Only issues which have been published several peer-reviewed journals are mentioned here. This is not 'shady science'.
Discovered by NASA, JPL and Los Alamos National Laboratory, which have been studying this over the past 15 years without finding an explanation.
The main people behind this, John D. Anderson (JPL), Michael Martin Nieto (LANL) and Slava G. Turyshev (JPL) officially hope that they will find an easy explanation for this anomalous sunward acceleration, but also propose to launch a space mission to more properly research this phenomenon.
FIXME: needs links
When we do this for the entire universe, and several ways are available, we get a figure. If we then count the amount of matter we see, we find that a staggering 95% is missing.
Because saying that you can't find 95% sounds bad, the discussion has been reworded into the study of 'dark matter' - it isn't missing, we just can't see it right now. The magnitude of the problem can accurately be gauged by the fanciness of the theories proposed to explain this dark matter, which needs to be 20 times more prevalent than the 'light matter' we see:
This discussion is very open and nowhere near being solved. Renaming 'the missing mass problem' to 'Dark Matter Research' hasn't helped. No credible theories are available right now, mostly for lack of evidence. By its very nature, dark matter must be pretty hard to spot!
March 31 2003 UPDATE: The results are in! And they are even weirder than previously thought. 4% of matter consists of atoms we can see, 23% is 'Cold Dark Matter' and a staggering 73% is proposed to be the even more elusive 'Dark Energy', which is rapidly being renamed to 'Phantom Energy'.
The two obvious solutions to this problem are that the sun works differently or that the neutrinos disappear before we can measure them.
The debate has raged since 1962. Currently we believe that while travelling from the sun to the earth, part of the neutrinos 'oscillate' into a variety we cannot detect.
This oscillation however means that the neutrino has suddenly acquired a mass which, even when tiny, has huge consequences. In short, if neutrinos have mass, they don't travel at the speed of light anymore. However, in the SN1987a supernova, the neutrinos arrived 18 hours before the photons. This in itself does not prove anything but it certainly does not prove that neutrinos move slower than light.
Low temperature superconductivity is explained pretty well in a 1957 publication by John Bardeen, Leon N. Cooper, and J. Robert Schrieffer, known as the BCS theory, for which they were awarded the 1972 Nobel prize. The idea is that two electrons gang together to form a de facto boson which, like the bosonic photon, is transparent to other bosons and can thus travel without resistance.
In 1986 high-temperature superconductivity was discovered (leading to an uprecedentedly quick 1987 Nobel prize) for which the BCS theory does not hold - at higher temperatures the so-called Cooper pair boson cannot normally form.
There are literally thousands of theories on how high temperature superconductivity would work but none of these are definite and many of them are more like agglomerations of a number of ideas which put together give the right answers - but not a sense of explanation.
Many will claim that high temperature superconductivity is explained but as of late 2004, this is simply not true.