Virtual Book Club Thread: "Project Hail Mary" by Andy Weir (Spoilers)

[Marc_G]

I love this lively discussion. This is exactly what I hoped for in starting the thread. Thanks to all participants!

 

[user 13]

A "Bean Stalk" isn't built from "orbit down" it is built along its entire length simultaneously centered around that first thread dropped from orbit.
It has to be done this way because it is the outward centripetal force of the outreaching mass of the Bean Stalk that counterbalance the force of gravity attempting to drag it down, much like a vertical suspension bridge.
Earth's GEO is apx. 35,800 kilometers altitude and with Erid's gravity being twice (More?) that of Earth's its GEO would be even farther out.
Nothing self-supporting, which is what you would have if you built entirely from the ground up could possibly accomplish that, no matter what magic material you built it from.

So the Eridians would have to have had space travel first and then they could build their Elevator.

Good point, I had forgotten that the space elevator is in simplest terms, basically suspension bridge. As I said I only expended 10 min of thinking on it. I last read "The Fountains of Paradise" decades ago.

Marg G's post leaves open the possibility that the Eridians could have used nuclear rockets to get to orbit.
That, in and of itself, would be a huge incentive to find a less damaging way to orbit.

 

[OverTheTop]

A "Bean Stalk" isn't built from "orbit down" it is built along its entire length simultaneously centered around that first thread dropped from orbit.
It has to be done this way because it is the outward centripetal force of the outreaching mass of the Bean Stalk that counterbalance the force of gravity attempting to drag it down, much like a vertical suspension bridge.
Earth's GEO is apx. 35,800 kilometers altitude and with Erid's gravity being twice (More?) that of Earth's its GEO would be even farther out.
Nothing self-supporting, which is what you would have if you built entirely from the ground up could possibly accomplish that, no matter what magic material you built it from.

So the Eridians would have to have had space travel first and then they could build their Elevator.

I agree. Anything that tall is going to be skinny or the amount of resources to make it would be enormous and impractical. Anything long and skinny generally starts to behave like string at some point. You can't compress string, so that leaves only the top-down approach where it is in tension.

 

[Charles_McG]

I agree. Anything that tall is going to be skinny or the amount of resources to make it would be enormous and impractical. Anything long and skinny generally starts to behave like string at some point. You can't compress string, so that leaves only the top-down approach where it is in tension.

At the engineering school I went next to (I was a biologist - next building over), one of the three laws of engineering was 'you can't push on a rope' - so I like this answer.

Regardless of how they built the first one, it still puts a big gap in the ending. There's no reason to keep Grace in a dome on the surface under all that gravity. You can put a platform on either Z side of the elevator's 'stationary station' at any acceleration you wish.

 

[boomtube-mk2]

In recent years engineering teams have conducted computer models with regards to how a "Space Elevator" would behave after it is built.
One thing that was noted is that anything that long is, for all intents and purposes, a string under enormous tension and having capsules running up and down would be the equivalent of strumming a violin or cello string.
It was shown that even pumping the enormous energy levels needed to operate a Bean Stalk would result in the same effect.

Put simply it would start to vibrate and those vibrations would be impossible to quell or counter act.
Eventually it would shake itself apart much like the Tacoma Narrows Bridge did during a storm, Google "Galloping Gurdy or shatter like a crystal goblet when subjected to the correct sound frequency.

From these studies many now believe that the "Space Elevator" is more fiction than science.

 

[DaHabes]

In recent years engineering teams have conducted computer models with regards to how a "Space Elevator" would behave after it is built.
One thing that was noted is that anything that long is, for all intents and purposes, a string under enormous tension and having capsules running up and down would be the equivalent of strumming a violin or cello string.
It was shown that even pumping the enormous energy levels needed to operate a Bean Stalk would result in the same effect.

Put simply it would start to vibrate and those vibrations would be impossible to quell or counter act.
Eventually it would shake itself apart much like the Tacoma Narrows Bridge did during a storm, Google "Galloping Gurdy or shatter like a crystal goblet when subjected to the correct sound frequency.

From these studies many now believe that the "Space Elevator" is more fiction than science.

It would not be just a vibration but a vibration a wave function generated by vibration at the resonant frequency of the cable, which is what causes the Tacoma Narrows Bridge phenomena. The bridge only failed when the wind speed was in resonance with the bridges "natural" frequency. It's a feedback loop to be managed. You would need to run the elevator at a speed that does not generate a vibration in resonance with the cable. With three nodes on the cable (base on earth, Geo-station and counterweight), the formulation is different than a structure that is anchored at two ends, like a bridge. The Geo-station for dis-embarkment would be a space port and enormous, which would provide a lot of dampening on it's own. Add in the mass of the space tugs that then move cargo to and from the elevator and you have a varying mass ratio in the center for which a resonant frequency would be changing regularly. Not an insignificant engineering problem, but also not insurmountable.

If general AI comes to fruition and it doesn't turn into Skynet, the AI will figure it out in a few days.

 

[Charles_McG]

If general AI comes to fruition and it doesn't turn into Skynet, ...

Ultron would not be much better.

I think I'd take a limited Daneel over hoping for a Vision.

 

[OverTheTop]

It's a feedback loop to be managed. You would need to run the elevator at a speed that does not generate a vibration in resonance with the cable.

Or if you do have to go near the resonance speed you drive through it quickly. Depending on the Q factor of the resonance (amount of damping) it takes time for the oscillations to build in ampitude. Next time you are walking with a full cup of coffee see what happens if you vary the speed you walk, rather than walking at one speed, if you are at peril of spilling it.

 

[Kelly]

I've just finished reading this; so it's pretty fresh in my mind. Loved this book, definitely Weir's best so far. And I liked both The Martian and Artemis. These books were mostly problem solving stories - they dealt with technologies that are fairly familiar to all of us, if not fully implemented. Hail Mary, on the other hand, goes way beyond this and deals with technologies that we can only dream of.

I saw a few 'nits' above which I can respond to:

So, if a bit of taumoeba got into that tank of astrophage and was able to consume it, the Hail Mary would have gone up like a nova from energy release

Nah. The astrophage aren't full of energy. The cool thing about astrophage is that they can convert mass to energy, and vice versa. When they're basking on the sun, they're converting huge amounts of energy into tiny amounts of mass, according to E=mc^2. When they need to release energy - to travel, for example - they convert that tiny amount of mass into a huge amount of energy. Popping them doesn't release anything but mass.

I think the spin drives use lasers to pop the astrophage, releasing the energy.

The spin drive just uses the natural drive mechanism of the astrophage. It gets them pointed forward, then makes them think - via IR emissions - that they're headed to Venus, and the astrophage turn on their photon drive, creating forward thrust.

I too wondered why Grace didn't opt for an orbital habitat on Eridia to avoid the high gravity, but then I realized dealing with 1.5g isn't all that bad. Lots of Earthlings put on weight and have to support 1.5X (or much more!) of their 'natural' weight. It's not good, but then it's not "Oh my gosh we need to get these people into orbit" bad, either.

I also thought the food thing - the thought that Grace would die on Eridia, without Earth food - was kind of dumb. Food is just chemicals. Any society with a chemistry technology - which Eridia clearly has - would easily be capable of manufacturing food to his specifications. Especially with access to something like Wikipedia, which no doubt spells out all the compounds necessary in the human diet, as well as the chemistry to synthesize these. Not sure if I could eat a 'Meburger'.

Look forward to seeing the movie, though I'm sure I'll be disappointed, as I am in virtually all movies based on books I've read!

 

[user 13]

Ultron would not be much better.

I think I'd take a limited Daneel over hoping for a Vision.

R. Daneel is bound by the 3 (4) laws of robotics. Sadly, any AI we create won't have them.

 

[boomtube-mk2]

If general AI comes to fruition and it doesn't turn into Skynet, the AI will figure it out in a few days.

I'll believe in Artificial Intelligence when robots begin to worry if their hard drives are big enough and computers start asking; "Does this mainframe make me look fat?"

 

[boomtube-mk2]

I'm now reading; "Riding the Rails" a non-fiction book about teenage, and younger, "Hobos" during the Great Depression riding the rails toward what they hoped would be a better life.
Grimm to say the least.

For example; a couple of HUNDRED transients on a West bound train passing an East bound train with a couple of HUNDRED transients on it.
Think about it.

 

[Antares JS]

I'm almost done with Project Hail Mary and I think I might like it better than The Martian. The sense of discovery at the beginning of the book is something I always enjoy, and the Eridians are fascinating. It's always nice to see a writer come up with an alien, that's truly alien.

Also, Rocky has officially displaced Mass Effect's Garrus Vakarian in my mind as "greatest alien bro."

 

[boomtube-mk2]

It's always nice to see a writer come up with an alien, that's truly alien.

If you like reading about Aliens that are truly Alien; try the writings of Hal Clement and Robert L. Forward.

 

[Kelly]

My favorite line from the book: Grace and Rocky are about to part ways, and Grace has given Rocky one of the laptops full of Earth science & technology.

Grace: “All the information about relativity is in the laptop. Have your scientists take a look.”
Rocky: “Yes. They will be very pleased.”
Grace: “Not when they find out about quantum physics. Then they'll be really annoyed.”

 

[user 13]

My favorite line from the book: Grace and Rocky are about to part ways, and Grace has given Rocky one of the laptops full of Earth science & technology.

Grace: “All the information about relativity is in the laptop. Have your scientists take a look.”
Rocky: “Yes. They will be very pleased.”
Grace: “Not when they find out about quantum physics. Then they'll be really annoyed.”

I feel the same way as Grace about quantum physics!

As for alien aliens, I agree that Forward has done some good ones. The Cheela are really alien!

Niven has done some good aliens also. I nominate Speaker to Animals (Chmeee) as a great alien bro.

 

[IrisPinedo]

In recent years engineering teams have conducted computer models with regards to how a "Space Elevator" would behave after it is built.
One thing that was noted is that anything that long is, for all intents and purposes, a string under enormous tension and having capsules running up and down would be the equivalent of strumming a violin or cello string.
It was shown that even pumping the enormous energy levels needed to operate a Bean Stalk would result in the same effect.

Put simply it would start to vibrate and those vibrations would be impossible to quell or counter act.
Eventually it would shake itself apart much like the Tacoma Narrows Bridge did during a storm, Google "Galloping Gurdy or shatter like a crystal goblet when subjected to the correct sound frequency.
From these studies many now believe that the "Space Elevator" is more fiction than science. I understood the book better after reading its free book summary. Also, I found there the plot of "The Age of Innocence" by Edith Wharton. https://freebooksummary.com/category/the-age-of-innocence is the source that underlines change and progress, innocence versus experience. Check the book summaries to get deeper into their themes.

Even if it is an old thread, the topic of space elevators caught my interest enough to expose my point of view. I've checked some books, fiction, and nonfiction research literature, concluding that carbon nanotubes are sufficiently strong to build a real space elevator. But I bet the unique problem is the fear of scientists failing to build such an awesome and complex thing.

 

[The Artifex]

OK, I'll put in my nit to pick, but anyone who hasn't read the last chapter or two should skip this post!

So, the protagonist Ryland Grace eventually heads home to save Earth. But he finds out that his portable tank of astrophage was eaten by contaminating taumoeba. Uhhh... whatever happened to conservation of energy? Even a tiny amount of astrophage popping puts out a HUGE bunch of heat (recall the experiments done on earth, out in the middle of the ocean, where they slagged a giant block of silicon or somesuch with small amounts of astrophage, leading to adoption of the astrophage-based drive system.

So, if a bit of taumoeba got into that tank of astrophage and was able to consume it, the Hail Mary would have gone up like a nova from energy release pretty early in the consumption phase. Ryland would be simply an expanding vapor cloud. And I believe this would have also been an issue earlier on... if I recall (it's getting dimmer over time) he had contamination in some fuel tanks earlier and needed to get replacements made.
To put it bluntly: where did all the energy go?

When the Taumoeba eats the Astrophage, no energy is released.

 

[NTP2]

I'm almost done with Project Hail Mary and I think I might like it better than The Martian. The sense of discovery at the beginning of the book is something I always enjoy, and the Eridians are fascinating. It's always nice to see a writer come up with an alien, that's truly alien.

Also, Rocky has officially displaced Mass Effect's Garrus Vakarian in my mind as "greatest alien bro."

Agreed, it’s my favorite book of all time btw.

 

[Charles_McG]

When the Taumoeba eats the Astrophage, no energy is released.

I don't think popping/eating the astrophage releases energy as photons. I think it's released as neutrinos - which the remaining astrophage would soak, and wouldn't affect the ship at all. The astrophage can manipulate their cell walls to act as a metamaterial that can be a perfect adsorber, perfect reflector, or to be transparent to the wavelength of neutrino-antineutrino annihilation. It's that last that generates thrust for them - and cooks whatever is behind them. But they only do that when well fed and shown a CO2 emission line.