You are correct that from the point of view of an outside observer they would see material approaching the event horizon but would not see it 'fall in' as such.
Imagine two observers, Alice and Bob. Suppose that Alice falls into the black hole and Bob is stationary at infinity with respect to...
Homework Statement
Consider a quantum oscillator in a mixed state described by the density operator \rho = \frac{1}{2}( |\alpha><\alpha| + |-\alpha><-\alpha| ) . Calculate \Delta (\hat{X}^2)_1 and \Delta (\hat{X}^2)_2 in this case.
Where X1 and X2 are the dimensionless position and...
Unless I made a mistake, you should end up with something like:
|\psi|^2 = |a_0 \psi_0|^2 + |a_1 \psi_1|^2 + a_0a^{*}_1\psi_0\psi^{*}_1 + a_1a^{*}_0\psi_1\psi^{*}_0
Obviously the normalisation constants of the first two terms of that expression are going to be real. You can prove that by...
This is just an educated guess, but I'd say something like:
\psi = a_0 \psi_0 + a_1 \psi_1
So:
\int \psi \psi^{*} d^3r = \int (a_0 \psi_0 + a_1 \psi_1)(a^{*}_0 \psi^{*}_0 + a^{*}_1 \psi^{*}_1) d^3r
Now all you need to do is expand the RHS and see what you get (the integral is over all space...
Homework Statement
The question:
Explain why pair creation is expected to occur in the early universe, and estimate the redshift at which proton-antiproton pairs are created.Homework Equations
The Attempt at a Solution
My logic for the reason is that the process requires high energy gamma...
What exactly does a Bose-Einstein Condensate look like with the naked eye? Is there any special about what it looks like through the optical part of the spectrum? What are the electromagnetic properties of a BEC as a whole?
Homework Statement
A ball moves in a two-dimensional billiard comprising a horizontal frictionless table enclosed by two circular barriers of radii 2m and 1m and centred, respectively, at (x, y)=(0, 0) and (x, y)=(a, 0), where a<0.5m. The ball undergoes specular reflection at each barrier...
I'm confused about the terminator obeying the laws of physics, since a major part of the story is to do with time travel, and as far as I know that hasn't even been shown to be possible, even in principle.
Homework Statement
This is the first question from a past exam paper I'm doing at the moment, and I'm not sure if it's a case that I'm doing something stupid, or if there is a problem with the question.
Q: The wavefunction of a deuteron can be approximated by:
\psi (r) = \frac{C}{r}...
Homework Statement
a) Using the Robertson-Walker metric, write down an expression for the proper distance in terms of the coordinate r. For objects moving with the expansion of the universe, show that the proper distance increases with time in the manner described by the Hubble Law.
b) Use...
Homework Statement
a) Suppose particles can be adsorbed onto a surface such that each adsorption site can be occupied by up to 6 atoms each in single-particle quantum state \psi_i with an adsorption energy \epsilon_i. Write down the grand partition function for one site.
b) If...
I seriously doubt that ion cannons could be made into a superweapon, because if you think about what it actually is, all it is is a stream of ionized atoms, and so will have very little destructive power (mainly because of the atmosphere), and what's more, if the weapon was fired from space...