/sci/ - Science & Math

[Anonymous No.2289330]

Exactly how disastrous would it be if a space elevator somehow became uprooted or damaged in such a fashion that it was no longer mounted to the earth. Would it be more likely to hit the planet or would it be launched into space?

[Anonymous No.2289345]

It would wrap around the planet.

How much damage it would do depends on its mass.

[Anonymous No.2289348]

>>2289345
Why would it do that? Wouldn't it's inertia fling it into space?

[Anonymous No.2289351]

Fly an aircraft into it. 9-11 part 2

[Anonymous No.2289352]

>>2289330
Holy shit that would be bad.

But now I have this picture in my mind of terrorists attempting to crash a plane into a space elevator only to have the plane obliterated because of the elevators strength.

[Anonymous No.2289357]

>>2289352
>>2289351

Hivejack.

[Anonymous No.2289358]

The top half would be swung into orbit, it wouldn't all come down. You see this in Halo: ODST

[Anonymous No.2289363]

>>2289358
1) Video game.
2) Real world.

Please choose.

[Anonymous No.2289365]

1) A space elevator will be a very, very light tether that won't so much as damage a subdivision let alone devestate a planet.
2) Everything above the severed section of the tether will launch upward with the counterweight. Everything below will fall westward around the Earth.

[Anonymous No.2289366]

>>2289363
I wasn't citing it as a source, I simply said you see it happening in that game, if you're curious.

[Anonymous No.2289393]

>>2289363
I apologize.
Unfortunate, it's my only frame of reference to draw any 'reasonable' conclusion for such a hypothetical situation involving masses I've never encountered and materials that don't even exist yet.

What's yours?
Perhaps it will help me and others understand better the error of our ways.

[Anonymous No.2289394]

If it were severed at the base, the results would depend on the mass of the counterweight at the other end of the tether, but assuming the counterweight is significantly more massive than the tether the whole thing would just drift away.

The really bad situation is if the tether gets severed at the top, near the counterweight. The counterweight would drift away, but the tether would come crashing down to the surface. It would wrap around the planet two or three times, and by the end of that it would be doing serious damage when it hit the surface - the gravitational potential energy of even a very thin cable suspended 100,000km above the Earth's surface is huge.

[Anonymous No.2289408]

>>2289330
so you're assuming the elevator is tethered to the ground and extending upward, not tethered to the satellite and hanging down?

All that would happen is there would now be a 50-km strip of [material] scraping along the surface of the earth. Might cause some damage in towns.

[Anonymous No.2289409]

>>2289393
>>2289366
Wait... see, I would respond if I knew who the fuck was who.

Well, as you stated, the fact that we're dealing with things that don't even exist yet makes this a tad bit more difficult.

>>2289365
>>2289394
Methinks these two are on target.

Now, a good question would be: How the hell would we protect a space elevator from terrorist attacks, or even just military attacks?

[Anonymous No.2289417]

simple

blast the fuck out of anything flying inside a 20 mile no fly zone.

No exceptions. I don't care if you are the pope.

[Anonymous No.2289427]

>>2289358
http://www.youtube.com/watch?v=FZAHq_QADog

This looks barely like what I would imagine it looking like in real life, in fact, how they depict it, it doesn't look that harmless at all.

[Anonymous No.2289430]

since most of the tether is above the atmosphere, would it not just burn up as it de-orbits?

[Anonymous No.2289438]

hey...if you were at the front door and looked up, would it look curved like it's in the process of tipping over or straight as any regular building?

[Anonymous No.2289445]

>>2289393
Once again, I never cited it, I referenced it.

[Anonymous No.2289446]

scenario 1: obviously it would be shot into space if it were a true space tower, if it were large enough its upper end would have huge centrifugal forces because the earth is spinning and that would be like the how your hand feels a rush of blood when you twirl with your arms outstretched, so the only danger would be debris but that would only be relatively close to the breaking point also the upper end may experience g forces so strong that the cieling would pull on you making it appear that people on the top levels walk upside down
scenario 2: or if the "space elevator" merely gave a great view of the surrounding area so far unheard of but not yet into space its fall could crush buildings as far horizontaly as it is tall away
it could be easily calculated how high it would have to go but the hard part is making materials strong enough to support it

[Anonymous No.2289449]

>>2289409
>How the hell would we protect a space elevator from terrorist attacks, or even just military attacks?
1) Terrorists wouldn't have the means to destroying a space elevator. Any sort of elevator that would manifest itself in the foreseeable future wouldn't have much tension. The counterweight would be in approximate geosync orbit and thus would have little added velocity from severing the tether. The thrusters that got it into orbit would easily put it back into geosync. The last thing to be damaged would be the tether should terrorists try to sneak explosives onto an elevator car. Destroying the ground station would be similarly futile because the counterweight could be moved to reconnect the tether to a new ground station.
2) All space infrastructure is and will forever be relatively delicate. War will never happen because any space faring nation or metanational corporation with the capability to wage space warfare would have too much to lose.

[Anonymous No.2289454]

>>2289446
http://inhabitat.com/carbon-nanotubes-could-create-worlds-first-space-elevator/

[Anonymous No.2289476]

22,000 miles at a mere meter a second doesn't sound like a very fun ride all of a sudden

[Anonymous No.2289489]

>>2289476
That would take like a year right?
Travel would have to be leagues faster than that.

[Anonymous No.2289491]

>>2289476
"could change that — they claim that advances in carbon nanotubes could make it ‘theoretically’ possible"
"could" "they claim" "could make it 'theoretically possible"

[Anonymous No.2289502]

oh my no.
i didn't mean to suggest a 816 day round trip (assuming you never actually get OFF and ride back down straight away) was out of the realm of possibility...just it didn't seem so great to me personally all of a sudden

[Anonymous No.2289518]

>>2289408
It has to be under tension. There is no situation in which it would scrape along the ground. It is anchored at the bottom by the earth, and at the top by the counterweight above geo orbit. Any break and the two halves go in their opposite directions. Everything below geo (36,000 km) is pulling down. Everything above that altitude is pulling up.

[Anonymous No.2289522]

>>2289476
1 meter per second squared? Ugh, you're using miles. Fine.

ASSuming that all trips are to geostationary orbit, remember that it's a plane ride to infinite everything, not an elevator trip. There'll be in-flight meals. And naps.

1 minute: 1 mile up
5 minutes: 28 miles
10 minutes: 112 miles
1 hour: 4051 miles
94 minutes, turn-around time: 10000 miles
188 minutes, at geostationary orbit in 3.13 hours.

[Anonymous No.2289527]

>>2289522
And then you crash into the counter-weight at 3,000 mph, destroying it.

[Anonymous No.2289530]

>>2289522
That implies that it accelerates at 1 m/s for 5657 seconds then decelerates at the same rate. It can't go that fast bro. How fast?

int(x,x,0,5657) = 16000824 m/s

wtf?

[Anonymous No.2289534]

>>2289527
No, I clearly marked the turnaround time. Learn to read faggot, accelerate uniformly to half the displacement then decelerate along the same profile.

[Anonymous No.2289535]

88 feet per second...?
you joke, yes?

[Anonymous No.2289539]

yes. brilliant.
lets feed the people about to hit microgravity.

[Anonymous No.2289540]

>>2289527
Also that involves speeds of 16000 KM per SECOND.

[Anonymous No.2289551]

Jesus...who would WANT to eat or nap while pulling 2.75 G's?

[Anonymous No.2289553]

>>2289539
Quiet you with your flippant knowledge of anatomy. I'd expect a maximum feasible speed of about 1000 km/hr. Since that'll take all of 24 seconds to reach at 1 m/s^2
(24^2/2)/1000*60^2

then you can just say
"36000 km geostationary height"
"1000 km/hr"

Shit, 36 hours.

Maybe you can assume a much higher speed after the first 2 minutes.

[Anonymous No.2289571]

>>2289553
i would 'assume' the atmosphere is going to have something to say about moving out of the way of the car going up that fast...
I'd at least like to be somewhat reasonable about transit speeds here...

unless you also expect the car to go up a tube that's under a vacuum or something odd like that
then all okay by me i guess
*shrugs*

[Anonymous No.2289590]

>>2289551
There is no benefit to accelerating like that. Hell, no current transit systems can handle the speeds.

Standing still, you feel 1 g. Accelerating upwards at 1 meter per second squared, you'll feel about 1.1g. And after 24 seconds you're going 1000 fucking km/hr. That's twice as fast as current bullet trains. At 100% efficiency that's:

m*g*h per second
1kg * 9.81m/s^2 * 277.78 m/s = 2725 kg*m/s^2 per second
2725 N per second = 2.73 kW per kg

For me, that's 190 kW.

[Anonymous No.2289596]

>>2289571
No, the atmosphere isn't thick enough to matter. Let's say you go "only" bullet train speeds through the atmosphere. Above 11km, the air is 1/4 the density it was. Above 120km, it doesn't matter. Note that you'll be well past that within the first 15 minutes! But then you have another 35500 km to go.

[Anonymous No.2289602]

i never said squared.
i meant what i said.
1 meter a second.

however, i am revitalized.
it suddenly sounds way more fun than spending the 3 hour trip being smeared into a chair.

i hope sedation is an option. I truly do.

[Jennie !NSPcQQMvS. No.2289603]

Hi boys.

A space elevator would have a counter weight attached, possibly a meteor or something else. The meter would be moving slightly faster than its circular orbital speed at its height:

Anything above the split would go into an elliptical orbit, and anything below the split would come crashing down to earth. If a section is split from the bottom and the top and is at the right altitude above earth, it would go into an elliptical orbit around the earth with a considerably smaller apogee than it's upper half.

I want my space elevator. =\

[Jennie !NSPcQQMvS. No.2289606]

>>2289603
>meteor

>hint: she means asteroid.

[Anonymous No.2289608]

>>2289596
only a few minutes being broiled you say?

hmmmmm....


SOLD!

[Anonymous No.2289611]

If say, along one side there was a 1' x 22000 mile's worth of Solar panels, would this be a viable power station as well?

[Anonymous No.2289649]

>>2289611

161.9 petawatts?

you're damn tooting it could

[Anonymous No.2289657]

>>2289608
Good god man, learn to fucking think. Can you solve your way out of a wet paper bag?

A bullet train can go 500 km/hr. Those don't often burst into flames, do they? NO. So shut up.

In fifteen minutes at that speed you are ABOVE the ATMOSPHERE. It is beneath you, literally, and can no longer delay your journey. And if your space elevator elevator linear motor can beat a geriatric Otis machine from 1900 then you'll reach 500 km/hr in 16.5 seconds. After 15 minutes, you'd go to whatever safe speed it can manage, because you're above any frictional effects aside from the specially designed track it drives on.

[Anonymous No.2289661]

>>2289649
You can do the trig and see how little light this would get. An equatorial tower with solar panels? Admittedly the Earth's shadow would be a minor issue at that scale, but you spend half the time pointed at funny angles to the Sun.

[Anonymous No.2289700]

>>2289657

I'm thinking we ain't gonna be strapping a bullet train to one anytime soon.
It's gonna be more like a freaking ribbon with a bare bones metal box on it for cargo

to clarify my position, i once set a salad on fire by accident while cooking what passes for food for me

[Anonymous No.2289713]

>>2289700
>to clarify my position, i once set a salad on fire by accident while cooking what passes for food for me

That's got to be a good story. Share?

[Anonymous No.2289719]

does anyone actually have any idea what the temperature of the skin of a bullet train IS while it's in operation?

heat translates to wasted fuel/energy/whatever the hell you call it.
this, for the average person translates into wasted money. In to which no doubt, we will assume, some handsome sum they have already paid for..For a box to take one or two people at a time...and you have to wait for the box to come back before you can send anything else again.
peeps are going to save cost were they can, I assure you.

This accent you purpose is unsatisfactory though delightful in it's own way.

[Anonymous No.2289727]

i had to look up to make sure this wasn't /b/. im guessing anyone who's taken physics is just ignoring this thread lol. next question up for grabs: what if the sun grew four arms and started swimming through space, would it be hotter or colder than it is now?

[Anonymous No.2289729]

>>2289394
> It would wrap around the planet two or three times, and by the end of that it would be doing serious damage when it hit the surface - the gravitational potential energy of even a very thin cable suspended 100,000km above the Earth's surface is huge.

wait what, why the fuck would you need something that long just to get into orbit, I could see if you were needing to anchor the weight of hauling giant objects into space

[Anonymous No.2289732]

Aye..
a sad tale of failer and disapointment
grill...paper bag of salad nearby..
...a brief introduction to the curious concepts of kindling points, thermodynamics, wind vortexes, and toxic vapors...

lesson learned:
keep that rabbit food away for me, it's unhealthy

[Anonymous No.2289738]

>>2289732
Everything is unhealthy when you set it on fire.

[Anonymous No.2289743]

[Anonymous No.2289751]

>>2289743
>What's 2+2?
>4
>Sure is tard in here
>OMG don't derail the thread

[Anonymous No.2289761]

It happens in de mars trilogy, the first book, red mars.

Basically everything is destroyed where the space elevator wraps around the planet.

[Anonymous No.2289765]

>>2289743
>scenery isn't better than the average

[Anonymous No.2289768]

A space elevator will be too slow for humans to ride it. It would take days for the car to reach orbit and it would have to haul life support, living facilities, and food. Worst of all the slow ride would leave the passenger's dangerously exposed to radiation, especially in the Van Allen belt.

Space planes will carry humans and space elevators will carry cargo.

[Anonymous No.2289773]

that's much more reasonable i must agree

[Inurdaes !V1sPhobos. No.2289785]

Here is an idea I just thought up while stoned. Feel free to punch holes in it.

Would it be feasible to attach the solar panels to one end of the carbon nanotube (or whatever) ribbon that a previous anon suggested and then on the other attach a sort of continuous coil gun to rocket the elevator up at increasing speeds and then switching at the turn around point?

[Anonymous No.2289793]

>>2289727
dependent entirely on what direction the sun swims off to

[Anonymous No.2289811]

>>2289785
No offense but that is a stupid idea, you are a fucking idiot, and I hope you and everyone you have ever met dies a slow painful death before burning in Hell for eternity.

XOXO

[Inurdaes !V1sPhobos. No.2289822]

>>2289811
http://en.wikipedia.org/wiki/Ad_hominem

[снайпер No.2289835]

Space elevators are like thin paper ribbons.

They are extremely lightweight and extremely strong, however due to their low mass and high surface area, a collapsing space elevator will essentially act like a giant falling parachute in the atmosphere. I seriously doubt it would harm must of anything.

[Anonymous No.2289836]

>>2289822
http://en.wikipedia.org/wiki/Inurdaes_Is_Mad

[Anonymous No.2289860]

>>2289822
But I gave you hugs and kisses!

[Inurdaes !V1sPhobos. No.2289867]

>>2289836
Notrly.

[Anonymous No.2289971]

>>2289835
yeah...you're right...

i can't see how some odd 20000 miles of high strength, conductive, nearly indestructible ribbon piling up across interstates, water ways, and forests, while floating down through air traffic zones, and probably a couple of thunderstorms somewhere would cause to much trouble for anyone in particular.

Where do i sign?

[снайпер No.2289992]

>>2289971
I'm not saying it won't disrupt things, but you people seem to think it'll practically be a world ending event and destroy entire cities and kill hundreds of thousands of people.

But it wouldn't. The tether is a very thin, lightweight ribbon - any parts of the tether that enter the atmosphere at high speed are simply going to burn up, the parts that don't are going to float down like paper.

[Anonymous No.2290029]

>>2289971
Nobody would die. As soon as the tether is broken, let's say at the top, warnings would go out. Planes would stop flying over the equator. There would be plenty of time. After a few hours the fall of the ribbon will be accurately plotted and where it will hit for each of it's 6 and a half wraps around the Earth will be known with a great deal of accuracy. Some may be evacuated but most will just be told to stay indoors. The ribbon will cross roads and fall onto houses (causing little to no damage since it is virtually weightless). Crews will be dispatched to cut the tether where it crosses civilization and either recover portions of it or simply let it lie where it is for the rest of eternity.

Projected death toll: zero

[Anonymous No.2290069]

>>2290029
oh yes...indeed. I think i get it now.
not one giant chunk...just a shit load of tiny 3 or 4 mile lengths that can float like a mote of dust

i'm positive this highly conductive substance won't, say for example, land on any high tension power lines starting fires and electrocuting the fuck out of shit.
Fear not. It's all been plotted.

i can't wait for the weather girl to start forecasting this shit.

[Anonymous No.2290077]

>>2290069
>highly conductive
Nanotubes would only be conductive if they were doped... which they wouldn't be.

[Anonymous No.2290086]

>>2289971
>20000 miles
wut

[Anonymous No.2290092]

wait guys, why it has to be 20000+ miles long? Could we build it shorter?

[Anonymous No.2290093]

>>2290092
It has to reach past geosynchronous orbit.

[Anonymous No.2290100]

>>2290069
>float like a mote of dust
in the morning sky

[Anonymous No.2290140]

>>2290077
Gah?

We aren't going to use metallic nanotubes you say?

go on...

[Anonymous No.2290157]

>>2290140
>metallic nanotubes
You are Australian, aren't you...

[Anonymous No.2290158]

What do you think, where would be the best place to build elevator? I doubt they would place it near Washington, but if they place it in some deserted shithole cost of transporting things to that shithole would be enormous

[Anonymous No.2290161]

2 cables next to each other.

one is for the "freighttrains" up, one for the trains down.

screw time

[Anonymous No.2290162]

>>2290158
Ocean platform. There are regions of the Pacific Ocean that receive no precipitation.

[Anonymous No.2290172]

>>2290162

tsunami, anyone?

[Anonymous No.2290179]

>>2290172
Tsunamis don't do all that much damage in the open ocean. It'd be the earthquake that caused it that's the problem.

[Anonymous No.2290185]

>>2290172
>no precipitation
>tsunami
WTF AM I READING?!

[Anonymous No.2290211]

hurrrrr durrr

[Anonymous No.2290212]

Where would I poop? I need to poop on this elevator immediately.

[Anonymous No.2290217]

Would there be a problem with gravity while going down from space station to earth, i mean, with 20000 miles long trip we have to travel at big speeds, would gravity cause problems in human body while going down?

[Anonymous No.2290220]

my bet would be a platform in the equatorial Pacific.

A bare bones 'Sky Hook' could be done right this very second for a princely sum of roughly 10 billion dollars to hoist 5 tons every three days.

not to worry though, each ascending car will extrude a new ribbon on the way up so in about 2 1/2 years the load could exceed 20 tons per trip.

this is certainly more feasible and less technically challenging than for example, 13.5 billion for Millennium Tower or even the 20 billion projected to complete the Gibraltar Bridge project.
That fucker is going to chew up 1,600,000 kilometers of wire cables and sport towers twice as high as the world's tallest skyscraper.

[Anonymous No.2290225]

>>2290212
there won't be one.
weight is everything. You will be required to void your bowels before your trip.

[Anonymous No.2290228]

>>2290225
Astronauts don't eat before launches. It doesn't matter on a space elevator though because the trip will last days.

[Anonymous No.2290241]

>>2290220

look at this shit

http://www.worldinterestingfacts.com/human/top-10-most-expensive-projects-in-the-world.html

International space station- FUCKING 150 BILLION DOLLARS

We could build space elevator with that amount of money for sure!

[Anonymous No.2290243]

hey guys?


guys.

don't you remember what God did to us last time we tried to build stairs to heaven?

GUYS! TOWER OF BABEL! DON'T DO IT!

[Anonymous No.2290246]

>>2290243
We are going to build this elevator. We are going to build it, ride it to heaven, and then punch God in the face!

[Anonymous No.2290256]

>>2290225

But I don't have to go yet.

[Anonymous No.2290261]

that's a paddlin

[Anonymous No.2290263]

>>2290256
You go right now! Once we're on the elevator we're not stopping until we get there!

[Anonymous No.2290267]

>>2290243
We're bringing nukes this time.

[Anonymous No.2290269]

>>2290256
Hell's bells we have a time table to keep man!!
D:<

MEDIC! PREPARE AN ENEMA!

[Anonymous No.2290701]

You guys do realize that if a space elevator is constructed. It will take months to reach it's destination, right?

[Anonymous No.2290775]

>>2290701

Why?

[снайпер No.2291892]

>>2290241
No we couldn't.

I mean, we could, but it's space. Everything related to space gets its price jacked up. Then throw in politicians, pork barrels, and money grubbing corporations, and you set yourself up for trillions of dollars to build something that should only cost billions.

[Anonymous No.2293532]

>>2290775
You do realize it takes 6 months to go to Mars, right?

[Anonymous No.2293542]

>>2293532
Who said anything about Mars?

[Anonymous No.2293546]

>>2293532
>>2293532
>>2293532
>>2293532


you realize all figures are just estimates using the
figures of the speeds of rockets of the day. You can get to mars at any rate you just have to develop more powerful motors and more efficient braking systems.

[Anonymous No.2293553]

Hey guys, this weed is great, but where would the space elevator go?

[Anonymous No.2293564]

>>2293546
It's common knowledge you little shit. I bet you believe in God too.

[Colonel Coffee Mug !phJ7yIcs.Q No.2293574]

>>2293546

It's called a Hohmann transfer.

[Anonymous No.2293608]

>>2293553

Assuming the space elevator is on the equator, then if the center of gravity is above geocentric orbit it'll fly off, and if CG is below geocentric orbit it will fall. You can't just use the center of mass because the gravity depends on distance (you would need integrals). Geocentric orbit is about 22,000 miles so if the stations was at, for example, 25,000 miles but was super heavy compared to the elevator it could theoretically fly off if the base was destroyed. If the station was light compared to the elevator it would probably fall though.

[Anonymous No.2293610]

Space.

[Anonymous No.2293631]

>>2293608

same guy here just noting that this was assuming the BASE was destroyed. If the tether was destroyed next to the station the station would probably fly off (and the elevator might collapse under its own weight). If the tether was destroyed at a variable height you would need to do find the CG of the top with integrals and same with the bottom to see if it would collapse from its own weight. Also note the difference between CG and CM due to the variable gravity at different heights.

[Anonymous No.2293642]

>>2293608
Whatever you say dude, but I think you're responding to the wrong bro. Either that or you misundertood. I meant where would we build this space elevator to?

[Anonymous No.2293669]

http://en.wikipedia.org/wiki/Space_fountain

http://en.wikipedia.org/wiki/Launch_loop

http://en.wikipedia.org/wiki/Space_tether