First matter came from 'perfect' soup
It's a cliché to say that you can never know the primordial substance that became our material universe. Forget the cliché. Scientists have created the stuff at the Brookhaven National Laboratory on Long Island. They're ready to poke and probe it to their hearts' content.
It's the latest - and perhaps most spectacular - advance in a trend that's rapidly shortening the list of cosmic unknowables. Farsighted telescopes, powerful laboratory probes, and cutting-edge computer and mathematical analyses are turning unknowables into subjects for touchy-feely experimental research. The results don't always conform to expectations.
Primordial matter has been a key target. Incredibly hot and dense, it existed for only microseconds after the "Big Bang" birth of our universe. Out of it came the first particles that formed the first atoms some 400,000 years after the bang. Today, many particles, including protons and neutrons that make up atomic nuclei, are themselves composed of entities physicists call quarks. These, in turn, are bound together in those particles by so-called gluons, which represent a very strong force. You never see quarks wandering about on their own.
Things were different during those first few microseconds. Quarks and gluons were free agents. Cosmologists thought they would have formed a gas of charged particles called a plasma. Now the Brookhaven team has shown that this theory is mistaken.
The team's experiments show that the quarks and gluons probably created what Brookhaven scientist Samuel Aronson calls "the most nearly perfect liquid ever observed." That means a liquid with very low viscosity and fast interaction among its particles. It's the kind of liquid that classical hydrodynamic theory was designed to handle.
Brookhaven's Relativistic Heavy Ion Collider created this liquid by smashing gold atoms together. Collisions produced microscopic fireballs 150,000 times hotter than the center of the Sun and 100 times denser than an atomic nucleus. Deciphering the bursts of particles and radiation streaming from these fireballs is just beginning. However, the four teams studying them with four different types of detectors agree that they probably have produced bits of the early universe. They also agree that this substance appears to conform to the classical theoretical ideal of a perfect liquid - a startling finding.
Meanwhile, another nagging unknown has yielded to sophisticated astronomical research. Einstein's theory of general relativity predicts that material mass, say a galaxy, will act like a lens to distort and magnify the image of a more distant object. The distorting effect has been seen many times. The magnification effect has been elusive. Several research teams have claimed to detect it. Their data aren't persuasive. Now the Sloan Digital Sky Survey - an international effort to understand the structure of our universe - claims success.
Instead of peering into the heavens, the survey team looked into data on 13 million galaxies and 200,000 of the extremely bright objects called quasars. "We took cutting-edge ideas from the world of computer science and statistics and applied them to our data," explains Gordon Richards at Princeton University. Einstein's predicted magnification effect is confirmed. So too is the consistency of modern cosmological theory based on Einstein's work.
We have only begun to unravel the mysteries of the universe. But research typified by Brookhaven's atom smashing sets a new gold standard for efforts to penetrate what once seemed beyond our ken.
