Gre powerprep 2 quant solution h is the midpoint

Several long-baseline interferometric gravitational-wave detectors planned over a decade ago, GEO, VIRGO and TAMA ] have begun initial operations with unprecedented sensitivity levels and wide bandwidths at acoustic frequencies (10 HzвЂ“10 kHz). It might turn out to be as complex and interesting as the charged minor component, the part that we call вЂњnormalвЂќ matter.

Given that 96% of the mass-energy of the universe carries no charge, gravitational waves provide us with our first opportunity to observe directly a major part of the universe. These contrasts, and the history of serendipitous discovery in astronomy, all suggest that electromagnetic observations may be poor predictors of the phenomena that gravitational wave detectors will eventually discover. Electromagnetic waves couple strongly to charges and so are easy to detect but are also easily scattered or absorbed by material between us and the source gravitational waves couple extremely weakly to matter, making them very hard to detect but also allowing them to travel to us substantially unaffected by intervening matter, even from the earliest moments of the Big Bang. By contrast, gravitational waves are emitted by the cumulative mass and momentum of entire systems, so they have long wavelengths and convey direct information about large-scale regions. The primary emitters of electromagnetic radiation are charged elementary particles, mainly electrons because of overall charge neutrality, electromagnetic radiation is typically emitted in small regions, with short wavelengths, and conveys direct information about the physical conditions of small portions of the astronomical sources. The gravitational wave spectrum is completely distinct from, and complementary to, the electromagnetic spectrum. But, in addition, the potential of gravitational wave observations to produce more surprises is very high. There is keen interest in observing gravitational waves directly, in order to test EinsteinвЂ™s theory of general relativity and to observe some of the most exotic objects in nature, particularly black holes. Within a few years another new window on the universe will open up, with the first direct detection of gravitational waves. None of these discoveries was anticipated by the observing team, and in many cases the instruments were built to observe completely different phenomena. The fact that the expansion of the universe is accelerating (two teams ), which has led to the hunt for the nature of dark energy. ), which are not fully explained even today Gamma-ray bursts coming from immense distances (Klebesadel et al. X-ray binary systems (Giacconi and collaborators ), which now enable us to make detailed studies of black holes and neutron stars

Pulsars (Hewish and Bell ), which opened up the study of neutron stars and illuminated one endpoint for stellar evolution The fact that quasi-stellar objects are at cosmological distances (Maarten Schmidt ), which has developed into the understanding that they are powered by supermassive black holes The relic cosmic microwave background radiation (Penzias and Wilson ), which has become our primary tool for exploring the Big Bang These serendipitous discoveries have included: Each new window of observation has brought new surprises that have dramatically changed our understanding of the universe. The last six decades have witnessed a great revolution in astronomy, driven by improvements in observing capabilities across the electromagnetic spectrum: very large optical telescopes, radio antennas and arrays, a host of satellites to explore the infrared, X-ray, and gamma-ray parts of the spectrum, and the development of key new technologies (CCDs, adaptive optics).

Gre powerprep 2 quant solution h is the midpoint