Astronomy
drorzel | April 22, 2010What's the application? Producing artificial "stars" to serve as a reference for telescopes using adaptive optics to correct for atmospheric turbulence. This allows ground-based telescopes to produce images that are as good as those from the Hubble Space Telescope.
What problem(s) is it the solution to? "How can I make this giant telescope produce even more impressive pictures?"
How does it work?The basic problem with ground-based telescopes, as anyone who has ever looked at the stars or listened to nursery rhymes can tell you, is that stars "twinkle." They appear to fluctuate in brightness…
drorzel | April 21, 2010What's the application? An optical frequency comb is a short-duration pulsed laser whose output can be viewed as a regularly spaced series of different frequencies. If the pulses are short enough, this can span the entire visible spectrum, giving a "comb" of colored lines on a traditional spectrometer. This can be used for a wide variety of applications, from precision time standards to molecular spectroscopy to astronomy.
What problem(s) is it the solution to? 1) "How do I compare this optical frequency standard to a microwave frequency standard?" 2) "How do I calibrate my spectrometer well…
esiegel | April 16, 2010I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to Earth.
-John F. Kennedy, 1961
The entire human endeavor of spaceflight is -- without a doubt -- one of the greatest achievements in the history of humanity. Looking up into the heavens certainly provides some spectacular sights and a huge amount of insight into how space, stars, and galaxies work, among a myriad of other things. (And click the image below for an amazing high-resolution version.)
But my two biggest complaints about the…
jdupuis | April 15, 2010A month or so ago I posted on Scholarly Societies: Why Bother?, basically on the challenges that scholarly societies face in the digital age. I got a few good comments, getting a nice discussion going.
I also posed a few questions directly to scholarly societies but unfortunately didn't get any comments from any of the various societies themselves. I did find that a bit disappointing in that the public conversation seemed to be happening without them. Never a good thing in the digital age.
Today, however, Kevin Marvel of the American Astronomical Society added a comment to my original…
esiegel | April 14, 2010People are like stained-glass windows. They sparkle and shine when the sun is out, but when the darkness sets in their true beauty is revealed only if there is light from within. -Elisabeth Kübler-Ross
Welcome back to The Greatest Story Ever Told, where we're covering the natural history of the Universe from before the Big Bang to the present day. You can catch up on the first eight parts here, going forward from Inflation in part 1 to parts 2, 3, 4, 5, 6, 7, and reaching the formation of the first neutral atoms in part 8. But during all of this time, gravity has been working its magic.
In…
esiegel | April 9, 2010"Cosmologists are often in error, but never in doubt." -Lev Landau
I've been telling you about the Big Bang, the greatest story ever told, and the entire natural history of the Universe. Let's remind you -- historically -- of how our conception of the Universe changed as we learned more about our surroundings.
Maybe the first astronomical observation ever made was that the Sun rises in the East, passes overhead, and sets in the West. And it does this day after day, every day. It's no wonder that our first "cosmological model" of the Universe was that the Earth is stationary, and the Sun…
pontiff | April 8, 2010Items sharing a similar topic, meandered onto in the depths of a major outpouring of procrastination...
The path less traveled by Andrea Schweitzer (via @mattleifer) on a different way to have a career as a scientist. And for a description of one of the most successful scientists from quantum computing, an interview with Ignacio Cirac (sent to me by Daniel.) Somedays, however, one might wonder about all the time professors spend working and contemplate the idea of death by tenure track. Or if you care a lot about the notion of tenure versus non-tenure AND you don't mind reading redstate.…
sciencepunk | April 8, 2010Last year Neatorama's Alex Zavatone happened to find himself near Angola on the African continent. While driving through Grootfontein, Namibia, he spotted a road sign that simply said "Meteorite." Later he decided to make a 170 mile pilgrimage through beautiful and wild landscapes to Hoba to see what it was all about.
You'll have to go to the Neatorama website to see the money shot - but it's worth it! I've never seen such a well-presented interplanetary visitor. Read Alex's full tale here.
grrlscientist | March 29, 2010tags: Alex Filippenko, Josh Frieman, FermiLab, astronomy, astrophysics, Science Bulletins, research, American Museum of Natural History, AMNH, New York City, space, nature, universe, The Expanding Universe, streaming video
In 1998, astrophysicists discovered a baffling phenomenon: the Universe is expanding at an ever-faster rate. Either an enigmatic force called dark energy is to blame or a reworking of gravitational theory is in order. In this new Science Bulletins video, watch a FermiLab team assemble the Dark Energy Camera, a device that could finally solve this space-stretching mystery…
grrlscientist | March 28, 2010tags: marshmallow peeps, Astropeep, peeponaut, easter, space, humor, funny, silly, video, streaming video
I posted this last year, but I think it is worth repeating .. this streaming video lacks music, but it shows you the adventures of a very special marshmallow peep, an astropeep (or a peeponaut, depending upon which name you prefer) who traveled to the edge of space .. thanks to the Adler Planetarium's "Far Horizons 12" high altitude balloon mission, which rose to nearly to 97,000 feet.
rallain | March 23, 2010I happened to catch two parts of two different episodes of Meteorite Men - a show about two guys that look for meteorites. In both of the snippets I saw, they were talking about a debris field for a meteor that breaks up. In these fields, the larger chunks of the meteorite are further down in the field. Why is this?
Let me approach this first from a terminal velocity view. This requires a model for air resistance. I will use the following:
Where:
rho is the density of air
A is the cross sectional area of the object
C is a drag coefficient that depends on the shape of the object
v is…
esiegel | March 15, 2010Bart: Go, Dad, go!
Lisa: How doth the hero, strong and brave, a celestial path to the heavens paved!
(The family stares at her.)
Lisa (dejected): Go, Dad, go. -The Simpsons
Last week, I got a question from one of my online friends, cmgraves. His question was straightforward:
How do thrusters work in space? On Earth, when we want to speed up, slow down, change our direction, or to change our motion in general, we always have something to push against. This is true whether you're a runner and have the ground to push against,
or a turbofan engine with the air to push against.
But in the…
esiegel | March 5, 2010Better to light a candle than to curse the darkness. -Chinese Proverb
Every once in a while, we'll look out into the sky with a telescope, and see some spectacular glowing gas.
These nebulae typically come about from dead or dying stars, and are some of the most spectacular sight in the sky for astronomers, from amateur to professional.
But in the 1940s, an astronomer named Bart Bok observed these little dark "defects" in a few of these nebulae. It looked like something dark was simply sucking in all of the light around it, and refused to let any out.
In fact, looking even with modern…
esiegel | March 3, 2010What's in a name? That which we call a rose
By any other name would smell as sweet. -W. Shakespeare
After writing about the 80th Birthday of Pluto becoming a planet, I was asked about Pluto's planetary status, and whether I thought it deserves to be a planet or not. Let me just recap for you, very briefly, what this argument is all about.
Pluto, when it was discovered back in 1930, was the only object in the Solar System found out beyond Neptune. Although we imaged it, observed it, and surveyed the whole sky for other objects, it remained the only Solar System object out beyond Neptune until…
esiegel | February 19, 2010We used to think Pluto was a misfit. -Alan Stern
Eighty years ago, we solidly had eight planets in the Solar System: the same eight we have now.
But in the late 1920s, a young astronomer was looking up at the sky, night after night, searching for tiny moving objects that could possibly be planets out beyond Neptune. Using this technique of looking at a patch of sky repeatedly over the course of a week, Clyde Tombaugh searched for moving objects, finding many comets and asteroids, but -- like everyone else -- found no signs of a new planet.
Until January of 1930. I've managed to dig up Clyde…
grrlscientist | February 19, 2010tags: Sonic Boom Meets Sun Dog, amazing science, sonic boom, Atlas V, rocket launch, amazing, beautiful, atmosphere, physics, astronomy, streaming video
This amateur video is absolutely amazing: recording the precise moment when a rocket goes supersonic, which coincides with the moment it passes through a layer of ice crystals in the atmosphere, creating a rippled effect that is just astonishing to see.
Solar Dynamics Observatory Launch, Feb 11, 2010: A sun dog is a prismatic bright spot in the sky caused by sun shining through ice crystals. The Atlas V rocket exceeded the speed of sound in…
esiegel | February 16, 2010It is marvelous indeed to watch on television the rings of Saturn close; and to speculate on what we may yet find at galaxy's edge. But in the process, we have lost the human element; not to mention the high hope of those quaint days when flight would create ''one world.'' Instead of one world, we have ''star wars,'' and a future in which dumb dented human toys will drift mindlessly about the cosmos long after our small planet's dead. -Gore Vidal
Someone woke up on the wrong side of the bed when they wrote that, didn't you, Mr. Vidal? Because the marvelous is right in front of us. Yesterday's…
drorzel | February 11, 2010What's the application? Measuring the distance from the Earth to the Moon by bouncing a laser off one of the retro-reflector arrays left there by the Apollo missions.
What problem(s) is it the solution to? 1) "How does the distance from the Earth to the Moon vary over time due to things like tidal drag?" 2) "Does the strength of gravity change over time?" 3) "What can we do with a laser to really cheese off people who think the Moon landings were fake?"
How does it work? This concept is simplicity itself. You simply point a laser at the Moon, fire off a short pulse of light, and wait for it…
esiegel | February 10, 2010The New Age? It's just the old age stuck in a microwave oven for fifteen seconds. -James Randi
About two weeks ago, the WMAP (Wilkinson Microwave Anisotropy Probe) team released their seven-year results, and I'm finally ready to tell you all about it. WMAP, remember, is this guy.
By looking at two different points in the sky simultaneously, and looking at the proper frequencies of microwave light (it looks at five different frequencies every time it looks at the sky), it can measure the differences in the intensity of light left over from the big bang everywhere in the sky. Why is this so…
grrlscientist | February 9, 2010tags: NASA, Endeavour, International Space Station, spaceship launch, STS-130,Kennedy Space Center, space exploration, physics, astronomy, engineering, streaming video
Space shuttle Endeavour, carrying Commander George Zamka, pilot Terry Virts, and Mission Specialists Nicholas Patrick, Bob Behnken, Steve Robinson and Kay Hire, successfully launched from the Kennedy Space Center in the early hours of February 8, headed for its 13-day STS-130 mission to the International Space Station.