Vacuum decaycould the vacuum of the universe collapse?

Our vacuum may be metastable, but with an extremely long lifetime. The real physics behind the Cosmos Era ending “Vacuum decay”, from Coleman to the Higgs.

The "vacuum" beneath our feet may not be the most stable state. By current measurements, our vacuum could be metastable, with an expected lifetime of about 10¹³⁹ years. The theory of vacuum decay was worked out by Sidney Coleman and Frank De Luccia in 1980. That lifetime is so long it has nothing to do with us. The game's ending “Vacuum decay” lets the player "set it off" by hand, which is fiction.

This page first explains how to unlock the ending, then covers what vacuum decay really is and an interesting argument about high-energy experiments. After that it lists related research on the Higgs field and dark energy, and finally three related novels.

How to unlock it

  • Hint: Our vacuum may only be metastable.
  • Condition: Unlock “Triggering the vacuum”, then witness the end of the universe.
  • Reward: The next universe uses a different set of physics: generators double for every 10 you own, but event costs are ×4.

The ending belongs to the Physics category. The node “Triggering the vacuum” describes a new vacuum bubble smaller than an atom, expanding at nearly the speed of light. You cannot see it before it arrives.

What is real

  • A metastable vacuum: By current measurements, our vacuum could be metastable, with an expected lifetime of about 10¹³⁹ years.
  • Where the theory comes from: The theory of vacuum decay was worked out by Coleman and De Luccia in 1980 (Coleman also did related work in 1977).
  • Speed of the bubble: A real vacuum bubble would expand at nearly the speed of light.

Could a high-energy experiment set it off?

In Liu Cixin's Hear the Way at Dawn (2002), a group of physicists is about to start an experiment with enough energy to recreate the birth of the universe, when the "Risk Averter" suddenly appears and stops it. Behind the story is a real scientific question: could high-energy experiments trigger vacuum decay? It has been studied seriously. The conclusion is that cosmic rays have long carried far more energy than any collider, and the universe is still fine.

The studies below concern the Higgs field, inflation and dark energy. They are related real science, not evidence that the vacuum will decay. They only help explain what "vacuum" means in physics.

  • Where mass comes from: Peter Higgs proposed a field filling all of space that gives particles mass, and predicted a new particle (Higgs, Physical Review Letters, 1964).
  • Finding the Higgs particle: The Large Hadron Collider found a new particle at about 125 GeV, confirming a prediction that had waited 48 years (ATLAS Collaboration, Physics Letters B, 2012).
  • The inflationary universe: Alan Guth proposed that the early universe went through exponential expansion, explaining at one stroke why the universe is so flat and why its temperature is almost the same everywhere (Guth, Physical Review D, 1981).
  • Accelerating expansion: Using distant supernovae as "standard candles", astronomers found that the expansion of the universe is accelerating, and dark energy arrived on the scene. The work won the 2011 Nobel Prize (Riess et al., The Astronomical Journal, 1998).
  • 42 supernovae: Another team independently reached the same conclusion: there is some form of energy in the universe driving the accelerating expansion (Perlmutter et al., The Astrophysical Journal, 1999).
  • The last chapter of the universe: The fate of the universe trillions of years from now and beyond: stars burn out, protons may decay, and black holes eventually evaporate (Adams and Laughlin, Reviews of Modern Physics, 1997). Unlocking requires witnessing the end of the universe, which is why it relates to this ending.

Game lore, not real

Deliberately setting off the vacuum, and what a different set of physics inside a new vacuum would be like, are both fiction.

  • Schild's Ladder (Greg Egan, 2002): The theory of vacuum decay is real physics, and a real vacuum bubble would expand at nearly the speed of light. In the novel, a physics experiment accidentally creates a new kind of vacuum that expands outward at half the speed of light and swallows everything in its path. Twenty thousand years later, people are still trying to find a way to face it.
  • The Gods Themselves (Isaac Asimov, 1972): Energy conservation and the stability of physical constants have been tested to extremely high precision. Parallel universes with different physical laws are only speculation. In the novel, humans discover an "electron pump" that can exchange matter with a parallel universe, and get unlimited free energy. The price is that the physical laws of the two universes are slowly seeping into each other.
  • Hear the Way at Dawn (Liu Cixin, 2002): See above.

Want to read the originals? Search these titles

  • Higgs (1964): "Broken symmetries and the masses of gauge bosons"
  • ATLAS Collaboration (2012): "Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC"
  • Guth (1981): "Inflationary universe: A possible solution to the horizon and flatness problems"
  • Riess et al. (1998): "Observational evidence from supernovae for an accelerating universe and a cosmological constant"

Real basis

  • By current measurements our vacuum may be metastable, but with an expected lifetime of about 10¹³⁹ years; the theory of vacuum decay was given by Coleman and De Luccia in 1980.

  • Triggering the vacuum: A new vacuum bubble smaller than an atom, expanding at nearly the speed of light. You cannot see it before it arrives.

  • Schild’s Ladder (Greg Egan, 2002), the science: the theory of vacuum decay is real physics (Coleman 1977, Coleman and De Luccia 1980); a real vacuum bubble would expand at close to the speed of light.

  • The Gods Themselves (Isaac Asimov, 1972), the science: energy conservation and the stability of physical constants have been tested to extremely high precision; parallel universes with different physical laws are only speculation.

  • Hear the Way at Dawn (Liu Cixin, 2002), the science: whether high-energy experiments could trigger vacuum decay has been seriously studied: cosmic rays have long had far more energy than any collider, and the universe is still fine.

Related research

These studies relate to this topic but are not direct proof of this page.

  • Inflationary universe: Guth proposed that the early universe underwent exponential expansion, explaining in one stroke why it is so flat and why temperatures are almost the same everywhere.

    Source: Guth, Physical Review D 1981, "Inflationary universe: A possible solution to the horizon and flatness problems"

  • Accelerating expansion: Using distant supernovae as “standard candles,” they found the expansion of the universe is accelerating. Dark energy entered the picture, and the work won the 2011 Nobel Prize.

    Source: Riess et al., The Astronomical Journal 1998, "Observational evidence from supernovae for an accelerating universe and a cosmological constant"

  • 42 supernovae: Another team independently reached the same conclusion: some energy in the universe is driving the accelerating expansion.

    Source: Perlmutter et al., The Astrophysical Journal 1999, "Measurements of Omega and Lambda from 42 high-redshift supernovae"

  • Where mass comes from: Higgs proposed a field filling space that gives particles mass, and predicted a new particle.

    Source: Higgs, Physical Review Letters 1964, "Broken symmetries and the masses of gauge bosons"

  • Finding the Higgs particle: The Large Hadron Collider found a new particle at about 125 GeV, confirming a prediction made 48 years earlier.

    Source: ATLAS Collaboration, Physics Letters B 2012, "Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC"

  • The last chapter of the universe: Worked out the fate of the universe over trillions of years and beyond: stars go out, protons perhaps decay, and black holes finally evaporate.

    Source: Adams & Laughlin, Reviews of Modern Physics 1997, "A dying universe: the long-term fate and evolution of astrophysical objects"

Game lore (fictional)

  • Deliberately triggering the vacuum, and what different physics in the new vacuum would be like, are both fiction.
  • Summary of the novel Schild’s Ladder: A physics experiment accidentally creates a new kind of vacuum, which expands outward at half the speed of light and swallows everything in its path. Twenty thousand years later, people are still trying to find a way to face it.
  • Summary of the novel The Gods Themselves: Humans discover an “electron pump” that exchanges matter with a parallel universe, gaining unlimited free energy. The price is that the physical laws of the two universes are slowly seeping into each other.
  • Summary of the novel Hear the Way at Dawn: A group of physicists is about to start an experiment with enough energy to recreate the birth of the universe, when a Risk Averter suddenly appears and stops it, because such an experiment could destroy the entire universe.
See it in the game