Sunday, March 11, 2007

Dark Forces




Dark Matter and Dark energy, ominous and foreboding terms that only hint at the mystery they represent: nominal conjectures stamped on unknown forces that scientists theorize make up over 95 percent of the universe but of which they have found no direct evidence; and then, there is the startling possibility that they never will.





A wonderful article in the NYT today on Dark Matter and Dark Energy, and the ongoing speculation they have fuelled.

The article reviews key discoveries over the years that have shaken many foundations of certainty and raised a host of impossibly daunting questions about the universe at large.


The story reveals how early findings offered affirmations of established thinking.

The discovery in
1963 of a uniform pattern of microwave radiation emanating from the very farthest reaches of the universe, registering at a mere 2.3 degree flicker above absolute zero lent support to the Big Bang theory of our cosmos' beginnings.

In the 70's the clarity of our understanding of the universe took an obscure turn. Galaxies were observed to be spinning at what theory suggested were unsustainable rates. Some unaccounted source of gravity was holding things in check . Unable to measure or observe this inconcievably massive quantity scientist were left only with the option of giving it a label- Dark matter.
Dark was an apt name given its complete inaccesibility.



A few decades later the story became even more perplexing. In 1997 Saul
Permlutter working out of Berkley National Laboratory looked for evidence of what he expected to be the slowing of the expansion of the universe as a result of the gravitational pull of redistributed matter braking on its outward movement, and which would according to theory eventually cause it to reverse its direction back toward to its beginnings. This was the dominant paradigm of the time based on ineluctable logic.

Permlutter's subtle measurements of the light pattern changes of over 50 supernova stars had been expected to reveal the degree to which the universe's expansion was decreasing. The data revealed something else altogether. The light from the highly incandescent stars was found to be dimming in a way that that they later came to understsand mean't the universe's expansion was not slowing at all but instead expanding at an ever increasing rate. The implications of these findings were astonishing. Something was drving this expansion but again there was no evidence of it to be found. Stumped for explanation all that was possible was a variation on the old standby. Dark Energy was proposed,a label, like Dark Matter could say nothing of what it signified.



The article goes on to raise all the infinitely perplexing questions that have been raised by all these findings.






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