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Science Sidebar 5: NASA Ames

2014/10/24 Leave a comment

I had a chance to visite NASA Ames last Saturday.

Along with about 100,000 other people.  NASA Ames is a big research center which – as you might expect – does a lot of space and aeronautics research, but it’s a bit less well-known than other places like the Jet Propulsion Lab.

It has also been about 15 years since it last opened its doors to the public, which helps explain the truly enormous attendance.  It was quite the zoo.  (And apparently also at full capacity, according to the event announcement.)

So, I’m going to write about a few things that I saw while I was there.  Also, pictures.

That, in the background, is the heat shield for the Orion capsule.  Crowd included for scale.

That, in the background, is (a model of) the heat shield for the Orion capsule, the new human spacecraft in progress. Crowd included for scale.

Could You Do This More Often?

I’m afraid that a large part of my reaction to this event was to think of the popular restaurant that nobody goes to any more because it’s too crowded.

It was very, very crowded.

Like, twice the size of my hometown crowded — they “sold” (at the price of free) at least 100,000 tickets to the event.

NASA Ames is large enough to have enough things for that many people to look at, but it still required an intense effort on the public transit side and staggering when people entered.  The crowds made it difficult to get close to some of the demonstrations, too.  There was some triaging to only the most interesting, or easily visible, displays.

One remedy might be to have events like this more frequently.  After all… this was the 75th anniversary event, and the last time they had an open house was ages ago.  More, smaller events might be more effective at public outreach, too, since some people will be willing to wait for the next time… letting those who do come in a given year get a closer look.

Rovers: Not Just For Mars

JPL has its Mars Yard, but one of the cooler things they let the masses of people see was Ames’ rover yard.  The article I linked was old, but that just shows that they’ve been working on these for a long time.  The most recent version, which I saw, was geared towards a lunar rover.  It looks like this:

I want to do a science, but I don't think I'm actually on the Moon.  What's this fence doing here?

I want to do a science, but I don’t think I’m actually on the Moon. What’s this fence doing here?

Of course, the full set of “things done at Ames” runs the gamut of space science — from Kepler and exoplanets, to rovers, to complex computer simulations, to novel aircraft design.  I should have taken some pictures of the assorted giant wind tunnels… which are essentially entire, multi-story building for testing things like airplanes and the parachutes used to help rovers land on Mars.

Finally, and most entertaining to my mind, was the example of a “soft” robotics design.  This particular design is a joint effort between Ames and UC Berkeley, and has the name Tensegrity.  The idea is that the robot won’t need to do the whole “air bag” thing when being dropped from a height — the robot itself can safely stretch and compress in various ways.  The link earlier shows a video, but here’s the example that visitors could play with a bit at the open house.

This is a Tensegrity robot.  It's basically a bunch of metal sticks held together by a bunch of stretchy strings.  The controller part of the robot (which isn't in the image) would be held safely in the center of all that.

This is a Tensegrity robot. It’s basically a bunch of metal sticks held together by a bunch of stretchy strings. The controller part of the robot (which isn’t included in this demonstration) would be held safely in the center of all that.

Isn’t that awesome?  The whole thing would move by having the central controller adjust the tension in the strings, making the metal rods move back and forth.  I’m not sure how it would climb a significant slope, but I’m sure the folks at Ames are working on it.

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Categories: Science Sidebar

Science Sidebar 4: Skulls and Gastralia

2014/09/14 1 comment

While visiting Chicago for a wedding (congrats to Amanda and Nick!), I had a chance to visit the Field Museum.  It’s epic, and the group I was with only able to go through a small section in the time we had.

But!  While we were there, I learned a few things I hadn’t previously known or realized about tetrapods.  Which I will now inflict on you.

***

Your skull, less several hundred million years of modifications.  (via Wikipedia, synapsid skull)

Your skull, less several hundred million years of modifications. (via Wikipedia, synapsid skull)

A Tale of Skulls

Paleontologists like skulls.  They can tell you a lot about a critter — what kinds of things it ate based on its teeth, how big its brain was, how strong its jaw muscles were, and so forth.
Read more…

Science Sidebar 3: Relearning A Little Geology

2014/08/18 Leave a comment

Once again, stuff that missed the cut for the paper.

I discuss some geology stuffs.  That links to the article that I originally read, but I’ll be discussing a little of the general background, too.  Those of you on the west coast may find this particularly interesting… or boring, since you’re also likely to have heard it a thousand times before.

This is Mount St. Helens in 1982, after the big eruption.  (Shamelessly borrowed from Wikipedia.) Also, in a bout of tremendous false advertising, it is only tangentially relevant to the post at hand.

This is Mount St. Helens in 1982, after the big eruption. (Shamelessly borrowed from Wikipedia.)
Also, in a bout of tremendous false advertising, it is only tangentially relevant to the post at hand.

Earthquakes

Surprise!  The west coast of the US is prone to earthquakes.

We can blame plate tectonics for that.  The surface of the Earth is like a big jigsaw puzzle where the pieces don’t quite fit.  Floating on top of the more-liquid mantle, they slowly slip past, under or over or into each other.  Except, sometimes, they get stuck, and then move in sudden spurts when the pressure gets to be too high.

That’s the rough explanation for how earthquakes happen.

On the US West Coast, there are three tectonic plates that are relevant.  The first is the North American plate, which includes very nearly all of North America, including Mexico, Greenland, and parts of Russia and Japan.  The second is the aptly named Pacific plate, which covers — shockingly — much of the Pacific Ocean.  Those two border each other along a large fraction of the famed Ring of Fire, but there is one much smaller plate, the Juan de Fuca plate, which is nestled between them along the coasts of Washington, Oregon, and northern California a little bit further south than Eureka.  (And a bit of southern Canada, we can’t forget them.)

The North American and Pacific plates are sliding past each other (mostly) on the West Coast, but the Juan de Fuca plate is actually moving apart from the Pacific one, and sliding underneath the North American one.  The result is…

Subduction

And wow, volcanism.

Off the coast, Juan de Fuca sinks beneath the North American plate.  Deep underground, beneath the Cascade Mountains, the place eventually sinks away, ground up and melted into the Earth’s mantle.  While that happens, some of the material melts, and, being a lower density, rises up.  This forms mountains and powers a certain amount of volcanism — hence, Mount St. Helens.

For bonus points, the fault is large enough that when it slips it can cause very large earthquakes, although there have not been any truly massive quakes recently.  There was a large (~9) earthquake in 1700.  There was a big tsunami in Japan as a result.  The most recent earthquake I remember that was significant was around a 6.0 near Seattle.  (Now, remember that this is in the newer moment magnitude scale, instead of the old Richter magnitude scale, but yes, it’s logarithmic.)

But Is The Big One Going To Knock My House Down?

Don’t ask me.

The main point of the article I linked above is that the expert geologists and seismologists and geophysicists and paleoseismologists (and all appropriate variants thereof) are still working out the details.

The ongoing discussion is about how often earthquakes occurred in the past, over the last 10,000 years or so ago.  Scientists can estimate this by looking for sediment or rock layers deep in the ocean which show signs of having been disturbed by earthquakes.  This lets them estimate the frequency of large earthquakes in the area, and use that information to forecast how likely earthquakes are to occur in a given period in the future.

However, there are complications that depend on when the samples of the sea floor — called cores — were taken from the ocean, where they were taken, how well those positions are known, and how well understood the particular kinds of turbidite are.  In short, the jury is still out, and the science is ongoing.

So, depending on who you ask, the odds of another 9.0 quake happening along the Juan de Fuca subduction zone in the next fifty years is somewhere between 10 and 40 percent.

For bonus points, there’s some evidence that a large earthquake, particularly one that affects the southern part of the Juan de Fuca plate, could trigger a major earthquake along the northern part of the San Andreas fault a couple of decades later.  (Maybe.)

In short: earthquake preparedness, people.

Science Sidebar 2: Dark Matter

2014/07/31 1 comment

Another item that didn’t make the paper.

So, dark matter.  It’s stuff.

The comment is prompted by the announcement a little while ago that the US Department of Energy has chosen which three next-generation direct detection experiments it’s going to fund.

So, what is dark matter, and what are these experiments doing, anyway?

This is a doodle I made once of a sparticle, or supersymmetric particle.  Dark matter WIMPs may be sparticles.  (No, it's not an insult, stop waving that spear around.)

This is a doodle I made once of a sparticle, or supersymmetric particle. Dark matter WIMPs may be sparticles. (No, it’s not an insult, stop waving that spear around.)

Cold Dark Matter Search

Dark matter is like the force: it surrounds us and penetrates us, and binds the universe together.  (Thank you, Obi-wan.)

We know dark matter exists because we can see its effects on ordinary matter, which has a convenient tendency to glow in the dark.  We see stars orbiting around their galaxies too fast to be held in place unless there were dark matter we can’t see; we see galaxies orbiting each other, or in clusters, at such a great velocity that they would fly apart… unless there were dark matter.  And on and on.  There’s also evidence for the existence of additional, weakly-interacting matter imprinted on the Cosmic Microwave Background (CMB), the afterglow of the Big Bang.

There’s more evidence than I want to go into right now, but if you’re still skeptical, check out the Bullet Cluster.

The predominant current theory is that dark matter is a weakly interacting massive particle — or WIMP, because physicists can’t resist a good acronym.  Something like a supersized neutrino — bulky instead of super-light, and only interacting very infrequently with normal matter.  We’re inside a galaxy, so there’s conveniently a lot of dark matter around and in us all the time, but it generally doesn’t do much.

This is where CDMS comes in, with SuperCDMS as the successor.  Both versions work with large chunks of germanium or silicon metal, waiting to get lucky and have a dark matter particle slam into one of the nuclei.  Those particular elements are chosen both because they’re a convenient mass (close to the DM particle), and because they have nice properties for detecting collisions.

To avoid confusion with other particles (like neutrons from radioactive decays or cosmic rays or other things like that), the whole experiment has to be way underground.  The same is true for…

LUX-ZEPPELIN

Nope, it’s not a band.  And the acronym gets shorted to LZ.  They’re combining two previous experiments into one collaboration.  This one is similar in principle to SuperCDMS, except that it uses liquid Xenon instead of silicon or germanium.  (Cool, right?)

Anyway, the main difference in results is that LZ will be more sensitive to higher mass WIMP-type particles than SuperCDMS is.  But, there is a region of overlap: low-mass LZ may overlap with high-mass SuperCDMS, allowing the two different experiments to cross-check each other.

It’d be cool if dark matter existed there.

ADMX-Gen2

This is where stuff gets weird.  Weirder.

This experiment doesn’t try to detect dark matter with atoms.  Instead, it’s using microwaves.  It’s looking for a particle called an axion, which is much less massive, and hypothesized to have some strange properties when it interacts with light.

That particle was postulated to solve a fundamental problem in particle physics related to what’s called “CP violation”, but maybe it can handle the dark matter problem as well.  It’s not as popular as some of the more massive WIMP theories, but it should still be tested.  Since we don’t know what the right answer is yet.

 All The Other Things

Yes, there are lots of other experiments.  I have serious doubts about their claimed detections, though.

Also, it’s quite possible that dark matter is more than one thing.  Hey, maybe it’s two different kinds of WIMP, plus axions and something else we haven’t thought of yet.

And that’s that.  … no, let’s leave dark energy for another day.

Science Sidebar 1: Things That Go Boom In The Night

2014/07/01 2 comments

Since I’m currently working as a science reporting, I’m writing a whole bunch of actual non-fictional things about science.

The catch?  Since the newspaper is not my personal blog, there’s finite space.  So I don’t have room to include all the cool details.  Which made me kind of sad, until I realized that, hey… I could put some of those details on my personal blog.

Life is good.

And thus, this, the first installment, just in time for the Fourth of July.

sn1006c

Courtesy of Astronomy Picture of the Day (who got it with credits to NASA, ESA, and Zolt Levay), here’s SN 1006 — the remnant of a Type 1A supernova. Nice celestial fireworks. (Suffice it to say, don’t set off one of these in your back yard.)

The article I’m referring to is available online here.

So, what didn’t make it into the article?

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