MetaFilter posts tagged with astronomy and Astrophysics

The Size of Things

nola — Wed, 08 Jul 2009 15:13:16 -0800

Welcome to the Universe - III: The Size of Things . . .we take a breif trip through the Solar System and beyond to see the size of the Universe. A youtube video by AndromedasWake about the scale of the Universe.

Dark Flow

homunculus — Thu, 25 Sep 2008 14:28:16 -0800

Mysterious New 'Dark Flow' Discovered in Space. "As if the mysteries of dark matter and dark energy weren't vexing enough, another baffling cosmic puzzle has been discovered. Patches of matter in the universe seem to be moving at very high speeds and in a uniform direction that can't be explained by any of the known gravitational forces in the observable universe. Astronomers are calling the phenomenon 'dark flow.' The stuff that's pulling this matter must be outside the observable universe, researchers conclude." Here's the paper (subscription required): A Measurement of Large-Scale Peculiar Velocities of Clusters of Galaxies: Results and Cosmological Implications. NASA has preprints you can download: results and implications and technical details (PDFs).

Gamma Ray Bursts - they're neat

ikkyu2 — Sun, 23 Mar 2008 16:14:48 -0800

How far can the naked eye see? About 7.5 billion light-years. On March 19th, a Gamma Ray Burst was noticed by NASA's Swift satellite and given the name GRB 080319B. It left an optical afterglow estimated at +5 apparent magnitude for 30 seconds, about that of an average star. (Sadly, no one was looking at the area with an optical telescope at that exact time.) Read the original Burst Alert, including the email address of the Burst Advocate, here. Gamma ray bursts and other galaxy-sized energy events previously on MetaFilter.

The dark energy backlash

snoktruix — Sat, 21 Apr 2007 14:06:07 -0800

Prominent cosmologist Simon D.M. White has written a provocative paper posted to the astrophysics arxiv complaining that too much time is being devoted to the quest to understand the nature of the elusive dark energy: "Dark Energy is undeniably an interesting problem to attack through astronomical observation, but it is one of many and not necessarily the one where significant progress is most likely to follow a major investment of resources." He worries generally that observational cosmology/astrophysics/astronomy may turn away from the construction of instruments of general utility (such as the Hubble Space Telescope), to concentrate on a small number of massive experiments narrowly focused on solving particular problems (such as WMAP and the Large Hadron Collider), to the detriment of the "quirky small-science" type of astronomy.

Pioneer Anomaly

brownpau — Mon, 13 Jun 2005 12:00:34 -0800

The Pioneer Anomaly. Something's up in deep space: the Pioneer spacecraft, now out of contact, have shown an unexplained Doppler drift, indicating sunward acceleration, effectively decelerating the probes cumulatively. The effect may be be nongravitational, and could be explained by any number of factors: an undiscovered twist in Newtonian physics, localized cosmological contraction issues, or just venting gas. Other deep space probes may have experienced the anomaly as well, and a new mission could explore the puzzle; but for now, all we have is past Pioneer data, and that's stored on old 9 track tape which can only be read by antique readers. What's to be done? (Also see Pioneer Odyssey for a nostalgic romp through those early days of deep space exploration. And NASA, bring back the original Pioneer home page plz, kthx.)

Spitzer Space Telescope

homunculus — Sat, 20 Dec 2003 00:33:46 -0800

The first images from the Spitzer Space Telescope, formerly known as the Space Infrared Telescope Facility and renamed after astrophysicist Lyman Spitzer, Jr., were released on Thursday. Launched on August 25, it obtains images by detecting the infrared energy radiated by objects in space, and it will drift behind the Earth as the planet orbits the sun.

Talk about Johnny One-Note

GreyWingnut — Wed, 10 Sep 2003 08:20:49 -0800

In space, you can hear a black hole sing (WaPo link). Using the Chandra X-Ray Observatory, astrophysicists have detected a supermassive black hole in the Perseus Cluster which has been "playing" a B-flat for 3 billion years.

Fascinating as this seemingly counterintuitive discovery (sound carrying through space) is, the real significance lies in that these "sound waves" may explain why the superhot gases in such regions aren't cooling down and forming more stars.

Italo Calvino's Cosmicomics

vraxoin — Wed, 20 Nov 2002 08:17:09 -0800

"I was willing to bet that there was going to be a universe, and I hit the nail on the head." The other day we had Avram Davidson, which got me thinking of Calvino's Invisible Cities, but all the recent talk about black holes made me remember that Italo Calvino is at his most charming when he's playing with physics, math, and cosmology in Cosmicomics.

stuporJIX — Sat, 26 Jan 2002 03:36:52 -0800

Wot, no black holes? Those wacky boffins in science land have already had a pop at the Higg's boson, but now they're moving on to everybody's favourite theoretical singularity, with a new theory about what happens when a star kicks the astral bucket.

stuporJIX — Fri, 21 Dec 2001 07:03:04 -0800

So you think the expansion of the universe is accelerating? Think again! (Contains links to full paper in .pdf etc.)