# All Questions

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### Nobel Prize challenge: Could neutrinos be used for quantum information processing?

We know that two scientists, Takaaki Kajita and Arthur B. McDonald, working on Neutrinos have just been awarded the 2015 Nobel Prize in Physics. My question as a Nobel Prize Challenge Question is: ...
1k views

### Where does the force appear when considering object interactions in another reference frame?

Imagine I am sitting on an asteroid with my buddy and drinking a beer. When the bottles are empty we throw them simultaneously in opposite directions perpendicular to the asteroid's movement. What ...
20 views

### equilibrium state of a system in statistical mechanics

Why we consider the maximum number of micro states or complexions as equilibrium state of a macro state or a system in statistical physics?
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### Calculating maximum displacement [on hold]

I was wondering if we could calculate the maximum displacement of a particle given its position as a function of time, IN CASE MAXIMA-MINIMA APPROACH FAILS. For instance, consider ...
60 views

Here is the twin paradox with a twist. Scenario 1: An observer (A) leaves from the equator of the earth and travels with an acceleration of $9.8\,\mathrm{m/s^2}$ in a north direction ( i.e. in the ...
20 views

### Electrostatics and electric field [on hold]

What is the electric field on the surface of a charged hollow sphere? Please be mindful of the fact that i want to know the field exactly "on" the surface of the hollow sphere. My teacher told me ...
26 views

### Why does a block 2 on a oscillating block 1 start sliding at the maximum acceleration?

A block of mass $m_{1}$ is oscillating horizontally with another block on it of mass $m_{2}$. There's friction "k" between both blocks, so the thing is why the second mass starts sliding at the ...
38 views

### How Did the Universe Manage to “Explode”? [duplicate]

I'm taking a slightly different "look" at the Big Bang. I do not question the Big Bang's validity but there is one oddity about it I don't think I've ever seen adequately addressed. Our universe is ...
51 views

### Effect of position on a motorbike turning

While searching tips for driving a motorbike on wet roads safely, I heard some pilots saying to lean inside the slope makes the bike less tilted, so it's safer. I agree leaning make the bike less ...
38 views

### Why does thawing Coca-Cola generate force and expand the can as it thaws?

If I take a warm unopened aluminum can of Coca-Cola and place it in the freezer and let the Coca-Cola freeze solid, then take the can out of the freezer and let it thaw unopened in a typical room, the ...
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### Depletion region thickness in solar cells

It is well known that typical Si solar cells are rather thick (hundreds of micrometers). Now, Si has an indirect band-gap and therefore weak optical absorption (needing a phonon-assisted process to ...
23 views

### What could happen if you froze a laser into a super conductive state? [on hold]

what could happen if I froze a laser into a super conductive state would it became more powerful or flow on a hire Hz or maybe burn a hole right through the earth, has such thing ever been done ...
22 views

### Physics problem projectiles [on hold]

A ball is shot from the ground into the air. At a height of 9.1 m, its velocity is v=(7.6ı̂ +6.1ȷ̂ )m/s, with ı̂ horizontal and ȷ̂ upward. To what maximum height does the ball rise? What total ...
52 views

### Conserved quantities for the system, classical mechanics

In certain situations, particularly one-dimensional systems, it is possible to incorporate frictional effects without introducing the dissipation function. As an example, find the equations of motion ...
29 views

### Gas Mass Calcuation in Galaxy Cluster

Rob Jefferies found this document for me that describes how the X-Ray emissions from galaxy clusters are used to calculate the mass of the cluster. I'm unable to follow the steps to calculating the ...
39 views

### Interferences in a superposition of two energy states of a particle at rest

In Feynman's volume III, chapter 7, he describes a particle which is in a superposition of the energy states $E_1$ and $E_2$ as $$e^{-i(E_1/\hbar)t} |E_1\rangle + e^{-i(E_2/\hbar)t} |E_2\rangle$$ ...
23 views

### Linear or Circular Universe? [on hold]

The present calculated width of the Universe seems to give it a linear (Three dimensional+time) design (i.e if you throw an object in one direction it will continue in that direction only), whereas ...
3k views

### Physics behind this neutrino-related joke

In the comment section of a newspaper article reporting on the 2015 Nobel Prize for Physics, which was awarded for work on neutrino oscillation, I found the following joke: "I'm sorry, we do not ...
27 views

### FWHM of different spectra and separation in fine structure

I'm doing some research on spectroscopy and there are some phenomena I can't explain (only a second year physics student). I took some spectra of neon in the 659.89529 nm and then of hydrogen at ...
31 views

### Can the newly discovered mass of the neutrino explain in part, the missing matter [duplicate]

This question is related to the recent discovery of the neutrino mass 0.320 ± 0.081 eV/$c^2$. Could this account for at least some of the Dark Matter/Missing matter of the universe?
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### Extensivity Intensivity and mathematical definitions

Could someone explain how intensivity and extensivity are defined mathematically, I know via their homogeneity as functions of the particle number but how exactly is this done and why? This would ...
20 views

### Stimulated emission role in laser cooling

Laser cooling can be achieved by exciting an atomic system, in order to "pump" atoms in the excited state. This gives a recoil momentum $\hbar k$ the the atom, which then emits spontaneously. As ...
22 views

### Calculate speed of a moving object that is far and closer from Camera [on hold]

I am developing an Android application which can tell the speed of a moving object. I got the speed calculation technique already. But I am facing problem, how to calculate speed of a far or closer ...
I have been given the potential of a simple harmonic oscillator: $$V=\frac{1}{2}kx^{2}$$ I want to calculate the value $x(t)$ of a particle moving in this potential, with initial conditions ...