telcodad
Looks like the phys.org writer either has some reading comprehension issues, or is a bit too creative and inventive since nowhere in the actual paper states that the universe is “expected to decay in 10⁷⁸ years”. 😠
The actual paper at https://arxiv.org/pdf/2410.14734 takes a bit of time to read and digest; however, the abstract and conclusion shouldn’t take too long to read. Particular sections of interest:
For a putative black hole with a mass as low as M = 1.44 M⊙, we find (in the same spirit as formula (3.4) with the total flux at the radius of maximum emission, Rm ≈ 2.5 Rg (see [7])) Teff,o ≈ 72 nK and τ ≈ 3.0 × 1067 yr, where τ ∝ M 3. This is a factor four shorter than a neutron star of the same mass with ξ = 0. However, an actual stellar mass black hole of M = 3 M⊙ would last more than twice as long as an average neutron star. A white dwarf with M = 1.3 M⊙ and Rm = 2550 km would have Teff,o ≈ 5.5 pK and a lifetime of τ ≈ 3.3 × 1078 yr for ξ = 0. For the supermassive black hole M87∗ with M ≈ 6 × 109 M⊙, one gets τ ≈ 2 × 1096 yr.
In principle, the process could also be applicable to other astrophysical objects: The
Moon (ρ ≈ 3.4 g/cm3) has τ ∼ 3 × 1089 yr, a body with the density of water has τ ∼ 1090 yr,
the Local Interstellar Cloud (ρ ≈ 5 × 10−25 g/cm3) has τ ∼ 10127 yr, and a dark matter halo
of a supercluster (mass of 1017 M⊙, size of 160 Mpc) has τ ∼ 10135 yr. For the Moon this
translates to the decay of one proton roughly every ∼ 1040 yr, which, like Hawking radiation,
is not directly detectable. These lifetimes are put into perspective in Fig. 7. Of course, these
examples ignore other astrophysical evolution and decay channels and the induced change
in mass density. Therefore one should consider these timescales only as absolute theoretical
upper limits showing at least that the presence of this effect is not ruled out by the existence
of astrophysical objects.
There are quite a few zeros between 1078 and 1096 or 10135 – of course not as much as in 101100, but that’s a slightly different issue.
In addition, I always like to see some *concrete evidence* and proton decay happens to be one that has never been observed, so we can’t know for sure if it’s real or imagined.
In particle physics, proton decay is a hypothetical form of particle decay in which the proton decays into lighter subatomic particles, such as a neutral pion and a positron. The proton decay hypothesis was first formulated by Andrei Sakharov in 1967. Despite significant experimental effort, proton decay has never been observed. If it does decay via a positron, the proton’s half-life is constrained to be at least 1.67×1034 years.
https://en.wikipedia.org/wiki/Proton_decay
Another notable excerpt from the paper:
One could speculate that fossil neutron stars from a previous universe might still be around and be near the critical mass. This is only possible if inflation does not prevent universes from occupying the same phase space. If present, fossil neutron stars would now be growing by accretion from the intergalactic medium and the cosmic microwave background rather than shrinking, unless some instability would make them undergo such a phase transition after all.
I guess by the same token one can argue that God is just a self aware, left-over supercomputer from a previous universe with defective Li-ion batteries that only worked for a week. 😉