Quantum fluctuation & the Big bang

bogwalrus

The following is a piece from John Gribbins "Schrodingers's kittens" that i find really curious and think it would be great to have a chat on and possibly hear some criticisms. It has to do with how the universe came to be and from my limited knowledge of physics it seems plausible so far and is a theory i never heard/read before.

It is a bit technical but do read it all as the theory is quite interesting:)
If the mod's feel it belongs in the physics forum so be it.


Something for Nothing
The Energy needed to make a very light particle (such as a photon, which has zero mass, although it does carry energy) can pop up out of nothing at all for a relatively long time, but the energy needed to make more massive particles (such as an electron-positron pair) can only be 'borrowed' from the vacuum for a correspondingly shorter period of time (so the electron-positron pair quickly annihilate one another and give their borrowed energy back to the vacuum). "Nothing at all" is actually best pictured as a seething maelstrom of activity in which all kinds of particles are flickering in and out of existence.

In the most extreme example of this, some cosmologists have seriously suggested that the entire Universe may be a quantum fluctuation.
Since the Universe is about 15 billion years old and contains rather a lot of particles, this may seem hard to swallow at first. But it happens that the energy of a gravitational field is negative, in the same sense that mass energy is positive.
If a tiny bubble of energy corresponding to the mass of the Universe popped into existence on the quantum scale, its mass energy and its gravitational energy could, the theory tells us, exactly balance one another, allowing the quantum universe to have essentially zero overall energy and therefore a very long lifetime.

The final step in making the Universe out of nothing at all is to invoke a process called inflation, which swooshes this vastly subatomic seed up to about the size of a basketball in a fraction of a second, after which it continues expanding in a more sedate way.



Pretty cool i think as i have been reading a fair bit on quantum theory. This is the first theory i have heard about how the big bang happened etc. Cool:)

Nutlog!!!

Do you get the feeling that ever since string theory / M theory physicists have been mathematically going around in circles?

I mean, at the level of all this 'quantum foam' where the laws of physics seem to break down, I sometimes think, 'whats the point'? :rolleyes:

It's a fascinating realm of thought though!