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Post by Mighty Attack Tribble on Jul 14, 2022 13:58:32 GMT -5
OK, so, if there were sentient life in one of the galaxies with the red stars that are supposedly now dead, and they saw us with their own telescope, would they see us billions of years in the past, too? Correct.
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Dr. T is an alien
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Post by Dr. T is an alien on Jul 15, 2022 13:44:33 GMT -5
And the more red the galaxies are, the further away they are. There's galaxies in that photo that are potentially 10+ billion light years away. Here's a quick comparison between the JWST and the Hubble Telescope: Hubble needed 12 days of exposure to take that photo. The JWST needed just under 12 hours. Those red galaxies probably don't even exist as is anymore. Given how slow the speed of light is in these things, we're essentially looking at an after image from billions of years in the past. Why would the galaxies stop existing? Sure, they would change over time but the only way any galaxy stops existing in the cosmically short time since the Big Bang is if it got absorbed or ripped apart by a larger galaxy (the Milky Way is actively cannibalizing at least two of the galaxies in orbit around it, has done so with others in the past, and will itself be merged with the Andromeda Galaxy in 4-5 billion years).
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Johnny B. Decent
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Post by Johnny B. Decent on Jul 15, 2022 14:33:09 GMT -5
OK, so, if there were sentient life in one of the galaxies with the red stars that are supposedly now dead, and they saw us with their own telescope, would they see us billions of years in the past, too? Correct. Holy f***. That's insane to think about.
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Post by Cyno on Jul 15, 2022 14:47:03 GMT -5
Those red galaxies probably don't even exist as is anymore. Given how slow the speed of light is in these things, we're essentially looking at an after image from billions of years in the past. Why would the galaxies stop existing? Sure, they would change over time but the only way any galaxy stops existing in the cosmically short time since the Big Bang is if it got absorbed or ripped apart by a larger galaxy (the Milky Way is actively cannibalizing at least two of the galaxies in orbit around it, has done so with others in the past, and will itself be merged with the Andromeda Galaxy in 4-5 billion years). Not existing as is, not ceasing to exist altogether. By that I meant that a good portion of the trillions of stars in those red galaxies are, by now, either sad little white or black dwarf stars, went nova or supernova, or turned into something like a neutron star, pulsar, or black hole. There's also more dramatic events like a galaxy absorbing smaller satellite galaxies or something like what will happen to our galaxy when it merges with Andromeda.
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Post by Mighty Attack Tribble on Jul 15, 2022 15:00:45 GMT -5
Holy f***. That's insane to think about. You know what else is insane? This is our galaxy as it exists today: Because the Milky Way's characteristic spirals didn't form until about seven billion years ago, any intelligent life form looking at our galaxy from more than seven billion light-years away will see this: Or even further away than that:
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Dr. T is an alien
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Post by Dr. T is an alien on Jul 15, 2022 16:03:45 GMT -5
Why would the galaxies stop existing? Sure, they would change over time but the only way any galaxy stops existing in the cosmically short time since the Big Bang is if it got absorbed or ripped apart by a larger galaxy (the Milky Way is actively cannibalizing at least two of the galaxies in orbit around it, has done so with others in the past, and will itself be merged with the Andromeda Galaxy in 4-5 billion years). Not existing as is, not ceasing to exist altogether. By that I meant that a good portion of the trillions of stars in those red galaxies are, by now, either sad little white or black dwarf stars, went nova or supernova, or turned into something like a neutron star, pulsar, or black hole. There's also more dramatic events like a galaxy absorbing smaller satellite galaxies or something like what will happen to our galaxy when it merges with Andromeda. I am fairly certain that no black dwarves exist yet. No white dwarves would have had enough time to cool to black dwarf stage yet. If you find any that might suggest some really interesting theoretical possibilities though.
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Post by Legion on Jul 15, 2022 17:53:40 GMT -5
Holy f***. That's insane to think about. What it really shows is that if we can't figure out a warp drive, in essence, we wont be finding life. The universe is simply too big, any civilisation worth anything rises and falls before we can find them, or more realistically given then time scales, they can find us.
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Post by Cyno on Jul 15, 2022 18:06:53 GMT -5
Even with FTL travel we're never seeing those other galaxies. The universe is way too big. Andromeda, the closest major galaxy to ours, would take hundreds of years to travel to with theoretical FTL travel.
You'd need something that breaks the laws of physics as we know them over its knee like Star Trek's transwarp or Mass Effect's mass relays.
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Johnny B. Decent
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Post by Johnny B. Decent on Jul 15, 2022 18:34:25 GMT -5
It might be better if any aliens don't find us, as they probably would just conquer us. Still, I like to think there's something out there in the universe besides us.
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Post by Mighty Attack Tribble on Jul 15, 2022 18:45:35 GMT -5
Holy f***. That's insane to think about. What it really shows is that if we can't figure out a warp drive, in essence, we wont be finding life. The universe is simply too big, any civilisation worth anything rises and falls before we can find them, or more realistically given then time scales, they can find us. Exactly. Even the closest star system, Alpha Centauri, would take a ship four years and four months to reach – and that's if said ship could accelerate to light speed instantly and avoid being obliterated by colliding with a random piece of space dust or the inhabitants get cooked by radiation along the way. And that's not even taking special relativity into account. For those unfamiliar, the faster you travel the faster time passes around you, so while that four years and four months spent at light speed will still feel like four years and four months to those travelling, thanks to the wonders of time dilation they will be moving through time faster than everybody back on Earth. The result? A ten-year mission to Alpha Centauri and back from the travellers' perspectives will see them arrive back on Earth anywhere between a few decades to a few centuries after they left, depending on how long it takes them to accelerate and decelerate. So yeah, warp drive is going to be essential for making even "local" interstellar travel viable.
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Post by Mighty Attack Tribble on Jul 15, 2022 18:56:16 GMT -5
Even with FTL travel we're never seeing those other galaxies. The universe is way too big. Andromeda, the closest major galaxy to ours, would take hundreds of years to travel to with theoretical FTL travel. From Earth's perspective, yes, but as another quirk of special relativity a ship travelling on a one-way trip could reach Andromeda in just 28 years from the perspective of the travellers.
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Post by zrowsdower on Jul 15, 2022 22:21:22 GMT -5
Seeing that i kind of get why Evil Lyn got so disillusioned about life in the last He Man season.
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Post by aka Cthulhu on Jul 16, 2022 5:44:28 GMT -5
Really. To me, space is both utterly amazing and downright terrifying at the same time. I remember as a kid reading a school book that talked about comets and asteroids, suns so many times bigger than ours, and black holes.
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Post by Hit Girl on Jul 16, 2022 12:02:16 GMT -5
It might be better if any aliens don't find us, as they probably would just conquer us. Still, I like to think there's something out there in the universe besides us. It's entirely plausible that aliens have already formed some sort of federation and have agreed between themselves not to contact us if they think we are too violent or primitive.
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Post by Clash, Never a Meter Maid on Jul 16, 2022 13:07:37 GMT -5
Not existing as is, not ceasing to exist altogether. By that I meant that a good portion of the trillions of stars in those red galaxies are, by now, either sad little white or black dwarf stars, went nova or supernova, or turned into something like a neutron star, pulsar, or black hole. There's also more dramatic events like a galaxy absorbing smaller satellite galaxies or something like what will happen to our galaxy when it merges with Andromeda. I am fairly certain that no black dwarves exist yet. No white dwarves would have had enough time to cool to black dwarf stage yet. If you find any that might suggest some really interesting theoretical possibilities though. We can at least confirm that we have red dwarves and white holes.
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Post by Mighty Attack Tribble on Jul 20, 2022 10:12:59 GMT -5
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