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A comment on NASA says distant exoplanet could have rare water ocean, possible hint of life. Parent comment

Re:NASA says distant exoplanet could have rare water ocean, ... by konschubert on Tuesday September 12, 2023 @05:02AM (#37478430)
If you have enough acceleration , you can travel 1000 light years in a human lifetime.

It’s just that when you return, at least 2000 years will have passed on earth.

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Re:NASA says distant exoplanet could have rare water ocean, ... by pomtato on Tuesday September 12, 2023 @05:31AM (#37478629)
so you're implying speed atleast 10x the speed of light? i think you'll have better luck increasing the human lifespan instead.
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Re:NASA says distant exoplanet could have rare water ocean, ... by rowanG077 on Tuesday September 12, 2023 @05:35AM (#37478646)
Not that's not what he is implying. He is talking about time dilation.
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Re:NASA says distant exoplanet could have rare water ocean, ... by melvinmelih on Tuesday September 12, 2023 @06:16AM (#37478942)
How does one travel 1000 light years in a span of human lifetime (~80 yrs) if you’re not going faster than the speed of light?
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Re:NASA says distant exoplanet could have rare water ocean, ... by kawzeg on Tuesday September 12, 2023 @06:35AM (#37479037)
Time dilation! Time is relative. For an outside observer, over 1000 years pass, but aboard the ship, much less time passes. There are calculators for this, e.g. at [0]. If you constantly accelerate at 1g, flip around at the halfway point and accelerate in the opposite direction for the rest of the journey, roughly 13 years would pass from the traveler's perspective.

This site also has a "Newton's universe" mode, which pretends that relativity doesn't exist. Interestingly, in that case you would take over 44 years!

[0]: https://www.omnicalculator.com/physics/space-travel?c=EUR&v=...

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Re:NASA says distant exoplanet could have rare water ocean, ... by konschubert on Tuesday September 12, 2023 @09:15AM (#37480677)
I am pretty rusty in special relativity, but IIRC, in the ship it basically seems like the distance is contacting as you accelerate. And from earth, it seems like time is going slower inside the moving spaceship.
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Re:NASA says distant exoplanet could have rare water ocean, ... by Anarch157a on Tuesday September 12, 2023 @06:50AM (#37479155)
With relativistic time dilation. 1000 years will pass on Earth, but on tge ship, it will be only a couple of decades, assuming they're close enough to the speed of light.
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Re:NASA says distant exoplanet could have rare water ocean, ... by CalRobert on Tuesday September 12, 2023 @05:44AM (#37478728)
""" Time dilation is the difference in elapsed time as measured by two clocks, either due to a relative velocity between them (special relativity) or due to a difference in gravitational potential between their locations (general relativity). When unspecified, "time dilation" usually refers to the effect due to velocity. """

https://en.wikipedia.org/wiki/Time_dilation

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Re:NASA says distant exoplanet could have rare water ocean, ... by pomtato on Tuesday September 12, 2023 @10:13AM (#37481608)
wow thanks! this was super fun, do you happen to have some souce about the calculations that go into determining the time dilation based on different velocity? i'm aware about black holes being capable of well, doing time dilation thingy due to their massive gravitational force but nothing else.

edit: souce as in something a regular average joe can make sense of haha

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Re:NASA says distant exoplanet could have rare water ocean, ... by CalRobert on Tuesday September 12, 2023 @10:43AM (#37482068)
Well, depending on your preferred format there's a great book called A Brief History of Time - https://en.wikipedia.org/wiki/A_Brief_History_of_Time , or lots of videos about it at https://www.youtube.com/results?search_query=time+dilation

More broadly, the series Cosmos with Carl Sagan was excellent, and is worth a view. The bit about time dilation is at https://www.youtube.com/watch?v=kWgEzxi_A0w . The more recent one with Neil Degrasse Tyson is also good (but while I enjoy both, I think I prefer the older one)

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Re:NASA says distant exoplanet could have rare water ocean, ... by hermitcrab on Tuesday September 12, 2023 @02:32PM (#37485486)
The time dilation equation from special relativity only needs basic maths: https://www.omnicalculator.com/physics/time-dilation
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Re:NASA says distant exoplanet could have rare water ocean, ... by adhoc32 on Tuesday September 12, 2023 @08:20AM (#37479968)
1g constant acceleration is enough. But we don't have the technology yet.
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