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Results tagged with Search options user 2618

Questions regarding all of time and space and its contents.

15
votes
This question begs the question, does everything need a practical use? The answer is a resounding no. What's the practical use of the Louvre, or of your local neighborhood public park where you enjoy …
answered Apr 1 '15 by David Hammen
1
vote
How to fix a direction in the context of universe? Simple (or not so simple): Use the remote stars, or even better, use the extremely remote quasars. The former is what astronomers have done for …
answered Jan 25 '18 by David Hammen
15
votes
years, less than the age of the universe. Also note that that 0.8 billion years uncertainty is the standard error, or roughly one standard deviation. That revised age of 14.27 billion years makes the … dilemma essentially non-existent. That's older than the estimate age of the universe by 0.4 to 0.5 million years, and this is not significant even at the one sigma level. Particle physicists generally …
answered Dec 19 '16 by David Hammen
7
votes
Planets and stars are roundish due to gravity. The gravitational attraction of an object to other parts of itself grows as objects get ever larger. This self gravitational attraction is negligible for …
answered Nov 22 by David Hammen
3
votes
universe (regular matter vs dark matter, the Hubble constant, whether the universe is open, flat, or closed, etc.), and by assuming that that galaxy was and our galaxy is more or less moving with the … second calculation that is rather misleading. There's an underlying assumption in this calculation that the universe is not expanding. The universe is expanding, so it's not quite valid to multiple very …
answered Jul 17 '18 by David Hammen
8
votes
So, assuming my assumptions aren't assinine (they very well could be) ... Your words, not mine. Your "very well could be" is the case. Assume the universe is infinite The universe might well … be infinitely large, but the observable universe is all that we can possibly see. By all signs, the universe is 13.8 billion years old. We can't see the stuff that is beyond the observable universe
answered Aug 19 '17 by David Hammen