Eli5: Why does light travel so fast?
In: 130
You can easily push a light little pebble around, but you’re not going to even budge a massive boulder, right?
* The more mass something has, the harder it is to make it move.
Then even if you *do* push the boulder, you’re gonna have to push it *even harder* to make it move *faster*.
* The faster something is moving, the more energy it takes to make it go *even faster* – and *also* the more mass it has, the more it’ll take.
Light has *no* mass, so it moves at the fastest possible speed that anything can move. Light isn’t special here, either: anything else that also has no mass will move just as quickly.
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