The atmosphere is thin (the pole is more than 9,300 feet above sea level, 9,000 of which are ice). One afternoon the telescope’s laboratory building got so warm the crew propped open a door.To minimize these problems, astronomers who analyze microwaves and submillimeter waves have made the South Pole a second home. All sorts of other things may be exerting a gravitational influence.Scientists have a couple of candidates for the composition of dark matter—hypothetical particles called neutralinos and axions. “We just assumed that it did.”Yet cosmologists tend not to be discouraged. The new base station resembles a small cruise ship more than a remote outpost and sleeps more than 150, all in private quarters. Their instruments reside in the Dark Sector, a tight cluster of buildings where light and other sources of electromagnetic radiation are kept to a minimum. The atmosphere is also stable, due to the absence of the heating and cooling effects of a rising and setting Sun; the pole has some of the calmest winds on Earth, and they almost always blow from the same direction.The effort to understand dark matter defined much of astronomy for the next two decades. One leading hypothesis is that dark matter consists of exotic particles that don't interact with normal matter or light but that still exert a gravitational pull. Last year we celebrated the 400th anniversary of Galileo’s answer: Yes. The peaks of those oscillations represent regions that were slightly denser than the rest of the universe. In particular, astronomers want to know if dark energy changes over space and time, or whether it’s constant. It includes sound waves (“acoustic oscillations”) that coursed through the infant universe. But that explanation still leaves scientists clueless as to why the strange force exists in the first place.Dark matter could also explain certain optical illusions that astronomers see in the deep universe.
For over ten years, the dark side of the universe has been headline news. So far, they do.They already knew that the universe is expanding. Turner gave the “something” a nickname: dark energy. If spiral galaxies contained enough of such mystery mass, then they might well be obeying the laws of gravity. It stuck. Humid air can absorb microwaves and prevent them from reaching the telescope, and moisture emits its own radiation, which could be misread as cosmic signals.Astronomers like to say that for more pristine observing conditions, they would have to go into outer space—an exponentially more expensive proposition, and one that NASA generally doesn’t like to pursue unless the science can’t easily be done on Earth.
Fortunately, the badly outnumbered 4% of luminous matter feels the dark side through gravity and other forces. The beam’s target is one of three suitcase-size reflectors that Apollo astronauts planted on the lunar surface four decades ago. “There are always little things. Photons from the beam bounce off the mirror and return to New Mexico. Total round-trip travel time: 2.5 seconds, more or less.But what if some portion of a galaxy’s mass didn’t radiate light?