You could tell your self in the past this, if you found a way; but you would end up leading yourselves into an un-real universe, once you passed the point you sent the information to yourselves in the past, you would not know what to do next. Unless you told yourselves what to do and that would be like creating a big polo mint in space and driving through the hole! Where would that get you?

If you have a state psi(t) it will evolve into a state psi(t + &t) by the Schrodinger equation

where I will from now set hbar to one. The Hamiltonian H defines a unitary time development operator U(t) with

where the unitary operator is the exponential term on the right. We then consider the overlap of a state and its time development some small increment of time

which with the Taylor theorem gives

This is the overlap between a state and its time development into the future. Now what we do is to take the modulus square of this to get

The last two terms on the right are

with some compression of notation. The term in the parenthesis is the square of

Now this is the Heisenberg uncertainty principle for the whole package in the modulus squared is

This says that if I sample the system in a short time I will get a range of possible values for the energy of the system.

As a digression this has some interesting properties, for this is the metric of the Fubini-Study space and the fibration over the projective Hilbert space.

The quantum fluctuation is physically the result of sampling or measuring the system. Quantum mechanics is contrary to popular belief a completely deterministic physics. The Schr{\”o}dinger wave equation is completely deterministic. But since the wave is complex valued, and there is this fibration given by the unitary operator over the projective Hilbert space what we measure in real variables has this range of possible outcomes.

In thermodynamics there are also fluctuations, and a formula for them based on the deBroglie wavelength. It is analogous to this, but where one has to look at Fokker-Planck equations or Langevin processes. These are similar to quantum fluctuations, but are really different physics.

Lawrence B. Crowell

What they dont tell you at school is that it is possable to produce an imaginary black hole in your mind, information on its own is enough to do this. This is called frame setting, it makes your life real and observed up to that point. While you live on like being born again; in other words you exist in every single point in the universe as a real object. Then you simply are a universe at that point. Everthing before it simply is your imagination, that has become real. You surround the universe like a dyson sphere; like around a star and then you take everthing you need to carry on you life as yourself and nothing more. Doing this is the same as an animal that has no concious ablity to understand that its giving birth.

If I got something wrong then its your fault, because you used me to do it! You cant expect me to get “everything” right. Your frame is the one I set and unless you are “Your” then you can dismiss this as nonsense.
Its not wrong anyway, its entropy is just too high at the begining to be right, it needs to be a lot lower. The universe is not real, its proably a simulation and that really does suck!

Look left see blue “Think way of the mushroom!”, “Eyes forward!”, “A cat see’s with two eyes”, look right? “I cant remember?”

Do it yourselves next time!

If you dont understand this, then ignore it! And don’t comment!

Your conclusion does not follow from that. The average energy density for the entire universe may be decreasing with time, but that doesn’t imply that local densities might not increase.

We know that fundamental forces unify at higher energies, and we know the universe is expanding and energy density is decreasing. Thus we have a permanent record of the fact that the universe had a higher energy density early in its evolution

Please don’t post any more urls without explaining why you think that any of them are relevant. Why are any of those web pages relevant?

Let |Psi> and |Phi> be two different states of a quantum system involving many, many particles. Then the prediction of quantum mechanics is that the probability that the system, when put in state |Psi> at time 0 will be found in state |Phi> at a later time t is given by

P = |A|^2

where A = is the transition amplitude and where H is the Hamiltonian.

The question is: under what circumstances do we expect the transition amplitude A to be zero for all values of t? Well, certainly A will always be zero if Phi and Psi have different eignvalues for conserved quantities. But if that’s not the case; if Phi and Psi have the same values for charge, total momentum, total energy, total angular momentum, etc., then I would think that A would be nonzero for most values of t.

I don’t believe that you are correct. The laws of physics don’t in any way say that there must remain a record of past evolution.