Given the First Law of Thermodynamics: that you can't get something from nothing. Where did all the stuff in the universe come from and how is it still a law if it was once broken?
Asked by: Rob
The law you cite, applies only to 'closed systems',
i.e. where nothing can be added or subtracted
from the 'specimen'. Obviously if you apply the
law to an empty box, then open the box and dump in
a handful of sand, or quarks, or energy, you don't
expect the law to apply, because the system is
It is not known whether the universe as a whole is
a closed system now at present. As far as
conditions preceding and at the very
moment of the 'big bang', we can only speculate
whether the universe was closed, or open (to
another, larger system), or whether the First Law
(or lots of other laws) even applies under those
Answered by: Grant Hallman, Ph.D., Universtiy of Toronto, 1971/1967
In the macroscopic world, the domain of 'classical' physics, the laws of thermodynamics
are, and have always been, true.
However, on the quantum scale, it is a very different matter. Hiesenberg's uncertainty
states that there will always be a level of uncertainty when you try to make measurements
of particles and other quantum scale occurrences. You can never know everything about a
particle's position and motion at any one time. This is an intrinsic uncertainty, it is
not due to limitations on our measuring devices. This uncertainty of the energy of
anything of the Planck scale is size allows some very bizarre phenomena to occur.
To us, vacuums appear to contain nothing at all. But, it you were to look closely, very,
very closely (to the order of 10^-35m), space is actually a foaming mass of quantum
activity. This quantum foam is made of particles and micro-black holes popping in and out
of existence, apparently in contravention of the second law of thermodynamics, they
appear out of nothing with energy, then disappear again just as quickly. The key to this
is the uncertainty principle. The disturbance is permitted to 'borrow' a tiny amount of
energy and exist for a very short length of time, and then it must return the energy and
disappear again. But, the more energy it borrows, the less time it is allowed to exist.
These 'temporary' particles, called virtual particles, are not just theoretical, they
have been proven to have real effects on scientific experiment.
The only thing that prevents these virtual particles from coming into permanent existence
is a lack of energy. However, it is possible to artificially supply energy to the
particles therefore promoting them into reality. This could be done in a lab by creating
very strong electric fields, but these fields are very difficult to create. On the other
hand, intense gravitational fields could also do the job.
It is possible that during the big bang, black holes the size of a nucleus popped into
existence due to the quantum foam. The interesting thing is that the smaller a black hole
is, the more strongly space-time is distorted around it and distortions in space-time
imply the existence of very strong gravitational fields. Stephen Hawking has shown that
the gravitational field around such a hole would give enough energy to the quantum foam
to promote the particles into real existence. Calculations show that in the big bang the
initial extreme conditions would also have been enough to create real particles out of
the gravitational energy of the rapidly expanding universe.
And as for how the universe actually came into being itself, it is believed that also in
the quantum foam, virtual space-time bubbles also continually pop in and out of
existence, like virtual particles, only to disappear again. However, it is possible that
one of these space-time bubbles, which is actually an unimaginably small universe, could
avoid rapidly disappearing again and be promoted to a full size universe, such as ours.
However, for this to work some sort of repulsive force is needed, a sort of anti-gravity.
Many scientists believe in the existence of such a force at the time of the creation of
the universe, but as I've answered your question and that's a whole other topic, I think
I'll stop before I go off on too much of a tangent.
To summarise, due to the uncertainty principle, particles and space-time bubbles
continually pop in and out of existence for short times depending on their energy,
without breaking the law of conservation of energy as they dissapear again. Think of it
like an accountant (the universe) who balances the books at the end of every month. If
someone (a virtual particle) was to borrow some money on the 4th day of the month (pop
into existence)then put it back on the 8th day,(disappear again) then as far as the
bookkeeper would know, nothing had gone amiss and no rules (or laws) had been broken. If
a particle is to come into complete and real existence, it must take its energy from
somewhere, such as a gravitational field.
Answered by: Simon Hooks, Physics A-Level Student, Gosport, UK
'If one wishes to obtain a definite answer from Nature one must attack the question from a more general and less selfish point of view.'