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Sidereal messengers: neuroscience and the stars

By John Published: January 27, 2011

Researchers using the Hubble telescope have time-traveled closer and closer to the universe as it looked shortly after the Big Bang. The further away a galaxy is, the longer its light has taken to reach Earth. So the picture we get when the light finally arrives is a snapshot of what the galaxy looked like when the light first started its journey.

Here's a story in ScienceDaily about the discovery of a new galaxy that appears to us now as it did within 500 million years of the Big Bang.

''It's amazing that we finally believe that we have observed something at this epoch,'' said astronomer Rychard Bowens, now of Leiden University in the Netherlands, lead author of a paper to appear in the Jan. 27 Nature. ''It's like breaking the 4-minute mile in running. It's had a little bit of awe.''

The new galaxy, called UDFj-39546284, is about 13.2 billion light-years away. The last record holder was confirmed in October 2010 at 13.1 billion light-years away. Both galaxies were spotted in a Hubble image called the Ultra Deep Field, which captures 10,000 galaxies in the universe's earliest millennia.

Just think of those photons traveling across time and space until they hit a human retina and send signals to a living human brain. The folks at the Dana Foundation blog were thinking about that recently.
Every star in the skyand there are more than 9,000 of them visible to the naked eye at a given time in the clearest conditionshas a color. Unaided, our eyes can make out the colors of only the brightest stars thanks to the workings of our two types of photoreceptors, rods and cones. Rods perceive brightness while cones make out colors, which is difficult in dim light. Our eyes evolved to perceive the relatively small range of wavelengths emitted by the sun. The same is true in the case of other animals, to interesting effect: As red light does not penetrate water, fish can only see blue light.



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