# All Questions

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### Is light's path a wave?

In a lot of textbooks I see a schematic of light drawn as a squiggly line. I have even heard that some things are too small to be seen because they are smaller than the wavelength of light (and ...
153 views

### Bunsen Burners and the Sun

Why do Bunsen burners burn blue in the center? What element is being burned? Why does the sun glow yellow, and not blue-a Bunsen burner is much cooler and yet it burns blue. Is it because the ...
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### Peculiar Hamiltonian Phase space

I was solving an exercise of classical mechanics : Consider the following hamiltonian $H(p,q,t) = \frac{p^2}{2m} + \lambda pq + \frac{1}{2}m\lambda^2\frac{q^6}{q^4+\alpha^4}$ Where ...
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### Different batteries connected in parallel

If we have 2 batteries one of emf x and the other is of emf y and we connect them in series we get an effective emf of x+y. But what if we connect them in parallel, how to calculate the emf now?
531 views

### Bleaching groundstate

I'm reading an article about two-dimensional infrared spectroscopy and I don't understand the following sentence. Bleach or stimulated emission contributions yield negative signals. What are ...
114 views

### Assuming space is infinite can our observable universe be an island amongst an archipelego?

According to recent measurements our observable universe is roughly 93 billion light years in diameter; also it appears (according to WMAP measurements) that spacetime is flat. Supposing space is ...
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### Why is the angle of impact complementary to the angle of launch in the simple equations for the range of a projectile?

I'm using the standard equation for the range of a projectile: \begin{align} d &= \frac{v\ \text{cos}\theta}{g} \left( v\ \text{sin}\theta + \sqrt{v^2\ \text{sin}^2\theta + 2gy_0}\right) ...
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### Describing physical constants in alternate wording; c = there can only be 671million miles of space for every second of time [closed]

This spawns from part of an answer to a question I asked. All sorts of things go to 0 and/or ∞ if you start boosting at c, and so you cannot boost into and out of a photon's frame. It ...
130 views

### Why is there no UV catastrophe (divergence) in turbulence?

I have just read that as the Reynolds number is increased, the separation of macroscopic and microscopic scales increases and that this also means that there is no UV catastrophy (or equivalently UV ...
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### Defining the star as the ellipse focus rather than the barycenter, what does the other focus do? [duplicate]

There are a lot of images and animations on the internet depicting two bodies orbiting around their common barycenter. The barycenter is defined as the (let's say right) focus of the ellipse. If we ...
220 views

### What would happen if energy was conserved but phase space volume wasn't? (and vice-versa)

I'm trying to understand the relationship between the two conservation laws. As I understand, Liouville's result is a weaker condition: it relies merely on the particular form assumed by Hamilton's ...
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### What is three-photon interference?

Whilst reading this paper on a quantum processor that performs a type of matrix computation, I came across the concept of 'three-photon interference'. A quick Google search shows that this process is ...
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### The second resonance of string?

What is the relationship between "the second resonance " and string and the wavelength. Like in this question: if the length of the string is 2cm with second resonance, then what is wavelength?
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### Highest naturally occuring binding energy of electrons

I was wondering which element has the highest binding energy of an electron. Is it simply the 1s electron of the heaviest stable element? If so, can somebody tell me where I can find a table of ...
173 views

### Spherical inversion in terms of special conformal transformation

I want to consider conformal maps on suitable compactifications of $\mathbb{R}^{n}$. I know that a special conformal transformation: $$x_i\mapsto\frac{x_i-x^{2}b_i}{1-2b\cdot x+b^{2}x^{2}}$$ can be ...
1k views

### How is torque equal to moment of inertia times angular acceleration divided by g?

How is the following relation true $$\tau = \large\frac{I}{g} \times \alpha$$ where $\tau$ is torque, $I$ is moment of inertia, $g= 9.8ms^{-2}$, and $\alpha=$ angular acceleration.
745 views

### Stark Effect on the 1st excited state of Hydrogen

I know the ground state of hydrogen is unaffected by the Stark effect to first order. And I also know that the 1st excited state is split from 4 degenerate states to 2 distinct, and 1 degenerate state ...
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### Zero uncertainty constant and a unit change

So, we know the speed of light with zero uncertainty. We also know that values of $\epsilon_0$ (electric constant) and $\mu_0$ (magnetic constant) are known with zero uncertainty. My questions are ...