A discussion of the high-resolution background-radiation image from
its relation to the COBE data.
Max Tegmark also discusses the background radiation in general.
World Wide Web homepages are available for the past cosmic-background radiation spacecraft, COBE, and for the future MAP and COBRAS/SAMBA missions.
The cosmic deuterium abundance is an important tracer of the density of the Universe, since all the deuterium was formed in the first few minutes after the Big Bang. NASA has approved the Far Ultraviolet Spectroscopic Explorer satellite (FUSE), to be launched in 1998 for a three-year mission. The ultraviolet spectrograph will be able to make measurements of deuterium in a variety of stars.
The concept of "duality," in which some equations can be solved in one system and then provide solutions for a separate set of "dual" systems, has provided some breakthroughs. An example of duality is quarks clumping to form monopoles (making monopoles composite objects) versus monopoles clumping to form quarks (making quarks composite objects).
The whole matter, and the latest in superstring theory and the related 10- or 11-dimensional spaces, is described by Scientific American Staff Writer Madhusree Mukerjee in Scientific American for January 1996, pp. 88-94. The article is rough going, but it is good to be brought up to date on the work of Ed Witten of the Institute for Advanced Study and others working in the field.
In one of the most exciting discoveries in a decade, physicists at the Fermi National Accelerator Laboratory announced the discovery of the top quark on March 2, 1995. Its mass is astonishingly large compared with the masses of the other quarks, which may well be telling us something important, though we don't know what (yet). The leader of one of the experimental groups said "This monster, compared with all the other quarks, is like a big cowbird's egg in a nest of little sparrow eggs. It's so peculiar it must hold clues to some important new physics."
The roster of quarks, and their masses, is now known to be:
where MeV stands for millions of electron-volts.
An experiment at the Los Alamos National Laboratory seems to have shown that neutrinos have a small mass, at least 0.5 electron-volt. (An electron's mass is 511,000 electronvolts.) Even with this low mass, neutrinos could provide a major fraction of the mass in the Universe. But there have been prior reports of neutrino mass that didn't pan out, so many scientists are waiting for this result to be confirmed before they accept it.
An excellent article on the age of the Universe, how it is derived, and the discrepancy between the younger age from Hubble-law determinations and the younger age from globular-cluster studies, appeared in Time magazine for March 6, 1995, pp. 76-84.