Waste less time on Facebook — follow Brilliant.
×

The Speed of Reflection

Would you be able to see yourself in a mirror if you were travelling at the speed of light? Explain why.

Note by Sharky Kesa
3 years ago

No vote yet
1 vote

Comments

Sort by:

Top Newest

NO Because light rays cannot reach before us as we are travelling at the speed of light. So there will be no reflecting back of light into our eyes. Hence we can't see ourself in the mirror if we were travelling at the speed of light. Satyam Choudhary · 3 years ago

Log in to reply

Not at all Harsh Shah · 3 years ago

Log in to reply

noooo Akash Dheer · 3 years ago

Log in to reply

Light travels in such large quantities that it can be considered one mass (kind of). That's why you never have holes in your vision, because light is pretty much ALWAYS present, bouncing around all over the place. Anyways, if you move faster than the speed of light, three things will happen:

You will get larger You will expand. Remember \(E=mc^{2}\)? That says that nothing can travel the speed of light because then it will pick up mass and require more energy to move. That will be one thing happening to you.

You will warp It's part of the Theory of Relativity. Aside from the picking up mass, your physical being will be warped, stretched, but mass will not be gained. It's called length contraction.

Time will dilate Things going at fast speeds see everything else slower than they actually are. It's hard to say exactly how this would affect the experiment, but it would have some effect.

So when you zoom by the mirror, in theory, for you to see yourself, light must travel from the mirror to your eyes. Let \(d\) be that distance. Let \(l\) be your length. The light reflected by your stomach will have to travel \(2d\) distance (for the light to travel there and back) in the same time that half of your body covers distance (assuming that your eyes are halfway between you back and front). Thus \(2d \approx l/2\). There are many more factors to consider, so I'll leave that to other members. Anyways, depending on how far away the mirror is, you may or may not be able to see yourself. That is my conclusion. :D Finn Hulse · 3 years ago

Log in to reply

@Finn Hulse Your mass will increase, but that does not mean that you will get larger. Getting larger, I assume, means an increase in volume, which clearly isn't true. Just nit-picking, I suppose :P Daniel Liu · 3 years ago

Log in to reply

@Daniel Liu No, you're right. Sorry about that. Oops! Finn Hulse · 3 years ago

Log in to reply

@Finn Hulse time dilation doesn't start at the speed of light. Time literally stops at the speed of light and if you go faster you would find time reversing. Sharky Kesa · 3 years ago

Log in to reply

@Sharky Kesa Yeah, I know. Finn Hulse · 3 years ago

Log in to reply

@Finn Hulse I have thought of a way to travel through time. I call it the negative singularity. Sharky Kesa · 3 years ago

Log in to reply

@Sharky Kesa Cool! Also I don't know much about the topic, but if someone tried to reverse gravity, wouldn't you need to be able to harness a mass greater than that of the Earth. Are there other possible insane possibilities. Robert Fritz · 3 years ago

Log in to reply

@Robert Fritz No, it is the other way round. Since all objects with mass have gravity, and the higher the mass, the higher the gravity, 'anti-gravity' would require negative mass, which hasn't actually be observed but it has been theorised that black holes might convert particles into positive and negative mass, via Hawking Radiation this is hypothetical. Negative mass is the only one I know to reverse gravity although if gravity was polarised and you reversed the polarisation, it is possible to get 'anti-gravity'. Sharky Kesa · 3 years ago

Log in to reply

@Sharky Kesa Really? That's pretty cool! I thought that if a mass large enough to counter earths gravitational pull was able to be harnessed, then we could have anti gravity. Robert Fritz · 3 years ago

Log in to reply

@Robert Fritz That's not antigravity. That's just shifting gravity to another object. What you're saying is if, say, the moon became twice as large as Earth. Then everybody would fall towards the moon. That would suck, though, because it would be like falling on Earth from 384,000 kilometers above the surface. If what you're talking about is having an object with the exact same mass as earth, then theoretically, that would cause antigravity, but the construction presents many problems. Anyhow, it would be the same as if you were just floating around empty space. :D Finn Hulse · 3 years ago

Log in to reply

@Finn Hulse My thoughts exactly. Sharky Kesa · 3 years ago

Log in to reply

@Sharky Kesa :D Finn Hulse · 2 years, 12 months ago

Log in to reply

@Finn Hulse Jeez. I just wanted to be able to fly. Robert Fritz · 2 years, 12 months ago

Log in to reply

@Finn Hulse Wow, I would have to have at least a full school day to figure that out, and here it took you maybe a few minutes. Maybe even more because my World Studies teacher gets extremely mad when someone doesn't pay attention. She makes you humiliated and practically tells you that your stupid. Robert Fritz · 3 years ago

Log in to reply

@Robert Fritz :D I would like to humiliate your World Studies teacher, then. A taste of her own medicine. ;) Finn Hulse · 3 years ago

Log in to reply

@Finn Hulse No need, it's been taken care of😄 Robert Fritz · 3 years ago

Log in to reply

Nope, and there is one experiment can prove it. You drive a car on a road. The light traffic is light, but you can't see the light beam, except in the special weather like frog and you just can see the light traffic if you look staight at the light traffic :D Vladimir Tsiolkovsky · 3 years ago

Log in to reply

No. Because light need to be faster than me to fall on the miror and reflect back to my eye but in this case the light will not reflect Mena George · 3 years ago

Log in to reply

No Shashwat Pandey · 3 years ago

Log in to reply

×

Problem Loading...

Note Loading...

Set Loading...