[isgb]

> Space elevators are actually a possible idea being considered by scientists. > The hard part is making a strong enough cable. And finding enough elevator music...

Most engineers would bring up a lot more issues than just finding a strong cable. Also, most attempts with e.g. carbon nanotubes have been abandoned ages ago https://www.newscientist.com/article/2093356-carbon-nanotube....

- We don't have a good ascent mechanism other than rockets - and then we might just use rockets without building an elevator. - We don't have a good (and safe) descent mechanism. - Maintenance? Protection from space debris? Protection from oscillations? Ground-protection if the elevator collapses?

This is dyson-sphere level of fiction. We can do back-of-the-napkin calcualtions on how things would work, but the practicalities make it completely impossible or impractical.

[seanc]

Kim Stanley Robinson's description of a Martian space elevator falling and wrapping twice around the entire planet convinced me that they aren't a good idea.

https://www.kimstanleyrobinson.info/content/clarke

[indoordin0saur]

A fictional representation of a thing exaggerated for dramatic effect and to create plot tension shouldn't really convince you of many things at all. They're rarely accurate portrayals.

[enraged_camel]

A version of this also happens in the first season of Foundation, the Apple TV series based on Asimov's novels.

[joenot443]

Would you recommend that show to the HN crowd? The books are super well liked around here, for good reason.

Apple's put out a staggering amount of content the last few years, I wasn't even aware this one debuted!

[tw04]

I’ll give apparently a controversial take. The show is great. If you’re going into it expecting the books to be the guiding source material you’ll be severely disappointed. If you go into it assuming you’re watching a show that roughly takes high level concepts from the books but is its own thing and let it stand on its own, I think it’s worth watching.

[georgeecollins]

I'm fine with series not following the books. But the show bugs me because it has great production values -- particularly the third season -- and great actors. But the writing and plotting is all over the place ranging to very bad. It is a bit dumb and always pretentious. It's the 70's version of Battlestar Galactica of our age.

[senkora]

This is the issue that I have with many Apple TV+ shows. The production value is always very high, but it has no correlation with whether the writing is actually good.

[ajmurmann]

I also found the pacing to be inconsistent at best.

[MengerSponge]

Lee Pace is great, and the "genetic empire" is a brilliant solution to a hard problem unique to television.

Brother Dawn: How often do we make this choice?

Demerzel: You always make this choice.

[bananaflag]

Not the OP, but that show is a severely dumbed down adaptation of the books.

For example, each short story almost completely changes the cast (of course, with some descendants of characters appearing occasionally), as befits a saga that spans centuries. No producer was willing to run with that (as they didn't believe the audience smart enough to follow it would be big enough for the show to make a profit), so they introduced cryonics, clones, sorta-AIs (including robots out of their original context) to have some sort of continuing cast.

Also, the books have a quaint 1940s (NOT 1950s as people usually say it) atmosphere, with excitement about "atomic" energy (changed to "nuclear" in the 1950s publication), distant descendents of the slide rule, and generally weird-sounding math and science, that the show totally drops in favor of a "contemporary" feel.

And btw, the space elevator scene is lifted from Brin's Foundation's Triumph where it is described as a "future" event, part of Trantor's fall, predicted by Seldon's early team and trickled down to the general population.

[rtkwe]

It's definitely got problems as an adaptation of the Foundation series where it turns one of it's biggest themes on it's head by making a few people like Gail super special and having the answer to the crises where the books were more about setting up groups and organizations so that they as a whole had an advantage or edge that would be the answer to the crises he forsaw. I think it's mainly due to them wanting to have the same people across multiple seasons where the books were free to throw away the whole cast each time. Setting up new characters is much more expensive in shows/movies than books where you can just say what someone's 'deal' is and give them internal monologues to setup their internality where shows can't usually get away with that.

I think separated from that there's a good enough show in there.

[shagie]

> Also, the books have a quaint 1940s (NOT 1950s as people usually say it) atmosphere ...

    The next day’s hearings were entirely different. Hari Seldon and Gaal Dornick were alone with the Commission. They were seated at a table together, with scarcely a separation between the five judges and the two accused. They were even offered cigars from a box of iridescent plastic which had the appearance of water, endlessly flowing. The eyes were fooled into seeing the motion although the fingers reported it to be hard and dry.

If you've got a copy of the ebook, search for "cigar". The use of tobacco as a way to demonstrate luxuries beyond the regular is there.

In a recent re-reading of the series, I started having difficult with it in Second Foundation... and forced myself to finish Foundation's Edge. The amount of psionic ability and the... for lack of a better word "preaching" with the monologues was very much a science fiction of a different time.

Foundation (the TV series) had to do updates for modern audiences and media. I'm not sure if trying to remain perfectly faithful to the books would represent them well.

Foundation is a soft sci-fi about interactions between individuals and history and society. Trying to maintain the incidental harder parts of the written works that modern audiences expect to be somewhat consistent of far future technology with the 1950s lens on them would be quaint and a bit off-putting to people expecting future tech.

    He threw his cigar away and looked up at the outstretched Galaxy. “Back to oil and coal, are they?” he murmured—and what the rest of his thoughts were he kept to himself.

They took the major points, and wrote to follow the general path from one point to another given the expectations of an audience consuming it often for the first time - 80 years after the original was written... and given constraints of the format and continuity of actors (60 minute episodes rather than as a chapter of a short story in Campbell's Astounding Science Fiction).

[jvanderbot]

I long for a level of posthumanism that you can do things like smoke and drink for fun without any worry for long term health effects.

What at joy it'd be to fully experience life, not just a sanitized productized version, and have the safety net of perfect medicine to cure what ails ya.

[Frotag]

> For example, each short story almost completely changes the cast (of course, with some descendants of characters appearing occasionally)

I wish directors were brave enough to kill off characters if it serves the plot. I get that there's IRL reasons that make it difficult (like contracts, scheduling, etc) but each new season accumulates more subplots to the point it's like a 30 minute episode is really a compilation of 3x 10-minute shows.

This bugs me in multiple-protagonist books too. Just feels like an excuse to pad the page count with introductions and cliff hangers every POV switch.

[Frotag]

It's pretty and scratches that scifi itch. I've only read a little of the books but it's supposedly an entirely different story that coincidentally shares character names.

In terms of hardness, it probably on par with Expanse, so mostly technobabble with the magical tech only used when it's convenient for the plot. The abuse of "psychohistory" is particularly egregious. There's so many scenes where it's visualized a hologram of scribbles and they zoom in on more squiggles while divining the future.

But again it's pretty, so if you're okay with drama in space, it's maybe a 8/10.

[hermitcrab]

It's about 45 years since I read the books, but the whole idea of being able to predict the future of human societies accurately with maths seems rather silly. Especially since chaos theory became mainstream.

[lelandfe]

My friends who wanted an adaption of the series hated it.

My friends who like sci-fi enjoyed it.

It is regardless very striking and high budget.

[Larrikin]

It's the best possible adaptation of the books as possible. They made some changes to allow for having main characters. In my opinion they also lighten the down side of the Mule story line and how the world works.

[kingkawn]

If you go into it looking for interesting sci-fi, especially the story of the Cleons, you’ll enjoy it. If you go into it looking for Asimov’s Foundation you’ll be disappointed

[indoordin0saur]

I greatly enjoyed the first season (haven't seen the others) and I'm usually a curmudgeon when it comes to modern TV shows.

[noir_lord]

I enjoyed the first season, for me the others aren’t remotely as good and I abandoned it halfway through the latest season.

[gilbetron]

The Mars one is much more interesting and traumatic :)

[ben_w]

In adition to being fictional, what would happen on Mars does not reflect what would happen on Earth as the Martian atmosphere is so much thinner than ours.

[datadrivenangel]

Skyhooks may allow for much easier access to space within the limits of likely practical carbon nanotube based structures. A rotating tether that orbits the planet could be timed to 'catch and throw' supersonic aircraft into space. Lots of engineering still required, but potentially actually feasible compared to space elevators.

[bombcar]

All we have to do is make the global religion require bringing a rock to a specific location; after long enough we’ll have a mountain so high it extends out of the atmosphere!

[kubanczyk]

This presents a considerable risk of splitting English into several languages, none of them intelligible with the others.

[SSLy]

have you ever been to Newcastle?

[ben_w]

Aye man, wey aye, went doon there worra bairn, didn’t ah? Cannae remember much like, was only a wee nipper at the time, knaa what ah mean? Me mam an’ da took us doon the Toon when ah was nowt but a little’un, like. Divvent really remember owt aboot it proper, but aye, been the once when ah was just a littl’ bairn, me. Proper yonks ago that was, pet!

(Translation: yes, once as a kid).

[notahacker]

The deity in question would also have to smite purveyors of LLM translation. This might of course not be considered a drawback...

[rigmarole]

Related and recommended: Greg Egan “Phoresis” a sci-fi novel of two twin planets in extreme proximity to each other. (I think I read it in one of his anthologies.)

[hermitcrab]

To get to the Kármán line (100k) a mountain with a 60 degree slope would require a base of 115km. A cone with 115km diameter base has a volume of 3.5×10^5 km^3. Which is 3.5x10^14 m^3, which is about 10^15 kg of rock. So it is going to take you a while!

[bombcar]

3.5x10⁵ km³ you say?

1.08321×10¹² km³ is the volume of Earth, feasibility study done! Implement!

[hermitcrab]

The molten core probably isn't going to be much use.

Surface area is 5x10^8 km^2. So it it 'only' the first ~2m of the crust (~6m if you don't count ocean).

[honkostani]

The material is actually not a problem, if you consider active structures. https://en.wikipedia.org/wiki/Active_structure https://en.wikipedia.org/wiki/Space_fountain

Then again, when doing mega structures, a launch loop is more plausible.

[mrkickling]

You didn't even mention the music!

[thijson]

I think a space elevator on the Moon would be more practical, pointing towards earth. The gravity force is smaller, so existing materials could work. There's not as much of an atmosphere to deal with. It would go past the L1 point between earth and the moon. It could be extended from the poles, where it's most likely where bases might exist.

[Symmetry]

Impractical on Earth given existing technology, but there are a lot of bodies in the solar system which have enough gravity to make them worth while but where they're small enough that the materials needed are ones we have right now. The Moon in particular.

[michaelbuckbee]

In John Scalzi's Old Man's War, there is a discussion of how the more advanced society that they're interacting with deliberately put a space elevator on Earth, not because it was the easiest or cheapest solution, but as a sort of constant reminder of just how much more technologically sophisticated they were.

[cmpb]

Really great book (and series). Though it's not "hard sci-fi" by any means, the technology feels real enough to keep my brain from focusing on the holes and enjoy the fun philosophical and ethical problems that Scalzi comes up with

[shagie]

IIRC, it started out as a reimagining of Space Cadet by Heinlein but instead of the young it was with the old.

After the first book, he then goes to explore all the questions that it brought up. The question of identity (to me) seems like the most reoccurring question.

Btw, there's a new book in the series. The Shattering Peace was released in September.

[gizmo686]

Isn't the entire point of the space elevator to be the ascent/descent mechanism?

Once you have the cable up, you can grab onto it and pull yourself up.

[bisby]

A space elevator doesnt just take you to the karman line (like in the OP website), to get to orbit, you'd need to get up to geostationary height. That's 22,000 miles.

What's the best way to pull yourself directly vertical along a cable for 22,000 miles?

What's the best way to descend 22,000 miles quickly, but also with a braking mechanism that isn't going to require a heat shield?

Some sort of slow cable car going at 10mph even is going to take 2200 hours... 1000mph is going to take 22 hours still. That's a full day to orbit even going REALLY fast. And getting up to 1000mph vertically, for a sustained 22 hours... that's not an easy feat.

And if the goal is just to get up past the karman line and use the elevator as a stage 1 for a rocket launch and detaching from the elevator while suborbital is fine, then it's a one way trip, and still need to re-enter the old fashion way.

The scale of space makes all of the problems far more complicated (edit: not just the cable strength issue, but traversing the cable)

[notahacker]

Unless we're using it for humans the transit time isn't that big a deal; "last mile" orbital transfer times are often measured in days anyway.

That "last mile" bit is going to entail independent propulsion anyway. Getting to the altitude if the ISS is a mere 10 hour trip at a sedately 40kph which isn't unpleasant even for humans, but the ISS orbits at nearly 29000kph (as will you if you let go of the space elevator at that altitude) and the velocities are only half as scary at the far end, so your rendezvous anywhere other than one specific point in geo is going to be complicated. But you've saved the fuel costs of escaping the earth's atmosphere that's rather significantly more than the fuel costs of other bits of your satellite mission, including reentry. (At least until the costs of building and maintaining and protecting the elevator are factored in, but who knows what unobtanium costs?)

[gizmo686]

> as will you if you let go of the space elevator at that altitude)

Doesn't the teather have a constant (24 hour) rotational period at every elevation? That is significantly slower than the ISS

[notahacker]

fair point, you'd need to be orbiting at that speed to stay in that orbit, but you'd need propulsion to get the delta v to get there after letting go of the tether, but a lot less than to launch from ground level through the atmosphere. Or you could figure out the point higher up the tether to release where your orbital decay would intersect the IS orbits, but given the precision involved in that rendezvous you'd still want propulsion. You'd want propulsion for the last mile bit for pretty much anything other than building a station attached to the tether was kind of my whole point :)

[oofbey]

You don’t need to get to geostationary to get to orbit. The reason elevators need to get that high is because that’s the lowest place you could “anchor” the top of the elevator to something fixed relative to the earth.

[kingkawn]

Doesn’t the weight of the cable itself let alone any payload preclude this from becoming real based on all plausible material science

[gizmo686]

It's more of the strength-to-weight ratio than just weight. But yes, there is no known material that would work as a cable for a space elevator.

[reaperducer]

Most engineers would bring up a lot more issues than just finding a strong cable.

He did. The elevator music!