Going the Distance: Galaxies may hail from early universe

Using a cosmic magnifying glass to peer into the deepest reaches of space, two teams of astronomers have discovered tiny galaxies that may be among the most distant known. Images suggest that one of the galaxies is so remote that the light now reaching Earth left this starlit body when the 13.7-billion-year-old universe was only about 700 million years old.

The discoveries are important, notes Tim Heckman of Johns Hopkins University in Baltimore, because they probe a special time in the universe, when the cosmos changed from a place filled with neutral gas to a place ionized by the emergence of the first substantial population of stars and black holes. Studies of distant galaxies help pinpoint when that critical era happened.

All of the galaxies are so small that even the keen eye of the Hubble Space Telescope couldn't have spotted them without nature providing a gravitational assist. According to Einstein's theory of general relativity, a massive foreground body acts like a lens, bending and magnifying light from a more remote galaxy that lies along the same line of sight to Earth.

That's why Garth Illingworth and Rychard Bouwens of the University of California, Santa Cruz and their colleagues went hunting for distant galaxies around a nearby cluster of galaxies called Abell 1689.

The cluster's gravity distorts images of background galaxies, bending them into arcs and magnifying their brightness. One of these galaxies proved especially intriguing because it appeared bright at several infrared wavelengths recorded by Hubble but disappeared in visible light.

That's a sign that the galaxy, dubbed A1689-zD1, is both extraordinarily distant and youthful. The data also indicate that the galaxy forms stars at a rate equivalent to five suns a year, typical of the small galaxies thought to be common in the early universe, says Bouwens...

Most welcome, thanks for the kind comments.

Here is another related one I quite like, from a writer named Harry Mulisch. It is the idea of an "historiscope". Since as we look farther away, we are looking backward in time, the idea is to exploit this to look backward in time right where we are, aka to literally see our own history. All it would require is something shiny and reflective enough at a great enough distance, combined with a powerfully enough telescope to see the reflection.

Imagine a giant mirror 1000 light years away, directly aligned to face us, and a monster telescope array the size of a whole solar system or something similar. Focus the telescope on the mirror. Then the light impacting the telescope this instant, will be photons that left the mirror 1000 years ago. But some of those are photons that left earth 1000 years before *that*, travel to the mirror for a thousand years, hit it and bounced, and have now spent another thousand years on the return journey. So as you looked in the mirror, you would literally see the earth 2000 years ago.

The beautiful thought involved in this is that the past is not gone. Information about it is streaking off into space at the speed of light, and bouncing in ripples off everything it touches, and some of those ripples can come right back here. The past is in principle directly observable. Not just the light years distant, astronomical past, but in principle even local happenings.

Of course the practicalities of actually exploiting this are daunting. Very few photons hit any given object a long way away, most things aren't that shiny and aren't aligned, few of the scattered photons come back to any local detector, etc. But the principle of the thing is still mindblowing, in my humble opinion, and indescribably beautiful.

For what it is worth...

Should you be interested in REAL science and TRUTH, your local community college will lead you in courses in Physics and Astronomy....of course...you really have to want TRUTH.

As an amature astronomer I run into your kind all the time on the Internet. Its sad that our schools have failed to bring the public up to a level of knowledge that would make clear the difference between Science FACT and science fiction.

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