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abstraction > mathematical concept > number > constant > astronomical constant > omega

omega
subject			fact

omega	has definition Heavy short-lived baryon.
	has definition The ratio of the average density of mass in the universe to the critical mass density, the latter being the density of mass needed to eventually halt the outward expansion of the universe. In an open universe, omega is always less than 1; in a closed universe, it is always greater than 1; in a flat universe it is always exactly equal to 1. Unless omega is exactly equal to 1, it changes in time, constantly decreasing in an open universe and constantly increasing in a closed universe. Omega has been measured to be about 0.1, although such measurements are difficult and uncertain. (See critical mass density; closed universe; flat universe; open universe.)
	is an instance of hyperon
	is an instance of astronomical constant
hyperon	has lifetime 10-8 to 10-10 seconds
	has spin 1/2 or 3/2
baryon	has number of quarks 3
radioactive particle	has desintegration energy the total energy produced when the particle decays
	has decay products the products produced immediately after decay
number	has value
fermion	has quantum behavior Fermi-Dirac statistics
	obeys exclusion principle
particle	obeys uncertainty principle
	has frequency inversely proportional to the wavelength
	has wavelength inversely proportional to its momentum
	has charge
	has mass
physical object	has location or center of gravity
	has angular momentum
	has velocity
	has momentum
	has temperature
	has volume
	has extent
	has material

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