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One of the main ideas explained in this video is that the very early universe (i.e. the universe “right after the Big Bang” in cosmic timescales) might have bee

by adolph 3y ago

One of the main ideas explained in this video is that the very early universe (i.e. the universe “right after the Big Bang” in cosmic timescales) might have been habitable for a short period of time. During this time window, the right temperature to support life wouldn’t have been restricted to the proximity of stars, but would have instead taken place absolutely everywhere in space due to the intrinsic temperature of the universe itself. https://sites.google.com/view/sources-big-bang-life/ https://sites.google.com/view/sources-big-bang-life/ https://youtu.be/JOiGEI9pQBs?si=kOHM_l0saPkEhWcX https://youtu.be/JOiGEI9pQBs?si=kOHM_l0saPkEhWcX

anonymouskimmer 3y ago
> The second one is an observation about the rate at which the different genomes on Earth have changed over evolutionary history. When extrapolated back into the past, this evolution rate of genomes suggests that the current lineage of life on Earth might be at least 10 billion years old, I wonder to what extent the scientists who study these evolutionary clocks are able to factor in increasingly (or decreasingly) capable DNA replication and repair mechanisms. More faithful DNA replication and repair would artificially show a slower rate of genome evolution.
- adolph 3y ago
  It sometimes sounds the state of the art is headed there, see Cronin et al regarding “Assembly theory explains and quantifies selection and evolution” https://www.nature.com/articles/s41586-023-06600-9 https://www.nature.com/articles/s41586-023-06600-9
nkrisc 3y ago
We often think about life arising in one location and then spreading across the galaxy or universe. Quite interesting to consider instead life arising everywhere and then being reduced to only a few (maybe one) remaining pockets across the entire universe, or not at all. Of course that likely doesn’t apply to life as we know it, assuming our estimates of the age of the sun and the universe are correct.
s1artibartfast 3y ago
My understanding is the time when the universe was at life supporting temperatures, was long before the formation of the first stars and fusion of heavier atoms than hydrogen. It is hard to imagine life without a large variety of atoms.
- JumpCrisscross 3y ago
  > the time when the universe was at life supporting temperatures, was long before the formation of the first stars and fusion of heavier atoms than hydrogen Stars with rocky planets during the habitable epoch "lie ∼8.5 standard deviations (σ) away on the exponential tail of the Gaussian probability distribution of initial density perturbations," though "their abundance could have been significantly enhanced by primordial non-Gaussianity." [1] https://arxiv.org/pdf/1312.0613.pdf https://arxiv.org/pdf/1312.0613.pdf
  - s1artibartfast 3y ago
    Interesting! It Sounds like the paper supports my statement as a generalization, but explores extreme outliers in stellar formation. It sounds like there is a chance some atomic fusion could have occurred at this time, but It would be isolated to a few instances in our light cone. This is a pretty different than the entire universe awash in favorable conditions to life.

by adolph 3y ago

anonymouskimmer 3y ago

> The second one is an observation about the rate at which the different genomes on Earth have changed over evolutionary history. When extrapolated back into the past, this evolution rate of genomes suggests that the current lineage of life on Earth might be at least 10 billion years old, I wonder to what extent the scientists who study these evolutionary clocks are able to factor in increasingly (or decreasingly) capable DNA replication and repair mechanisms. More faithful DNA replication and repair would artificially show a slower rate of genome evolution.

adolph 3y ago
It sometimes sounds the state of the art is headed there, see Cronin et al regarding “Assembly theory explains and quantifies selection and evolution” https://www.nature.com/articles/s41586-023-06600-9 https://www.nature.com/articles/s41586-023-06600-9

nkrisc 3y ago

We often think about life arising in one location and then spreading across the galaxy or universe. Quite interesting to consider instead life arising everywhere and then being reduced to only a few (maybe one) remaining pockets across the entire universe, or not at all. Of course that likely doesn’t apply to life as we know it, assuming our estimates of the age of the sun and the universe are correct.

s1artibartfast 3y ago

My understanding is the time when the universe was at life supporting temperatures, was long before the formation of the first stars and fusion of heavier atoms than hydrogen. It is hard to imagine life without a large variety of atoms.

JumpCrisscross 3y ago
> the time when the universe was at life supporting temperatures, was long before the formation of the first stars and fusion of heavier atoms than hydrogen Stars with rocky planets during the habitable epoch "lie ∼8.5 standard deviations (σ) away on the exponential tail of the Gaussian probability distribution of initial density perturbations," though "their abundance could have been significantly enhanced by primordial non-Gaussianity." [1] https://arxiv.org/pdf/1312.0613.pdf https://arxiv.org/pdf/1312.0613.pdf
- s1artibartfast 3y ago
  Interesting! It Sounds like the paper supports my statement as a generalization, but explores extreme outliers in stellar formation. It sounds like there is a chance some atomic fusion could have occurred at this time, but It would be isolated to a few instances in our light cone. This is a pretty different than the entire universe awash in favorable conditions to life.