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ToSeek
2002-Apr-08, 11:48 AM
I get an almost daily email missive from the Science Fiction Book Club, partially plugging their offerings but also with a little bit of background on an aspect of science, science fiction, or writing. I found these interesting up until today's offering, from which I submit this excerpt:



By 1955, researcher Ralph Alpher suggested searching for radiation traces as evidence of an explosion. He was right--a decade later, two radio antenna operators accidentally detected an unfamiliar static hiss. It was cosmic background radiation, and its temperature (-270 degrees) was what it should be according to the theory of relativity.

NASA launched the Cosmic Background Explorer (COBE) in 1989 to study the radiation, searching for any distortions that might indicate the formation of galaxies, stars, planets, or people. At first, the data appeared smooth, but in April 1992, NASA detected ripples--variations in the temperature of the radiation--hard evidence at last for the "Big Bang" theory.


Correct me if I'm wrong, but:

- Relativity has little or nothing to do with predicting the cosmic background radiation.
- The smoothness, not the ripples, were the key evidence for the Big Bang (though the wrong sort of ripples could have been problematic, too).

David Hall
2002-Apr-08, 12:19 PM
If I recall, the original idea was that it would support the big bang theory (not relativity, but at least partially built on relativity) if they could find variations in the background radiation. They wanted to find anisotropies because that would give evidence of how matter started clumping together. But the data was too smooth for the theory. So they did two things. They kept looking closer and closer for these variations, and they kept modifying and testing the theory so that the lack of large anisotropies could be explained. Eventually the theory was modified to accept much smaller variations, and the telescopes were finally made sensitive enough to detect variations in this range, so everything fit.

This is what I understand. Someone correct me if I'm wrong (and I'm sure you will). /phpBB/images/smiles/icon_smile.gif

Hale_Bopp
2002-Apr-08, 12:51 PM
The Microwave Anisotropy Probe's web site is at

http://map.gsfc.nasa.gov/

Check it out. I haven't read much of it yet, but the cosmic microwave background tells us that space is flat (from the Boomerang experiement) which is part of general relativity, so there is at least some relation between the two.

Rob

GrapesOfWrath
2002-Apr-08, 12:59 PM
Alpher wrote a paper with Gamow in 1948 (http://aether.lbl.gov/www/science/CMBTimeLine.html). What did he say in 1955?

Russ
2002-Apr-15, 12:57 PM
By 1955, researcher Ralph Alpher suggested searching for radiation traces as evidence of an explosion. He was right--a decade later, two radio antenna operators accidentally detected an unfamiliar static hiss. It was cosmic background radiation, and its temperature (-270 degrees) was what it should be according to the theory of relativity.


It was Wilson & Penzais of Bell Labs, Murry Hill, N.J. that made that discovery. The goal of their work was to remove static from microwave telephone circuits but they discovered the fires of creation instead. /phpBB/images/smiles/icon_lol.gif

Wiley
2002-Apr-15, 10:12 PM
On 2002-04-15 08:57, Russ wrote:


By 1955, researcher Ralph Alpher suggested searching for radiation traces as evidence of an explosion. He was right--a decade later, two radio antenna operators accidentally detected an unfamiliar static hiss. It was cosmic background radiation, and its temperature (-270 degrees) was what it should be according to the theory of relativity.


It was Wilson & Penzais of Bell Labs, Murry Hill, N.J. that made that discovery. The goal of their work was to remove static from microwave telephone circuits but they discovered the fires of creation instead. /phpBB/images/smiles/icon_lol.gif



Calling Penzias and Wilson "two radio antenna operators" is a bit of an understatement: they won the Nobel prize for their work. Arno Penzias later became the Chief Scientist at Bell Labs, a position in which a Nobel prize seems like a prerequisite.

More info can be found here (http://www.nobel.se/physics/laureates/1978/index.html).


<font size=-1>[ This Message was edited by: Wiley on 2002-04-15 18:19 ]</font>