4 ms·

If protons decay. There isn't really any reason to believe they're not stable.

by Sharlin 8mo ago

hnuser123456 8mo ago
And recent DESI data suggests that dark energy is not constant and the universe will experience a big crunch in a little more than double its current age, for a total lifespan of 33 billion years, no need to get wild with the orders of magnitude on years into the future. The infinite expansion to heat death over 10^100 years is looking less likely, 10^11 years should be plenty. https://www.sciencedaily.com/releases/2026/02/260215225537.htm https://www.sciencedaily.com/releases/2026/02/260215225537.h...
- disconcision 8mo ago
  not obvious to me this makes things better as opposed to worse? sure, the time bound helps but in the runup to a crunch won't we get vastly more devices in causal range at an asymptotically increasing rate?
  - Towaway69 8mo ago
    Who’s there doing the counting? I would assume the temperatures at those extremes won’t support life in its known forms. Perhaps some Adamesque (as in douglas adams) creature whose sole purpose is to collect all unique UUIDs and give them names.
    - throwaway290 8mo ago
      Runup to the crunch is a looong time lots of which is probably very habitable. in 5 billion years life can arise from scratch become conscious and exterminate itself
frikit 8mo ago
Protons can decay because the distinction between matter and energy isn't permanent. Two quarks inside the proton interact via a massive messenger particle. This exchange flips their identity, turning the proton into a positron and a neutral pion. The pion then immediately converts into gamma rays. Proton decayed!
- itishappy 8mo ago
  This destroys a baryon, an operation which is prohibited by the standard model.
  - giraldorich 8mo ago
    Baryon number is an accidental symmetry, not a fundamental one. Unlike charge or color, it is not protected by a gauge principle and is just a consequence of the field content and renormalizability at low energies. The standard model is almost certainly an effective field theory and a low-energy approximation of a more comprehensive framework. In any ultraviolet completion, such as a GUT, quarks and leptons inhabit the same multiplets. At these scales, the distinction between matter types blurs, and the heavy gauge bosons provide the exact mediation mechanism described to bypass the baryon barrier. Furthermore, the existence of the universe is an empirical mandate for baryon-violation. If baryon number were a strict, immutable law, the Sakharov conditions could not be met, and the primordial matter-antimatter symmetry would have resulted in a total annihilation. Our existence is proof that baryon number is not conserved. Even within the current framework, non-perturbative effects like sphalerons demonstrate that the Standard Model vacuum itself does not strictly forbid the destruction of baryons.
    - adrian_b 8mo ago
      The sum of the conserved quantities, e.g. chromatic charge, electric charge and spin, is null for the set of 8 particles formed by the 3 u quarks, the 3 d quarks and the electron and the neutrino, i.e. for the components of a proton plus a neutron plus an electron plus a neutrino. This is the only case of a null sum for these quantities, where no antiparticles are involved. The sum is also null for 2 particles, where one is the antiparticle of the other, allowing their generation or annihilation, and it is also null for the 4 particles that take part in any weak interaction, like the decay of a neutron into a proton, which involves a u quark, a d antiquark, an electron and an antineutrino, and this is what allows the transmutations between elementary particles that cannot happen just through generation and annihilation of particle-antiparticle pairs. Thus generation and annihilation of groups of such 8 particles are not forbidden by the known laws. The Big Bang model is based on equal quantities of these 8 particles at the beginning, which is consistent with their simultaneous generation at the origin. On the other hand, the annihilation of such a group of 8 particles, which would lead to the disappearance of some matter, appears as an extraordinarily improbable event. For annihilation, all 8 particles would have to come simultaneously at a distance from each other much smaller than the diameter of an atomic nucleus, inside which quarks move at very high speeds, not much less than the speed of light, so they are never close to each other. The probability of a proton colliding simultaneously with a neutron, with an electron and with a neutrino, while at the same time the 6 quarks composing the nucleons would also be gathering at the same internal spot seems so low that such an event is extremely unlikely to ever have happened in the entire Universe, since its beginning.

If protons decay. There isn't really any reason to believe they're not stable.

by Sharlin 8mo ago

If protons decay. There isn't really any reason to believe they're not stable.

And recent DESI data suggests that dark energy is not constant and the universe will experience a big crunch in a little more than double its current age, for a total lifespan of 33 billion years, no need to get wild with the orders of magnitude on years into the future. The infinite expansion to heat death over 10^100 years is looking less likely, 10^11 years should be plenty. https://www.sciencedaily.com/releases/2026/02/260215225537.htm https://www.sciencedaily.com/releases/2026/02/260215225537.h...

disconcision 8mo ago
not obvious to me this makes things better as opposed to worse? sure, the time bound helps but in the runup to a crunch won't we get vastly more devices in causal range at an asymptotically increasing rate?
- Towaway69 8mo ago
  Who’s there doing the counting? I would assume the temperatures at those extremes won’t support life in its known forms. Perhaps some Adamesque (as in douglas adams) creature whose sole purpose is to collect all unique UUIDs and give them names.
  - throwaway290 8mo ago
    Runup to the crunch is a looong time lots of which is probably very habitable. in 5 billion years life can arise from scratch become conscious and exterminate itself

frikit 8mo ago

Protons can decay because the distinction between matter and energy isn't permanent. Two quarks inside the proton interact via a massive messenger particle. This exchange flips their identity, turning the proton into a positron and a neutral pion. The pion then immediately converts into gamma rays. Proton decayed!

itishappy 8mo ago
This destroys a baryon, an operation which is prohibited by the standard model.
- giraldorich 8mo ago
  Baryon number is an accidental symmetry, not a fundamental one. Unlike charge or color, it is not protected by a gauge principle and is just a consequence of the field content and renormalizability at low energies. The standard model is almost certainly an effective field theory and a low-energy approximation of a more comprehensive framework. In any ultraviolet completion, such as a GUT, quarks and leptons inhabit the same multiplets. At these scales, the distinction between matter types blurs, and the heavy gauge bosons provide the exact mediation mechanism described to bypass the baryon barrier. Furthermore, the existence of the universe is an empirical mandate for baryon-violation. If baryon number were a strict, immutable law, the Sakharov conditions could not be met, and the primordial matter-antimatter symmetry would have resulted in a total annihilation. Our existence is proof that baryon number is not conserved. Even within the current framework, non-perturbative effects like sphalerons demonstrate that the Standard Model vacuum itself does not strictly forbid the destruction of baryons.
  - adrian_b 8mo ago
    The sum of the conserved quantities, e.g. chromatic charge, electric charge and spin, is null for the set of 8 particles formed by the 3 u quarks, the 3 d quarks and the electron and the neutrino, i.e. for the components of a proton plus a neutron plus an electron plus a neutrino. This is the only case of a null sum for these quantities, where no antiparticles are involved. The sum is also null for 2 particles, where one is the antiparticle of the other, allowing their generation or annihilation, and it is also null for the 4 particles that take part in any weak interaction, like the decay of a neutron into a proton, which involves a u quark, a d antiquark, an electron and an antineutrino, and this is what allows the transmutations between elementary particles that cannot happen just through generation and annihilation of particle-antiparticle pairs. Thus generation and annihilation of groups of such 8 particles are not forbidden by the known laws. The Big Bang model is based on equal quantities of these 8 particles at the beginning, which is consistent with their simultaneous generation at the origin. On the other hand, the annihilation of such a group of 8 particles, which would lead to the disappearance of some matter, appears as an extraordinarily improbable event. For annihilation, all 8 particles would have to come simultaneously at a distance from each other much smaller than the diameter of an atomic nucleus, inside which quarks move at very high speeds, not much less than the speed of light, so they are never close to each other. The probability of a proton colliding simultaneously with a neutron, with an electron and with a neutrino, while at the same time the 6 quarks composing the nucleons would also be gathering at the same internal spot seems so low that such an event is extremely unlikely to ever have happened in the entire Universe, since its beginning.