5 ms·

If built using a 'plasma cutters oriented in a fibonacci spiral' this thing will only be able to cut through conductive materials. Additionally it will only be

If built using a 'plasma cutters oriented in a fibonacci spiral' this thing will only be able to cut through conductive materials. Additionally it will only be able to cut tunnels through material that don't require supporting walls. Not to be cynical, but this is 100% never going to see the light of day.

BurningFrog 4y ago
Tunnels typically don't see the light of day...
- robert_foss 4y ago
  lol
johnbcoughlin 4y ago
Based on a few minutes of Googling, I think you're thinking of a plasma cutter which creates a closed circuit through plasma, through a cut line in the conductive material, and back to the machine. This seems to be just torches which shoot out plasma at high temperature with no closed circuit required.
bigiain 4y ago
Awwww, don't spoil my idle apocalyptic speculation here. I've been wondering about what will happen when one of these carves itself a several kilometre long tunnel with molten rock/glass walls, then burns through into a very large aquifer which fills up the last kilometre or so of well above boiling point temp tunnel and surrounding rock. The superheated steam carrying out the pulverised rock tailings and condensing into at least some water, would make _the best_ high pressure water/abrasive cutter ever! If you reckon jet fuel can't melt steel beams, wait until you see a plume of steam/water/tailings cutting 1m circular boreholes straight through reinforced concrete buildings and freeway overpasses!
- Schroedingersat 4y ago
  Fun! But presumably you'd be pumping out the heat somehow so the entirety of your power cabling and waste cart system doesn't need to be made of inconel or tungsten. If half went into the ground somehow you'd need to boil about a tonne of water a second. The entrance to the tunnel sounds like it'd be fun with high pressure steam coming out at 100s of km/h. At least until the tunnel got long enough to dissipate the heat and it becomes a river of boiling mud. I wonder why they'd even need the carts. Edit: Whoops, I accidentally some orders of magnitude. It's 'only' 50kg/s of steam.
- tetha 4y ago
  Hm. I'm not sure if you'd end up with a geyser. Assume a chimney fire first. It's like a square pipe with 20cm - 30cm side length and - depending on how active it is - 200 - 400 degrees in there. That's already a condition you cannot introduce water into, because if water flash-boils into steam, it can expand it's volume by a factor of up to 1700. This can cause the chimney to turn into pretty much a pipe bomb, with the additional bonus that it's going to distribute the fire previously contained inside the chimney all over the house. And now we're talking about some much, much hotter situation (melting rock), pretty much contained (because that 1m hole isn't going to vent much) hitting ideally a large amount of water? That's not a geyser, that'll be a bomb. For example, one of the largest steam explosion in the US was caused by a pipe 0.61 meters in diameter with steam at 400 degrees C. It left some 4.5 meter crater.

BurningFrog 4y ago

Tunnels typically don't see the light of day...

robert_foss 4y ago
lol

johnbcoughlin 4y ago

Based on a few minutes of Googling, I think you're thinking of a plasma cutter which creates a closed circuit through plasma, through a cut line in the conductive material, and back to the machine. This seems to be just torches which shoot out plasma at high temperature with no closed circuit required.

bigiain 4y ago

Awwww, don't spoil my idle apocalyptic speculation here. I've been wondering about what will happen when one of these carves itself a several kilometre long tunnel with molten rock/glass walls, then burns through into a very large aquifer which fills up the last kilometre or so of well above boiling point temp tunnel and surrounding rock. The superheated steam carrying out the pulverised rock tailings and condensing into at least some water, would make _the best_ high pressure water/abrasive cutter ever! If you reckon jet fuel can't melt steel beams, wait until you see a plume of steam/water/tailings cutting 1m circular boreholes straight through reinforced concrete buildings and freeway overpasses!

Schroedingersat 4y ago
Fun! But presumably you'd be pumping out the heat somehow so the entirety of your power cabling and waste cart system doesn't need to be made of inconel or tungsten. If half went into the ground somehow you'd need to boil about a tonne of water a second. The entrance to the tunnel sounds like it'd be fun with high pressure steam coming out at 100s of km/h. At least until the tunnel got long enough to dissipate the heat and it becomes a river of boiling mud. I wonder why they'd even need the carts. Edit: Whoops, I accidentally some orders of magnitude. It's 'only' 50kg/s of steam.
tetha 4y ago
Hm. I'm not sure if you'd end up with a geyser. Assume a chimney fire first. It's like a square pipe with 20cm - 30cm side length and - depending on how active it is - 200 - 400 degrees in there. That's already a condition you cannot introduce water into, because if water flash-boils into steam, it can expand it's volume by a factor of up to 1700. This can cause the chimney to turn into pretty much a pipe bomb, with the additional bonus that it's going to distribute the fire previously contained inside the chimney all over the house. And now we're talking about some much, much hotter situation (melting rock), pretty much contained (because that 1m hole isn't going to vent much) hitting ideally a large amount of water? That's not a geyser, that'll be a bomb. For example, one of the largest steam explosion in the US was caused by a pipe 0.61 meters in diameter with steam at 400 degrees C. It left some 4.5 meter crater.