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Carefully Timed Jerks Could Power Space Elevator

ScuttleMonkey posted more than 5 years ago | from the pull-harder-and-faster dept.

Transportation 270

Hugh Pickens writes "BBC has an interesting article on the long-standing issue of how to power the 'climber' that would ascend a space elevator into space. Previous ideas have included delivering microwave or laser power to the climber beamed from the Earth's surface, but now European Space Agency ground station engineer Age-Raymond Riise has demonstrated a device that could provide a "lift into space" for cheaper space missions along a 100,000-km long tether anchored to the Earth. Riise demonstrated sending power mechanically by providing carefully timed jerks of the cable at its base with a broomstick to represent the cable held in tension, an electric sander to provide a rhythmic vibration to the bottom of the stick, and three brushes representing the climber with their bristles pointing downwards allowing the climber assembly to slide upward along the broomstick as it moved slightly downward, but grip it as it moved slightly upward. 'It would be possible to make a suspension system that completely decouples the cabin where the passengers are,' says Riise. 'For them it would be a linear movement with very little disturbance.' Riise says that he has been approached by commercial elevator companies, who are researching new ideas for elevators in superscrapers where the simplicity of the approach makes it attractive when compared to other ideas for powering lifts, such as compressed air."

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frist (-1, Offtopic)

Anonymous Coward | more than 5 years ago | (#26336873)

p0st

Re:frist (5, Funny)

Anthony_Cargile (1336739) | more than 5 years ago | (#26336917)

Yeah? Well the jerk store called and they're running out of you!

Re:frist (5, Funny)

l3ert (231568) | more than 5 years ago | (#26336957)

What's the difference? You're their all-time best seller.

Re:frist (5, Funny)

Anonymous Coward | more than 5 years ago | (#26337153)

Yeah? Well, I had sex with your wife!

Re:frist (5, Funny)

geekmansworld (950281) | more than 5 years ago | (#26337191)

His wife's in a coma...

Re:frist (-1, Troll)

Anonymous Coward | more than 5 years ago | (#26337207)

Shit! We've jerked too hard and now it's all gonna crash!

Re:frist (4, Funny)

Anthony_Cargile (1336739) | more than 5 years ago | (#26337315)

(mumbles to self) Well the life support machine called... Wait! Thats it! You just screwed yourself Riley!

Re:frist (0)

Anonymous Coward | more than 5 years ago | (#26337695)

His wife is dead...

....dead sexy!

Re:frist (3, Informative)

Anthony_Cargile (1336739) | more than 5 years ago | (#26337155)

This is not flamebait - its a classic seinfeld episode: Synopsis [wikipedia.org] full episode [seinfeldx.net] .

Re:frist (0, Offtopic)

anothersockpuppet (1445793) | more than 5 years ago | (#26337397)

That seinfeldx site is incredible! Thanks for the link! Please mod parent up, maybe after visiting the best online Seinfeld video repository in the world!

This is slashdot (5, Funny)

ciaohound (118419) | more than 5 years ago | (#26337185)

The jerk store called. They want the third derivative of the position function back.

Re:This is slashdot (0)

Anonymous Coward | more than 5 years ago | (#26337209)

genius

Re:frist (4, Funny)

philspear (1142299) | more than 5 years ago | (#26337223)

So if I'm reading the title correctly, Lawyers with rolexes could get us into space?

Are those crickets?

Re:frist (1)

Xistenz99 (1395377) | more than 5 years ago | (#26337313)

You beat me to it, to perfect for a Seinfeld qoute.

"jerks" (5, Funny)

Anonymous Coward | more than 5 years ago | (#26336875)

Something tells me the average slashdotter might be able to offer assistance in this "scientific research"

Re:"jerks" (5, Insightful)

biryokumaru (822262) | more than 5 years ago | (#26337057)

Actually, this is something the average person can see at home. The idea he's describing is a ratcheting mechanism, and is an excellent idea easily seen to be of use in any amateur environment.

My only concern is what happens when those bristles get a little worn out after all that high intensity cyclic stress and an elevator load of passengers plummet to their doom from 100 km up. Gonna need a really good preventative maintenance regimen, not something commercial operations are typically known for in the industrial sector.

Re:"jerks" (5, Funny)

uniquename72 (1169497) | more than 5 years ago | (#26337395)

Great - you've ruined a perfectly good joke with a bunch of "information".

What's next, Mr. Brainiac? Are you gonna tell us you read the article, too?

Re:"jerks" (0)

Anonymous Coward | more than 5 years ago | (#26337431)

...is an excellent idea easily seen to be of use in any amateur environment.

I'm a big fan of "amateur environments," too -- but sometimes you just need that extra professional quality to really rocket you into space.

Re:"jerks" (0)

Anonymous Coward | more than 5 years ago | (#26337447)

Not unless they make the shaft out of regenerative organic matter that heals itself. It would be like an umbilical chord for the planet. I'd flesh out this idea a bit more but I don't want John Scalzi to jack this premise and write another stupid novel about Septuagenarians in space. That guy sucks really hard.

Re:"jerks" (1)

Tubal-Cain (1289912) | more than 5 years ago | (#26337495)

My only concern is what happens when those bristles get a little worn out after all that high intensity cyclic stress and an elevator load of passengers plummet to their doom from 100 km up.

It shouldn't be too hard to add a braking system.

Has been seeing for decades, too (5, Interesting)

Chemisor (97276) | more than 5 years ago | (#26337693)

> Actually, this is something the average person can see at home.

If anyone here had been a kid back in the last century, we could all have shared the memory of kite riders (no, I don't really know what they are called in english). While flying a kite, put a piece of paper on the string, and in a strong wind it will ratchet itself up. You could improve them, of course, one of the favorite mods being a release rod which would release the payload upon reaching the kite. You couldn't lift a lot of weight this way, but strategic stinkbomb bombardment was possible. Yes... Kids these days are sure missing out on a lot of things...

The power released during descent... (2, Insightful)

Anonymous Coward | more than 5 years ago | (#26336879)

...can be used to power the space kleenex dispenser.

What a dumb idea... (-1, Troll)

Anonymous Coward | more than 5 years ago | (#26336887)

Articles about space elevators should be in the "idle" section. Only a stupid, retarded fuck would even believe for a split second that space elecators are, or will EVER be, viable.

Re:What a dumb idea... (2, Insightful)

QuantumG (50515) | more than 5 years ago | (#26336915)

EVER is a long time.

The Space Elevator is something an advanced civilization with a few hours to kill might whip up.

Re:What a dumb idea... (3, Funny)

TerranFury (726743) | more than 5 years ago | (#26337393)

an advanced civilization with a few hours to kill

There isn't any evidence that such things exist, of course... :-) "Advanced civilizations," that is.

Re:What a dumb idea... (2, Insightful)

QuantumG (50515) | more than 5 years ago | (#26337527)

I was talking about us.. in a few thousand years.. hopefully after all the dickwads who think making the earth a utopia is achievable have buggered off.

But who are ... (0)

Anonymous Coward | more than 5 years ago | (#26336891)

these jerks of whom you speak?

Oh no! (5, Funny)

HaveNoMouth (556104) | more than 5 years ago | (#26336897)

providing carefully timed jerks of the cable at its base

Too...many...jokes... [head explodes]

Re:Oh no! (5, Funny)

IthnkImParanoid (410494) | more than 5 years ago | (#26336997)

No, there's really only two: one involving rude people and one involving masturbation. Of course, the second one makes the [head explodes] tag all the more understandable.

There's one additional joke to be made about the relevance of your username to this topic left as an exercise to the reader.

Re:Oh no! (5, Funny)

GodlikeDoglike (600594) | more than 5 years ago | (#26337277)

People like you are why we can't have nice things.

Re:Oh no! (-1, Offtopic)

Anonymous Coward | more than 5 years ago | (#26337457)

one involving rude people and one involving masturbation [...] There's one additional joke to be made about the relevance of your username to this topic left as an exercise to the reader.

That's, like, 11 jokes right there! 11 jokes is usually a lot.

One other joke (1)

Jabbrwokk (1015725) | more than 5 years ago | (#26337681)

Don't forget the Aerosmith jokes about "love in an elevator."

Re:Oh no! (4, Funny)

mkiwi (585287) | more than 5 years ago | (#26337013)

After all these years, I can't believe there's no +5 "Masturbation Reference" mod. C'mon Rob!

Re:Oh no! (0)

Anonymous Coward | more than 5 years ago | (#26337455)

Larry Wall, is that you?

Re:Oh no! (-1, Redundant)

Anonymous Coward | more than 5 years ago | (#26337429)

[head explodes]

...

Re:Oh no! (4, Funny)

Al Al Cool J (234559) | more than 5 years ago | (#26337559)

What about:

an electric sander to provide a rhythmic vibration to the bottom of the stick

Do not try this at home!

Jerks? (1, Interesting)

Anonymous Coward | more than 5 years ago | (#26336901)

How do you time a jerk? What exact activity of said jerk would you measure? I mean, I don't like mean people, but how will they power the space elevator? This is more ridiculous than the buttered bread on cat's back train to Chicago.

Re:Jerks? (1)

OrangeTide (124937) | more than 5 years ago | (#26336923)

Try it as a verb. Pretty sure that all slashdotters carefully time their jerks late at night.

Good (0)

Anonymous Coward | more than 5 years ago | (#26336913)

I've had it with jerks sitting around doing nothing, it's about time they do something useful.

Hmmmmm. (5, Funny)

Oloryn (3236) | more than 5 years ago | (#26336921)

Y'know, this just might work, seeing that there is such a plentiful supply of jerks on the planet.

Re:Hmmmmm. (1)

ScrewMaster (602015) | more than 5 years ago | (#26336967)

Y'know, this just might work, seeing that there is such a plentiful supply of jerks on the planet.

Yes, but as the summary states, it's all in the timing. We'll have to leave this up to the professionals: where are The Three Stooges when you need them?

Re:Hmmmmm. (4, Funny)

R3d M3rcury (871886) | more than 5 years ago | (#26337163)

Unfortunately, it's been my experience that most jerks have a horrible sense of timing, so they may not be all that useful

Re:Hmmmmm. (4, Funny)

rhizome (115711) | more than 5 years ago | (#26337521)

Y'know, this just might work, seeing that there is such a plentiful supply of jerks on the planet.

Since the Bush Administration is about to be unemployed, this timing is fortuitous indeed.

Just give up already... (-1, Redundant)

Red Samurai (893134) | more than 5 years ago | (#26336933)

Why is everyone so obsessed with this terrible idea? Even if we got it to work, there's no way we'd be able to afford the maintenance and energy costs. It just isn't viable.

Re:Just give up already... (3, Funny)

Anonymous Coward | more than 5 years ago | (#26336985)

With criticism like this, I would say this idea is destined to succeed.

I call bullshit (4, Insightful)

deft (253558) | more than 5 years ago | (#26337009)

"Why is everyone so obsessed with this terrible idea? Even if we got it to work, there's no way we'd be able to afford the maintenance and energy costs. It just isn't viable."

This guy just copied and pasted his post. I found this same post about plane flight, the space shuttle, the hubble, the mars rover, and the lightbulb.

ok, i lied, but you get the point :)

Re:I call bullshit (1)

moniker127 (1290002) | more than 5 years ago | (#26337113)

Damn it edison! You with your sorcery! Damn it wright brothers, you're going to get yourself killed! Damn it NASA, you will be over budget off schedule! (works for three).

Re:I call bullshit (0)

Anonymous Coward | more than 5 years ago | (#26337147)

.....but they were right about the space shuttle. It wasn't viable (or safe) as built.

Re:I call bullshit (1, Funny)

Anonymous Coward | more than 5 years ago | (#26337149)

They laughed at Edison. They laughed at the Wright Brothers. But they also laughed at Bozo the Clown.

Re:Just give up already... (0)

Anonymous Coward | more than 5 years ago | (#26337031)

Something that uses orders of magnitude less power than rockets is not viable? We'd build space elevators today if we knew how to work carbon nanotubes. It's just that much more efficient. As for the maintanence, it's manageable if we build multiple space elevators so we could have redundancy, a platform to work on the elevators from, etc.

New Countdown (0, Funny)

Anonymous Coward | more than 5 years ago | (#26336935)

Will there be a new countdown system?

5..4..3..2..1..JERK OFF!

Re:New Countdown (2, Funny)

ExploHD (888637) | more than 5 years ago | (#26337053)

Suppose that the elevator's cables are in a ring formation, does that mean we'll have a circle jerk?

So for a circular orbit you use circle jerks? (-1, Redundant)

Anonymous Coward | more than 5 years ago | (#26336947)

Those crazy scientists finally found a use for everything.

Sign Me up I will go! (0)

Anonymous Coward | more than 5 years ago | (#26336955)

#!/usr/bin/perl require "Echo.pm";
Jeez I knew it could make ya blind.. but space?

Now I can tell mom all that practice in the bathtub was good for something!

Slashdot: Setup lines for bad jokes... (5, Funny)

istartedi (132515) | more than 5 years ago | (#26336965)

Slashdot: Setup lines for bad jokes. Stuff that splatters.

Re:Slashdot: Setup lines for bad jokes... (0)

Anonymous Coward | more than 5 years ago | (#26337215)

Jerk.

Re:Slashdot: Setup lines for bad jokes... (0, Offtopic)

rfreedman (987798) | more than 5 years ago | (#26337281)

At the risk of _being_ a jerk.....

The commonly used phrase is "for all intents and purposes", and please, google "begs the question".

Re:Slashdot: Setup lines for bad jokes... (0)

Anonymous Coward | more than 5 years ago | (#26337453)

Was this supposed to be a reply to a different comment?

Re:Slashdot: Setup lines for bad jokes... (5, Funny)

Bromskloss (750445) | more than 5 years ago | (#26337503)

please, google "begs the question".

Right away, sir. To whom shall I send the results?

Cool (1)

QuietYou (629140) | more than 5 years ago | (#26336987)

I'll file "Jerk powered space-elevators" right next to "Anger powered jetpacks".

http://www.legorobotcomics.com/?id=68 [legorobotcomics.com]

Your mom (-1, Troll)

Anonymous Coward | more than 5 years ago | (#26337003)

Your mom is a carefully timed jerk.

I don't think this will work (3, Insightful)

Cthefuture (665326) | more than 5 years ago | (#26337105)

Consider how much energy it would take to move this massively long cable. There is no way in hell that is going to be efficient. You're going to be wasting a massive amount of energy as you move the entire cable the whole time the thing is climbing.

To the naive this approach seems workable because it looks simple. The fact is that it takes a certain amount of energy to do things and this is probably a very poor method that will become quite obvious at the scale we are talking about. In this house we obey the laws of thermodynamics and all that...

Then you have to consider the wear and tear on the mechanical parts, especially that really expensive long cable into space. This just seems like a bad idea all around.

Re:I don't think this will work (3, Insightful)

SethJohnson (112166) | more than 5 years ago | (#26337235)

Your point about the energy is spot-on. Additionally, this concept totally ignores the orbiting anchor for the space elevator. For every 'yank' performed on the cable, you pull the anchor lower in orbit. The anchor then has to reposition itself USING ENERGY. Probably rocket fuel, I'd imagine. Either that, or the anchor releases the cable to allow it to go downwards, then has to pull it up again. That's the "lift" for the elevator- the pulling up of the cable.

Seth

Re:I don't think this will work (3, Informative)

seanadams.com (463190) | more than 5 years ago | (#26337445)

For every 'yank' performed on the cable, you pull the anchor lower in orbit.

This is wrong - the transmitting end (ground station) can and would "push" just as readily as it would "pull". Then the vehicle would absorb this wavefront as it converts it to potential energy, such that there is very little energy propagating past it up the cable. You have to consider that this cable is very very long, and at such a scale it becomes more like a slinky, or a piece of string with a cup on each end.

Re:I don't think this will work (2, Informative)

Q-Hack! (37846) | more than 5 years ago | (#26337567)

Your assuming that the cable is rigid... most designs for this that I have seen are usually a ribbon/cable that can flex in either one or two dimensions. This would mean that you could not push it, only pull.

Also, we are having enough trouble creating a cable that can withstand the incredible force required for a simple tether... now they want to add vibration on purpose? This has disaster written all over it.

Re:I don't think this will work (2, Insightful)

Tubal-Cain (1289912) | more than 5 years ago | (#26337545)

If you put the anchor far enough out there that centripetal force pulls it away harder than the base station's vibrations pull it, it should work.

Re:I don't think this will work (4, Insightful)

seanadams.com (463190) | more than 5 years ago | (#26337261)

Consider how much energy it would take to move this massively long cable. There is no way in hell that is going to be efficient. You're going to be wasting a massive amount of energy as you move the entire cable the whole time the thing is climbing.

That was my initial reaction too, but then I thought about it for a minute and it occurred to me that this is probably analogous to an electrical/RF transmission line. The cable has some (very low) impedance in the sense that it is quite rigid, but it's not zero. You're not "moving the whole cable" by jerking on it, what you're really doing is transmitting a wavefront along a medium. Provided the whole system is impedance matched, nearly all the power could be delivered to the vehicle.

I'm not sure how well this holds up when you consider internal friction of the cable and other inefficiencies, but I wouldn't dismiss it off hand. The simplicity of it in that it works purely on kinetic energy makes it pretty intriguing. It may even have applications besides a space elevator.

Re:I don't think this will work (2, Interesting)

SixAndFiftyThree (1020048) | more than 5 years ago | (#26337535)

Some things you should consider:

1. you'll need either high amplitude or high frequency to get up to a useful speed

2. the design of a space elevator is already constrained by tension in the cable, and this scheme will lead to more tension, plus risk of fatigue fracture

3. how to power more than one vehicle at a time

4. what to do about the person who confuses vibration with jerking

Re:I don't think this will work (1)

Plekto (1018050) | more than 5 years ago | (#26337649)

Consider how much energy it would take to move this massively long cable. There is no way in hell that is going to be efficient. You're going to be wasting a massive amount of energy as you move the entire cable the whole time the thing is climbing.
****

If the entire system is powered from the ground, we have essentially unlimited power available. Just build a couple of reactors nearby to power it exclusively. The major problem with getting materials up to space isn't a lack of power, it's a lack of space to hold the fuel. And, of course, the safety factor. Nearly one in every 30 launches still is a failure (3% even with the best technology). This appears to do away with all of that. At least for the trip up.

http://www.g2mil.com/safety.htm [g2mil.com]
It's horribly dangerous to try to get up to and back from space. Speed isn't the real issue here.

http://www.nasa.gov/centers/kennedy/about/information/shuttle_faq.html [nasa.gov]
It costs 450 million to do a single Shuttle launch. That buys a LOT of electricity or other fuel down on the ground to power a space elevator. Honestly, I can't imagine how much fuel that would buy. Dozens? Hundreds of climbs? It's worth exploring this technology in any case, as the potential long term savings is huge.

Vibration (4, Funny)

phrostie (121428) | more than 5 years ago | (#26337145)

although i like the beauty of it's simplicity, wasn't vibration in the tether already a problem?

it's like a 300 mile long guitar string with a slide going up and down.

one of these days we'll have a /. story about the music of the space elevator.

Re:Vibration (0)

Anonymous Coward | more than 5 years ago | (#26337533)

more like a 60,000 mile long guitar string. Now you're thinking big.

Re:Vibration (1)

Tubal-Cain (1289912) | more than 5 years ago | (#26337577)

Sounds to me like this is turning a problem into a solution.

Carefully Timed Jerks Could Power Space Elevator (1)

Shuh (13578) | more than 5 years ago | (#26337161)




C'mon now. I know hourly workers in the high tech industry can be a pain sometimes, but that's no reason to slander them!

100,000-km (4, Funny)

DanWS6 (1248650) | more than 5 years ago | (#26337205)

That would take a while to get up. Then again, with enough jerking I'm sure anything is possibly.

It is moot (0, Troll)

DaveV1.0 (203135) | more than 5 years ago | (#26337217)

Considering that it appears that the space elevator will not work from a suspension point of view, isn't it kind of moot to think about how to power the thing?

In Soviet Slashdot (0)

fishthegeek (943099) | more than 5 years ago | (#26337241)

jerks power you!

Interesting summary but... (1)

ComputerPhreak (1057874) | more than 5 years ago | (#26337287)

Interesting summary but for some strange reason after I finished reading it I felt like I had just finished watching an Enzyte commercial...

The Headline (1)

D Ninja (825055) | more than 5 years ago | (#26337293)

Carefully timed jerks could power space elevator? Hmmm...I'm not too sure about that. I've been to frat parties and those guys can't even play beer pong all that well.

Jerking the wrong end... (5, Funny)

werdnapk (706357) | more than 5 years ago | (#26337305)

Jerking at the base is ok, but jerking at the top works much better.

In old country... (0, Redundant)

DreadfulGrape (398188) | more than 5 years ago | (#26337307)

...space elevator jerks you!

Manditory Masterbation Jokes (1)

itsybitsy (149808) | more than 5 years ago | (#26337327)

Hey, what kind of comment do you think this is???

Oh yeah, a towering jerk is an unraveled circle jerk?

Testosterone supplements anyone?

They have a new term for, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, Jerk Off!

Ok these are really bad jokes but don't cry over spilled milk.

ObFarSide (3, Funny)

HiVizDiver (640486) | more than 5 years ago | (#26337335)

Jerks. [photobucket.com]

We need to get Steve Jobs on this right away. (4, Funny)

The Breeze (140484) | more than 5 years ago | (#26337339)

After all, he is a jerk with an impeccable sense of timing.

Mod me offtopic, but... (1)

SanityInAnarchy (655584) | more than 5 years ago | (#26337341)

Ok, that's a cool little video clip... Notice how the ad in front of it was longer than the clip itself, though?

OMGWTFBBC?

Just finished grading Intro Physics exams... (0)

goodmanj (234846) | more than 5 years ago | (#26337343)

...and I find this bit of idiocy.

To make the elevator car climb along the cable, we must accelerate the cable downward with an acceleration exceeding g=9.8 m/s2, so that it descends faster than the car falls.

So the article's answer to the problem of providing a force of mass-of-car * gravity to the elevator car is to provide a force of mass-of-cable * gravity to the cable.

Congratulations, you just made the problem a million times harder.

Well... (1)

polyomninym (648843) | more than 5 years ago | (#26337355)

at least this seems to work in politics. *snicker*

The converse is an ultrasonic motor (0)

Anonymous Coward | more than 5 years ago | (#26337361)

strength of cable is the problem.. (0)

Anonymous Coward | more than 5 years ago | (#26337363)

the elevator lift mechanism is a secondary problem when compared to the seemingly insurmountable material science problem. Namely, there is no material in the world with a high enough strength to weight ratio to sustain a space elevator!!!

Great Idea! (0)

Anonymous Coward | more than 5 years ago | (#26337367)

Finally we have a way of recycling old Politicians

Carefully time jerks (1)

DrugCheese (266151) | more than 5 years ago | (#26337381)

power Slashdot

Time... (1)

boowax (229348) | more than 5 years ago | (#26337383)

...to get a better watch

Don't count on them (1)

jvollmer (456588) | more than 5 years ago | (#26337415)

>Carefully timed jerks could power space elevator

In my experience, jerks don't even listen to instructions - I wouldn't count on them to carefully time anything.

If it's not Consolidated Lint, it's just fuzz!

dirty minds prevail (1)

Ogive17 (691899) | more than 5 years ago | (#26337421)

For a moment I wasn't sure if I was reading /. or penthouse...

...providing carefully timed jerks of the cable at its base...
...with their bristles pointing downwards allowing the climber assembly to slide upward along the broomstick as it moved slightly downward, but grip it as it moved slightly upward...

Looooong cable (0)

Anonymous Coward | more than 5 years ago | (#26337423)

a 100,000-km long tether anchored to the Earth.

The space elevator cable is a quarter of the distance from the earth to the moon? 8 times the diameter of the earth?

Sign Me up Ma! All that practice was for somethin' (5, Funny)

I_Can't_Fly (1442225) | more than 5 years ago | (#26337441)

2:00 A.M Somewhere on a lonely street near the outskirts of Des Moines.

Mom: "Hello"
Me: "Mom, uh mom, I know it is late but.."
Mom: "Oh hi honey..."
Me: "Hey Mom, do you remember those sincere times when you tearfully told me to quit playing with myself and stop using so much water back in the day and how no good would come of it?"
Mom: "Honey.. It was in your best interest..."

Pause for dramatic effect, a little static on the line, the sound of dad snoring and breathing heavy..

Me: "Mom, NASA just called. They need an expert. I am going to space Momma!..."
Mom: "Oh Darling! I never knew you would succeed like this.. Your father will be so proud! What...what time is it? 2 o'clock?">BR> *rustling covers* *wierd pause* Space? I thought you were happy bagging groceries...
Me: "Well they needed an expert. That's what us experts do. I just got a call on the emergency line. I am gonna have step up training, and need to get started. Tell Dad I love him Mah. Tell dad I love him. If I don't make it.. you can have the cats..."
Mom:" What will you be doing again?"

In case of power failure (1)

Bromskloss (750445) | more than 5 years ago | (#26337449)

it might be necessary to power manually: "You, jerk!" "What?! I didn't cut the power!"

But will it scale? (2, Insightful)

merreborn (853723) | more than 5 years ago | (#26337463)

It's one thing to vibrate a broomstick in that manner, and quite another to do so with a 36,000 km space elevator. No matter what material you're using, you're looking at a very large mass; wikipedia estimates "a minimal, very low payload space elevator 'seed ribbon' could have a mass of at least 18,000 kg." -- or just shy of 20 tons. For hauling passengers and goods, you'll need much more. Now, we're talking about accelerating and decelerating this mass of at least 20 tons multiple times per second.

Think about that. We're talking bringing something the weight of a big-rig, accelerating it to a decent speed, and then bringing it back to a stop in a fraction of a second. That requires incredible force. Now, think about the time it takes to accelerate a big rig to highway speeds, and then bring it to a full stop. Now, remember, that's the *minimum* mass we're dealing with. A full-scale elevator is likely to be quite a bit heavier. For another point of reference, the 250 ton commuter train I ride to work every day, if it applies full breaking force in an emergency situation, takes roughly 2,500 feet to come to a complete stop.

And not only do you have to do that, you have to not shake the thing apart in the process. And on top of that, you have to do that without exerting too much force on your passengers; humans can't handle much more than a few Gs.

The other glaring hole is the brush bristles. It's one thing for a coarse brush to support a few ounces of wood, and quite another for it to support a multi-ton cargo container while undergoing rapid acceleration multiple times per second.

Has anyone done the math necessary to show that this idea can actually scale? Because at first blush, it sounds ridiculous.

So... (2, Funny)

pondermaster (1445839) | more than 5 years ago | (#26337537)

...from take offs to jerk offs? Evolution!

Don't you hate it (1)

Bromskloss (750445) | more than 5 years ago | (#26337595)

when you make a jerk tick?

Yeah, I'd much rather have them manually triggered than timed.

So if we harnessed all the terrorists (1)

WillAffleckUW (858324) | more than 5 years ago | (#26337683)

So, if we harnessed all the terrorists and just convinced them that delivering "jerks" to the space elevator would damage it, then they wouldn't destroy it with their explosions, but could propel it?

But ... what if they happened to fall off the side during this action or their makeshift ropes broke and killed people?

A space elevator might work fine on the moon, and maybe even on Mars, but I can't think of a safe place to build one on Earth, and that's due to vulnerabilities that someone will want to expose.

Expecting rational behavior from irrational people is the classic definition of insanity.

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