Hubble’s Law of the Universe Expanding

Although widely attributed to Edwin Hubble, the notion of the universe expanding at a calculable rate was first derived from the general relativity equations in 1922 by Alexander Friedmann. Friedmann published a set of equations, now known as the Friedmann equations, showing that the universe might expand, and presenting the expansion speed if this was the case. Then Georges LemaĆ®tre, in a 1927 article, independently derived that the universe might be expanding, observed the proportionality between recessional velocity of and distance to distant bodies, and suggested an estimated value of the proportionality constant, which when corrected by Hubble became known as the Hubble constant. Though the Hubble constant H0{displaystyle H_{0}} is roughly constant in the velocity-distance space at any given moment in time, the Hubble parameter H{displaystyle H}, which the Hubble constant is the current value of, varies with time, so the term ‘constant’ is sometimes thought of as somewhat of a misnomer. Moreover, two years later Edwin Hubble confirmed the existence of cosmic expansion, and determined a more accurate value for the constant that now bears his name.
Hubble inferred the recession velocity of the objects from their redshifts, many of which were earlier measured and related to velocity by Vesto Slipher in 1917.



Dr. Soderblom further explained to the press that the gravity signatures of the larger craters especially may shed new light into the number of impacts Earth's Moon, and other bodies in our Solar System, suffered during the asteroid-rampage that characterized the Late Heavy Bombardment. Jupiter is circled by a bewitching duo of moons that are potentially capable of nurturing delicate tidbits of life as we know it. Like its more famous sister-moon, Europa, Ganymede might harbor a life-loving subsurface ocean of liquid water in contact with a rocky seafloor. This special arrangement would make possible a bubbling cauldron of fascinating chemical reactions--and these reactions could potentially include the same kind that allowed life to evolve on our own planet! Second, there is the issue of sharing wealth. The Third World wants to redistribute wealth in its favor, and it pursues this end by a combination of moral persuasion and threats of terrorism using weapons of mass destruction. A frontier could make such threats less persuasive. The Third World reaction to a space frontier initiative is unpredictable and possibly violent. This makes pioneering a taboo for Western governments. And that's why they would keep it secret.