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# Physics/Speed of Light

Question

Dragon God Zarama
QUESTION: Hello, this may be a very rudimentary question, and my confusion is a product of pure lack of knowledge, but I have a question regarding the speed of light. I've heard numerous times that mass can't travel pass 186,000 mps, and that only light travels at that speed. I was wondering what if something was colossal in size to the point it dwarfed galaxies. This came to me while I was watching anime. There is a new Dragon in Dragon Ball, I'll attach images. If he were to just move a finger, it would be technically travelling at millions of lightyears per second right? Somebody told me speed is relative so no laws would be broken, but I need more explanation to fully understand. It's a hypothetical question, so I'm wondering if something was that big in reality.

ANSWER: While Dragon Ball has nothing to do with science, I get what you're asking.  No, no physical thing with mass can move faster than the speed of light, it would take an infinite amount of energy to get it to move that fast.  However, defined points that are not (like the point where two blades met in a pair of scissors) physical masses can, because the physical parts don't have to move that fast.  The world of physics is still full of unexplained pieces, however, like dark matter.  Perhaps Dragons have no mass...

---------- FOLLOW-UP ----------

QUESTION: I know it was a completely out-there question in regards to reality and that science doesn't apply to fiction. But just for the sake of understanding, say for example you were sitting on this Dragon's claw. Due to his size you would be riding past entire galaxies in seconds, while at the speed of light, if my memory serves me right, it would take 100,000 years to cross the Milky Way. Sorry for my scientific illiteracy, but the scissor reference flew right over my head. The claw you would be riding on would be a physical mass rather than a defined point correct? Or am I completely missing something simple? Thanks for your timely response!

If Dragon Ball depicts an object with mass moving at faster than the speed of light (as you describe), then it is ignoring physics.  Kind of obvious, we're talking about anime and not reality.  However, perhaps I could describe what would happen as you approached the speed of light in traveling through space a little better (as if you were "riding on the claw," as you put it):

If you were to travel that fast, you would experience length contraction and time dilation.  To you, it would appear as if the distance you were traveling were getting shorter and shorter.  Time, for you, would also be slowing down.  So to you, it would appear as if the galaxies you were heading toward were actually getting closer (the distance to them were shrinking), and you would see them aging rapidly (that one is trickier to explain to someone who has studied only special relativity, but the acceleration takes care of it).  Yes, you would see yourself passing galaxies, but nothing would be moving faster than the speed of light because you would see the distance shrink as you approached light speed.

Physics

Volunteer

#### Dr. Stephen O. Nelson

##### Expertise

I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.

##### Experience

I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Education/Credentials
Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.