Dark Energy And The Joy Of Being Wrong

It wasn't long ago that we thought expansion of the universe was slowing down. Whoops! Science then identified Dark Energy as a force acting against deceleration. The discovery upended cosmology almost overnight.

by Adam Frank

WMAP/NASA

Sometimes nature just throws you a loop. All your carefully laid plans, all your exquisite calculations, all your deeply held beliefs and expectations get blown away in the simple eloquence of real data from the real world. That is how Dark Energy made its appearance into the world of cosmology. Its not just that folks weren't expecting it. They were, in fact, expecting the very opposite. Last week I explained how Dark Matter was "discovered" (inferred really), based on observations over decades of the gravitational influence it exerts on matter we can see (the stuff we are made of). Dark Energy was discovered in a similar way, except that it arrived all at once in one big, fat surprise package. The year was 1998 and two highly competitive groups of astronomers were each rushing toward the same goal: they hoped to ...