Originally published at: https://boingboing.net/2020/04/08/what-happens-when-you-shoot-a-2.html
…
5 Likes
But bullets always fall to the ground.
ETA: unless they hit something or someone, of course.
12 Likes
Yeah, but what happens when you shine a flashlight forward while traveling at the speed of light? Answer that one, Action Man.
14 Likes
We all know what happens then, but I’ve never thought about turning the flashlight around.
5 Likes
Obviously, the beam of light would fall to the ground.
25 Likes
That was pretty cool!
FYI - I have one of those Rival Nerf guns. They made a Boba Fett branded one so I had to. And wow - they are hella accurate compared to the dart guns.
3 Likes
It’s like playing a record (you know…the vinyl version) where the middle is going at c m/s.
What’s the outside doing? Dunno. Lost in time.
3 Likes
Whatever the outcome, that sure is some lovely countryside.
3 Likes
A nerf ball is fun, but there is a ton of turbulence on that foam ball. Less cool (or maybe more cool?) would be a large ball bearing slingshot (like the german youtube guy: https://www.youtube.com/channel/UCVZlxkKqlvVqzRJXhAGq42Q ) would be less torn by the wind.
2 Likes
Is it bad that all I can think about is that he should have had a passenger shooting the ball? Safety first!
17 Likes
In case you actually wanted an answer:
You and the photons from your flashlight would both be going the speed of light. You would cruise along together.
This is more fun. You would keep going at the speed of light in one direction, and the photons would go at the speed of light in the other direction.
“The speed of light. It’s not just a good idea. It’s the law.”
5 Likes
So we would move apart at twice the speed of light?
3 Likes
That was really cool. It probably would have been safer to recruit a friend so he wasn’t handling the gun, watching for where to fire it, and driving the car all at the same time.
1 Like
4 Likes
No, you would measure a speed of precisely 1x the speed of light. Because time is slower for you than for a motionless observer watching the two of you.
(Moving “at” the speed of light can’t actually happen, so replace “moving at the speed of light” with “moving at 0.999999x the speed of light”.)
7 Likes
I’m pretty sure I saw this principle demonstrated before somewhere…
20 Likes
I would, but not the observer? But I couldn’t observe any speed at all, right, because for me time would have stopped?
17 Likes
klossner answered as well. The weird part is that from the perspective of you or the photons, your relative velocity would still appear to be the speed of light.
(I glossed over the fact that an object with mass can’t actually get to the speed of light.)
1 Like
But from the perspective of third party observer it would be 2c, or would they also detect c for the combined separation?
Even a freight train (the conventional speed of light traveler with a headlamp in the thought experiments)?
