## If extraterrestrials look like us, then how can we tell them apart from us?

That may be difficult.   I know that during the biblical times, Yahweh freaked out and killed the brother of Aaron, when he shined a purple light near him.  So it may give us a clue that certain frequencies of light, near the ultra-violet band, might be able to point them out to us.  I am not positive that that method will work with all of the groups or even with the current crop, but we will find other ways by asking the friendly group what they suggest.

###### What are some unethical life hacks which come handy in India?

When standing in long queue near rickshaw stand, it is better if you avoid the queue and start walking a few 50 metres or so. There you will find rickshaws empty and even the drivers don't mind allowing you many times(for they don't want to go an extra

###### What are some best popular science articles?

Anything on Wait But Why. His expose on Elon Musk was one of the best things I read last year in popular science, AND it had 4 parts. Other articles are very interesting as well, I LOVE the

###### How can photons have no mass and yet still have energy given that $E=mc^2$?

From relativity, we have the energy of an object $E = mc^2$, given by its mass and the speed of light, c.  According to this theory, mass depends on velocity v: $m = \frac{m_0}{\sqrt{1-\frac{v^2}{c^2}}}$, where $m_0$ is the "rest mass" - the