# false vacuum ![[falsevacuum.svg.png]] a scalar field φ (which represents physical position) in a false vacuum. the energy e is higher in the false vacuum than that in the true vacuum or ground state but there is a barrier preventing the field from classically rolling down to the true vacuum. therefore the transition to the true vacuum must be stimulated by the creation of high-energy particles or through quantum-mechanical tunneling in quantum field theory a false vacuum is a hypothetical vacuum state that is locally stable but does not occupy the most stable possible ground state. in this condition it is called metastable. it may last for a very long time in this state but could eventually decay to the more stable one an event known as false vacuum decay. the most common suggestion of how such a decay might happen in our universe is called bubble nucleation - if a small region of the universe by chance reached a more stable vacuum this "bubble" (also called "bounce") would spread a false vacuum exists at a local minimum of energy and is therefore not completely stable in contrast to a true vacuum which exists at a global minimum and is stable # definition of true vs. false vacuum a vacuum is defined as a space with as little energy in it as possible. despite the name the vacuum still has quantum fields. a true vacuum is stable because it is at a global minimum of energy and is commonly assumed to coincide with the physical vacuum state we live in. it is possible that a physical vacuum state is a configuration of quantum fields representing a local minimum but not global minimum of energy. this type of vacuum state is called a "false vacuum" if our universe is in a false vacuum state rather than a true vacuum state then the decay from the less stable false vacuum to the more stable true vacuum (called false vacuum decay) could have dramatic consequences. the effects could range from complete cessation of existing fundamental forces elementary particles and structures comprising them to subtle change in some cosmological parameters mostly depending on the potential difference between true and false vacuum. some false vacuum decay scenarios are compatible with the survival of structures like galaxies stars and even biological life while others involve the full destruction of baryonic matter or even immediate gravitational collapse of the universe. in this more extreme case the likelihood of a "bubble" forming is very low (ie false vacuum decay may be impossible) a paper by coleman and de luccia that attempted to include simple gravitational assumptions into these theories noted that if this was an accurate representation of nature then the resulting universe "inside the bubble" in such a case would appear to be extremely unstable and would almost immediately collapse > in general gravitation makes the probability of vacuum decay smaller; in the extreme case of minimal energy-density difference it can even stabilize the false vacuum preventing vacuum decay altogether. we believe we understand this. for the vacuum to decay building a bubble of total energy zero must be possible. in the absence of gravitation this is no problem no matter how small the energy-density difference; all one has to do is make the bubble big enough and the volume/surface ratio will do the job. in the presence of gravitation though the negative energy density of the true vacuum distorts geometry within the bubble with the result that for a small enough energy density there is no bubble with a big enough volume/surface ratio. within the bubble the effects of gravitation are more dramatic. the geometry of space-time within the bubble is that of anti-de sitter space a space much like conventional de sitter space except that its group of symmetries is o(3 2) rather than o(4 1.) although this space-time is free of singularities it is unstable under small perturbations and inevitably suffers gravitational collapse of the same sort as the end state of a contracting friedmann universe. the time required for the collapse of the interior universe is on the order of ... microseconds or less > > the possibility that we are living in a false vacuum has never been a cheering one to contemplate. vacuum decay is the ultimate ecological catastrophe; in the new vacuum there are new constants of nature; after vacuum decay not only is life as we know it impossible so is chemistry as we know it. nonetheless one could always draw stoic comfort from the possibility that perhaps over time the new vacuum would sustain if not life as we know it at least some structures capable of knowing joy. this possibility has now been eliminated > > the second special case is decay into a space of vanishing cosmological constant the case that applies if we are now living in the debris of a false vacuum that decayed at some early cosmic epoch. this case presents us with less interesting physics and with fewer occasions for rhetorical excess than the preceding one. it is now the interior of the bubble that is ordinary minkowski space in a 2005 paper published in nature as part of ir investigation into global catastrophic risks mit physicist max tegmark and oxford philosopher nick bostrom calculate the natural risks of the destruction of the earth at less than 1/109 per year from all natural (ie non-anthropogenic) events including a transition to a lower vacuum state. they argue that due to observer selection effects we might underestimate the chances of being destroyed by vacuum decay because any information about this event would reach us only at the instant when we too were destroyed. this is in contrast to events like risks from impacts gamma-ray bursts supernovae and hypernovae the frequencies of which we have adequate direct measures a number of theories suggest that cosmic inflation may be an effect of a false vacuum decaying into the true vacuum. the inflation itself may be the consequence of the higgs field trapped in a false vacuum state with higgs self-coupling λ and its βλ function very close to zero at the planck scale.: 218 a future electron-positron collider would be able to provide the precise measurements of the top quark needed for such calculations chaotic inflation theory suggests that the universe may be in either a false vacuum or a true vacuum state. alan guth in ir original proposal for cosmic inflation proposed that inflation could end through quantum mechanical bubble nucleation of the sort described above. see history of chaotic inflation theory. it was soon understood that a homogeneous and isotropic universe could not be preserved through the violent tunneling process. this led andrei linde and independently andreas albrecht and paul steinhardt to propose "new inflation" or "slow roll inflation" in which no tunnelling occurs and the inflationary scalar field instead graphs as a gentle slope in 2014 researchers at the chinese academy of sciences' wuhan institute of physics and mathematics gave an actual mathematical demonstration of the already existing idea that the universe could have been spontaneously created from nothing (no space time nor matter) by quantum fluctuations of a metastable false vacuum causing an expanding bubble of true vacuum#false vacuum decay in fiction false vacuum decay event is occasionally used as a plot device in works picturing a doomsday event **+** 1980 by jack l. chalker.in ir science-fiction novel the return of nathan brazil the fourth book in the well of souls series (although not named as such in the novel) **+** 1988 by geoffrey a. landis in ir science-fiction short story vacuum states **+** 2000 by stephen baxter in ir science fiction novel time **+** 2002 by greg egan in ir science fiction novel schild's ladder **+** 2002 by liu cixin in ir science fiction novel zhao wen dao **+** 2008 by koji suzuki in ir science fiction novel edge **+** 2015 by alastair reynolds in ir science fiction novel poseidon's wake **+** 2018 by system erasure in ir video garme zeroranger **+** eternal inflation - hypothetical inflationary universe model **+** supercooling - lowering the temperature of a liquid below its freezing point without it becoming a solid **+** superheating - heating a liquid to a temperature above its boiling point without boiling **+** void - vast empty spaces between filaments with few or no galaxies **+** quantum cosmology - attempts to develop a quantum mechanical theory of cosmology **+** why is there anything at all? something may exist necessarily - metaphysical question // republic of bob