3 ms·

If space is discretized, we should see "upscaling artifacts" in the CMB, but we don't.

by astrange 2y ago

defrost 2y ago
Maybe we would .. but Musk has to turn off his leaky Starlink over the Murchison (not so) Quiet (anymore) Zone first.
- astrange 2y ago
  We got space telescopes and stuff.
  - defrost 2y ago
    More expensive, harder to maintain and keep current, and a tangent to the core matter; Starlink satellites leak radiation and could be shielded, Starlink satellites could be {switched off | turned low} off over Quiet Zones but are not. Statements were made that shielding would improve after Ver 1.0 .. it got worse. Statements were made that sats would go low power over quiet zones, they do not. Returning to your erudite point "and stuff" The NASA Cosmic Background Explorer (COBE) satellite orbited Earth in 1989–1996 ... Inspired by the COBE results, a series of ground and balloon-based experiments measured cosmic microwave background anisotropies on smaller angular scales ... The sensitivity of the new experiments improved dramatically, with a reduction in internal noise by three orders of magnitude. ~ https://en.wikipedia.org/wiki/Cosmic_microwave_background https://en.wikipedia.org/wiki/Cosmic_microwave_background Hmmm, it appears the ground based results were a dramatic improvement over the sat based data.
    - mensetmanusman 2y ago
      A moon base with regular travel might make maintenance on the dark side of the moon possible.
      - defrost 2y ago
        Sure, when we get there again, can make regular trips, and have consequence free energy to burn that'd be great. In the interim, and as a general rule for all private entities, it'd be nice to not pollute the commons with unnecessary discharges and sparkles and to carry through on pinky promises to maybe do something about that.
        mensetmanusman 2y ago
        It might be a necessary intermediate for advanced civilizations.
    - LargoLasskhyfv 2y ago
      > More expensive, harder to maintain and keep current... Not necessarily so? https://en.wikipedia.org/wiki/Xuntian https://en.wikipedia.org/wiki/Xuntian As of 2024, Xuntian is scheduled for launch no earlier than late 2026 on a Long March 5B rocket to co-orbit with the Tiangong space station in slightly different orbital phases, which will allow for periodic docking with the station.
      - defrost 2y ago
        It's unclear what your point is. Leaving aside the fact that an optical telescope isn't a microwave array nor is it a Square Kilomtre Array of radio telescopes with each component larger than your example ... Putting an instrument in orbit has all the costs of development of a ground based instrument, additional costs to space harden and test, additional costs to lift, limited ability to tune, tweak or extend when in orbit, hard constraints on size and weight, and other issues. Xuntian allows for periodic docking, sure. How will this not be more expensive and limited than (say) walking | driving out daily or weekly to much lager instruments on the ground?
        LargoLasskhyfv 2y ago
        > Leaving aside the fact that an optical telescope isn't a microwave array... https://en.wikipedia.org/wiki/Xuntian#Instruments https://en.wikipedia.org/wiki/Xuntian#Instruments <- Terahertz receiver ( https://en.wikipedia.org/wiki/Terahertz_radiation https://en.wikipedia.org/wiki/Terahertz_radiation This band of electromagnetic radiation lies within the transition region between microwave and far infrared, and can be regarded as either. ) > Putting an instrument in orbit has all the costs of development of a ground based instrument, additional costs to space harden and test, additional costs to lift, limited ability to tune, tweak or extend when in orbit, hard constraints on size and weight, and other issues. Who is to say they won't pull a Space-X, maybe even overtaking it, going fully reusable? Which allegedly lowers the costs, giving more economically access to space and lessening the constraints on payloads, while giving all the advantages of being in space?
        2y ago
naasking 2y ago
This is a common belief and true of many discrete models because they violate symmetries, but that is not true of all discrete models: A Noether Theorem for discrete Covariant Mechanics, https://arxiv.org/abs/1902.08997 https://arxiv.org/abs/1902.08997

If space is discretized, we should see "upscaling artifacts" in the CMB, but we don't.

defrost 2y ago

Maybe we would .. but Musk has to turn off his leaky Starlink over the Murchison (not so) Quiet (anymore) Zone first.

astrange 2y ago
We got space telescopes and stuff.
- defrost 2y ago
  More expensive, harder to maintain and keep current, and a tangent to the core matter; Starlink satellites leak radiation and could be shielded, Starlink satellites could be {switched off | turned low} off over Quiet Zones but are not. Statements were made that shielding would improve after Ver 1.0 .. it got worse. Statements were made that sats would go low power over quiet zones, they do not. Returning to your erudite point "and stuff" The NASA Cosmic Background Explorer (COBE) satellite orbited Earth in 1989–1996 ... Inspired by the COBE results, a series of ground and balloon-based experiments measured cosmic microwave background anisotropies on smaller angular scales ... The sensitivity of the new experiments improved dramatically, with a reduction in internal noise by three orders of magnitude. ~ https://en.wikipedia.org/wiki/Cosmic_microwave_background https://en.wikipedia.org/wiki/Cosmic_microwave_background Hmmm, it appears the ground based results were a dramatic improvement over the sat based data.
  - mensetmanusman 2y ago
    A moon base with regular travel might make maintenance on the dark side of the moon possible.
    - defrost 2y ago
      Sure, when we get there again, can make regular trips, and have consequence free energy to burn that'd be great. In the interim, and as a general rule for all private entities, it'd be nice to not pollute the commons with unnecessary discharges and sparkles and to carry through on pinky promises to maybe do something about that.
      - mensetmanusman 2y ago
        It might be a necessary intermediate for advanced civilizations.
  - LargoLasskhyfv 2y ago
    > More expensive, harder to maintain and keep current... Not necessarily so? https://en.wikipedia.org/wiki/Xuntian https://en.wikipedia.org/wiki/Xuntian As of 2024, Xuntian is scheduled for launch no earlier than late 2026 on a Long March 5B rocket to co-orbit with the Tiangong space station in slightly different orbital phases, which will allow for periodic docking with the station.
    - defrost 2y ago
      It's unclear what your point is. Leaving aside the fact that an optical telescope isn't a microwave array nor is it a Square Kilomtre Array of radio telescopes with each component larger than your example ... Putting an instrument in orbit has all the costs of development of a ground based instrument, additional costs to space harden and test, additional costs to lift, limited ability to tune, tweak or extend when in orbit, hard constraints on size and weight, and other issues. Xuntian allows for periodic docking, sure. How will this not be more expensive and limited than (say) walking | driving out daily or weekly to much lager instruments on the ground?
      - LargoLasskhyfv 2y ago
        > Leaving aside the fact that an optical telescope isn't a microwave array... https://en.wikipedia.org/wiki/Xuntian#Instruments https://en.wikipedia.org/wiki/Xuntian#Instruments <- Terahertz receiver ( https://en.wikipedia.org/wiki/Terahertz_radiation https://en.wikipedia.org/wiki/Terahertz_radiation This band of electromagnetic radiation lies within the transition region between microwave and far infrared, and can be regarded as either. ) > Putting an instrument in orbit has all the costs of development of a ground based instrument, additional costs to space harden and test, additional costs to lift, limited ability to tune, tweak or extend when in orbit, hard constraints on size and weight, and other issues. Who is to say they won't pull a Space-X, maybe even overtaking it, going fully reusable? Which allegedly lowers the costs, giving more economically access to space and lessening the constraints on payloads, while giving all the advantages of being in space?
        2y ago

naasking 2y ago

This is a common belief and true of many discrete models because they violate symmetries, but that is not true of all discrete models: A Noether Theorem for discrete Covariant Mechanics, https://arxiv.org/abs/1902.08997 https://arxiv.org/abs/1902.08997