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Written by Kelly Herbst, Astronomy Curator for the Virginia Living Museum. Updated every two weeks, more or less.

Thursday, February 13, 2014

It's A Hoax!

*gasp*  You'll never guess why I missed that last blog post!  Aliens!  They abducted me and took me away to their secret lair somewhere in North America and performed experiments on me!  I can't believe I made it out alive!
This is SOOOOO NOT what happened.  Image from the vast internets.

Okay, that's not what happened.  But after being gone for a month, I figured I owed you a good one.

What really happened is far more mundane, but does lead to an interesting point.  Actually, two things kept me away from the computer for an extended period of time.  Thing number one: the various and sundry snowpocalypse (snowmageddon?) events taking place here in Virginia over the past couple of weeks.

January saw not only the so-called Polar Vortex come through our area, but another round of even deeper snow as well.  And yesterday a weird, sloppy, wintry mess cascaded over again, sending me home early before I could log in to write.  Three snow events in the space of a month in what is usually a maybe-one-good-snowfall-a-year kind of area.  What gives?

Many people claim that the existence of such wintry weather completely negates the idea of global warming.  Not so...in fact, the weirdness and intensity of the weather we're seeing is, in fact, evidence of changes to our global climate.  See, there's the difference.  There's weather - whatever is going on now in the atmosphere - and there's climate - what the environment is like over a wide area averaged over time.  Weather and climate are not the same thing.  Just because the climate of a desert is warm and dry does not mean it never rains there.
A graph showing the departure from a standard global temperature averaged over one year (blue data) and averaged over 5 years (red line).  Such graphs are not always clear in what they are trying to tell us about our global climate.  This one, in fact, comes from a group attempting to deny the existence of climate change.  Image from New Scientist.

Global climate change is a real thing, and it existed long before humans came along.  The climate of the Earth has changed dramatically over the millennia of our planet's existence.  Glacial periods dominated by very cool global temperatures and expanses of ice covering much of the planet, followed by warm interglacial periods where, at some times, even the poles lacked major ice coverage.  Change will happen, whether we contribute to it or not.  But contribute to it we do, also whether we like it or not.  Simply by existing on the surface of the planet, life contributes to the Earth's ever-changing climate.

But we humans are getting good at changing things rapidly without being exactly sure of what we're doing.  No reputable scientist disputes the idea of human-driven change to the global climate - the evidence for it is too strong.  No, the real question is, have we set in motion something that will end up biting us in the tail?  Will the climate change so much, so fast, that we humans won't be able to adapt?  The planet will be fine - it has dealt with great changes before.  But can we?

The unsettled weather we are seeing is likely being at least somewhat driven by the average rise in global temperatures in the past many years.  Raising the temperature of something adds energy to it.  When there's more energy in the atmosphere, that energy is going move things around in different, more extreme ways - including in wintry ways. Just because the weather is cold doesn't mean global warming isn't real.  If you want more detail on why scientists know that global climate change is real, check out Phil Plait's wonderful blog, Bad Astronomy.  He's a wealth of information on the subject.

The other thing that kept me from writing was a nasty cold I picked up that migrated down into my lungs and became bronchitis.  And this even after I got my flu shot.  Why?  Because the virus that causes the flu and the virus (or possibly even bacteria, in the case of the bronchial infection) that causes colds are not the same.  We can vaccinate against the flu...but the rhinoviruses that cause colds...not so much.  And no, I'm in no danger from the flu vaccine itself.  Vaccines are quite safe, and there's no credible link between vaccines and autism.  Again, Phil Plait can point you towards tons of evidence that says yes, you should get your flu shot.

Well, now that I'm finally mostly better and the winter weather is at least somewhat abated, I need to get back to work.  I've got to go move Jimmy Hoffa from under the planetarium projector, and I really wish I could remember where I put that flag I got from the set where they filmed the moon landings...

Just kidding.

Back again in two weeks (assuming we're not buried in a snowtastrophe)...
Carpe noctem!
Kelly


Thursday, January 16, 2014

Mr. Mojo Rising

You know, maybe I should just go ahead and say that I'll update this every other Thursday.  Wednesday just seems to have some kind of bad mojo about it that makes getting an update done impossible.

However...it was worth the delay, because boy do I have some cool stuff to tell you about.

Yesterday I attended a regional Math & Science meeting held at NASA Langely.  The first part of the morning was devoted to touring around.  Now, I've worked with folks from NASA  Langley for years, and I figured I'd seen most everything cool there at least once.

Man, was I wrong!

First, we went to see the National Transonic Facility.  This extraordinary wind tunnel is one of only two in the world that can effectively scale the "air" in the wind tunnel to match the scale of the model.  This can be critical in testing models of aircraft and even submarines where the forces created by the movement of air or water around the vehicle can translate into huge changes in performance of the craft or fuel consumption of the vehicle.  They've tested many, many type of craft in the tunnel, and it's an amazing process.  We got to walk all around the facility with Scott (our guide), and even stood directly under part of the tunnel itself.  We also got to play a little with liquid nitrogen, which is always fun.  The most amazing tidbits I carried away from our tour:

  • When it was constructed, the NTF wind tunnel used up ALL of the stainless steel available in the U.S. at the time.  ALL OF IT.  They had to buy more from Japan to finish the tunnel!
  • The thickness of the tunnel's stainless steel ranges from 6" down to only 1".  One inch of stainless steel may sound like a lot, but it's nothing when you consider the tunnel is essentially a giant pressure vessel that can be pumped up to 120 psi!  (That's almost 9 times normal air pressure!)
  • To scale the "air" in the tunnel appropriately, sometimes they use liquid nitrogen instead of air.  When that supercold material is used, the entire tunnel can contract 8-10"!  Therefore, the tunnel is fixed in only 2 places...the other stability points have to be flexible to allow for this expansion and contraction, or the tunnel would rip itself apart!

A blended wing-body aircraft model is set up for tests in the NTF's unique wind tunnel.  Even the models have to be made to exact specifications or the testing can damage them!  Image courtesy NASA.

Our second way cool stop used to be known as the Lunar Landing Research Facility.  Under that name, it was where the Apollo astronauts came to learn to land the LEM.  They used a system of pulleys to simulate 1/6th gravity and gave Neil Armstrong, Buzz Aldrin, and all the rest of the Apollo team the chance get a feel for what it would be like to set the LEM down on the Moon!  Incredible!  The facility is now a National Historic Landmark, and would be incredible to visit, just because of that.  Heck, I stood on the same spot where the astronauts were learning to settle down on the Moon!

Today, the facility has been repurposed as  the Landing Impact Research Facility...and its new mission is just as awesome as its old one!  They now use the massive rig and newly-added hyrdo-impact basin (it's NOT a pool!) to perform crash tests of a variety of air- and space- craft!  We even got to see the body of a helicopter that had been used for crash testing!  You can see videos of tests performed at the LandIR Facility on NASA Langley's You Tube channel.  Talk about some guys with serious mojo!  Martin and Justin have what must be one of the coolest jobs ON THE PLANET!

The new Orion space capsule is tossed into the hydro-impact basin at the LandIR Facility.  What a fun job - dropping and breaking things for science!  Image courtesy NASA.

If all that wasn't enough, we got treated to an incredible spectacle while talking with the guys at the LandIR Facility.  Overhead, low and loud, was an F-22 fighter jet performing the most incredible aerobatic stunts I've ever seen!  Turns out these guys have to re-certify every year to be able to perform at airshows, and this guy happened to be doing his re-certification just as we were touring around.  Now that pilot definitely had some wicked mojo rising, let me tell you...his plane looked suspended in mid-air, rolling and pitching and yawing in ways that made me queasy just watching him!  It was an amazing spectacle!

The F-22 Raptor.  Wicked cool at aerobatics too.  Image courtesy Wikipedia

So...I guess what I'm trying to say is, if there's a NASA center near you - get on a tour!  You'll never know what amazing things might be right there in your backyard unless you take the time to check them out!

More mojo in two weeks...
Until then...carpe noctem!
Kelly