Nothing. The speed of light is so fast that our intuitive understanding of the world doesn’t apply, when going that fast.
Light travels at the speed of light relative to you. It doesn’t matter where you are or how fast you’re moving light will travel around you at the speed of light.
Imagine you’re in a space ship passing a planet at half the speed of light. You would measure your headlight’s beam as travelling away from you at the speed of light. Someone on the planet would see you going 0.5c and your headlights going 1c, and would conclude your headlight beam is traveling away from you at half the speed of light.
How does the universe deal with these contradictory observations? Time dilation. Time will flow at a different rate on your ship than the planet. The universe is weird at high speeds.
As far as your speed, it would be the same as turning on the headlights of your car. The lights will slow you down, but such a small amount you need a special lab to even measure it.
You would see your normal headlights because your subjective experience of time wouldn’t change.
Surely that depends whether you’re in the vehicle (and can see the lights) or an observer outside of the vehicle
Absolutely. The wavelengths would be significantly increased or decreased depending if viewed from the outside standing standing still in respect to the spacecrafts motion.
From inside the spacecraft it would appear normal. What would seem weird is that objects you are traveling towards would appear much closer than if you were stationary to said objects. Objects behind you would appear much farther away.
This is a technicality, but the wavelengths wouldn’t actually change. They would be the same length from both perspectives. What actually changes between the two different observers is how long a foot/meter actually is.
Although even that isn’t technically right either.
I think you might be incorrect. To a stationary person on the ground, the light they emit would be red or blue shifted depending on the direction they are going. Red or Blue shifting is the same as saying your wave length is changing.
What I think you meant to say is that the speed of light does not change at all. Which is correct. That has nothing to do with the wave length which can change in frequency.
Edit. Will clarify. Only the stationary person will see the wavelength or other term, frequency change. The person in the spaceship will not notice any changes in the light they emit as it will be entirely cancelled out by the time dilation.
That’s the fun part of light, it is the same speed regardless of reference frame.
Einstein himself has actually used this scenario in his first article about relativity, and he derived the formulas for the transformation of length and of time from it
https://onlinelibrary.wiley.com/doi/abs/10.1002/andp.19053221004
Just wanted to say this was an awesome thread with a lot of great explanations- really interesting read, thanks for the great question!
If you are in the car, the headlights would look normal. If the car is driving towards you, the light would be blue shifted. If it is driving away from you (I guess you would be seeing the taillights), they would be red shifted. That is what happens when you look at the light from distant galaxies. Because the universe is expanding, the galaxies are moving away from us rather fast. Because you know the emission spectra of the stars in them, you can calculate the red shift, and that tells you how far away the galaxy is.
Where would you be located relative to the light?
If you were observing as a third person watching in the slowest of slow motion, would the light from the headlights creep forward illuminating the void infront only slightly faster than the speed of which the vehicle is travelling?
Edit: assuming the vehicle is going factional slower than the speed of light.
You roll a 1. Power failure. Gotta reroute the annular nucleonic power convertor through the macguffin relays just to get back up to speed.
Pretty sure you can just reverse the polarity.
You always try reversing the polarity. It’s not like I’m walking around with variable phase inverters in my prison pocket.
It would slow down a little
