13 Things That Do Not Make Sense

13 Things that do not Make Sense -- NewScientist reports on 13 areas in science that is in need of more studying. These are areas where observations just don't jive with theory. The 13 are: 1) the placebo effect - why do placebos work just as well as the cure? 2) the horizon problem - the universe has a uniform temperature, that inflation was concocted to explain - scientists just aren't too comfortable with it however. (See also Wikipedia.) 3) ultra-energetic cosmic rays [PDF] - we detect some pretty energetic cosmic rays, yet, according to theories, they should have lost energy before arriving at Earth; 4) Belfast homeopathy results - homeopathy works ... sometimes when there is little or no active ingredient ... why? 5) Dark Matter - what is the stuff? If it is there at all. 6) Viking's methane - and evidence for life on Mars. 7) Tetraneutrons [PDF] - in 2001, researchers detected four neutrons bound together in a way that defied the laws of physics. Is it real? 8) The Pioneer anomaly - Pioneer 10 & 11 are at the outer reaches of our solar system, but for some reason, they have been slowly veering off course. In the case of Pioneer 10, by about 400,000 km. What's pulling them off course? 9) Dark Energy - the rate of expansion of the universe is growing. What gives? Dark energy. Oh, sure! 10) The Kuiper cliff - past Pluto, into the outer reaches of the solar system, lies the Kuiper belt, made up of remnants of the early solar system. But it falls off suddenly. The Kuiper cliff. What caused it? Speculation is of a 10th planet. As large as Earth perhaps. 11) The Wow signal - in 1977, a 37 second radio signal was picked up from the direction of Sagittarius. Since then, nothing. What was it? 12) Not-so-constant constants - a signal from distant quasars received in 1997 revealed something unexpected. On its 12-billion-year journey, unexpected frequencies were absorbed by interstellar clouds. The only explanation that seems to make sense is that the fine structure constant was different in the past. 13) Cold fusion - there are still cold fusion experiments going on, and there are many believers, even if it is impossible by accepted scientific theories. Could the theories be wrong?