If the stars we see are light from millions of light years away and they see our Sun’s light the same, is the whole universe “existing” in the same time?

Question

Hi all, I didn’t know how to formulate the question in a non stupid way so I’ll explain.

If the light we see from stars in the sky are actually “the past” as they’ve left their source light years ago, from another point in the universe another planet sees our Sun’s light the same way, correct?

If that’s the case, if there was an “universal year” or an “Universe’s current year”, would all the stars and planets be living in the same year?

Maybe I am 5, I feel 5 right now.

Thanks 🙂

In: 466

Answer 1

It’s something like that, but not quite because of what you said. “Right now”, if such a thing existed with precision, people from millions of light years away would see our sun as it was millions of years ago.

The real reason there is no true universal timeline is that time stretches or contracts (speeds up or slows down) depending on how fast you’re going compared to whatever exerts some force upon you (usually gravity). Everything travels at different relative speeds, which means there’s no true universal clock.

Even here on earth, time passes differently for astronauts in the ISS than it does for us. People on top of mountains don’t see time at the same rythm as people on the bottom of ocean, one of them gains something like a trillionth of a second per year on the other.

Here on earth, at the local level, establishing a timeline is easy because everything has a frame of reference that references the same things: The Earth, sun and moon. Get wider than this, and the idea of a universal timeline starts looking like a wild simplification or approximation at best.