can we space elevator? should we space elevator?
ฝัง
- เผยแพร่เมื่อ 23 ก.ย. 2023
- I am so sorry but I don’t understand why anyone wants a space elevator.
Coffee and the problem Episode 1: The science fiction writer R. A. Heinlen describes a skyhook satellite that consists of a long rope placed in orbit at the equators, aligned along a radius from the center of the earth, and moving so that the rope appears suspended in space above a fixed point on the equator. The bottom of the rope hangs free just above the surface of the earth (radius R). Assuming that the rope has uniform mass per unit length (and that the rope is strong enough to resist breaking!), find the length of the rope.
Space Elevator Background from Nixeen’s Screenshot: steamcommunity.com/sharedfile... the Cryptic: / crackingthecryptic
Princeton Problems in Physics with Solutions: press.princeton.edu/books/pap...
3Blue1Brown (essence of calculus): • The essence of calculus
Tacoma Bridge footage: • Tacoma Bridge
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I would watch the crap out of a 7 hour video on why leaf blowers shouldn't exist.
Right? Leaf blower video coming when?
i want to see it too
#LeafBlowersHate
x10
i would hook my laptop to a PA and put it outside and play the video at max decibels so everyone could hear it.
If we built a space escalator instead, then when it breaks down, it will simply be space stairs.
Really makes me wonder
It would be a litteral stairway to heaven !
"... sorry for the convenience"
I miss Mitch. The good thing is that he hasn't done hard drugs in 18 years. He used to do hard drugs, but he don't do them no more.
Thank you Barack Lesnar
"calculus isn't that scary, just learn it, then this is fun" This is a woman who had to TA freshman. I applaud you
I had two TA's, one spoke only Japanese, the other Italian. Neither could speak with the other or the small class, duplicating balls rolling down an incline, incredible precision and good data being the point not the learned lesson. This is how research is done. This is how peer review is done. This was back in the 60's. Today with pressures, many studies are spread out. Being immersed and expected to learn the math at the same time as the physics as the computer was daunting. Throw in 1 credit hour courses in Fortran ( turn in your punch cards and wait for the error stack from the one and only main frame ), and mandatory Saturday quiz sections we were immersed. Our failure rate freshman year soared to 60%. It was also an engineering school. Later taking computer science classes the cheating was rampant, my professor dealing with irate parents asking about bad grades. It became a party school. All games all the way up and down. Sad sad sad.
Calculus... Lol is awesome... It is just find the acceleration at any point of velocity at any point... Meaning... Let's do what any mortar or artillery or tank crew does.. lol
1. A space elevator would block off a whole class of orbits for satellites. Imagine the lawyer fights over this territory.
2. If the tether is in any way conductive, imagine a Carrington event with massive induced current running up/down the tether. That would be fun.
3. Is Angela turning into "old man yells at clouds"? If so, welcome to the club.
#1 is completely solvable,
#2 is the first thing I've heard that gave me a pause for a moment, but that's why we have civil, electrical, mechanical, and materials engineers to solve those hurdles and I think that we actually might be able to make that Carrington event a selling feature with a little thought.
#3. yes.
@@qsquared8833I agree, we have a single intercontinental internet cable between Europe and america
And probably wouldn't be good if a hurricane when through it either. I assume these elevators would need to be at the equator if they are to be stationary.
@@qsquared8833 Go with enough of them, you'd not need those LEO birds, just put small stations at those orbital altitudes on the elevator "cable".
A conductive cable with extremely low resistance would likely happily carry that current to ground. Don't recall any wires being reported destroyed during the Carrington event.
But, a ride on a space elevator reminds me of a candy bar commercial, "Gonna be a while?", only with a *lot* of candy bars needed...
@@spvillano I literally almost came back here and edited this comment to basically say the charge should go to ground and be no big deal like any building being struck my lightening, but decided to leave it thinking someone will surely realize it's not a big deal and write a reply. Looks like that would be you, and thanks for that.
Also fully agree a space elevator isn't about LEO, it's to get things well and truly up high enough that they'd be useful
I‘ve listened to too many Well There’s Your Problem episodes to ever believe a space elevator wouldn’t result in the worst engineering disaster in a century.
More like the worst engineering disaster in human history
@@PatheticApatheticidk man the boston molasses flood was pretty bad
my first and only thought every time the concept of a space elevator comes up is "yknow what happens when you accidentally hit your leg with a weedwhacker, but with like half of the planet"
speaking of which, here is their hyatt regency walkway collapse episode:
th-cam.com/video/Hw2t0MOGnVc/w-d-xo.html
honestly angela would be a great guest on it
babe wake up, new acollierastro video just dropped
I love acollierastro videos
I'm up, babe.
"We are going to be late for church c'mon what are you doing" "watching Physics Mom solve math word problems obviously"
Just did that. Fiance not impressed
Already up. I guess Dr. Collier is conspiring to make my insomnia worse because these videos come up only at ungodly hours.
"I suck at video games"
*shreds through Isaac casually in 40 minutes while explaining science history without a script, no edits"
I zoned out to a talk about space elevators and when i zoned back in, you were all of a sudden ranting about terabytes of fridge data. This is what im here for
For context on the Hyatt disaster, it was caused by a smalll cost saving change made AFTER the engineering was done. They had two walkways. The engineer had them both anchored to the ceiling. They made the cost saving decision to anchor the bottom one to the top one. The anchors for the top one could not hold the weight of both and they failed.
The engineers had rods anchored to the roof and it ran through the beams that held up the walkways. But they hadn't designed a way to hold the upper beams to the rods (edit)that was constructible.. I am not assigning blame here. We do so far too easily these days. Ultimately it was small errors by a number of companies that lead to tragedy which is often the case. (end of edit)
@@indetigersscifireview4360 No, that's not correct, the upper beams were secured to the rods by nuts. OP is correct. Your comment only adds misinformation and confusion.
@@indetigersscifireview4360they had a way to do this, the complication was that because they would attach the it via nuts, the rods would have to be threaded their whole length. They were very long, and manufacturing a rod with that long of a thread and installing it without somehow damaging the threads was considered infeasible. So, they split the rod in two. This effectively meant that then nuts for the upper platform were supporting both the upper platform and the lower platform, which they were not designed to do.
@@aidanwarren4980the issue with the threads seems like a callback to the video talking about making a rope for the elevator so long without breaking it. it’s an even more apt comparison than it already was, lol
Here's a >5min explanation with diagrams if anyone's interested
th-cam.com/video/VnvGwFegbC8/w-d-xo.htmlsi=PGFmnM4QIm26kPAT
One note about helicopters: they're actually pretty damn safe. More dangerous than commercial planes, sure, but safer than private ones, and *much* safer than cars. Considering they are typically used in risky rescue operations, this is actually really impressive. One common misconception is that you die if the engines fails, which is simply not true. Helicopters can safely come down if you turn off the engine thanks to autorotation, as the air causes the unpowered blades to rotate
helicopter has to fly high to achieve autorotation, but intuition says you should go closer to the ground to quickly land, as well as you are ascending from low height while taking-off. In short, autorotation didn't provide safety when helicopter is flying low.
@@xponensame goes fro gliding a plane
you generally should not go low forl ogner than ecessary if your goal is safe air transportation
well, they're a LOT safer than a rocket
Well yes, but no. Helicopters are safer than cars because there isn't the equivalent volume of traffic going through them. Couple that with the bell curve spreading out on safety checks, helicopters are dangerous as fuck as "flying cars."
@@Pho7onper hour spent in them helicopters are about 50 times as dangeorus as cars, how that translates to per kilometer or per flight/drive dependso n how fast/where/how far you go in each
motorcycles are comparable to helicopters in deaths per gigahour though
also depends on who's flyign it and how and why, etc
just like with general aviation you get a lot of crashes from private owners with lax safety standards and a you can really bump up the safety by sticking to a few rules
I am a 60+ physicist. I envy your ability to work on formulas on a tablet. I need pen and paper for that. And this is actually the only thing I need a notebook for.
I am 64, and I have a similar dependence on paper. Though the other day I was using a paper map and tried to zoom in on it. I am very disappointed that I now have no fluency with both paper and electronic maps.
@@marymegrant1130 That's hilarious. You're still probably pretty good on pen and paper tho. It's just now that you like your maps of a digital variety. Back then they need reading glasses to do that
I’m 42 and I still prefer math on paper, and I still prefer physical books when I’m doing serious work. Quick stuff I use tablets.
I think that difficulty may point toward aspects of human learning, memory, and thought which are tied to embodiment. That is to say, there are unconscious processes that are tied to, even utilizing or built upon, things like tactile sensation and proprioceptive feedback.
Where I notice it most in myself is a pronounced difference in retention and ability to apply concepts when reading the same textbook from a tablet versus from the printed hardcover. My son reports the opposite effect I experience. He has trouble retaining from a printed book and is better when using a tablet, but then he has been using a tablet since before he could walk. That’s a pretty small _n_ to be sure (heh!) but it’s fascinating to me.
That story about refrigerators at 32:20 reminded me of how LG is planning to do subscriptions for their connected appliances.
I wonder if the frig that "broke" was an LG. I know ours sure was. Linear compressors are junk.
The best bit about this channel is how the videos start calm and normal and end up with a really entertaining rant, but only the people that make it through the first 30 mins get to the rant part.
It's almost or exactly like Marvel Post Credit Scenes
Only that Acolierastro Cinematic Universe post credit scenes are relevant to the plot
"So there's this TH-cam channel called Cracking the Cryptic and I watch them to sudoku puzzles."
She's just like me fr fr
"I have absolutely no positive feelings towards any human achievement. Ever."
Oh.
@@SeanMcPseudonymbobbins!! 😂
Truly the prog rock of science channels
It was so funny how you learned to play factorio and spent so many hours building a space elevator, definitely cool and worth it.
I was surprised that the video was over 200 hours long and took 6 me hours to buffer, but then when it got the section of the video that was the footage of her playing factorio (real and true) it all made sense and added so much to the overall viewing experience.
Satisfactory would've been a good candidate, you can get one there in a few hours easy.
The factory must grow. (acollierastro plays gregtech when?)
@@najawin8348greg
Props on bringing up the Hyatt disaster. It's my "favorite" case (in so far as one could favor a disaster, i suppose), because what caused it was SO so easily avoided. Everyone should know about the Hyatt disaster, not just engineers, specialists, scientists, etc. It's literally knowledge with common household application!
You should have included a link
en.wikipedia.org/wiki/Hyatt_Regency_walkway_collapse
In the investigation section, there's a schematic of the original designed hanger setup versus what they ended up doing. That adjustment made it to where the nuts holding the top walkway's weight were now carrying the load of all the walkways below, too.
@@scum-scum - thank you!
33:42 I'm so happy to see when there's people outside of tech industry/open source activists who are voicing their dismay at the state of tech. Granted you're in STEM so that's tech industry adjacent, but all too often I spoke to professors who were blissfully ignorant of this softcore dystopia we ended up in. The more awareness we raise the better shot we have at changing things. Thank you!
My favorite structural engineering channel is "Building Integrity."
Space elevators were a lot more attractive an idea when we were only using rockets once. If we had to build a new ship or airplane every time we wanted to cross the ocean, we'd be talking seriously about building a bridge.
The most appealing part to me is using them to sling stuff off into higher solar orbits. Making a trip to mars last a couple of months rather than a six month trip.
@@atashgallagher5139 You'd need an even longer, and tougher, rope for that!
This video made me realize how lucky we are to live in a time when the sky hasn't been turned into a giant endless stream of advertisements.
yet
@@OnisanTbeat me to it lol
And you can actually go see a living giraffe!!!
I mean if you live in a densely populated city it pretty much is. I struggled to put my eyes somewhere there wasn't an ad in New York City.
@@chicken29843 this is why I’ve only been, twice. And not for long, and not for literally any other reason than a couple hardcore/punk/metal shows.
I love hearing you say. “It’s sooner than you think.” The first video i ever saw of yours was about space elevators. That alone was worth a subscription. You never disappoint.
Oh. My. God. The better help on the orb bit ripped straight out of my nightmares.
I love cracking the cryptic! It's always such a chill time, but I do get a little stressed whenever he flies off the handle and says "bobbins". Also strong recommend for their The Witness playthrough.
🎤 That’s 3 in the corner! 🕺
I hate it when he says bobbins, sends shiver down my spine
@@TerkanTyr That's when he truly shows his monstrous, violent side.
@@excrubulent Yeah it's why I can't watch him anymore. I live next door to an English man and it fucking sucks. Like people think it's funny that some people can't handle that shit but it's really not and I wish they'd just stop.
I love it every time I find someone who enjoys watching two middle-aged British former accountants solve Sudoku puzzles because there's no way to explain it to anyone else.
Great idea for a video, as always. Can't wait to watch it.
I absolutely appreciate your content. These are the types of questions I would ask as a child but no one could answer them, now as an adult I love learning all this stuff and letting my inner child get excited to learn.
What's wild about the sky hook concept (aside from normal space elevator stuff) is that it's not only orbiting the Earth, but also is rotating at just the right angular velocity such that the hook at the lower end will remain horizontally stationary. So it's essentially a planet-sized trebuchet.
Eternal trebuchet… 😅
That's actually the entire point of a skyhook!
Maybe that's why people want them. People in 2023 are building supersonic trebuchets on TH-cam.
Who's behind this? Are trebuchets numinous?
I think the idea that a lot of people have with a space elevator is that they know they're never going to ride a rocket to space.
going to space as a normal person sounds a lot more attainable in an elevator than a rocket
That guy's a genius, I've seen him solve Sudoku that I previously would have considered impossible
right?! Dude is B A N A N A S at sudoku
Both of the guys in that channel are insane, it's such an amazing watch everytime
Simon hates doing sudoku in his sudoku puzzles.@@facingup1624
@@facingup1624 whether you like it or not, both pronunciations are *very* well-attested in English. It would be unreasonable to consider "suduko" to be incorrect in English when nearly half of English speakers (according to my personal experience) say it that way. Go be a grammar Nazi somewhere else.
We need space elevators because I think it’s cool. Why doesn’t the world revolve around what I think looks cool?
Ok Elon
this is obviously the only reason physics exists
To answer 'why space elevator?' from what I've always understood, I think the point was we're generally better at converting energy into mechanical motion than we are at using the rocket formula. Sure a trip by rocket is pretty quick, but the fuel is always gonna be nasty stuff, and dangerous, and there are pretty hard limits on the amount of stuff you can lift at once (not to mention when you factor in the time it takes to stack, fuel, and load a rocket the time savings isn't that great). So for space elevator however it works it's a pretty simple transfer of electricity into climb/descent motion. It may take a while but it's efficient. Additionally, if designed correctly nothing would stop you from making it like a ski lift, just running car after car up one side and down the other as fast as you can slot them onto the cable.
I absolutely agree from a materials standpoint it's impossible, but I never had trouble understanding why you'd want one.
Impossible is too much, no?
@@fernandoterra4108 the materials needed to handle the stresses involved over the distances required don't exist and aren't even hinted at from what we know about chemistry and physics. Existing manufacturing isn't close to the scale required. So yes, impossible in any timescale less than centuries.
"Impossible in any time scale less than centuries". Better said.
One of the most distressing things about playing Starfield is how often when you jump into a settled system, there is space crap everywhere.
They want a space elevator to escape the rocket equation. If the elevator could be powered by electricity from the ground, then the energy needed to lift something would be proportional to the mass.
Thank you. It's literally referred to as "the tyranny of the rocket equation". I felt like I was taking crazy pills watching this.
Most of the engineering papers about a space elevator I've read suggest a kind of solar-panel powered elevator car being energized by high-power ground-based lasers or microwave beams, which is only slightly less hand-wavey than the materials tech they need to engineer a cable capable of withstanding the tensile forces in play, and honestly I don't recall any of them ever addressing the oscillation issue.
Not only that, but using regenerative braking, you can use the potential energy of stuff going down to power stuff going up. If the masses balance, you only have to provide power to overcome friction, and other losses in the system.
She addresses the reasons. She doesn't mention the rocket equation, but I'm pretty confident that someone with a PhD in astrophysics is aware of it. The real question is: what would you use a space elevator *for?* It's useless for putting stuff in Earth orbit, and interstellar travel is even more impossible than space elevators. That leaves missions within the solar system, and there aren't enough of those for a space elevator to ever pay for itself.
@@MarianneExJohnson The reason usually used in science fiction is to bring people and cargo up to a huge station at the top, and then shuttle things from the station to wherever they are needed. It's feasible, kinda, but the level of infrastructure needed to make it practical is a lot more than just the elevator itself.
Some notes about solving the practical issues with space elevators (other than the tether material)
- impact shielding from micrometeorites is probably feasible when you can also create the tether material. For larger objects like satellites, tracking them and predicting a collision, then sending out a satellite-hunting satellite to change thier course if the object cannot itself maneuver could be reasonably practical. The tether itself, like modern ropeways on earth, could likely have multiple redundant cables, allowing one to be damaged and repaired while the other(s) held the load. For what it's worth, modern ropeways on earth have possibly the best safety record of any form of transit, with well-maintained systems that aren't hit by a plane having a flawless record.
- similar to some of the buildings you mention, the tether could have active mass dampers at regular intervals ro counter vibrations.
- the car could be hauled or powered by the cable, from the ground, which is sort of the main advantage of the cable system.
- finally, i think the best practical use case in the nearish term for a space elevator would be resource gathering from space. Not sure if it would ever be competitive, but if equipment can be brought to space and raw materials available in asteroids and the moon can be brought down for a small fraction of what that would currently cost in terms of money, pollution, and land, it could be worth it, especially in a future world where we incresingly care about the impacts of resouce extraction on earth.
I’m so so glad to hear you’re a Cracking the Cryptic enjoyer! I love them!
Impressive run of Factorio! Less then 30 mins to space elevator is impressive.
Meanwhile my K2SE play through at 500 hours still hasn’t unlocked them.
We'll need the space elevator to get past the billboards in space in order to do astronomy. It'll cost $500/kg to look at the stars
surface-to-space adblock
Well, that's one way to sell diet plans.
@@Adam_Stoke promising alternative: surface-to-air missiles
A subscripiton to a live stream of the night sky for only 10€ a month, and a night sky+ to look at the nothern lights
There's a reason rent seeking is a sin, this is hell on earth.
Good Luck saving the world chinas already buying stars
Not a space elevator fan, but since you asked, here's why I would want a space elevator:
Assuming one exists that would also mean we more than likely have the technology to make asteroid mining plausible. Having a central facility to process and move all of that material makes sense.
From Robert Forward who wrote on this back in the 80s, the expense analysis was that the cost of electricity to power it would be about 10% of the cost of a rocket (on a per kg basis). Time to orbit would be about 5-7 days, compared to 7-8 hours by rocket.
I like your point about vibrations - which has _not_ anywhere I have seen - been addressed. I think pulling it more taught would be a bad idea, as that would increase the frequency, right? Assuming you could - because increasing the tension might cause the thing to break.
Two things I think about are (1) how much potential energy is stored in that cable? If it breaks towards the counterweight, how much energy will be released onto the Earth as it falls? (2) what is the tension in that cable? It's easy to talk about getting some unobtanium - sure, spun diamond carbon fiber, whatever. How strong does it actually need to be? What are the vibration modes of the cable? (to get to your point).
Ignoring the accidental failure (SpaceX satellite hitting it, Musk's car loops back, whatever), what is the risk of sabotage or terrorist attack? How could that be mitigated?
I would like a space escalator.
Honestly take the space stairs if you are physically able, it's good exercise.
Space escalator can never break, it just becomes space stairs.
And he’s buuuying a motorized staaaairway to heaaaaven
@@nefariousyawn also, the further up you are, the easier it becomes 😂😂
That would be a fun follow up, if you were to assume that the space escalator travels at a 45 degree angle, how much sorry material would be required to reach space?
While not strictly a structural failures channel, "Practical Engineering" does cover a number of disasters from time to time (among other equally excellent videos about various aspects of civ-eng). He actually does cover the Hyatt disaster in a shorter sub-video for Tom Scott's channel. It goes by the title 'The Disaster That Changed Engineering: The Hyatt Regency Collapse'. He also covers the Tacoma Narrows Bridge collapse in an earlier video.
You would love the channel "Building Integrity". The channel started after the surfside condo collapse, the creator is a licensed structural engineer and he does an *amazing* job of analyzing the evidence collected from engineering disasters.
New to your channel and have been binging your content for a week. Literally jumped at the Cracking the Cryptic reference. I watch them every day!
this was just a brief aside you made but I'd LOVE a video from you about the moon landings and why we haven't gone back since the 70s
They always ask or "Can we space elevator?" but never "How is space elevator?", which saddens me greatly.
I'll do you one better: Why is space elevator?
Who is space elevator?
When is space elevator
@@personzorz Never
I liked the idea of space elevators and really thought they were an interesting solution to a lot of problems with putting stuff in orbit. And now I just remembered that I first heard about them from Michio Kako and now my day is ruined and my disappointment is immesurable
Is there something wrong with Michio Kaku?
@@halcyonacoustic7366 You mean besides the fact that he is an idiot peddling nonsensical string theory as well as other ridiculous sci fi fantasies?
Who is that?
@@ruinmasters You're better off not knowing.
@@halcyonacoustic7366 Kako is very likely a nice fellow and a gentleman, but he's also a credentialed Ivy League Physics Professor who makes endless TV and internet appearances as a "science communicator" presenting wildly speculative prognostications about sci-fi technologies and sensational unfounded takes on theoretical topics outside his field.
My new favourite TH-cam channel. Smart AF and completely hilarious.
I'm surprised the Red, Geen, Blue Mars book series wasn't mentioned. It has a pretty strong case against (and kinda for) space elevators.
I think in a different video she talks about finding that series boring. For those interested, the ending of Red Mars includes a vivid description of a space elevator collapse.
Don't worry about the Factorio bit. I've played the mod you're referencing for ~250 hours and I still don't have the space elevator. Granted I'm not the fastest but still I would say 100-150 hours would be blazingly fast to get there.
I'll bite on a couple of these points.
* How to power it: I feel like you didn't think very hard about this one because here's 2 reasonable solutions: 1. electrical cables running along the elevator, like trams, or any other electrified rail type thing. Am I missing something? This one feels very obvious. 2. a laser emitter at the base of the elevator aimed at the bottom of the space wagon, which has a laser receiver (sci-fi technology, but fairly reasonable, I think).
* Why? We don't live in star trek: But it's kind of a chicken and the egg problem. The egg being the ability to climb out of the gravity well. If there was a reasonably cheap shuttle to space every week or month, maybe we would then... become star trek. No?
A transmission cable that goes those sorts of distances has massive issues in terms of loss and efficiency. A laser as you describe would need extreme levels of accuracy and would also probably set fire to anything that flew into its path, or would lose effectiveness by the next cloud passing by.
These aren't bad ideas at the speculation phase, but everything gets harder when you have to factor in the chaotic environment of the real world.
The other issue is that like... the cable has to be super strong and stuff, and now it also has to carry power extremely effectively. This puts even more restrictions on the material used - it has to be conductive itself, or somehow has to have supports for the cables, which are also undergoing their own gravity
@@RhettAultman I would expect if we ever start to build a space elevator we would also have a proper super conductor to build the cable out of. It's just one more unobtanium we will have to obtain, easy stuff
@@tillschlothauer5377 Ah, yes. I forgot about the unobtanium ductile superconductor.
Granted, once we have unobtanium, surely we could hypothesize something better than a space elevator anyway?
I love your videos. I like the physics, the maths and the engineering. Please don't stop talking about stuff and your feelings about the stuff, it is wonderfully real. Your worries about the space elevator are much like my fears about how Superman plucks people out of the air when a building is falling on them and thus instantly killing them due to the instant acceleration. I also liked the fact that I followed the integral calculus. I fear I am shallow. C'est la vie.
Absolutely loving the music. Nothing says "slightly wonky vision of the future" better than that "Look Around You" style. And I'm betting Angela has never even heard of "Look Around You". Natural convergence of ideas. Maybe scope for a video about that?
as requested ;)
Well There's Your Problem | Episode 4: Hyatt Regency Walkway Collapse:
th-cam.com/video/Hw2t0MOGnVc/w-d-xo.html
What is elevator?
Should we elevator?
If so, how much?
Should we do it should we do it should we do it should we do it?
Tick-ticky-tick-ticky-tick-ticky-ticky-ticky-tick
What is this referencing? I remember this songs rythm but cannot remember the original and it's killing me
@@IdeoLogs The dark matter rap
It is not a moon. It is a list of scientific observations.
Throw the Pentagon budget at it. Convince them it's for Space Force logistics lol. Build the sky screen!!
oh my god?? like a month ago i became absolutely obsessed with the cracking the cryptic channel, i watch them everyday. and like a week ago i started to watch your videos and i must say that you, cracking the cryptic and one sims4 channel are all my top 3 watched channels for a while. And im so surprised and so happy for how suddenly two of them somehow connected (even if only briefly here).
I love your description of the fridge of the future.
The author of the book seemed to have a space hook and a space elevator confused. Space elevators are what you described in this video. A space hook does something similar but between two orbits, which facilitates Hohmann transfers. Isaac Arthur has an excellent video on both.
I'm an old engineering physics grad (working in spacecraft engineering) and you completely nailed the difference in how physicists and engineers see this problem 😂 (and really I don't think physicists believe it either, science media loves to sensationalize) like yes! We can do the equations and get all the numbers we want to "solve" the basic problem, but engineers are still gonna look at those answers and giggle and then go do practical things instead because there's SO MUCH that goes into making physical structures not kill everyone building or using them.
Also I love hearing you rant about late stage capitalism, I feel so seen 💜
Point well taken. But not so many good applied physicists, and good engineers, see it so differently. This content creator is a good example.
This is also known as AM/FM thinking, aka actual mechanics / fucking magic
I agree it's impractical, but I thought the space elevator was supposed to be a solution to get past the problem where you need exponentially more fuel when you increase payload weight. If you lower the depth of the gravity well by launching from the top of the space elevator, the idea is you can grow the effective payload you could launch with a given amount of fuel.
As it turns out, we already have a stable satellite from which we could launch stuff: the moon. You'd use several trips by rockets in that case, since a space elevator doesn't even mathematically work, but the fundamental idea is the same
I first heard about that as a potential cost effective solution to getting stuff off the surface of a planet. But if I'm being honest the reason space elevators excited me is because it's the first mega "space age" construction I could conceive of. It's kind of like building a big pyramid but in SPACE.
I understand almost none of the science/math, but I find extreme comfort in knowing there are people passionate about this stuff. Makes me feel safer knowing there are tons of smarter people than me out in the world.
I know none of the science/math, but I'm passionate about learning the science/math
I often find myself saying, I like your funny words magic man
Cracking The Cryptic & acollierastro is the crossover I didn't know I needed
Never expected to see Cracking the Cryptic here! Great work as always.
"You might have seen the trick where people fill a bucket with water and then spin it" - In undergrad physics 1 we had a new grad student lecturer that was very gung ho about using all the demos that had been gathering dust. After some practice he did this demo in lecture and it worked! We all applauded!
...then he launched the cup, hitting the head of someone in the first row and splashing someone's leg in the second row.
So, I work for a company that is making a satellite constellation to provide internet services, in fact I design the guidance and control system. I’m a big fan btw, love your content. The time it takes to de orbit a Leo satellite (roughly 600 km altitude) is roughly 10 years. At 800 km it’s more like 100 years. Go higher and it gets really long. This is because at this low altitude, there’s a pretty significant atmospheric density. In effect, if a vehicle is low enough, the altitude is “self-cleaning “. I know maybe you think everyone in this industry is an irresponsible ass, and it’s generally a pretty safe assumption, particularly with an x-fascist, but the problem of accumulating space debris is considered and dealt with. Fly low, use a really efficient electric thruster to restore the energy loss from drag, and it’s possible to not ruin space forever. Worst case, you fuck up a decade. Finally, these vehicles are really really flimsy. Not a lot of ceramic or quartz or hard steel. Aluminum and composite and thin silicon solar arrays. They burn up in the atmosphere, so nobody is going to be hit by anything. Now, is it great to oblate thousands of kg of this stuff? I don’t know, but no one is going to be hit by this stuff directly.
'Don't worry, we only ruined access to space for a decade and also destroyed all vital communications and meteorological satellites. Good thing we were so responsible.'
Literally every time someone steps up to try and defend space bro bullshit, it just really makes it clear how dangerous the industry is & how entitled the industry feels it is to LEO. Like it just owns the place and if they ruin it for 10~ years or so, eh, what's a lost decade here or there?
Fully agree with you, I wanted to mention this too. 99% of the debris burns in high atmosphere, the rest has 70% chances to land in ocean. Biggest chunks are the only ones that can survive reentry and those are tracked. Still, we should consider the probabilities of a Kessler syndrome when deploying large fleets of satellites with an appropriate risk analysis.
@@ItWasSaucerShapedI would imagine that having a debris field at 400km does not impede sattelite communication and metreology satellites at all. it might not be worth the risk to send a sattelite up to space because theres so much debris, but it will only cover a very small area of the earth so imaging and communication through that layer should be alright.
I worked on GOES-R, it's a geo, not a leo, but keep tryin! If snark were an argument you win!@@ItWasSaucerShaped
The "how would you power it?" feels flippant. If we're in Magical Christmas Land, and have a Space Elevator, the advantage of it is: we don't have to lift fuel, and the return trip's potential energy can be recycled. At worst, its electic, and we use regenerative breaking, it takes like a year to climb it, but its OK because its rhe equivalent of a container ship for space.
Outside of Magical Christmas Land, its just a gigantic danger and waste.
um
it would take about 64 megajoules per kilgoram to crawl up the cable
batteries prettymuch go up to 0.7, perhaps 0.9 megajoules per kilogram
a cable to the ground could work or thi nwires in the elevator cable or solar panels
@@JulianDanzerHAL9001 That's about 50kw/ton over two weeks. The much bigger problem is transmitting the power to the elevator over the tens of thousands of miles. Even copper doesn't conduct electricity that well. You'd need superconductors or some kind of beamed power.
@@tomweinstein how far you can take electricity in something always dependso n the voltage you put on it and how much power you actually wanna draw
of course any cable would have to be reinforced to hold up over that length as well and you have to drag it with you
from 80 tons of copper you could make wiring that long with a resistance of 2.5 megaohm
there ar some plastics that are insulative enough to make an insulating sleeve that has a higher lateral resistance even over the whole sruface area over that length
of course the currnet has to go both ways so you need 160 tons of copper and you get 5 megaohm rseistance
that means with 1 megavolt (about hte highest voltage used for transmission lines) could get 0.02A through this wire at 90% efficiency
thats 20000W or 125W/ton over the wieght of the copper wire
enough to get a cabin twice as heavy as the wire up in 30 years
thats kinda long but it would go down proportionally if you allow more inefficiency in the transmission and it would go down squared if you increase the voltage
also thats still a somewhat inaccurate estiamte because most of the energy gets used in the first 10% of the way so overall on average you only need to transmit the power about 1/6 or so as far
still an impractical concept overall but the idea of using cable pwoer isn't entirely implausible
we can produce 25MV in a lab, transforming it that high would let you shorten the travel to about 2 weeks
@@JulianDanzerHAL9001 good comment, it's unfortunate how few people actually understand the theory behind AC transmission lines. The comment you're replying to is a classic example of a physicist thinking they know engineering.
"Engineering is real shit." I love it. You really know how to drop a truth bomb in the middle of someone else's fantasy idea. Keep it up!
favorite video on this channel right now
the US chemical safety board is not exactly about structural failures but *super* interesting if a bit grim, after major incidents they often release videos to accompany their reports. lots of engineering youtube channels dabble in structural failure post mortems though. looking forward to the leaf blower essay!
My favorite structural failure channel is Practical Engineering. They don't have a Hyatt walkway video, but they do have a video on space elevators and a lot of other disasters.
Ok I lied, it's more of an infrastructure channel that talks about failures in dams, bridges, and buildings from time to time.
Practical Engineering actually covered the Hyatt disaster in a guest video on Tom Scott’s channel.
@@w13storageroomB Ok, I thought I remembered seeing it but couldn't find it on his channel.
He has a great playlist with structural failure (and adjacent topics): th-cam.com/play/PLTZM4MrZKfW_kLNg2HZxzCBEF-2AuR_vP.html
So glad i found this channel today, awesome videos!
I fricken love these videos. You should do this full time. I know selling your soul to the man for a paycheck is...unavoidable...this is your calling for sure.
Unobtanium and “you have to pay gravity” are the two most awesome words and phrases I’ve heard this week. OK, it’s only Monday, but I’m pretty sure the week will end with nothing better.
I loved "we have flying cars: they're called helicopters, and they crash all the time"
You must have not seen the film "Avatar". The term unobtanium is actually decades older than that and was a running joke in film/ science fiction criticism.
@@iankrasnow5383 Adamantium in Gulliver's Travels is what keeps the floating island levitating. At some point, people just replaced Adamantium with Unobtanium.
@@iankrasnow5383 Fun fact, the unobtanium in Avatar was actually a room temperature superconductor, which is the reason why the mountains on Pandora float.
@@Jackissimus Room temperature superconductors, space elevators, hyper loops,... Is it just me or does it feel like the frequency of big funding scams is increasing rapidly?
This video brings the total number of times a physicist has said “we gotta get the engineers in here” to…
…one.
Let’s be real - I’m surprised the physicists actually knew the engineers existed in the first place.
@@tomkelley4119oh they knew, but it was easier to just assume they rounded to zero
We're just physicists who multiply our results by this unitless constant that cannot be derived from physics and math fundamentals called a "Safety Factor".
Dr. Collier is not your everyday Physicist
I love the way this starts out as a straightforward classical-mechanics problem, worked out nice and clearly, then blossoms into a righteous rant against outer-space hype and pop-science nonsense. We never saw it coming! Great video
I love Cracking the Cryptic! Glad to see them get a shout out
My best guess as to how you'd power the cable car is by using high voltage DC supplied from the ground station to the cable, two graphite brushes would need to interface with the cable once the energy was on board the cable car there would probably be a variable frequency drive that would operate a three phase motor which would then rotate a gear against a huge pinion built into the cable itself. Another benefit of the system is the vfd can put power back into the grid as the cable car descends back from the space station to Earth. No matter how you slice it though there's a litany of engineering problems to overcome.
Being a depressed old man, I'd like to thank influencer Dr. Collier for consistently raising my spirits. She is the future as I imagined it. Oh brave new world...
You have a knack for making content I didn’t know I wanted.
Congratulations on reaching 100,000 subscribers!!!
The basic idea to my understanding is generally that if you have a space elevator then the cost of getting stuff into space goes down. This allows you to do stuff in space that requires large amounts of stuff from earth like moon and mars colonies or enormous space stations for far less resources than using rockets.
That is the dream of the space elevator after you hand wave away all the things that make it impossible, that it will allow for a space based future, not in a Star Trek instersteller way but in a neo-colonial solar system way. And depending on your views that’s either inspiring, troubling or both.
Also, what would happen before colonies, mining materials from space objects more cheaply and more easily getting it back to the ground to be turned into more things to mine shit in space. So basically capitalism again. Basically the only way to get capital interested in space development, other than as a pet project for someone unimaginably wealthy.
Get one rock mostly made of incredibly rare metal here on Earth, tow or mine it on site and bring it back here. Then watch as quite a few countries IMPLODE as their economies are ANNHILATED because their economies were before forced to exclusively just mine this material.
At least till the operations up there are developed enough to be mostly based on space based labour. IF we can transfer most of our production processes to work in near zero G.
You really are a cancer man hug a tree and realize your whole worlds upside down idiot
@@cancermcaids7688 if you think "neo-colonial" is an absurd concept think about the Beltalowda from The Expanse series. That's what we'll get if people like Bezos and Musk have it their way
Also if your country wins the "build the space elevator race" it become the next super power because you can basically controll the economic flow of people/things to space
oh, it would be a colonial project eitehr way because you need at least three major places along the equator in the right spacing and the countries or companies most likely to build one currently have 0 land at the equator so someones gonna tell everyone near the equator to die except in a very friendly, brand safe way but still thats basically gonna be the message
I went to a presentation about 15 years ago on space elevators (80% for entertainment, and 20% because I want to live in Star Trek even though I know I can't). Honestly, a little bit of the talk was about the idea and the promise of it, but most of the discussion was about the issues that they haven't solved so at least at that time, so at least it wasn't all sunshine, rainbows, and tricorders. So these are some of the ideas that they had at the time (at least what I remember of what they said) ... posted as my time capsule of space elevator BS:
THE CABLE: The cable would be a carbon nanotube ribbon. According to them a ribbon would actually be stronger than a round cable and more resilient to damage (don't remember exactly how now). But they did mention that the longest pieces of carbon nanotubes were measured in centimeters (reminder ... 15 years ago)
POWER: Their idea was that if they could use carbon nanotube ribbons, they could actually transmit the power through the ribbon at low resistance saving them any power generation or storage on the elevator itself.
SLOW RIDE: While they did say that the payload would be less than the shuttle (it was still running back then), the turnaround for an elevator trip would still have been far less than the many weeks of cycle time to inspect and prep a returned shuttle for another flight, making the space elevator total throughput greater than the shuttle.
DYNAMIC COMPENSATION: As far as balancing for the changes in the physical system as the elevator takes mass up and down the ribbon to space, the counterweight could be reeled in and out to adjust for the mass and position of the elevator. Basically reel it out when the elevator is low and reel it in as the elevator pulls itself up so that the center mass remains in the geosynchronous range.
SAFETY: I believe they said that if the ribbon broke, the elevator itself would act as a reentry vehicle and have a deployable parachute system. The geosynchronous station could essentially cut the tie to the counterweight and remain in orbit. At that point you would have to go through the whole process of replacing the counterweight and lowering and attaching a new ribbon.
WHY: There were a few reasons they gave. One was for lowered cost. . Beyond that was holy grail of space tourism ... basically making it cheaper for people to go to space and, um ... do space things ... space selfies? idk. Part of the lowered cost idea was to make human exploration of other planets easier, as well as asteroid mining ... and I think He3 from the moon (though I might be conflating that with something else). There was no mention of billboards ... but also no mention of banning them ...
OTHER PROBLEMS: In addition to all the issues you already mentioned, they did mention one thing that you didn't. That was the geopolitics problem. Essentially that the elevator has to be somewhere that is near the equator and if you look at the countries that are near the equator usually aren't the most stable of places. And it's something that could potentially become a target, which is a bad combo.
So I hope this is, um ... useful doesn't seem to be the right word ... but I hope it's ... something ...
This is informative, and I think genuinely starts to answer Collier's main questions of "why, and is it worth it to try". My followup question is under SAFETY: what about the part of the ribbon below the break? How do you stop that from impacting the ground at high velocity?
Was that the group from the Keck Institute? I remember reading their feasibility study some years ago and these were pretty much the same ideas they floated.
Re: the damage resistance I think they calculated (or 'calculated', I don't recall) that the ribbon should retain structural integrity even with numerous holes from micrometeorites and the like until patching up. Although, in all honesty, they were speculating about the management of a non-existing material. In hindsight, all of it sounds like a slightly more prestidigitative handwaving.
Still, fun to think about.
1) Cables: Still not sure the "one long cable" notion is anything but retro-futurism as for as design is concerned.
2) Billboards: Space billboards are pretty much inevitable. They might not look like we imagine, but commercial advertising is almost certain.
Skyhook better
lol. Clarke solved the geography problem by moving his adopted home south to the equator.
Great book. Also proposed carbon nano tubes as structure going on 40 years ago. He wove a great story around the physics
CONGRATULATIONS 100k Subscribers!!!
🎉⭐
Glad to see Angela's finally using TH-cam Shorts
To two of your criticism of a space elevator.
1.) We could use electricity to go up into space instead of fuel.
2.) Also counter weights. Have 2 elevators going at all times. One going down and one coming up. Tramways do this.
The unobtanium rope and the physical stresses is what makes it impossible.
This was in the book of Arthur Clarke
The channel “Plainly Difficult” is probably my favourite (for lack of a better term) youtuber that takes a very fact based approach to structural failures and general engineering incompetence. They do a lot of UK based things, but cover some larger north american events too
I heard about a proposal to power the car by laser. Like, shoot a laser from a ground station and the car receives the light and uses it for power. I'm not saying that would solve the problem. Idk how good that would be, especially at long distance. Just thought I'd mention it.
This channel is genuinely awesome.
I love cracking the cryptic. I love it when he gets that childlike joy when finding a trick to the problem. Just wholesome.
I've started saying "Bobbins!" at work.
33:43 -- "When I was a child the future seemed really exciting, and now everything's just the worst possible version." I feel the same, and I couldn't have said it better myself. //Rick
Same here 😕
This feeling, everything is getting worse/will only get worse is a constant going back to the earliest records we have... taking a look at the Egyptian early failed pyramid shows is they tried it before they found out their slope was too steep and they had to build the later pyramids less steep so the darn things wouldn't fall over before their building was done...
@@DavidRayBurroughs The old adage "a broken clock is right twice per day" comes to mind. Quality of life is decreasing for huge swathes of the population, even if the metrics used to measure it are being redefined to pretend it's not.
@@mallninja9805 - as in all True Sayings, these are subject to more than one description often outlining the defined reality, or more nearly so, or nearly more complete. That is, for example, huge medical advances leading to far fewer infant deaths and its increased population and feeding problems and perhaps too many people alive at one time - yet, still and all, we all eventually die. No wonder true believers rely on ginning up god beliefs and immortality of the soul and the reincarnation crap, etc.
People love to say, "just this one thing more, and all our problems are solved!" but it is always "welllllll, not quite..."
The end credits bit bit deserves more recognition. ❤
Dr Collier - I hate you just a little bit for this video :P.
I'm a mature student in my final year of forensic chemistry as an undergraduate, currently applying to masters programs abroad writing thesis proposals, and teaching myself a new language because half of the courses I've applied to are in French...and now...after watching this...I have to go learn calculus and integrals because of the wizardry you just performed! Absolutely awe inspiring! Loved it!
Cracking the Cryptic representation!!! Simon's videos carried my sanity through the pandemic
Well There's Your Problem, the best engineering failures podcast with slides
Hi, it's me phyphor, I'm the person commenting right now, and my pronouns are it/it, yay liam
I was introduced to space elevators through Kim Stanley Robinson's Red Mars trilogy, and yup he does in fact go into the scenario of what happens when it comes down. It doesn't just fall straight down, the angular momentum makes it fall to the side. Fun fact, on Mars the cable would have to be longer than the circumference of the planet, so when it comes down it actually wraps all the way around the planet and then some. It's a really bad day for everybody.
The description of the space elevator collapse is such a cool read; my favorite part of Red Mars.
I'm no earth-ologist but I'm pretty sure 1.5 * 10^8 is a few kilometers longer than the circumference of earth ...
Congrats on 100k subs! :)
Favorite structural disaster channels are Brick Immortar, Plainly Difficult, and Fascinating Horror. All three have great Hyatt videos.
Yes yes yes 🙌🙌
Don't forget "Building Integrity"
22:07 pulling a vibrating string taught would actually make it worse, because if you force a vibration to decrease in amplitude without dissipating its energy, it increases its frequency. That could easily cause the cable to experience forces outside its tolerances. You'd need to have some kind of harmonic negation device that pumps an opposing wave into the vibrating cable to cancel it out. And you'd need them all along the cable because the speed of sound (aka the speed of wave motion in the object) would be waaaay too slow for a cable of that size to stop an out of control oscillation in time.
But all of this is moot! Because the MAIN problem with space elevators that I never see talked about is the actual building part. Not material building, mind you. Leave aside materials, since we could always make one on a friendlier planet like Mars, which I *think* has requirements within the limits of steel. The Moon is also technically possible, but because of its slow rotation it'd be way too long (relative to things that are already WAY too long for us to make right now!) But forget all that, here's the bigger problem: orbital mechanics! People talk about going up and unravelling this cable from space, but you're not stationary up there, you're going in circles and - guess what? - so is that cable! Not only that, but that cable, you can't just "lower" it. Anything in your orbital plane wants to stay there. To drop or rise requires energy, and dropping is harder, because to go literally "down" relative to a gravity well, you need to match the speed of your current orbital velocity in the opposite direction. But not the orbital velocity of the thing you're leaving, YOUR orbital velocity, which INCREASES as you lower your orbit, meaning you need to accelerate. But not just accelerate, you need to accelerate exponentially, by the factor of gravity's increasing strength as you near the surface of the body. AND, because we're talking about a cable and not a single object, you ALSO have to take into account that this needs to remain true for every segment above you! This entire cable line would need to be covered in thrusters with their own fuel reserves, and a LOT of it because they'll need to burn hard to stay under control. You could very easily wind up making a thing that spirals into the planet and it useless and horribly dangerous, or worst case it turns into an enormous whip and you accidentally invent the most inefficient yet also most devastating superweapon in human history
A mitigation method would be to make sections of the cable have different resonant frequencies through variations in stiffness. This would make it difficult for standing waves to arise.
@@TheAntibozo Firstly, the 300 word ramble is hardly worth a comment, he's joined the circus. Then you propose how to "mitigate" the vibration something of unknown geometry, under unknown forcing functions, that doesn't exist, and never will. Removing "Anti" from your handle would be a good plan for some mitigation.
@@AndriasTravels Did you watch the video? Poster is correctly responding to acollierastro's proposal. You can't damp a vibration by tightening the cable. Energy needs to be shed. As for my comment, your quick turn to a laughably lame attempt at insult suggests that you simply don't understand it, which is fine.
@@TheAntibozo Firstly, a string or cable would be a small part of a "space elevator" design. The "cable" would have to be part of an integrated, impossible, complex structure with unknown resonance, stiffness and geometry. These terms you learn in elementary theory of vibrations. In the video, all external effects are assumed to be absent in her initial stick model. You are in over your head. Come back when you have 20 years of mechanical design engineering experience.
@@emperorbailey Call it what you want, it is education, well deserved. If crybabies want to talk fantasy and not learn anything, they are part of the problem.
Congrats on 100K subscribers!
This reminded me of a space shuttle experiment on Feb 25, 1996, where they extended a tether with a spherical sat on the end. The tether, cutting through earth's magnetic lines of force, generated a current and voltage so high it turned a portion of the cable (where there was a manufacturing defect) into plasma, ending the experiment.
On the upside, I think we found your elevator power source 😂
That's a bit misleading. The manufacturing defect allowed the porous core to release trapped air, and the air was dense enough that holes in the insulation assumed to be fine became an issue, and that caused the plasma.
@@aeroandspace I think the word you were looking for was "inaccurate", not "misleading" (which implies a motive to deceive). Materials, and manufactured components destined for space environments undergo extensive testing to limit the potential for destructive outgassing. This was a far greater failure of quality control. Trapped air within the tether wiring led to both a structural and insulation breakdown in the wiring which led to a current induced plasma that vaporized that section of the tether.
I appreciate your constructive emphasis that I could have been more technically detailed in my original post. I'm sure your reply was made in that spirit... Or am I being misled?
@@jamesplant5280 it was definitely meant to be constructive. I did intentionally choose misleading over inaccurate, though, since your facts were all correct, just presented in a way that could induce the wrong answers. The current induced wasn't necessarily greater than the researchers expected. My understanding from NASA's page on the article is that the holes in the insulator were expected, as well. It read that it was the air flowing out of the porous core that was unexpected. While space tools are very heavily tested, it isn't uncommon for novel procedures to uncover unknown unknowns.
I seem to recall there was an issue with the spool as well. Almost forgot that experiment hazy in my memory
Grant (3Blue1Brown) is pretty awesome. I wished all math was taught in his style--would take so much stigma out of it.
Seconded, he is absolutely incredible! I can credit Khan Academy for getting me from "confused math-illiterate adult going back to college" to Calc III-ish, and then 3Blue1Brown helped me finish the Calc IV and linear algebra for my EE degree. I'm so grateful for all the work these guys put into making math more accessible.
@@jadecutter1760I didnt know calc went all the way to four 😢 what is calc 4?
@@lixxark47 It depends; for some schools on the quarter system, it's Calc 3, more or less, since the calculus sequence gets sliced up into four parts instead of three. For others, especially those on semesters, it's just another name for what's more commonly called Ordinary Differential Equations (a.k.a. ODEs or DiffEq). None of the universities or colleges I've taught at had a course named Calc 4, though; names vary, check the descriptions/syllabi.
I went to a mid-tier university (NIU) for my PhD and we did the 4 exams thing. The grad students all studied for the qualifiers together. One of us had that book, and we were shocked to find that it was basically undergrad problems. We had previous semester exams from our university to practice on and they were all upper level grad problems. The EM section was 4 homework problems from Jackson. The passing bar was fairly low though. You needed 50% on every exam, or any one exam with a 75% meant you passed the whole thing. I liked that system, because I feel like that was the only time I ever really learned to solve high level problems in a general sense. Even the classes that had those same problems on tests, you always went in knowing fairly narrowly what the test would be on. I know the environment is totally different and now that I'm a post-doc at a higher tier university, I can see that the students are held to a higher standard in other ways, but I'll always be proud that I passed a test that was harder than the one at an Ivy league school.
This is your best video. being able to solve a real example physics/math problem beside a bonafide PHD astrophysicist is an honour. all the other physics channels by professors and doctors of physics are dumbed down,and given click-baitey titles. whereas your channel is so informal, authentic -another day in the life of an astrophysicist. watching from london, england.
I think the least improbable (and also coolest) version would be a stack of electro magnetically suspended rings which could like Coilgun fire the elevator capsule up and down.
As soon as we have room temperature super conductors....