The concept of nothing is as old as zero itself. How do we grapple with the concept of nothing? From the best laboratory vacuums on Earth to the vacuum of space to what lies beyond, the idea of nothing continues to intrigue professionals and the public alike.
Join moderator and Hayden Planetarium Director Neil deGrasse Tyson
as he leads a spirited discussion with a group of physicists, philosophers and journalists about the existence of nothing. The event, which was streamed live to the web, took place at the American Museum of Natural History on March 20, 2013. [more inside]
posted by lazaruslong
on Mar 25, 2013 -
The light from a primary rainbow is partially polarised
. Now, in a paper accepted
by the journal Astronomy and Astrophysics, the authors show how to use the weak signal from rainbows in starlight reflected by exoplanets to detect the presence of liquid water clouds. [arXiv preprint link
In particular, liquid water clouds covering as little as 10%-20% of the planetary surface, with more than half of these covered by ice clouds, still create a polarized rainbow feature in the planetary signal. Indeed, calculations of flux and polarization signals of an exoplanet with a realistic Earth-like cloud coverage, show a strong polarized rainbow feature.
posted by Talkie Toaster
on Nov 7, 2012 -
"...I'm here to present to you - not lectures that are part of some curriculum; but in fact, I've combed the universe for my favorite subjects, and I'm going to spend twelve lectures bringing those favorite subjects to you."
Renowned astrophysicist and television host Neil deGrasse Tyson
discusses the various aspects of our universe in twelve separate half-hour long lectures (MLYT). [more inside]
posted by Evernix
on Nov 26, 2011 -
The "Great Filter
" is a hypothetical barrier to explain why civilisations are so unlikely to progress to the point of inter-stellar colonisation that we have not encountered any in 40 years of looking. Maybe humanity has already negotiated the filter - as some massive evolutionary improbability - or perhaps it lies in our future as an almost-certain threat to our existence? We should hold our breath as we look for evidence of life on Mars
posted by rongorongo
on May 12, 2008 -
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.
posted by snoktruix
on Apr 21, 2007 -
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
posted by brownpau
on Jun 13, 2005 -
So you think the expansion of the universe is accelerating? Think again!
(Contains links to full paper in .pdf etc.)
posted by stuporJIX
on Dec 21, 2001 -
When NASA scientists watch Michael Bay films, comedy ensues. 'The technology is not at all far-fetched,' said Dr Greg Laughlin, of the Nasa Ames Research Center in California. 'It involves the same techniques that people now suggest could be used to deflect asteroids or comets heading towards Earth. We don't need raw power to move Earth, we just require delicacy of planning and manoeuvring.'
Oh yeah, nothing could possibly go wrong with this
plan. I'm not being a Luddite here...I realize the scientists involved aren't going to be doing this any time soon, if ever. It still spooks me, though.
posted by Ezrael
on Jun 11, 2001 -