4
votes
1answer
79 views

Is it proven that all “solar” neutrinos are coming from the Sun direction?

In "Observation of 8B solar neutrinos in the Kamiokande-II detector" (Phys.Rev.Lett., 63, 16(1989), http://prl.aps.org/pdf/PRL/v63/i1/p16_1) the Figure 2 shows that only small percentage of registered ...
2
votes
3answers
824 views

is lightning attracted to pointy objects?

Advice I was given when growing up: in a thunderstorm, stay away from tall, pointy things. It's pretty obvious why lightning would prefer to strike tall objects, but pointy ones? Is there any truth ...
0
votes
3answers
257 views

3 inertial frames compared in STR

Suppose an event is observed in 3 inertial frames K, K' and K''. The coordinates in K are $(x,t)$ in K' are $(x',t')$ in K'' are $(x'',t'')$. The K' and K'' coordinates are then Lorentz-transformed to ...
3
votes
3answers
796 views

Is it possible that QM is just GR?

The more I learn about General Relativity, the more it seems like it isn't fully understood. It seems that before it's full consequences were exhaustively understood, not 10 years after its discovery, ...
2
votes
0answers
52 views

dynamical operator and $SU(n+1)$

I want to know precisely by example what is dynamical operator? what is the relationship between dynamical operators and the $SU(n+1)$ How to show all the eigen states of a dynamical operator form ...
2
votes
0answers
383 views

What is effective mass approximation

Currently i am studing about quantum confinement in semiconductors and came across effective mass approximation.but i am unable to understand this concept. what is the use of effective mass ...
2
votes
1answer
62 views

Observable universe does it account for farther away galaxies measure of the observable universe?

From our planet we can only see so far on any direction. If a galaxy farther out than ours had a planet would its view extend beyond our measurements?
0
votes
1answer
186 views

uncertainty principle of spin in (super)string theory

In quantum mechanics, uncertainty principle states that we can only measure the quantity of spin in one axis but not others. Then what about in superstring theory? As quantum mechanics is basically ...
2
votes
2answers
297 views

How seriously do string theorists take the “landscape”

The string theory landscape seems to this outside observer to be an intermediate step in the intellectual progress toward a more robust theory that explains why our one universe has the particular ...
4
votes
4answers
454 views

Spontaneous radiation

The usual explanation of spontaneous radiation is that the energy eigenstates are perturbed by QED interaction, so that the eigenstates obtained from single-particle QM are no longer eigenstates of ...
0
votes
2answers
832 views

Calculating two particle position and velocity with each other?

I've calculated the displacements and average velocities of both particles. $A$ average velocity $= 1.1180m/s$ displacement is $11.1803m$. $B$ average velocity $= 0m/s$ displacement is $0m$. ...
0
votes
2answers
1k views

Is carbon dioxide a greenhouse gas? [duplicate]

Possible Duplicate: What experiments prove the greenhouse effect? I am seeking for a proof that CO2 is a greenhouse gas. I posted this on Skeptic.SE recently but found no help in seeking ...
4
votes
3answers
165 views

If the universe started again with exactly the same conditions… would it be the same?

Sorry if this is a basic question but I can't find anywhere to ask else to ask it: If the universe was created again and exactly the same conditions where in place at the beginning, would everything ...
6
votes
2answers
154 views

Would it be possible for geophysicists/geoengineers to develop an artificial way of trapping carbon in the ocean?

There's a mechanism by which the southern ocean sequesters carbon from the atmosphere. It happens when strong winds displace a large slab of surface water, accumulating in a specific region where the ...
1
vote
3answers
622 views

Extract energy from magnets

Is it possible to "extract" energy from a magnet, making it lose its magnetism? Or, to put in another way, is magnetism a form of energy? (I am not talking about potential energy in a magnetic field). ...
12
votes
4answers
2k views

Is a 1D vector also a scalar?

A vector in one dimension has only one component. Can we consider it as a scalar at the same time? Why time is not a vector, although it can be negative and positive (when solving for time the ...
2
votes
2answers
216 views

Is the gravitational constant G a minimum value in some sense?

Assume a central body of mass $M$, and call $a$ the acceleration of a test body at a distance $r$ due to any interaction whatsoever with the central body. Is is correct to say that the ratio $a r^2/ ...
1
vote
2answers
229 views

What is the Schechter luminosity function's domain of support?

I'm trying to fit a Schechter luminosity function to some data points, but it's not clear from this definition what the domain of support of the PDF should be. I'm familiar with the standard Pareto ...
7
votes
3answers
336 views

why there is no accuracy of the measured value of $G$?

With the advancement of Modern Technology still there is no accuracy of the measured value of $G$ Gravitational Constant, why!?
2
votes
2answers
965 views

What the difference between “orbital” and “orbit”?

What's the difference between "ortibal" and "orbit"? Which one should be used in physics? In quantum mechanics, is "atomic orbital" or "atomic orbit" used? And what about in classical mechanics? A ...
1
vote
3answers
195 views

In Copenhagen, can this idea preserve locality for Bell inequalities?

Generate an entangled pair of qubits. Send to Alice and Bob far away from each other. Both measure along basis in one of two possible orientations. The result is sent to Charlie at some later time, ...
5
votes
1answer
147 views

Optical laser pumping and reflectors

Let's say we are building Nd:YAG laser. It is optically pumped by some linear xenon flash lamps, it absorbs light around 750nm and 800nm, and emitted light is at 1064nm. The question is why doesn't ...
7
votes
1answer
390 views

Mathematical concept of supersymmetry

I wish to study supersymmetry in field theory(sometime in december). However, I am quite not sure what is needed for its study. In supersymmetry, I just want to get the mathematical idea, such as its ...
3
votes
1answer
761 views

Would Titan moon blow up if you light a match?

Given that the atmosphere of Titan is mostly methane, and from a comment on this TED talk... Would it blow up from a lighted match-stick? Seems like it's at least plausible. But, wouldn't the lack of ...
3
votes
1answer
669 views

Collision between Neutron stars and Black holes

When two neutron stars or black-holes come closer and closer, their angular velocity increases with decrease of distance and they start to revolve around a constant center with high relativistic ...
5
votes
1answer
664 views

How often does a cosmic ray hit our eyes when we are on Earth?

Astronauts often see flashes when they are in space. How often these particles make their ways down to the Earth and hit us? What's the chance they hit our eyes and see flashes?
1
vote
2answers
398 views

Interference, photon's phase, and the Hilbert space

Dirac said that a photon can only interfere with itself. This is consistent with the tensor product of two photon spaces representation. On the other hand, it is known that there is interference ...
2
votes
2answers
203 views

Einsteins equation : Black hole solution

Let Einstein's equations satisfy $ R_{\mu \nu } = 0 $. Suppose we solve it numerically with the aid of a computer. Can we know from the numerical solution if there is a black HOle in the solutions? ...
2
votes
1answer
93 views

Numerical renormalization

is there a numerical algorithm (Numerical methods) to get 'renormalization' ?? i mean you have the action $ S[ \phi] = \int d^{4}x L (\phi , \partial _{\mu} \phi ) $ for a given theory and you want to ...
7
votes
4answers
2k views

Why is the Heisenberg uncertainty principle stated the way it is?

I spent a long time being confused by the Heisenberg uncertainty principle in my quantum chemistry class. It is frequently stated that the "position and momentum of a particle cannot be ...
4
votes
1answer
151 views

Open String Coupling

I'm reading Zwiebach's First Course in String Theory. At present I'm learning about string coupling. Zwiebach says it's possible to prove that $g_o^2=g_c$ where $g_o,\ g_c$ are open and closed string ...
0
votes
0answers
142 views

Can experiment distinguish the basis in which a singlet state is represented?

Let $\left(|\uparrow\rangle,|\downarrow\rangle\right)$ and $\left(|\nearrow\rangle,|\swarrow\rangle\right)$ be two bases of the $2$-dimensional Hilbert space $H$. Can an experiment distinguish ...
3
votes
1answer
145 views

Eq. (5.3.20) Weinberg Volume 1, p. 209

Weinberg claims that it is obvious that the $\sigma = 0$ component of $u^\mu$ at zero spatial momentum points in the 3-direction. This is supposed to follow from (5.3.6). Unfortunately I am not seeing ...
0
votes
1answer
87 views

Vehicle acceleration

What I'm essentially doing is Kalman Filter. If anyone is familiar with (but it doesn't really matter in this case). Consider the following formulas: $$x_k=x_{k-1}+v_{k-1}dt+a_{k-1}\frac{dt^2}{2}$$ ...
4
votes
1answer
309 views

Reasons to suspect that matter is emitted from black holes nonthermally

Quote: "One has reasons to suspect that this matter is emitted from the black hole nonthermally, more or less as it came in, after doing a traversal of the interior regions." Ron Maimon in Do black ...
1
vote
1answer
90 views

Kaluza Klein Particles and Mini Black Holes

Are the Kaluza Klein Particles and Mini Black Holes associated with the ADD and Randal-Sundrum models different names for the same class of particles or are they distinct.
3
votes
2answers
268 views

Do black holes accelerate in spin as they obtain more mass?

It is known that - When a star collapses during the formation of the black hole, the black hole obtains the spin of the star which it collapsed from... What I'd like to know is, If this spin ...
16
votes
3answers
656 views

Is there a thought experiment which brings to light the contradiction between General Relativity and Quantum Mechanics?

I've been told that GR and QM are not compatible, is there an intuitive reason/thought experiment which demonstrates the issue? (Or one of the issues?)
2
votes
0answers
93 views

Macroscopic chromodynamics

Lately I've been reading about gamma ray lasing phenomena, and I've been wondering about the applications of this. More concretely, the above fantastic question led me to wonder if we could somehow ...
10
votes
2answers
652 views

Is there a strong force analog to magnetic fields?

In special relativity, magnetism can be re-interpreted as an aspect of how electric charges interact when viewed from different inertial frames. Color charge is more complex than electric charge, but ...
2
votes
1answer
128 views

Does unitarity apply in between measurements?

Sorry if this is a silly question (engineer here), but I was wondering if the math in particle physics assumes that unitarity applies even between measurements. In other words, I take it that the ...
2
votes
4answers
1k views

Which angle causes an object to land quickest?

Say a canon is where the circle is, and it shoots two different canonballs at different angles, but at the same speed, which angle would make the cannonball hit the ground first? Intuitively I'd ...
2
votes
1answer
235 views

Time reversal effect on time derivative in Quantum Mechanics

I am reading Zee's Quantum field theory in a nutshell. On time reversal he has Consider the transformation $t\rightarrow t'= -t$. We want to find $\Psi'(t')$ such that $i(\partial/\partial ...
5
votes
1answer
358 views

If quantum mechanics is ultimately deterministic, would Shor's factorization algorithm still work for large integers?

Victor Stenger argues that the apparent randomness in quantum mechanics is a result of the randomness in the macroscopic detectors (similar to the randomness in the laws of thermodynamics) and is not ...
0
votes
1answer
40 views

Reference for stellar figures

Could anybody suggest a reference for the present stellar models? In particular, I would appreciate references containing the core temperatures and pressures of neutron stars...
3
votes
1answer
153 views

Do Maxwell equeations change somehow after Higg's boson finding?

When I was in some physics -lesson, probably something to do with Quantum Physics -- the teacher said that certain Maxwell equations would change if the Higg's boson is found. It is also possible that ...
1
vote
2answers
87 views

Atomic layer deposition applications?

What unexplored areas (known unknowns) are there in atomic layer deposition (ALD)? What unexplored applications of ALD are there? It seems like people use it a lot for coatings of either insulators or ...
3
votes
1answer
151 views

Why a star commonly exhibits 6 rays?

Have you realized, that often the photo of a star shows 6 rays spreaded symmetrically around it, independently of the camera chosen? Do you have idea of what kind of optical phenomena is behind it?
-1
votes
1answer
659 views

Oscillating Dipole: Principle of Receiving and Transmitting Electromagnetic wave?

I am practising to Tfy-0.1064 -elementary-physics-exam and doing this practise -exam here. The problem in Finnish goes like this: "Selosta lyhyesti sähkömagneettisen säteilyn lähettämisen ja ...
2
votes
2answers
225 views

The physics behind The Great Flood [closed]

The book of Genesis floats (pardon the pun) some interesting numbers when discussing the Great Flood. For example, it rained for 40 days and 40 nights, and at the end of that time, the entire planet ...

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