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See the article about the ultimate fate of the Universe for more discussion of these issues.

• Shorter times
• 7.7 × 10¹⁵ years – half-life of cadmium-113
• 1.4 × 10¹⁷ years – half-life of vanadium-50
• >1.8 × 10¹⁷ years – half life of chromium-50
• >6×10¹⁸ years – half life of calcium-48
• (1.9 +/- 0.2) × 10¹⁹ years – alpha emission half-life of bismuth

The following times all assume that the Universe is "open":

• 10¹⁴ years – the estimated time until low-mass stars cool off. The smallest red dwarf stars are the longest-lived stars, and are believed to have a lifetime of up to 14 trillion years (1.4 x 10¹³ years). Star formation is expected to cease in galaxies in about 10¹³ to 10¹⁴ years as galaxies are depleted of the gas clouds they need to form stars. The longest-lived stars formed from the last gas clouds will therefore cool off after about 2 x 10¹⁴ years.
• 10¹⁵ years – the estimated time until planets detach from stars. Whenever two stars pass close to each other, the orbits of the planets can be disrupted and the planets can be ejected from orbit around their parent star. Planets that orbit closer to their stars take longer to be ejected in this manner on average because a passing star must make a closer pass to the planet's star to eject the planet.
• 10¹⁹ years – the estimated time until stars detach from galaxies. When two stars pass close enough to each other, the stars exchange orbital energy with lower-mass stars tending to gain energy. The lower-mass stars can gain enough energy in this manner through repeated encounters to be ejected from the galaxy. This process can cause the galaxy to eject the majority of its stars.
• 10²⁰ years – the estimated time until orbits decay by gravitational radiation
• 10³⁰ years – the estimated time until galaxies disappear due to black holes
• 10³⁶ years – the estimated time until proton decayFor a long time, protons were thought to be stable—that the laws of physics would not allow for a proton (which is baryonic matter) to spontaneously decay into a positron and photons (non-baryonic matter) because of conservation of the baryon number., if GUT theories are right
• 10⁶⁴ years – the estimated time until black holes decay by the Hawking process
• 10⁶⁵ years – the estimated timescale at which all matter is liquid at zero temperature due to tunneling effectIn quantum mechanics, the tunneling effect refers to various processes whereby particles appear to violate classical physics by instantaneously changing their location within the space-time continuum without passing observably through the intervening spacs
• 10¹⁰⁰ years – the estimated time until supermassive black holeA supermassive black hole is a black hole with a mass in the range of millions or billions solar masses. The Milky Way is believed to have one supermassive black hole, at the Galactic Center. Most if not all galaxies are thought to host a supermassive blas decay by the Hawking process
• 10¹⁵⁰⁰ years – the estimated time until all matter decays to ironThis article is about metallic iron. For the ironing device, see ironing manganese iron cobalt Fe Ru Full table General Name, Symbol, Number iron, Fe, 26 Chemical series transition metal Group, Period, Block 8 (VIIIB), 4 , d Density, Hardness 7874 kg/m3, (if the protonFor alternative meanings see proton (disambiguation). Proton Classification Subatomic particle Fermion Hadron Baryon Nucleon Proton Properties Mass: 938 MeV/ c2 Electric Charge: 1. 6 × 10−19 C Spin: 1/2 In physics, the proton is a subatomic particle does not decay)
• 10^{100,000,000,000,000,000,000,000,000} years () – low estimate for the time until all matter collapses into black holes
• 10^{10,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000} years () – high estimate for the time until all matter collapses into neutron stars or black holes