Eli5: Why does light travel so fast?
In: 130
Instead of a physical thing, the universe can be thought of as the collection of how all things connect to each other.
Distance and time are two ways in which things can be connected to each other.
If I am far away from you, it means we are loosely connected. If I want to get closer to you, I need to make one of our connections stronger. In this case the distance connection.
To get to you I can either go really fast, or at a slow and steady pace.
If I go fast the con
Jpk
Because it is a fundamental wave propagation. And by that, I mean it is a movement of waves of the electromagnetic force, a fundamental force in the universe. Waves of the gravitational force do a similar thing also at “the speed of light”. If I remember correctly, even the strong and weak nuclear forces are limited to the same speed again
Does it though? Or is it all… relative?
Some follow up points:
We don’t know the speed of light, we know the speed of the roundtrip of light when measured. Light could go faster in one direction hit and object and return to us slower and we won’t be able to tell the difference from an scenario were speed of light is constant in all directions.
Light travels in space, and space is not bound to the same rules as light. For instance, space can move faster than the speed of light. In the universe there is light that will never reach us because patches of space that contains light is moving faster away from us than light is moving towards us.
Fast relative to what?
Your perception?
Imagine we built an AI intelligence whose mind was powered by water flowing through tubes. By the time it could process a single thought about anything, this water would have had to have flowed an extremely long distance through its mind to generate that complex thought. When the AI saw water flowing outside of it’s mind, it would consider water flow to be extremely fast, as by the time it could even process anything that water would have had to have flowed at least the distance of all the folds of the tubes in its mind to do that.
“If something doesn’t have mass it must always travel at c” – Then why is light faster than sound? Neither have mass so shouldn’t they travel at the same speed?
I would phrase your question from a slightly different perspective. Not just light, but all things without mass travel the same speed. It’s only historical convention to call that speed the “speed of light”. But it is not some special property of light. It seems to be the norm considering the amount of massless particles. The only deviation from that norm are things with mass.
Mass, or inertia, fundamentally is a resistance to acceleration. Massless things can therefore be thought of as having ‘infinite’ acceleration. Which in our universe translates to going at a constant speed; the speed of light.
So from our perspective as massive beings, it’s natural to assume that light travels fast. But I think the more natural question to ask on a universal scale is why does mass makes us so slow?
so speed requires energy, the more mass you need to push up to speed, the more energy you need, light has no mass at all and is pure energy, so it can use all its energy to go fast since it doesn’t need to push any mass around,
Latest Answers