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I'm currently a student of physics at the University of Heidelberg.

My interests lie in theoretical physics of all kinds, and currently I am most fluent in gauge theory. I'm particularly interested in most forms of QFT.

My profile picture is obviously not of me, but if you know where it is from, you're awesome.

Having all the answers just means that you've been asking boring questions.

"The more we learn about the world, and the deeper our learning, the more conscious, specific, and articulate will be our knowledge of what we do not know, our knowledge of our ignorance." ~ Karl Popper

"Rigor cleans the window through which intuition shines." ~ Ellis D. Cooper

reviewed Leave Closed What is the future of complexity theory in black-hole physics and string theory?
reviewed Leave Closed Proof that the trace ${\rm tr}(\rho^2)=1 $ of the square of a pure state density matrix $\rho$ is always one
comment What does it mean to say “Gravity is the weakest of the forces”?
While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes.
reviewed Close Pressure required on a wing to lift a plane and the speed required to create this pressure difference
reviewed Close Physics11 vietnamese
reviewed Close Calculating impact force for bulk material
reviewed Leave Open Conservation of linear momentum for a system with a small mass inside a cylinder
answered how is an electron able to emit and absorb the same (virtual) photon?
comment Can't understand the meaning of a formula describing a stable equilibrium?
Which book? Also, $\frac{\mathrm{d}f}{\mathrm{d}x}\rvert_{x = x_0}$ is indeed a common way of writing $f'(x_0)$, so it is quite probable this is a typo.
reviewed Close Gravitational field strength inside the Earth
comment Complex integration by shifting the contour
Not quite sure, but: When time-ordering $\langle\Omega\vert T\phi(x)\phi(y)\vert\Omega\rangle$, we essentially switch from "prob. of particle being emitted at y and detected at x" to "prob. of particle being emitted at x and detected at y" the instant the time-order of x and y changes, i.e. we have the particle travelling forward in time always. Now, CPT symmetry tells us this means antiparticles travelling backward in time always. Supposing the correspondence between energy modes and (anti-)particles, this means the Feynman propagator follows the same "idea" as time-ordering.
comment How to convert measurements in a game world to real life measurements
This question appears to be off-topic because it is about finding a "real life scale" in a game where none should be expected.
reviewed Approve suggested edit on Classical Hamiltonian involving product of factors whose quantum analogues don't commute
reviewed Close Can you pull and also grind a material through a length of cylinder?
comment Complex integration by shifting the contour
There is a "simple" way to understand what the Feynman propagator is doing: While the advanced and retarded propagators propagate all energy modes forward/backward in time (corresponding to shifting both poles up/down), the Feynman propagator propagates the "positive energy modes" (right pole, shifted down) forward and the "negative energy modes" (left pole, shifted up) backward in time, corresponding to the picture of antiparticles being 'holes' of negative energy travelling backwards in time.
comment If electrons aren't revolving around the nucleus, why do atoms have orbital magnetic moment?
Note that although the electrons do not literally orbit the nucleus, their orbital states, in general, do possess angular momentum.
revised 2 fluids in a rotating U-tube
deleted 74 characters in body; edited tags
revised Functional relationship of pressure and position(1d)
edited tags
reviewed Approve suggested edit on earth tag wiki excerpt
revised Physical meaning behind causal massless scalar propogator