Figure 8.15

The picture of many vacuums that may characterise the forces and interactions of Nature gives rise to the possibility of inflation. There are many options as to how the change from one ephemerally stable vacuum to another true vacuum might occur and we have no knowledge as yet of the identity of the scalar field en.wikipedia.org/wiki/Scalar_field which might be the culprit. In this way of looking at vacuum, we have so far imagined that the vacuum state in which we now find ourselves is a deep and stable one, a ‘true’ vacuum. The lowest of the low.

When if we are not in such a vacuum basement? It is entirely possible that the state of the Universe in which we find ourselves is that of a temporarily stable, or ‘false’, vacuum. Instead of being on the ground floor of the vacuum landscape, we may be higher up, in a state that is only stable for a period of time. that period is pretty long, because the Universe seems to have possessed the same general laws and properties for about fourteen billion years. But one day things may change very suddenly, without the slightest warning. The situation could be like that picture in figure 8.15. if inflation left us lodged in on the shallow ledge in the potential landscape shown in figure 8.15, then e might suddenly find ourselves nudged over the brink and on the way down to a lower minimum. That nudge might be supplied by a very high energy events in the Universe. If collisions between stars or black holes generated cosmic rays of sufficiently high energies, they might be able to initiate the transition to the new vacuum in a region of space. The properties of the new vacuum will determine what happens next. We could find ourselves suddenly falling into a vacuum state in which all particles have zero mass and behave like radiation. We would disappear in a flash of light without warning. The way in which our form of biochemical life relies on rather particular coincidences between the strengths and properties of the different forces of Nature means that any change of vacuum state would very likely be catastrophic for us. It would leave us in a new world where other forms of life might be possible but there is no reason why they should be small revolutionary steps away from our own biochemical forms.

This picture of vacuum landscape is a speculative one. We do not know the overall form of the landscape well enough to be able to tell whether we are already on the ground floor or whether there is other vacuums downstairs into which the states of matter in our locale can fall, either accidentally or deliberately. As one contemplates this radical possibility of an unannounced change in some of the basic properties of the forces of Nature, it is tempting to portray it as a ultimate extension of the idea of punctuated equilibrium that Niles Eldridge and Stephen Jay Gould have promoted. They proposed the course of biological evolution by natural selection of Earth proceeds by succession of slow changes interspersed by sudden jumps rather than as a steady ongoing process. Indeed, w3e can characterize it as a movement through a landscape with many hills and valleys in which a force is dragging someone along. The pattern of change under these circumstances is for a slow climb up each hill but when the top is reached there will be a sudden jump across to the side of the next hill and another spell of steady hill climbing. If the Universe follows this lead there may be a shock for our descendants in aeons to come. As with the puzzle of why the lambda force en.wikipedia.org/wiki/Cosmological_constant
Should come into play so close to our time, so we might regard it as unlikely that the epoch at which the fall ‘downstairs’ could occur should be close to the time of human existence in the Universe – unless, of course, there is a link with lambda, or the presence of life can do something inadvertent to precipitate the great fall downstairs. Prophets of doom: do not give up hope. ~ Pages 262 to 265