5 ms·

Do the math exercise with him for how much volume 2 miles of string takes up

Flammy 3y ago
Do the math for the weight of a string 2 miles long. Then take a look at how much weight a string can hold up. Then you're ready to be taking on space elevators
- someweirdperson 3y ago
  > Do the math for the weight of a string 2 miles long. There are materials that are a bit more dense and others a bit less dense than water. It should be possible to craft a string with a "weight" of zero, when submerged.
- deleted 3y ago
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- flangola7 3y ago
  Weight and mass are not the same.
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thehappypm 3y ago
Seems doable to be honest—huge spools of undersea cables are deployed on ships all the time. A spool 20 feet wide has a circumference of ~60 feet, and 3 miles of cable is ~15,000 feet, so 250 loops around the spool. Seems doable.
madaxe_again 3y ago
You’re aware of ROVs? They usually communicate with an umbilical, which is considerably fatter than a piece of string. It’s deployed from the surface vessel, not from the ROV. The same could just as easily apply.
rhyst 3y ago
Using 9mm diameter semi static climbing rope as an example. For volume: Volume of 4km of rope is 0.009^23.144000 = 1.02m^2 which seems like an amount that would fit on a large spool on a ship. For weight: rope itself weighs about 60g per meter so 0.06*4000=230kg of rope. It has a breaking strength of 22kN, which is roughly 2000kg static load. Given everything is probably roughly neutrally buoyant seems like enough. Not saying its practical but it seems like the actual volume/weight of rope would not be a problem.
- gcanyon 3y ago
  I haven't checked your math, but your volume should have a ^3 on it, not a ^2
J_cst 3y ago
Couldn't it be that the spool with the rope floats on the surface and only one end of it is connected to the submarine with a snap hook? It may work and saves me the maths exercise lol :)
bagels 3y ago
String would not work, it's not strong enough. Steel cable would likely work. Depends on tensile strength of the material.

Do the math for the weight of a string 2 miles long. Then take a look at how much weight a string can hold up. Then you're ready to be taking on space elevators

someweirdperson 3y ago
> Do the math for the weight of a string 2 miles long. There are materials that are a bit more dense and others a bit less dense than water. It should be possible to craft a string with a "weight" of zero, when submerged.
deleted 3y ago
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flangola7 3y ago
Weight and mass are not the same.

deleted 3y ago

[deleted]

thehappypm 3y ago

Seems doable to be honest—huge spools of undersea cables are deployed on ships all the time. A spool 20 feet wide has a circumference of ~60 feet, and 3 miles of cable is ~15,000 feet, so 250 loops around the spool. Seems doable.

madaxe_again 3y ago

You’re aware of ROVs? They usually communicate with an umbilical, which is considerably fatter than a piece of string. It’s deployed from the surface vessel, not from the ROV. The same could just as easily apply.

rhyst 3y ago

Using 9mm diameter semi static climbing rope as an example. For volume: Volume of 4km of rope is 0.009^23.144000 = 1.02m^2 which seems like an amount that would fit on a large spool on a ship. For weight: rope itself weighs about 60g per meter so 0.06*4000=230kg of rope. It has a breaking strength of 22kN, which is roughly 2000kg static load. Given everything is probably roughly neutrally buoyant seems like enough. Not saying its practical but it seems like the actual volume/weight of rope would not be a problem.

gcanyon 3y ago
I haven't checked your math, but your volume should have a ^3 on it, not a ^2

J_cst 3y ago

Couldn't it be that the spool with the rope floats on the surface and only one end of it is connected to the submarine with a snap hook? It may work and saves me the maths exercise lol :)

bagels 3y ago

String would not work, it's not strong enough. Steel cable would likely work. Depends on tensile strength of the material.