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In cosmology, a Hubble volume (named for the astronomer Edwin Hubble) or Hubble sphere, Hubble bubble, subluminal sphere, causal sphere and sphere of causality is a spherical region of the observable universe surrounding an observer beyond which objects recede from that observer at a rate greater than the speed of light due to the expansion of ...
Hubble radius, Hubble sphere (not to be confused with a Hubble bubble), Hubble volume, or Hubble horizon is a conceptual horizon defining the boundary between particles that are moving slower and faster than the speed of light relative to an observer at one given time. Note that this does not mean the particle is unobservable; the light from ...
The Hubble eXtreme Deep Field (XDF) was completed in September 2012 and shows the farthest galaxies ever photographed at that time. Except for the few stars in the foreground (which are bright and easily recognizable because only they have diffraction spikes), every speck of light in the photo is an individual galaxy, some of them as old as 13.2 billion years; the observable universe is ...
Specifically, using 1-D models, which represent Earth as a single point (instead of something that varies across 3 dimensions) scientists have determined that at 4.5 Ga, with a 30% dimmer Sun, a minimum partial pressure of 0.1 bar of CO 2 is required to maintain an above-freezing surface temperature; 10 bar of CO 2 has been suggested as a ...
Hubble's early estimate of his constant [3] was 550 (km/s)/Mpc, and the inverse of that is 1.8 billion years. It was believed by many geologists in the 1920s that the Earth was probably around 2 billion years old, but with large uncertainty. [4]
By way of comparison, Hubble orbits 550 km (340 mi) above Earth's surface, and the Moon is roughly 400,000 km (250,000 mi) from Earth. Objects near this Sun–Earth L 2 point can orbit the Sun in synchrony with the Earth, allowing the telescope to remain at a roughly constant distance [29] with continuous orientation of its sunshield and ...
Volume of a red giant the same mass as the Sun 1.4 × 10 33: Volume of γ Crucis, a red giant in Crux [10] [11] ~1 × 10 34: Volume of Deneb, a white supergiant in Cygnus [12] 6.4 × 10 34: Volume of η Carinae, a white supergiant in Cygnus [12] 1.3 × 10 35: Estimated volume of S Orionis [13] 1.5 × 10 35: Volume of Antares, a Mira variable in ...
The Hubble constant, named for astronomer Edwin Hubble, whose work made clear the expansion of the universe, measures the rate at which expansion occurs. In accordance with the Copernican principle that the Earth is not in a central, specially favored position, one would expect that measuring this constant at any point in the universe would ...