Radiometric dating wiki answers accommodating inns
Certainly, there’s a little less because it’s constantly running into things, but the universe is, to a reasonable approximation, empty. The expansion of the universe does have some important effects, of course.
Each responds in their own time to changing climate.
In fact, the night sky today radiates energy at the same intensity as anything chilled to about -270 °C (That’s why it’s cold at night! So, while the oldest light is only about 14 billion years old (and has traveled only 14 billion light years), the location from which it was emitted can be calculated to be about 46 billion light years away right now! *The universe may be “closed”, in which case it’s curved and finite (like the surface of a balloon), or “open”, in which case it’s flat and infinite in all directions (like an infinite rubber sheet).
“Curved” and “flat” are a little hard to picture when you’re talking about 3 dimensional space, but there’s a little help here.
The first statement is the Big Bang, but we can use it to infer some interesting things about what was happening within the first second (which is the next best thing to actually being able to see the first second).
That light is now the Microwave Background Radiation. First, when someone says that all of the matter and energy in the universe was in a region smaller than the head of a pin, what they’re actually talking about is the universe, which is just all of the galaxies and whatnot that we can see.