How Will the Universe End? | Space Time
PBS Space Time・14 minutes read
In the far future, the universe will face ultimate heat death as stars fade away, with civilizations potentially adapting to survive through mechanisms to cool down. Quantum mechanics and g-factor theories play a crucial role in understanding the behavior of particles and fitting mathematical theories to observations for a consistent model of reality.
Insights
- The universe's fate involves a series of eras, from the Red Dwarf Era to the Black Hole Era, leading to ultimate heat death, with civilizations potentially adapting to cooling mechanisms to endure through vast expanses of time.
- Understanding the behavior of electrons involves complex theories like Dirac's g-factor, quantum mechanics' view of electrons as point particles dictated by wave functions, and the continuous refinement of mathematical models to align with observations and predict new phenomena.
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Recent questions
What will happen to the universe in 100 trillion years?
Darkness will prevail as stars fade to black.
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Summary
00:00
"Future Universe: From Stars to Black Holes"
- In 100 trillion years, the last star in the universe will expand, the final atoms of hydrogen fuel and settle quietly into a dim white dwarf before slowly fading to black as it radiates away its remaining heat.
- The universe will spend almost all of its infinite time in darkness, slowly crawling towards maximum entropy and ultimate heat death.
- Far-future civilizations may be able to harness mechanisms for the universe to cool down, dissipate energy, and gain entropy to cling to existence through uncountable eons.
- The merged Milky Way-Andromeda Galaxy will consist of stellar remnants, neutron stars, black holes, and white dwarfs, with civilizations potentially persisting in the Red Dwarf Era.
- The accelerating expansion of the universe will drag all galaxies beyond the Virgo Supercluster outside of the cosmic event horizon, leading to no evidence of a universe beyond the local galaxy.
- The universe will enter the Degenerate Age, with neutron stars, black dwarfs, and white dwarfs made of degenerate matter, eventually leading to the obliteration of all planetary systems in the galaxy.
- The complete dissolution of galaxies will occur, with 90% to 99% of stars scattered into the void in around 10 to the power of 18 years, followed by the potential decay of protons after 10 to the power of 39 or 10 to the power of 40 years.
- If protons decay, the universe will enter the Black Hole Era, with black holes being the only mass of bodies left after 10 to the power of 40 years, eventually evaporating via Hawking radiation.
- Dark matter will likely be gone, with black holes being the last remnants in the universe, eventually evaporating and leaving only particles and light.
- Quantum tunneling may lead to the fusion or decay of all matter into iron, with iron stars evolving into neutron stars over an unimaginable timescale, potentially bringing on the Black Hole Era much earlier if small black holes are possible.
13:55
Understanding Electron Behavior in Quantum Mechanics
- The g-factor of the electron is crucial in understanding its behavior, with classical theory suggesting a value of 1 and Dirac's theory predicting a value of 2 due to different distributions of charge and mass.
- Electrons are considered infinitesimal points in quantum mechanics because elementary particles themselves do not have size; their quantum wave function determines their properties and probabilities of location.
- The process of fitting mathematical theories to observations, like virtual particles, involves creating and refining theories that consistently match observations and predict new phenomena, ensuring models of reality are internally consistent and not based on random chance.
