The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory doesn't have anywhere near the name recognition of the Large Hadron Collider (LHC) at CERN. But for the time being, it can lay claim to its own impressive achievement: it's just been recognized by Guinness World Records for achieving the "Highest Manmade Temperature." Go, RHIC!
The honor comes courtesy of the PHENIX collaboration, designed to study the formation and characteristics of the quark-gluon plasma (QGP), a state of matter believed to have existed for ten-millionths of a second after the universe's birth.
In those first fractions of a second, the universe was so hot that no nuclei could exist. Instead, there was the QGP, made of quarks and gluons (the massless particles that "carry" the force between quarks). But making this exotic plasma in a laboratory requires enormous energies.
That's where RHIC comes in. In RHIC's 2.4-mile-long ring, gold ions whip around the ring in both directions at once, further accelerated by strategically placed coils of wire that emit radiofrequency radiation. There are six different sites around the ring where collisions can occur.
When those gold nuclei collide head-on, a hot, dense plasma of quarks and gluons forms — or, more accurately, something akin to a near-frictionless liquid (a very surprising result, needless to say).
The folks at Guinness are right: It is the hottest temperature yet created by mankind: 4 trillion degrees Celsius, 250,000 times hotter than the center of the sun.
And here's the fascinating bit: physicists have now observed the same "near perfect liquid" state of matter at temperatures near absolute zero.
That's a whopping ten million trillion times colder than RHIC's quark-gluon plasma, according to Brookhaven physicist Steve Vigdor. "This is just one among many unexpected connections we've found between RHIC physics and other scientific forefronts," he told the Bits and Bytes blog. "The unity of physics is a beautiful thing!"
As impressive as this achievement is, RHIC has some pretty stiff competition coming down the pike, by the name of ALICE (A Large Ion Collider Experiment). ALICE is one of the other major collaborations at the LHC. Unlike ATLAS and CMS, which are focused on hunting for the Higgs boson, ALICE is focused on studying the QCP and other conditions in the primordial universe.
That means ALICE needs to create ultra-high temperatures, and it's also a newer machine. CERN physicist Despina Hatzifotiadou told Bits and Bytes that ALICE has an energy density three times higher than RHIC, translating into a 30 percent increase in absolutely temperature. "So I would say that ALICE has the record."
Ah, but the good scientists of ALICE have yet to publish an official temperature measurement — and that's what those sticklers at Guinness require before conferring such an honor on a candidate. SO for now, at least, RHIC still wins on a technicality.
Images: (top) A silicon pixel detector within ALICE. Source: Brookhaven/RHIC.