1,849 reputation
617
bio website math.berkeley.edu/~cgerig
location UC Berkeley
age 26
visits member for 3 years, 8 months
seen 3 hours ago

After doing my BS in engineering physics (with experimental research on gravity), I started my PhD in experimental atomic physics. But I quit to do math, and am now a 4th year student of Michael Hutchings.


Jun
29
awarded  Custodian
Jun
29
reviewed Reject What is the magnetic field inside hollow ball of magnets?
Jun
27
comment I know light's speed in vacuum is constant, but what about its velocity?
@JohnRennie You're not fixing the vacuum, an accelerated observer is the same as a stationary one in a gravitational field. The question refers to the object of light itself, which implicitly assumes you have a fixed observer. If you make an edit which clarifies this, I would gladly remove my downvote.
Jun
27
comment I know light's speed in vacuum is constant, but what about its velocity?
@JohnRennie Your last paragraph doesn't make any sense to me, and you have yet to explain it despite multiple people asking. I don't think you have an explanation, because light itself does not change in vacuum.
Jun
27
comment I know light's speed in vacuum is constant, but what about its velocity?
@JohnDuffield your answer is wrong because "vacuum" requires the absence of gravity.
Apr
12
comment Destroying currents in superconducting rings by vortex tunneling
Do you have a reference for details concerning your last paragraph?
Apr
9
revised Seiberg-Witten theory and Superconductivity
added 693 characters in body
Apr
9
answered Seiberg-Witten theory and Superconductivity
Apr
9
accepted Destroying currents in superconducting rings by vortex tunneling
Apr
8
revised Destroying currents in superconducting rings by vortex tunneling
deleted 34 characters in body; edited title
Apr
7
revised Destroying currents in superconducting rings by vortex tunneling
added 16 characters in body
Apr
7
comment Destroying currents in superconducting rings by vortex tunneling
Thanks for bringing up this related problem; I take it this has negligible effect on the role of SQUIDs. Can you elaborate on your last sentence? I would think the system size $L$ depends on both the ring's thickness $\delta$ and its length $l$. (I initially guessed that the rate of occurrence of vortex tunneling looked like $\text{exp}(-\frac{\delta}{\lambda}\frac{l}{\xi})$, but had no good basis for that guess.)
Apr
7
answered Destroying currents in superconducting rings by vortex tunneling
Apr
6
asked Destroying currents in superconducting rings by vortex tunneling
Apr
4
comment Magnetic field and electric field induce one another forever
Here is Alred's comment rephrased, in case it helps: The magnetic field and electric field are "one and the same thing", the point being that I can derive the magnetic field from the (changing) electric field and vice versa. So at any point in time for your system (circuit with changing current), the electromagnetic field is $(B(t),E(t))$ and they satisfy the relations that you describe (i.e. the Maxwell equations).
Feb
28
comment Can you put a magnetic ball into a hollow magnetic sphere?
Your statement "If the search for magnetic monopoles ever turns up something, then it will confirm that such a sphere can exist" is false. Monopoles have nothing to do with building a sphere -- the sphere consists of dipoles, and there is no way to create a monopole from a collection of dipoles.
Feb
17
answered When does Pauli's exclusion principle kick in?
Nov
30
answered Mathematical subtlety in a physics problem
Nov
14
awarded  Yearling
Oct
8
answered Visible light and colors