about? All that we know, see, and observe is just one tiny region that slid down that hill fast enough to end inflation, but most of it just keeps on inflating forever and ever. Aren't we the lucky ones?! Read the comments on this post...

The Time for Mars is Now [Life at the SETI Institute]

SETI Institute none@example.com — Wed, 27 Oct 2010 19:37:40 -0500

By Dr. Adrian Brown
Planetary physicist at the Carl Sagan Center for the Study of Life in the Universe, SETI Institute, and Gail Jacobs

When most people look at photos of the Martian landscape, they see the kind of dry topography that, while attractive, shows only that at first glance Mars resembles many of the desert areas of Earth. By analyzing spectroscopic data gathered by the Mars Reconnaissance Orbiter, however, SETI Institute planetary scientist Dr. Adrian Brown sees clues to where liquid water might once have puddled and pooled on the Red Planet, and possibly spawned life. Adrian is interested in finding subtle hints that large bodies of water might once have flooded the northern regions of this now-dry world, hints that the Orbiter's infrared spectrometer could provide. In addition to his search for water, Adrian hunts for clues to volcanic activity in these same northern realms, because the energy provided by such eruptions could fuel microscopic life.

Adrian, pertaining to your scientific work, what motivates you?
I'm motivated by the fact that when it comes to Mars, there are always new challenges to tackle and solve every day. It's exciting knowing that each day may bring a new piece of the jigsaw puzzle. It's as if I have 50 pieces of the puzzle but there are 1,000 pieces out there, and they're not all in the same box. If I can find another 100, I can figure out this little corner of the puzzle. It's exciting to read the latest Mars Orbiter findings or to search for the most important books or papers to read and work out how to do it in an efficient way that will take me one step closer to finding another relevant piece of the puzzle.

I might come across some information that doesn't even seem like a piece of the puzzle. Then it will dawn on me that the puzzle parts can interrelate with another piece that I hadn't considered, and that's very cool. I'm continually learning about new physics, mathematics, and computer programs, and different ways to put them together to try and answer a scientific question that I thought of some time previously. I'm always motivated by finding new pieces of the jigsaw puzzle and then watching the overall picture grow over time.

Give us an overview of your research projects.
Most of my research revolves around Mars. One area I focus on is the polar regions of Mars. In spite of their extreme cold, most of the action on Mars occurs in those bitterly cold regions today. Ice is continually condensing and subliming throughout the year, so there are a lot of dynamic processes that cause Mars' atmosphere to inflate and deflate like a little ball. It's as if we can see it breathing every seasonal period. It gets so cold on Mars that the carbon dioxide in the atmosphere actually freezes out onto the surface. It would be like the nitrogen freezing out in our atmosphere. Can you imagine what sort of havoc that would create here on Earth? That's one reason I'm interested in studying these dynamics, which are actually quite different at the Martian North and South Poles.

Artist's concept of the Mars Reconnaissance Orbiter on the Martian landscape.
-- Image courtesy of NASA/JPL

I'm also very interested in the most ancient rocks on Mars. This area of research allows me to learn more about the many stages of development Mars has gone through. We can locate these rocks by using imaging, or infrared, spectroscopy to detect minerals on the surface. I use an instrument called the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on the Mars Reconnaissance Orbiter that looks at the way light from the sun is reflected off rocks on the surface and bounces back to the satellite. We look for areas where light is absorbed in the electromagnetic spectrum. By looking for particular telltale absorptions, we can tell what minerals are on the surface. Using this technique, we can identify clays on the surface of Mars, which usually occur in the most ancient areas of the planet.

I've recently been interested in a place called Nili Fossae -- a region where we find carbonate minerals in the rocks. Carbonate is fairly common on Earth but is very rare on Mars. In these most ancient parts of Mars, we have found that running liquid water altered the original mineral structures in some of the basaltic, olivine-bearing rocks into carbonate-bearing rocks. We know this because once the rocks have changed into carbonate, their structure doesn't change again. This allows us to identify where olivine has changed into carbonate, and that's an indication of the action of heat and water in Mars' past. And very excitingly, that same heat and water might not just have altered minerals -- in the very early stages of Mars' development, they may have also provided energy for life on Mars. -- Image courtesy of NASA/JPL-Caltech/Univ. of Arizona

What is the coolest thing about your research?
I'm driven by the fact that Mars is tangible. Since 1997, we've had at least one satellite orbiting Mars continuously. There is a deluge of information coming back from the planet. We're getting new pictures of unprecedented accuracy. We're learning incredible new things about Mars all the time. For example, at the moment there is a lot of excitement because there might be methane in Mars' atmosphere. That hasn't actually been proven to my satisfaction, but it is an exciting and tantalizing possibility that could prove to be a potential link to life and geological activity on Mars today. While our ignorance with regards to Mars is still overwhelming, it's so exciting to research a subject with such a wealth of new information.

The time for Mars is now! Mars exploration can be likened to the old Wild West of today. We're the early settlers, wondering what is beyond the next mountain range. We've crossed the Appalachians and are heading into the plains of the expansive Midwest. We're in our infancy of understanding Mars, and that's pretty cool -- there are so many surprises waiting for us to uncover!

As with the early pioneers heading West across America, do you envision humans settling on Mars?
As humans, we're going to go to Mars -- that is if we don't destroy ourselves beforehand. We're finding out as much as we can about our nearest habitable neighbor in order to lay the groundwork for the eventual colonization of Mars. There is nothing scientifically stopping us. Lots of challenges remain and not everyone may live on Mars, but one possible scenario is that Mars could turn into a region like the sparsely populated Antarctica. It's not very comfortable there, but they have some interesting activities and research you can't do anywhere else.

In the far-distant future, anywhere from 200 to 1,000 years from today, Mars could be much more Earth-like than today. With the intervention of humankind, Mars could be turned into another Earth, or at least similar enough to Earth that we could breathe the atmosphere and live pretty much as we do today on Earth. That's certainly physically possible. So Mars holds a lot of promise for humanity. If our bodies remain in their present form, Mars is the best place for humans to create a new Earth -- and hopefully we will act with more awareness of our actions than we do now.

Would you like to walk on the Martian landscape if you had the opportunity?
Absolutely! I think humans can play a role in the exploration of Mars. Some people say robots can do it all for us. I don't think our Rovers are going to provide us with all the answers unless we get extremely lucky and land in an area that is or was burdened with biology. That hasn't happened as of today and it may not happen within the next 15 years.

Martian landscape -- Image courtesy of NASA/JPL

This 15-year period will provide the private company SpaceX with enough time to develop their rockets for human travel. Elon Musk, CEO of SpaceX, would like to send humans to Mars. If they continue on their successful trajectory, humans could be exploring Mars within 15-20 years on the SpaceX rockets. We'll see -- a lot of things have to go right for that to happen, but the strong possibility exists that we'll see private commercial flights to Mars within our lifetimes.

As a scientist, does it worry you that Mars could become a vacation destination before scientists have the opportunity to land on Mars and fully explore the planet for evidence of life?
The scientists of our generation, and particularly the next two generations, have a window of time when they will have to answer the question of life on Mars before humankind arrives in strength. Within that period, I don't think we can change our ways and develop an ability to live side-by-side with a possibly extant Martian biosphere. I also don't think Mars will be saved for science. Humankind will likely want to utilize Mars as a second Earth. It's important for scientists of this generation to push for the answer of whether Mars has -- or had -- a biosphere. Once we're armed with that information, or at least we've tried as much as possible to find life on Mars using robotics, then perhaps the colonization of the Red Planet will begin. This is going to be a very interesting period and I hope to stay involved in it. It's a fascinating stage in our development as a species.

Is there one fact about your research that surprises most people?
I am surprised by new findings all the time! The possibility of sending humans to Mars and then terraforming Mars, or changing it so it becomes more like Earth, is something that may not cross a lot of people's minds. Also, some people are surprised that the Polar Regions are so active. There are geysers that shoot up to 20 meters and create big dust fields around them on the ice. It's a very cool environment. Of course, you wouldn't want to step on the surface because your boots would probably stick to the ice. Our Phoenix lander was crushed by the CO2 ice; so if we can't get a robot to operate there, we are going to have a lot of challenges. The polar regions of Mars will long be an exploration frontier for humans. Image at left: Mars' north polar ice cap, Olympus Mons and three accompanying volcanoes, clouds over those volcanoes and the west edge of Valles Marineris -- Image courtesy of NASA/MSSS

What do you currently consider your biggest challenge?
Funding my research would definitely be my biggest challenge at the moment. The scientific career I have is very liberating because I get to run my own projects and be my own boss. The ability to make up the projects I want to work on is exceptionally cool and it's what I'm so excited about. You're not pursuing anybody else's dreams; you get to invent the dreams that you will pursue. But it does come at a price, which is having to convince others to give you that funding in order to realize your dreams. The U.S. government supports research through NASA but that funding program is extremely competitive and scientists have to write 6-10 proposals in order to get just one funded.

Why should the general public care about your research?
As Mars becomes more important in the coming decades, I think the general public's interest will increase. We're about to see Virgin Galactic launch humans into space. There was a recent successful drop test of Virgin Galactic's spacecraft, and we're going to see a lot of activity in space over the next decade that will capture the public's attention much more. Costs may be prohibitive at first and wealthy people will be the ones to go into space. But prices will eventually come down, and regular people like you and me will be able to afford a pretty amazing getaway in space. The public will gradually expect to travel beyond the edge of space. They'll want to go to a space station, around or to the Moon, or destinations beyond. Over time, the capabilities of these commercial companies will increase. That will be tricky to do, but I don't think Richard Branson will stop at the edge of space as his current spacecraft do. Branson or those who follow him will want to travel beyond that, and they'll have the public watching and eagerly waiting.

Adrian Brown conducting research in Australia

People have inquisitive minds and have always been interested in planetary science and the nature of the universe. This curiosity can lead to a strong interest in subjects such as Mars and what's really going on around us in the universe. We're learning more about our solar system and beyond all the time. Astronauts will soon be visiting near-Earth asteroids and a next generation of spacecraft will hopefully be replacing the retiring shuttle in the next decade. For those who have an interest in the universe, these quests for knowledge and discovery will always be an important part of their lives.

In addition to your research projects, you organize the SETI Institute's Colloquium Series, which is taped and available to the public. Tell us about the program and its importance to you and the broader community.
I'm of the opinion there is not enough news or news sources about space and space science at the moment. We might catch a news-byte on the radio or TV about a new near-Earth asteroid that was discovered streaking toward us and missed us by two seconds. But usually that's it and you can't hear any more. If I was a member of the non-scientific general public, I'd love to see a "click here for more information" button on my radio or TV so I could learn more. That was one main motivator in creating the SETI Institute Talk series. And our viewers are showing there is a strong public interest in the content of these Talks. We have a growing audience that attends the Talks at our building in Mountain View, California. Even more so, we have a growing audience online. I encourage people to tell their friends to check out the Talks on YouTube. They're there to stay and people can watch them on their television or computer at their convenience.

I'm also seeing that YouTube is taking over as the new TV. If you buy an Apple TV, for example, a dropdown menu will take you to YouTube where you can watch our talks for free. Viewers will see very engaging videos that give them a high-quality presentation on fascinating topics by experts in their fields, and our production efforts are getting better all the time.

For whom are these talks intended?
Viewers do not need to have a strong scientific background in order to enjoy the talks. I always learn something new at every talk, which is really cool. We intend to deliver content just a bit above the Discovery channel level. The Discovery or History channels occasionally have some good programming but once you've seen it, you may have to wait another year for their next good program. Our format offers something new on a weekly basis. While you might not find each instant of every talk amazing, I think you'll be amazed at least once in every one of these talks.

The next time you're relaxing at home and find that the latest episode of your favorite TV show is a rerun, I hope you'll check out our growing list of Talks archived on a vast variety of subjects. I'm sure you'll find something of interest that's engaging, entertaining, and you just might hear something new that will amaze you.

If you could take a 6-12 month sabbatical, what would you like to learn or do?
In a typical job, you're working for somebody else and you're working on their goals. I think of a sabbatical as something you take when you need a break from your job in order to do what you really want to be working on. That is really different from my job. I don't have a need for a sabbatical. I'm working on exactly what I want to. I think I have the most fun job in the world!

Learn more about Adrian and his fascinating research in his full interview.

Watch a video of Dr. Adrian Brown giving a one-minute summary of his work. This one-minute excerpt comes from a special colloquium celebrating the 25th anniversary of the SETI Institute.

Read Adrian's "Future Direction of Martian Exploration" blog.

Learn more about Adrian by visiting his web page.

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High mass neutron star [Dynamics of Cats]

Wed, 27 Oct 2010 13:43:14 -0500

There is a beautiful pulsar paper coming out in Nature tomorrow, 28th of October issue (Demorest et al 467, 1081, 2010)

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Conceptual Physics Costumes for Halloween [Uncertain Principles]

Chad Orzel none@example.com — Wed, 27 Oct 2010 12:23:36 -0500

It's late October, which means that the thoughts of small children and adults who have never quite grown up turn to selecting appropriate costumes for Halloween. In the spirit of these literary suggestions and these abstract concept suggestions, I thought it would be useful to offer some suggestions for physics-themed costumes, for those who want to dress as something from the greatest science.

Of course, there are some really obvious choices for physics-themed costumes (Einstein: rumpled clothes, white hair, distracted manner, German accent; Feynman: black pants, white shirt, brushed-back hair, bongo drums. Both of these are accentuated by shamelessly hitting on every woman at the party.), but here are a few ideas for costumes that might not be so obvious, to add a physics flavor to your Halloween party:

The Heisenberg Uncertainty Principle: As soon as you arrive, hide in a secluded place and remain perfectly still. If anybody sees you, run really fast in a random direction.

The Pauli Exclusion Principle (Requires two people): Dress in identical outfits, and refuse to be in the same room with one another. If circumstances force you to be close together, one of you must stand on your head.

Schrödinger's Cat: Wear an ordinary cat costume, but when you get to the party, go hide in a closet. When somebody opens the door to check on you, flip a coin, and if it comes up heads, pretend to be dead.

The Higgs Boson: Stand in a narrow hallway, and impede the motion of anybody who tries to get past you.

Isaac Newton, Alchemist: Wear a long silver wig, and babble to people about the transmutation of elements and the nature of God. For the Method-actor version of this, drink a bunch of mercury a week before the party, and then just be yourself.

P. A. M. Dirac: Dark suit, thin mustache. Don't say anything.

Suggestions are welcome in the comments.

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Atlantic Storminess and Minnesota Weather Woes [Greg Laden's Blog]

Greg Laden none@example.com — Wed, 27 Oct 2010 09:50:07 -0500

I think we are having a land hurricane here in Minnesota. The tree in front of my daughter's other house (her mom's place) that was topped by a tornado the week after we bought it has lost a big dead branch, a bunch of firs at the junction of 10 and 35W are down, a colleague of my wife lost a fence, traffic lights have been knocked out on University in Blaine, Monica lost power in the cities last night, all sorts of things like that happening as we experience a steady drum of 35 mph winds with gusts reaching 80 now and then, but more commonly, about 55 mph.

The precip is horizontal, but it is moving so fast it is hard to tell if it is rain or snow, and truthfully, it seems to be both. But I've seen no accumulation here. Just the occasional car dusted with slush, obviously come from a different micro-climate.

But then there was this: Driving south on 35W, I spotted what I thought was a chunk of slush snowy icy stuff like that which accumulates under a car behind a wheel, about soft-ball size. That would require snow on the ground, and I don't think there is any in short driving distance. So I convinced myself that it was a Styrofoam cup and not a chunk of snow. Never mind that Styrofoam cups are no longer used and you no longer see them along the highway, at least around these parts.

Then, three miles down the road we saw it. The same exact thing ... slush icy snow-stuff like would fall off the bottom of a car, but larger. About as big as a medium-size dog, a bit bigger than a bushel basket, roughly the dimensions of an old CRT TV. In the middle of the road, people driving around it. If it was blue, I would have figured it to be something that dropped out of an airplane. I have no idea how to explain this.

Meanwhile, in the tropical regions of the Atlantic Ocean, we have this:

No really well organized storms, but two blobs that look like pre-tropical storm features. Each one is tagged by the Hurricane Prediction Center as having a mere 10% chance of forming into a storm over then next 48 hours, but there is a reasonable chance that either or both will eventually do so.

Shary and Tomas. Those are the next two names on the list. So now, we have the question: Which of the two blobs will turn into a storm and get named first, the westerly one or the easterly one, and will either one or the other, both or neither even do so?

I'm guessing they both will be named storms, the westerly forming first.

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Academic Poll: Exam Philosophy [Uncertain Principles]

Chad Orzel none@example.com — Wed, 27 Oct 2010 09:46:38 -0500

I'm spending a good chunk of the morning grading the exam that I gave yesterday, so here's a poll on what you might call exam philosophy. Our classes are small, so the bulk of our exams are free-response problems, and we tend to break those problems into sub-parts (1a, 1b, 1c, etc.). There are two approaches to writing these questions that I have seen: one is to use the sub-parts to break a single problem into steps, thus leading students through the question; the other is to write questions where the sub-parts are independent, so that a student who has no clue how to answer part a can still go on to parts b-f without needing the answer from a.

There are reasonable arguments for each of these, so I'm interested to hear what other people think:

The exam in question is about classical E&M, so you can only choose one answer, not a superposition of multiple answers.

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Another week of GW News, October 24, 2010 [A Few Things Ill Considered]

coby none@example.com — Mon, 25 Oct 2010 07:22:02 -0800

Logging the Onset of The Bottleneck Years

This weekly posting is brought to you courtesy of H. E. Taylor. Happy reading, I hope you enjoy this week's Global Warming news roundup

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How to Teach Physics to Your Dog Around the World [Uncertain Principles]

Chad Orzel none@example.com — Sun, 24 Oct 2010 09:31:29 -0500

Between my long-ago high-school French and Google Translate, I can tell that this is a good review of How to Teach Physics to Your Dog. It does note, though, that reading the book requires knowledge of English to understand it, which is a problem. And, as far as I know, French translation rights haven't been sold yet... French publishers, je vous regarde.

In other foreign-edition news, we've sold German and Turkish rights, so there will be editions in those languages eventually. Emmy was very happy to hear that the book will be published in Turkey, though that was mostly a case of preposition confusion. She originally thought that it was going to be published on turkey, and she's always wanted an edible edition.

Regarding editions that are out, word from the UK is that the UK edition is selling very nicely. The vanity search keeps turning it up in a sidebar widget listing top sellers in the Guardian Bookshop, which is a kick. British leftists love talking dogs and physics.

Progress on the next book is not exactly linear. Chapter 4 turned out to be a little too dense, and has spawned off a new Chapter 6, while Chapter 5 currently consists of only dog dialogue. I know how it's all going to fit together in the end, but finding the time to fit it together is a little difficult.

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Science Is Solitary? [Uncertain Principles]

Chad Orzel none@example.com — Sat, 23 Oct 2010 15:49:10 -0500

Some time back, I took issue with an article about "masculine" and "feminine" approaches to science that struck me as a little off. The author of the original post, Alexandra Jellicoe, has a new post on the same topic that she pointed out in comments to my original post.

I have two major problems with this article. One of them is a problem I have with the whole genre (as it were), and I'll save that for another time, because it will be difficult to write. The bigger and more immediate problem that I have, though, is that I don't recognize Jellicoe's description of science. She writes:

The whole structure of science is biased towards this more masculine approach to problem solving. You have a professor looking for the truth in his chosen scientific subject and he commands his researchers to solitarily go out, find the answers and report back. As many people may be looking for the same truth, it fosters a culture of secrecy and competitiveness. Your work is only revealed when you have gone through the painful peer review process of publishing in a journal and beaten your competitors to the punch.

It's kind of hard to imagine anything more foreign to my experience of science. There was never any point, from my undergrad days on up through my post-doc, when I felt that physics was a solitary endeavor.

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Weekend Diversion: VOTE FOR ME! [Starts With A Bang]

Ethan Siegel none@example.com — Sat, 23 Oct 2010 12:08:16 -0500

"In science, 'fact' can only mean 'confirmed to such a degree that it would be perverse to withhold provisional assent.' I suppose that apples might start to rise tomorrow, but the possibility does not merit equal time in physics classrooms." -Stephen Jay Gould

It's been almost three years since I started science writing, and almost two years since I moved over here, to ScienceBlogs. And together, you and I have been through over five hundred posts, nearly ten thousand comments, and more than two million pageviews. No one can take that away from us, just like Billie Holiday sings:

They Can't Take That Away From Me

Well, folks, we may finally have hit the big time!

Starts With A Bang has been nominated and shortlisted for the best Physics blog in the whole world!

Physics.org is giving out their web awards for 2010, and you can vote for your favorites! The other nominees are also great: Bad Astronomy, Physics Buzz, Cosmic Variance, and former ScienceBlog Dot Physics.

Somehow, Starts With A Bang does not have five stars! You should fix that! And vote! Registration is not only easy, but they won't send you any annoying emails unless you explicitly tell them to. But how can you vote? Let me walk you through it, and make it easy as 1-2-3:

Register with physics.org (you must register to vote).
Log in with your new registration and password.
Go to the Web Awards Shortlist for Best Blog! You can vote for the others, too, if you like (they're good, trust me!), but make sure you vote for us!

And while you're there, you can check out all seven of their categories for the best of the web! Thanks for all of your support and interest over the years, and I'm happy to share all the good news with you! Voting closes in just two weeks, and we're up against some of the titans of the web here; make sure you don't forget to vote! It's as easy as register, log in, and vote for Starts With A Bang!

And no matter who you vote for or what you vote, have a great weekend! (And tell your friends!) Read the comments on this post...