anuttarasammyak's latest activity

You may find some classic books of your taste at "Books in Astronomy" in Project Gutenberg, free, though I am not good at astronomy.

I have some solemn news to report. Many in the community had been wondering where the prolific @Vanadium 50 has been. V50 hasn't posted...

I would like to expalin it in the case of ellipse orbit of planets as shown in the figure below. You see that F has components that is...

At least energy, momentum, angular momentum of the system is conserved. I hesitate to refer spin or helicity or other pure quantum...

An electron and a positron meet and become two photons. The system quantum state is conserved and photons are compressible. The reverse...

The angular momentum before and after the change in the moment of inertia is conserved: $$M=I_1\omega_1=I_2\omega_2$$ Assuming ##I_1 >...

To show that ##\sin (\frac{n^2}{n+a} x)## has partially bounded sums for ##x \in [1,2]##: Write \begin{align*} \frac{n^2}{n+a} = n - a...

As for the special case ##x=\frac{\pi}{2}## for n=0 (mod 4) $$a_n=-\frac{1}{n^b}\sin c_n$$ for n=1 (mod 4) $$a_n=\frac{1}{n^b}\cos...

It may help to note that $$\frac{n^2}{n + \frac15} = n - \frac{1}{5 + \frac 1n}.$$

Thanks you all for good teachings. I add would add a rough hand drawing explaining the event.

From "general theory of relativity" by Dirac, as for Einstein pseudotensor, (32.3) where ##\mathcal{L}=\sqrt{}\ L## with (26.3) , we got...

In the restframe of the train, the bridge-length maybe even smaller than the train-length due to length contraction, if the bridge moves...

From the graph in ＃7, we observe for |x| >> 1 only n=1 term survives so it is sinusoidal between -1 and 1. From the graph in #3 , for...

Once, I calculated the integral of the Einstein energy–momentum pseudotensor for a Schwarzschild black hole in the region outside the...

Order does not matter for real number inner products. However, in (c), $$<u|v> = <v|u>^*$$a conjugate complex.