Not a planet, still interesting February 7, 2010
Posted by sarah in: new astronomy, pics . Add a comment
Despite Mike Brown’s best efforts, Pluto is not dead (yet). These cool new images of the tiny non-planet taken with the Hubble Space Telescope show that it is by no means a boring lump of icy rock. When comparing these images, taken in 2002-2003, to a previous set dating back to 1994, scientists noticed some striking changes. This would suggest that Pluto, just like many bodies in the solar system, shows seasonal activity and all kinds of interesting chemistry as it moves along its looong orbit around the Sun.
Image: NASA, ESA, and M. Buie (Southwest Research Institute)
The end of gravity as we know it? February 4, 2010
Posted by sarah in: science . 4comments
Black hole/massive star pair (artist's conception)
When a physicist is on the front page of a newspaper, you know the story is either really bad, or really good. Just before Christmas, the Dutch paper De Volkskrant ran a big story on theoretical physicist Erik Verlinde, who has been making waves with his new theory for the origin of gravity. Since the story ran, Verlinde published a paper explaining his new theory to the Arxiv. In it, he postulates that gravity is an emergent phenomenon resulting from changes in entropy rather than the fundamental force of nature we currently think it is, and demonstrates this using simple thought experiments. Gravity, he says, is an entropic force – a bit like, say, osmosis.
So when Verlinde, who works at the University of Amsterdam, turned up on the colloquium schedule of Leiden’s Lorentz Institute, I thought it was worth checking out.
Don’t be such a scientist February 3, 2010
Posted by sarah in: science . Add a commentI just finished reading a book called Don’t Be Such a Scientist: Talking Substance in an Age of Style
For all his good advice, I have to say Olson picked a rather unfortunate title. It’s impossible to buy this book as a gift for someone without seeming, well, rude. Being a scientist, obviously, I did just that for the scientist I share my life with. He wasn’t too impressed (but did finish the book, then placed it on my side of the bed).
Shape matters in black hole growth January 31, 2010
Posted by sarah in: astronomy, new astronomy . 2comments
Fig. 1 (from Schawinski et al., 2010)
Active galaxies have gone by many names: active galactic nuclei, quasars, QSOs, Seyfert galaxies, radio galaxies. Astronomers used to think these were all distinct types of objects, unified by the observation of large amounts of energy emerging from a compact region at the centre of the galaxy. These days, despite a great variety in observational characteristics, active galaxies’ engines are generally thought to be driven by a single mechanism, the accretion of material onto a supermassive central black hole.
In a paper published to the Arxiv last week, Kevin Schawinski and collaborators have used Galaxy Zoo classifications of local Universe galaxies to show that active elliptical galaxies are markedly different from those with a more disk-like or spiral shapes, adding morphology as an additional factor to consider in our model of active galaxies.
The Astronomer’s Mating Call January 28, 2010
Posted by sarah in: astronomy, politics . 1 comment so far
Every winter is the time for an age-old mating ritual that takes place in the astronomy community: a special courtship dance where graduate students and postdocs parade round, flashing their colourful feathers, trying to appear smarter and savvier than their peers in the desperate quest for a new mecenas who will support their addiction to MacBooks and airmiles. It’s jobs season, when the friendships we’ve cherished for the past year become meaningless and it’s each astronomer to their own.
