This is actually one of those mind blowing things.
When you look into space with a telescope, you’re seeing the way it looked when light left that area. So depending on how far out you’re looking, you’re directly seeing deeper and deeper into the past.
It’s like obvious but also 🤯
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Ok here’s a nugget for your sci-fi novel.
Our hero needs to know exactly what was said many years ago in the Oval Office, so he wormholes many light years away, then points a super powerful telescope back at earth and reconstructs the conversation between the president and his chief of staff by analyzing the vibrations on the window during their conversation. From this he is able to decipher what the seed phrase is to the US strategic bitcoin reserve because the fools were saying the words out loud as they copied them down
It's so mind-blowing that we can't even comprehend it.
Just imagine how many of the stars we see in the sky are already dead and what we're really looking at are ghosts.
Another cool part: the universe is expanding. That means the thing you're looking at is moving away from you as you're looking at it. The speed at which it moves away increases the further it is away from you (like a dough expanding in the oven, you're the raisin in the bread). But the speed of light is constant. So combining these two facts, it means there are things that are so far away that they move faster away from us than the light they can emit to reach us, which means their light never reaches us. Never.
It's your (personal) edge of the universe.
Its the visible universe
Well but they can't expand past the speed of light, light is still faster
Expansion may well be faster than light because the speed limit for the latter is in a vacuum, in space, inside the universe, but the universe, hence space itself expands.
There is no global. 🤣
How does this affect Bitcoin when we break past the bounds of earth? How is a 10 minute block enforced when gravity dilates time more in some places than others?
There are not enough photos at that distance to see the dinosaurs. Nonetheless, cool idea!
Neil degrasse Tyson sucks these days but he talked about stuff like this on ‘cosmos’,which I thought was very good at the time.
So was ‘How the universe works’ , mike Rowe did the voiceover on that
Also interesting and related, there is a sweet spot in time for your species to even know anything outside your solar system exists. Soon after the big bang, not enough time for sentience to be able to grasp what they are seeing. To long after the big bang, the expansion of the universe put all those distant stars too far away to see and you only see your own solar system when you look up.
What tells you that the only thing the universe can do is keep expanding?
Only the fact that we have only ever seen it expand. I'm not saying that in the smug "duh" sense. If we found out tomorrow that it oscillates expanding and contracting in very slow cycles and just started contracting back to a finite point, I'd believe it. The behavior would be very wavelike and physics loves waves.
It would take 65 million years for that photo to reach us.
Coolest gift we have ever bought the family has been our 10" Dobsonian telescope (get the 8" if you don't have a decent sized truck/SUV - then ten is a choker). We were able to see the rings on Saturn two weekends ago - absolutely mind bending for us normies who spend most of our time seeing digital representations of space objects
Light doesn't travel. It is a rate of induction of the medium.
Unless someone wants to explain where it gets the energy to speed up once it exits a denser medium.
Dark matter
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#Meditation
But it'll take 65M years before their telescope starts seing the earth also, no?
mind-blowing is that for photon is the moment it was emited and the moment it hit your eye the same moment
