Recent comments in /f/space

zephyer19 OP t1_j9qk406 wrote

Reply to comment by demanbmore in Could they move ice from the planets to Earth? by zephyer19

I don't know. Company in New Mexico and been working on a high tech catapult that if successful will throw things into space.

I forget, are their ice fields on Mars? Robot craft would cut the ice and perhaps assemble it and float back towards earth, guided by rockets somehow.

What you do with the salt is important. Just going to toss it outside on some field?

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DudeWithAnAxeToGrind t1_j9q4l6z wrote

Reply to comment by Siliskk in Time dilation question by [deleted]

Here's where somebody actually did the math:

https://www.quora.com/In-Interstellar-movie-2014-how-close-exactly-is-Miller-planet-has-to-get-from-the-Gargantua-black-hole-distance-in-km-in-order-to-has-such-extreme-time-dilation-1-hour-equal-7-years-back-on-Earth-Need-accurate/answer/Bill-C-Riemers-1?ch=10&oid=395871518&share=b3c1ff02&srid=tze0&target_type=answer

TL;DR For such extreme time dilation, the planet would need to orbit just outside of photon sphere. There are no stable orbits that close to the event horizon; the planet would either fall into the black hole, or it'd be flung out into space.

The photon sphere is a sphere around the black hole where gravity is so extreme, photons are orbiting black hole in circles.

The black hole would need to be supermassive. Because anything smaller (e.g. solar mass black holes), the tidal forces that close to the event horizon would be so large, they'd shred the planet into tiny pieces... Or basically anything else, such as spaceship or a human.

For entire solar system to be so deep in the gravity well to experience time dilation as extreme as in the movie, and not be either destroyed or stripped of its planets, the black hole would need to be many orders of magnitude larger than anything we have ever observed. From what we know, no such black hole can exist. There was simply not enough time since Big Bang for any to grow that large, and due to the expansion of universe, no black hole will ever be able to grow to such a large size.

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demanbmore t1_j9pzdus wrote

Reply to comment by zephyer19 in Could they move ice from the planets to Earth? by zephyer19

It will never be better environmentally or economically to harvest ice from extraterrestrial sources to provide fresh water on Earth. The carbon footprint from space flight is enormous, and the sheer number of ships that would be required to obtain any meaningful amount of water from hundreds of millions of miles away make local desalinization a hugely better option from any perspective no matter what conditions become on Earth. Put the salt anywhere - doesn't matter, it's a drop in the proverbial bucket. There's plenty of rain and snowfall, it's just in different places than we're used to seeing it. And melting glaciers and ice fields just add to the amount of liquid water available. Getting water from 100 or 1,000 miles away because that's where the rain falls now or that's where the desalinization plants are is still much cheaper and more environmentally sound than launching thousands and thousands of spacecraft constantly.

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zephyer19 OP t1_j9png3j wrote

Reply to comment by demanbmore in Could they move ice from the planets to Earth? by zephyer19

Well Climate Change and already existing uses of aquifers, how long before fresh water gets real hard to find.

Ice fields and glaciers are melting faster every day, record temperatures, lack of rain and snowfall.

Use the ocean water and do what with the salt? Put it back in the ocean?

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zephyer19 OP t1_j9pn3dj wrote

Reply to comment by gadget850 in Could they move ice from the planets to Earth? by zephyer19

Trouble is, what to do with the salt?

I understand Saudi Arbia gets a lot of their water from the ocean, as does Israel.

I don't know what Israel does with their salt but the Saudis put a lot of it back into the ocean and one study I read said it is affecting the Gulf of Oman.

What if most coastal oceans start using ocean water?

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