A friend of mine asked me a question about something scientific during lunch, as he knows I am scientific. He asked," If a napkin (just a cheap, cloth napkin) moves at the speed of light and hits a wall, would the wall break?" Now, and this is assuming that the napkin is a few meters away, my answer would be no. The speed of light is around 299,792,458 meters per second (info via Wikipedia). a napkin would not even hit the wall at those speeds, due to the pressure being to high, and would rip the napkin in half. I am able to rip a napkin in half with extremes ease, exerting little force. But the force exerted from the speed of light is far greater, so clearly it would rip the napkin in half. Yet my friend disagreed with me, but I am sure my theory is correct. Comment below your answer to this problem, and your reasoning behind it.

Assuming you mean a napkin traveling at just below the speed of light, since it cannot actually travel at the speed of light, the energies involved would be such that I'm not sure how much would be left of either napkin or wall.

The situation is slightly different, but Randall Munroe does a pretty thorough job of explaining what would happen of you threw a baseball near relativistic speeds. The bulk of this would still be true for a napkin.

 

https://what-if.xkcd.com/1/

The basic issue here is that ANY material object moving that fast is going to release a lot of energy interacting with whatever it hits, including the atmosphere. It really doesn't matter what the material is - and whatever effects you observe at non-relativistic speeds may no longer hold true.

 

Which is why I often say you cannot do physics by common sense.

The situation is slightly different, but Randall Munroe does a pretty thorough job of explaining what would happen of you threw a baseball near relativistic speeds. The bulk of this would still be true for a napkin.

 

https://what-if.xkcd.com/1/

Lol good article, love the last line in particular.