3 ms·

Hubble's law: https://en.wikipedia.org/wiki/Hubble%27s_law https://en.wikipedia.org/wiki/Hubble%27s_law Expansion of the universe: https://en.wikipedia.org/wik

Hubble's law: https://en.wikipedia.org/wiki/Hubble%27s_law https://en.wikipedia.org/wiki/Hubble%27s_law Expansion of the universe: https://en.wikipedia.org/wiki/Expansion_of_the_universe https://en.wikipedia.org/wiki/Expansion_of_the_universe : > While objects cannot move faster than light, this limitation only applies with respect to local reference frames and does not limit the recession rates of cosmologically distant objects Given that v is velocity in the opposite direction, and c is the constant reference frame speed of light; do we account for velocity in determining whether light traveling at c towards earth will ever reach us? v - c < 0 if v>c v + c > c if v>0 Are tachyons FTL, is there entanglement FTL? How far away in light years does a mirror in space need to be in order to see dinosaurs that existed say 100 million years ago?

blackbear_ 3y ago
> do we account for velocity in determining whether light traveling at c towards earth will ever reach us? As far as I know this is not necessary because the speed of light is constant regardless of the velocity of both the source and the observer (this is Einstein's special relativity: https://en.m.wikipedia.org/wiki/Special_relativity https://en.m.wikipedia.org/wiki/Special_relativity)
- westurner 3y ago
  > Expansion of the universe: https://en.wikipedia.org/wiki/Expansion_of_the_universe https://en.wikipedia.org/wiki/Expansion_of_the_universe : >> While objects cannot move faster than light, this limitation only applies with respect to local reference frames and does not limit the recession rates of cosmologically distant objects Then the length traveled changes for two photons emitted when they cross the starting line at different velocities: const d = distance = 1 # d_start = 0 # d_finish = d c: Velocity # of a photon in a vacuum v1: Velocity # of photon emission source 1 v2: Velocity # of photon emission source 2 v1 + c != v2 + c distance / (v1 + c) ?= distance / (v2 + c) ((v1 + c)*t) - ((v2+c)*t) ?!= 0 Should (v + c) be prematurely reduced to just (c), with a confirmed universal expansion rate?
arbitrage 3y ago
Tachyons aren't a thing. Tachyons are sci-fi nonsense. Nothing in the universe can travel faster than the speed of light. This does not hold for the universe itself. It can and does expand faster than the speed of light, using specific reference frames (i.e., big enough). So, space can increase FTL. Particles do not travel faster than light tho, that is nonsense.
- rthnbgrredf 3y ago
  Well, we have (virtual) particles that can travel backwards in time, without breaking causality. There's no proof that Tachyons exist, they are purely hypothetical, but they are not outright nonsense.
  - westurner 3y ago
    From https://news.ycombinator.com/item?id=38045112#38047149 https://news.ycombinator.com/item?id=38045112#38047149 : > from https://news.ycombinator.com/item?id=35877402#35886041 https://news.ycombinator.com/item?id=35877402#35886041 : "EM Wave Polarization Transductions" Lt. Col. T.E Bearden (1999) : >> Physical observation (via the transverse photon interaction) is the process given by applying the operator ∂/∂t to (L^3)t, yielding an L3 output [and "time-polarized photons"]
- cbolton 3y ago
  Take a star in a region of the universe that recedes from us at 3c. In what sense is the star not traveling faster than the speed of light relative to us?
  - westurner 3y ago
    . v - c < 0 -3c + c = 2c +3c - c = 2c
- westurner 3y ago
  If the universe is expanding faster than the speed of light, how are particles not traveling faster than the speed of light indeed with zero acceleration relative to the expansion? If the Copenhagen interpretation is correct, particle states are correlated after a photonic beam splitter; if you measure entangled photons after a beam splitter, their states are still linked. If virtual particle states are entangled with particle states in black holes or through ER=EPR bridges, is there effectively FTL? There is FTL within dielectric antennae.
a_random_canuck 3y ago
> do we account for velocity in determining whether light traveling at c towards earth will ever reach us? No, because the speed of light is constant for all observers. From our frame of reference on earth, light from distant receding galaxies is always moving towards us at exactly the speed of light, c. Those galaxies also observe the light moving away from them at exactly c. That seems contradictory and unintuitive, that two observers moving away from each other both measure light moving c relative to themselves, but that’s reality. It’s another measurement that changes: if c is always constant, then it must be the passage of time and the distance travelled that we observe differently.
- pigpang 3y ago
  > That seems contradictory and unintuitive, that two observers moving away from each other both measure light moving c relative to themselves, but that’s reality. Light is a wave. Photon is a complex thing (Hopfion?), but it's a wave, so it waves something, a medium. Speed of wave propagation in a medium is constant. IMHO, it's intuitive.
  - mrguyorama 3y ago
    >but it's a wave, so it waves something, a medium. Which was unobserved in the michleson-morely experiment and other followup experiments because....?
    - pigpang 3y ago
      LIGO/Virgo are better version of Michelson-Morely experiment. Gravitational waves are found, so existence of a medium is confirmed.
      - mrguyorama 3y ago
        Gravitational waves existing doesn't confirm the existence of a medium any more than discovering light behaves like a wave confirms the existence of the aether. If you want to posit that light has a medium, you need to redo 100 years of physics, so start showing your work. You mention elsewhere "doing a calculation", and that's just not nearly good enough. You want to overturn perfectly working physics, you NEED to show up with receipts. That's table stakes.
westurner 3y ago
> How far away in light years does a mirror in space need to be in order to see dinosaurs that existed say 100 million years ago? A mirror in a vacuum 1ly away will return the photonic signal from t=0 at t=2 light years, with diffraction (due to matter in [solid, liquid, gas, plasma, and superfluid/superconductor] phases describable with superfluid quantum gravity (e.g. Fedi's with Bernoulli pressure)) # m = meters # s = f(decay_rate_of_cesium_atom) # c = const x: meters/second Time = TimeInLightYears t_tx = t_transmitted: Time = 0 t_rx = t_received: Time d = distance: Time # d == d_ab == d_ba # t_tx, d, t_rx, test_data = [ [0, 0, 0.0], [0, 2, 1], [0, 1, 0.5], [-1, 0, None], [-100e6, 0, None], # dinosaurs ] @pytest.mark.parametrized('t_tx, d, t_rx', test_data) def test_test_data(ttx, d, trx'): assert trx == ttx + (2*d) m = scattering_matrix: # FluidDiffractionTensorMatrix assert is_YangBaxterMatrix(m) A water droplet [in space] reflects enough [photonic,] information to recover a modulated signal and also a curvilinear transformation of Escher looking into a crystal ball, with c the speed of light as a consideration only at cosmological distances. How large of water droplet, a regular or irregular spheroid or reflective and/or lensing matter configuration is necessary to reflect a sufficient amount of photonic information to recover information from cosmological information medium, in terms of constructor theory? Inverse scattering transform: https://en.wikipedia.org/wiki/Inverse_scattering_transform https://en.wikipedia.org/wiki/Inverse_scattering_transform R-matrix > R-matrix method in quantum mechanics: https://en.m.wikipedia.org/wiki/R-matrix https://en.m.wikipedia.org/wiki/R-matrix : > [now generalized for photonic diffraction] Quantum inverse scattering method > Procedure: https://en.wikipedia.org/wiki/Quantum_inverse_scattering_method#Procedure https://en.wikipedia.org/wiki/Quantum_inverse_scattering_met... : > 1. Take an R-matrix which solves the Yang–Baxter equation. > 2. Take a representation of an algebra T_R satisfying the RTT relations. [[clarification needed]] > 3. Find the spectrum of the generating function t(u) of the centre of T_R > 4. Find correlators

blackbear_ 3y ago

> do we account for velocity in determining whether light traveling at c towards earth will ever reach us? As far as I know this is not necessary because the speed of light is constant regardless of the velocity of both the source and the observer (this is Einstein's special relativity: https://en.m.wikipedia.org/wiki/Special_relativity https://en.m.wikipedia.org/wiki/Special_relativity)

westurner 3y ago
> Expansion of the universe: https://en.wikipedia.org/wiki/Expansion_of_the_universe https://en.wikipedia.org/wiki/Expansion_of_the_universe : >> While objects cannot move faster than light, this limitation only applies with respect to local reference frames and does not limit the recession rates of cosmologically distant objects Then the length traveled changes for two photons emitted when they cross the starting line at different velocities: const d = distance = 1 # d_start = 0 # d_finish = d c: Velocity # of a photon in a vacuum v1: Velocity # of photon emission source 1 v2: Velocity # of photon emission source 2 v1 + c != v2 + c distance / (v1 + c) ?= distance / (v2 + c) ((v1 + c)*t) - ((v2+c)*t) ?!= 0 Should (v + c) be prematurely reduced to just (c), with a confirmed universal expansion rate?

arbitrage 3y ago

Tachyons aren't a thing. Tachyons are sci-fi nonsense. Nothing in the universe can travel faster than the speed of light. This does not hold for the universe itself. It can and does expand faster than the speed of light, using specific reference frames (i.e., big enough). So, space can increase FTL. Particles do not travel faster than light tho, that is nonsense.

rthnbgrredf 3y ago
Well, we have (virtual) particles that can travel backwards in time, without breaking causality. There's no proof that Tachyons exist, they are purely hypothetical, but they are not outright nonsense.
- westurner 3y ago
  From https://news.ycombinator.com/item?id=38045112#38047149 https://news.ycombinator.com/item?id=38045112#38047149 : > from https://news.ycombinator.com/item?id=35877402#35886041 https://news.ycombinator.com/item?id=35877402#35886041 : "EM Wave Polarization Transductions" Lt. Col. T.E Bearden (1999) : >> Physical observation (via the transverse photon interaction) is the process given by applying the operator ∂/∂t to (L^3)t, yielding an L3 output [and "time-polarized photons"]
cbolton 3y ago
Take a star in a region of the universe that recedes from us at 3c. In what sense is the star not traveling faster than the speed of light relative to us?
- westurner 3y ago
  . v - c < 0 -3c + c = 2c +3c - c = 2c
westurner 3y ago
If the universe is expanding faster than the speed of light, how are particles not traveling faster than the speed of light indeed with zero acceleration relative to the expansion? If the Copenhagen interpretation is correct, particle states are correlated after a photonic beam splitter; if you measure entangled photons after a beam splitter, their states are still linked. If virtual particle states are entangled with particle states in black holes or through ER=EPR bridges, is there effectively FTL? There is FTL within dielectric antennae.

a_random_canuck 3y ago

> do we account for velocity in determining whether light traveling at c towards earth will ever reach us? No, because the speed of light is constant for all observers. From our frame of reference on earth, light from distant receding galaxies is always moving towards us at exactly the speed of light, c. Those galaxies also observe the light moving away from them at exactly c. That seems contradictory and unintuitive, that two observers moving away from each other both measure light moving c relative to themselves, but that’s reality. It’s another measurement that changes: if c is always constant, then it must be the passage of time and the distance travelled that we observe differently.

pigpang 3y ago
> That seems contradictory and unintuitive, that two observers moving away from each other both measure light moving c relative to themselves, but that’s reality. Light is a wave. Photon is a complex thing (Hopfion?), but it's a wave, so it waves something, a medium. Speed of wave propagation in a medium is constant. IMHO, it's intuitive.
- mrguyorama 3y ago
  >but it's a wave, so it waves something, a medium. Which was unobserved in the michleson-morely experiment and other followup experiments because....?
  - pigpang 3y ago
    LIGO/Virgo are better version of Michelson-Morely experiment. Gravitational waves are found, so existence of a medium is confirmed.
    - mrguyorama 3y ago
      Gravitational waves existing doesn't confirm the existence of a medium any more than discovering light behaves like a wave confirms the existence of the aether. If you want to posit that light has a medium, you need to redo 100 years of physics, so start showing your work. You mention elsewhere "doing a calculation", and that's just not nearly good enough. You want to overturn perfectly working physics, you NEED to show up with receipts. That's table stakes.

westurner 3y ago

> How far away in light years does a mirror in space need to be in order to see dinosaurs that existed say 100 million years ago? A mirror in a vacuum 1ly away will return the photonic signal from t=0 at t=2 light years, with diffraction (due to matter in [solid, liquid, gas, plasma, and superfluid/superconductor] phases describable with superfluid quantum gravity (e.g. Fedi's with Bernoulli pressure)) # m = meters # s = f(decay_rate_of_cesium_atom) # c = const x: meters/second Time = TimeInLightYears t_tx = t_transmitted: Time = 0 t_rx = t_received: Time d = distance: Time # d == d_ab == d_ba # t_tx, d, t_rx, test_data = [ [0, 0, 0.0], [0, 2, 1], [0, 1, 0.5], [-1, 0, None], [-100e6, 0, None], # dinosaurs ] @pytest.mark.parametrized('t_tx, d, t_rx', test_data) def test_test_data(ttx, d, trx'): assert trx == ttx + (2*d) m = scattering_matrix: # FluidDiffractionTensorMatrix assert is_YangBaxterMatrix(m) A water droplet [in space] reflects enough [photonic,] information to recover a modulated signal and also a curvilinear transformation of Escher looking into a crystal ball, with c the speed of light as a consideration only at cosmological distances. How large of water droplet, a regular or irregular spheroid or reflective and/or lensing matter configuration is necessary to reflect a sufficient amount of photonic information to recover information from cosmological information medium, in terms of constructor theory? Inverse scattering transform: https://en.wikipedia.org/wiki/Inverse_scattering_transform https://en.wikipedia.org/wiki/Inverse_scattering_transform R-matrix > R-matrix method in quantum mechanics: https://en.m.wikipedia.org/wiki/R-matrix https://en.m.wikipedia.org/wiki/R-matrix : > [now generalized for photonic diffraction] Quantum inverse scattering method > Procedure: https://en.wikipedia.org/wiki/Quantum_inverse_scattering_method#Procedure https://en.wikipedia.org/wiki/Quantum_inverse_scattering_met... : > 1. Take an R-matrix which solves the Yang–Baxter equation. > 2. Take a representation of an algebra T_R satisfying the RTT relations. [[clarification needed]] > 3. Find the spectrum of the generating function t(u) of the centre of T_R > 4. Find correlators