Studies of the CMB during the 1960s and 1970s revealed two basic facts. First, the “average temperature” of the universe was only about 3 degrees above Absolute Zero on the Kelvin scale (equivalent to -459 degrees F or -273 degrees C). Second, this was the observed temperature NO MATTER WHICH WAY YOU LOOKED INTO SPACE. This fact, along with some additional handwaving we won’t go into here, is basically why we think the universe blew up in a “big bang” and is still expanding today. In the 1980s a satellite called COBE discovered that although the AVERAGE temperature was indeed around 3 degrees K no matter where you looked, in fact some parts of the sky were hotter or colder by a mere millionth-of-a-degree. Doesn’t sound like much, and it isn’t – but it’s enough to give scientists significantly more data and almost religious levels of insight on what the initial “big bang” explosion had to be like. The COBE data was so exciting that NASA immediately sent up an even more sensitive satellite called MAP that is still slowly making a temperature map of the sky today in its ongoing mission. The problem with space missions like COBE and MAP is that they depend on a limited supply of liquid helium coolant to work – once the helium is gone, the mission is over.
The next best place to make temperature maps of the sky besides satellites in space is Antarctica. One instrument at the South Pole set up to do this is the Arcminute Cosmology Bolometer Array Receiver (ACBAR). In the past week, initial results from ACBAR have been released and they show that major new discoveries remain to be made regarding the CMB. In particular, the data seems to say our universe made of 65% dark energy, 30% so-called dark matter and only 5% of the normal-energy light and normal-matter atoms with which humans are familiar. MAP is expected to shed even more, er, light, on this 95% of the universe that is only now penetrating our awareness. No word yet on editing or correcting Genesis…