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Eternally Causal

Questions about what happened before creation, its onset, or the big bang. Plenty of speculation, but no one knows what put the Universe in place or how it formed. Is the presence of time within this Universe unique? Is there no such thing as time among other Universes, were they to exist?

Range of Light

This shot from the NASA/ESA Hubble Space Telescope shows a maelstrom of glowing gas and dark dust within one of the Milky Way’s satellite galaxies, the Large Magellanic Cloud (LMC). This stormy scene shows a stellar nursery known as N159, an HII region over 150 light-years across. N159 contains many hot young stars. These stars are emitting intense ultraviolet light, which causes nearby hydrogen gas to glow, and torrential stellar winds, which are carving out ridges, arcs, and filaments from the surrounding material. At the heart of this cosmic cloud lies the Papillon Nebula, a butterfly-shaped region of nebulosity. This small, dense object is classified as a High-Excitation Blob, and is thought to be tightly linked to the early stages of massive star formation. N159 is located over 160 000 light-years away. It resides just south of the Tarantula Nebula (heic1402), another massive star-forming complex within the LMC. It was previously imaged by Hubble’s Wide Field Planetary Camera 2, which also resolved the Papillon Nebula for the first time.

There comes a point when the rate of expansion of the universe outpaces the speed of light (c). Meaning, the universe shall or does expand beyond our ability to ever observe it or measure its full reach. 1 Gly = 1 Billion Light Years. We can see 13.7 billion light years out. The size of the universe is so far about 46.4 billion light years in all.

“1.3 x 1026 = 13.7 Gly = 4.22 Gpe (redshift z~1,089): Hubble radius of the Universe measured as the light travel distance to the source of cosmic background radiation; 

4.3 x 1026 = 46.4 Gly = 14 Gpc: particle horizon (present radius of the Universe measured as a comoving distance); it is larger than the Hubble radius, since the Universe is expanding). Also, it is ~ 2% larger that the radius of the visible universe, which includes only signals emitted later than ~380,000 years after the Big Bang; 

62 Gly: cosmological event horizon (or future visibility limit): the larges comoving distance from which light will ever reach us at any time in the future. 

The size of the whole Universe can be now much larger that the size of the observable one, even infinite, if its curvature is 0. If the Universe will be 1031 = 1014 years (last red dwarf stars die) and 1037 in 1020 years (stars have left galaxies). If protons decay, their half-life is >= 1035 years; the estimated number of protons in the Universe is 1077 

The Universe, in the current Heat Death scenario, achieves beyond 101000 years such a low-energy state that the quantum events become major macroscopic phenomena, and space-time loses its usual meaning again, as below the Planck time or length;

The hypothesis of parallel universes estimates that one can find another identical copy of our Universe within the distance of 1030118 m.”

Pg. 543. Encyclopedia of Distances. 2nd Edition. Deza. 

Dying Light


Do not go gentle into that good night
Dylan Thomas, 1914 – 1953

“Do not go gentle into that good night,
Old age should burn and rave at close of day;
Rage, rage against the dying of the light.

Though wise men at their end know dark is right,
Because their words had forked no lightning they
Do not go gentle into that good night.

Good men, the last wave by, crying how bright
Their frail deeds might have danced in a green bay,
Rage, rage against the dying of the light.

Wild men who caught and sang the sun in flight,
And learn, too late, they grieved it on its way,
Do not go gentle into that good night.

Grave men, near death, who see with blinding sight
Blind eyes could blaze like meteors and be gay,
Rage, rage against the dying of the light.

And you, my father, there on the sad height,
Curse, bless, me now with your fierce tears, I pray.
Do not go gentle into that good night.
Rage, rage against the dying of the light.”