Recent comments in /f/space

DudeWithAnAxeToGrind t1_jcqwb8m wrote

Reply to comment by House13Games in Where do photons go if they've been emitted but are destined to never be absorbed, and would these photons traveling ad infinitum define the edge of the universe (even if space itself were still larger)? by mysteryofthefieryeye

Are you trolling me here? Assuming you are not, the above answers exactly where they'll go. It'll simply take them forever to get there, because space they have to travel through is itself expanding.

To make an analogy, imagine an ant on the surface of a balloon trying to get from the bottom to the top of the balloon. Imagine you can just keep inflating this balloon indefinitely, making it bigger and bigger. If you are inflating balloon fast enough so that it increases in size faster than ant can move over its surface, the ant will make a progress in its journey, but it will never be able to reach the top of the balloon. If ant can keep going infinitely, there's a spot on the balloon it will eventually reach after infinite amount of time has passed.

This is what happens to a photon traveling through Universe. The universe is expanding, and the far regions of space are receding from this photon faster than the photon can travel through space.

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space-ModTeam t1_jcq4vz8 wrote

Reply to Space Talk with a curious 18 year old who has watched way too many youtube videos about random space facts. by Worth_Floor4303

Hello u/Worth_Floor4303, your submission "Space Talk with a curious 18 year old who has watched way too many youtube videos about random space facts." has been removed from r/space because:

  • Such questions should be asked in the "All space questions" thread stickied at the top of the sub.

Please read the rules in the sidebar and check r/space for duplicate submissions before posting. If you have any questions about this removal please message the r/space moderators. Thank you.

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BrotherBrutha t1_jcq4loj wrote

Reply to comment by RecognitionUnfair500 in Where do photons go if they've been emitted but are destined to never be absorbed, and would these photons traveling ad infinitum define the edge of the universe (even if space itself were still larger)? by mysteryofthefieryeye

I don’t think so, it was pretty specific. And it matches the answer given in the NRAO link I gave above.

Of course, I could be wrong!

Edit: is it possible that the physics can be interpreted in a bunch of different ways, and some will describe as I have, and some as you’ve done? Perhaps it’s just different conventions in Cosmology vs straight physics?

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reddit455 t1_jcq2jip wrote

Reply to Space Talk with a curious 18 year old who has watched way too many youtube videos about random space facts. by Worth_Floor4303

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

The Drake equation is a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way Galaxy.[1][2]

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

The Fermi paradox is the discrepancy between the lack of conclusive evidence of advanced extraterrestrial life compared to the apparently high a priori likelihood of its existence.[1][2] As a 2015 article put it, "If life is so easy, someone from somewhere must have come calling by now."[3]

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> It might sound far fetched but the universe is highly believed to be stretched out to infinity?

it's kind of hard to speculate about the number of fish in the ocean when all you have is a half drop of water.

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The Hubble Deep Field: The Most Important Image Ever Taken

https://www.youtube.com/watch?v=mcBV-cXVWFw

In 2003, the Hubble Space Telescope took the image of a millenium, an image that shows our place in the universe. Anyone who understands what this image represents, is forever changed by it.

20 years later, consider what JWST has done.

Hubble is cute little toy.

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even if ET picks up on the first ring... in 24,950 years, it's going to be another 25,000 until we hear back.

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

The message was aimed at the current location of M13, about 25,000 light years from Earth, because M13 was a large and relatively close collection of stars that was available in the sky at the time and place of the ceremony.

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Morning_Woodland t1_jcpzl1r wrote

Reply to Space Talk with a curious 18 year old who has watched way too many youtube videos about random space facts. by Worth_Floor4303

the question isn't if life exists out there, it's if it is intelligent
the universe relatively tends to infinity, so life out there isn't a possibility but certainty.
and yeah chemistry is the basis of all life anywhere, but if your question is if life could form in the vacuum of space, then imo no

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BrotherBrutha t1_jcpyji9 wrote

Reply to comment by RecognitionUnfair500 in Where do photons go if they've been emitted but are destined to never be absorbed, and would these photons traveling ad infinitum define the edge of the universe (even if space itself were still larger)? by mysteryofthefieryeye

It’s not just random blogs that say this though; I’m doing the online ANU EDX astrophysics course at the minute, and it was exactly the explanation they gave (one of the presenters is a Nobel prize winner, so I feel like it’s reasonably trustworthy!). And there are many places that give the same description.

Of course, I appreciate it may not necessarily be the full story, but it at least seems to be more than a daft idea!

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