Is that BEC in your laser-cooled magnetic trap, or are you just happy to see me?

evaporative cooling animated gif of Bose-Einstein condensate

As the temperature drops, the atoms suddenly collapse into a different state of matter, Bose-Einstein condensate (BEC)

The face of BEC, by Michael Hanna for

because it’s always nice to put a face with a name (even if it’s the name of a state of matter)

Carl Weiman and Eric Cornell

SUPERCOOL: Carl Weiman and Eric Cornell, the guys who made BEC in 1995.

On June 5, 1995, two guys made a really cold lump of Rubidium, and the world was never the same.

That’s right: it was 18 years ago today that Eric Cornell and Carl Weiman brought about 2,000 rubidium-87 atoms within 170 billionths of a degree from absolute zero. When you get something that cold, it “condenses” into a different state of matter (solid, liquid, gas, and plasma are the four most common states of matter). This state of matter was first predicted by Satyendra Nath Bose and Albert Einstein in 1924–25. Named after its predictors, the stuff is called Bose-Einstein condensate (BEC for short).

I’ve thrown in a couple of my own graphic representations (because it’s always nice to put a face with a name…), but the rest of this stuff comes from the University of Colorado Physics 2000 web portal. You really should check out their evaporative cooling applet. It’s very cool. In more ways than one.

BEC face equation for

if you get these two guys cold enough…

Bose-Einstein Condensation at 400, 200, and 50 nano-Kelvins

Bose-Einstein Condensation at 400, 200, and 50 nano-Kelvins

c + e


“Which came first, the chicken or the egg?”

This age-old question has been at the center of more than a few academic feuds over the years. Its polarizing effect has left a sharp and bitter divide in the world of Higher Rhetoric, much like Einstein and Bohr split the 20th-century physics community.

Last I heard, there was no consensus. Did the first chicken lay the first egg? Or did the first egg hatch the first chicken?

It’s really a question of cause and effect. Cause precedes effect, so we might say that the first chicken was the CAUSE of the first egg (the EFFECT of the first hen a-laying). Similarly, we might say that the first egg was the CAUSE of the first chicken (the EFFECT of the first egg a-hatching).

One day, while diagramming the chicken-and-egg question (something I do from time to time), I made an astonishing discovery. I had used the variables “C” and “E” to represent “CAUSE” and “EFFECT” (respectively). Since “cause” begins with a “C” and “effect” begins with an “E”, this seemed a logical choice.

But wait…what is another word that begins with “C”? CHICKEN. And another word that begins with “E”? EGG.

Coincidence? I think not.


If E = EFFECT and E = EGG, then EGG = EFFECT.

Since cause, by definition, precedes effect, we can safely say that the chicken preceded the egg.