Carefully Timed Jerks Could Power Space Elevator

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."

"jerks"

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

Re:"jerks"

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"

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?

Oh no!

providing carefully timed jerks of the cable at its base

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

Re:Oh no!

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!

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

Re:Oh no!

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

Hmmmmm.

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

Re:Hmmmmm.

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

Slashdot: Setup lines for bad jokes...

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

Re:Slashdot: Setup lines for bad jokes...

please, google "begs the question".

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

Vibration

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.

100,000-km

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

Jerking the wrong end...

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

We need to get Steve Jobs on this right away.

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

Sign Me up Ma! All that practice was for somethin'

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?"

Re:frist

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

Re:frist

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

Re:frist

Yeah? Well, I had sex with your wife!

Re:frist

His wife's in a coma...

Re:frist

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

This is slashdot

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

Re:frist

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

Are those crickets?

I call bullshit

"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 don't think this will work

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.