5 ms·

This sounds pretty amazing, but I also have no real idea what I'm reading. > A modest numerical analysis is carried out on a set of example configurations, fin

This sounds pretty amazing, but I also have no real idea what I'm reading. > A modest numerical analysis is carried out on a set of example configurations, finding total energy requirements four orders of magnitude smaller than the solar mass. Can someone smarter than me say whether this is within the (reasonable-ish?) realm of matter-antimatter reactions? Like Star Trek!? 4 orders of magnitude less than the sun's mass does sound like a positive development - still a lot but less than before, right?

perl4ever 5y ago
I think that's like 1/10th of Jupiter. Wasn't there a space drive that needed negative mass of about one Jupiter?
akiselev 5y ago
The first paper detailing the Alcubierre drive required exotic particles with negative mass to achieve a spacetime bubble (soliton) which is an issue since particles with negative mass have never been observed. The next big paper figured out how to do it with regular matter and it brought the requirements down to the energy equivalent of four solar masses. That would put it squarely into the realm of a type II or III civilization (1 solar mass worth of energy is in the same ballpark as the amount a star puts out over its entire lifetime). If this paper is correct, it brings the requirements down to a tenth of Jupiter's mass, which is probably somewhat achievable for a type I civilization. The Enterprise would be the size of a small gas giant to hold an equivalent amount of matter and antimatter. It'd be able to enter warp once.
- TrevorJ 5y ago
  Would be interesting if paired with the harvesting of energy from a black hole. It is theorized that you can do this 'remotely' by slingshotting a laser around a black hole. This functions the same way a normal gravity assist does, except in this case it's photons, and not spacecraft. Shoot a laser around one side of a black hole, it returns to you around the other side, but at a higher energy wavelength. In this way, perhaps you would not need to store the energy needed 'in' your spacecraft, but instead in a black hole that is some safe distance away.
  - AnimalMuppet 5y ago
    If your laser beam doesn't spread so far that you can't harvest enough energy to be net positive, then the black hole is not going to be a safe distance away.
    - TrevorJ 5y ago
      I supposed the term 'safe' is pretty relative in this case.
- samplatt 5y ago
  >It'd be able to enter warp once. ...why once? Are you assuming all matter+antimatter is destroyed in the single trip? If you have x amount of critical material, could you not warp for half the distance of the "fuel" in your "tank" and then come back? IANAPhyicist. I'm assuming that if we have the ability to contain and harvest energy from a matter/antimatter reaction then we also have the ability to stop it & start it at will.
  - emeraldd 5y ago
    IANAPhyicist but if I understand what’s being said correctly the amount of energy necessary to create the warp bubble in the first place, would require converting something roughly the mass of Jupiter. So you’d twice that to “come back”. It sounds much more like surfing a wave that something that get’s turned on or off.
  - akiselev 5y ago
    The way I said it is misleading for the sake of brevity. That's a small gas giant worth of matter and antimatter to power a warp drive for a ship so small that it's not even worth calculating its mass relative to the fuel. The entire mass of Mount Everest is something like 0.00000000001% of the mass you'd need to create the warp bubble. If the ship was in the center of the fuel, it'd be crushed into something so dense it'd resemble the earth's core. Best case scenario we're talking a mass effect style planetary megastructure that forms a warp bubble around a ship and shoots it with just enough "momentum" for the warp bubble to fail right at the destination.
- ClumsyPilot 5y ago
  The scale is all wrong. A type 1 civilisation is, rougly, civilisation that covered earth with solar panels. This drive needs a planet's mass in the form of pure energy, that's a totally different league. Also you dint have a planet to live on after that. This is a major stretch for even a type 2
beervirus 5y ago
> 4 orders of magnitude less than the sun's mass does sound like a positive development - still a lot but less than before, right? That’s something like 10^43 joules. Still not achievable anytime soon.
- XorNot 5y ago
  Progress in warp field research though has resulted in significant energy reductions though - everytime a more efficient formulation is found its a step on the way to a possible practical system. After all, if it was easy then everyone would be doing it.
  - TrevorJ 5y ago
    We've definitely achieved progress on this sort of scale with transistor density. Not that it's at all similar, but it's interesting to observe that we do seem to be able to occasionally bring things within our grasp that would have sounded absolutely silly a lifetime ago.
    - WJW 5y ago
      Did we though? From milli- to nanometers is "only" 9 orders of magnitude. 10^43 J is about 30 order of magnitude from practical application than the first transistor was. Also, warp bubble generation might be more like electric motors, which have gone from ~2% to ~95% efficiency and will never ever surpass 100%.
  - mcswell 5y ago
    "if it was easy then everyone would be doing it": And, I suppose, we'd see them. Little green men, I mean.
    - mathw 5y ago
      Well that supposes that they currently exist, that they're close enough and that they want to come here. Maybe it is feasible to build an FTL engine, but maybe it can only feasibly go at like 4c. That doesn't make it very easy to drop by our solar system and have a look at what all that radio noise means, even if anybody's heard it.
tobmlt 5y ago
The paper also gives recommendation for a starting point for some finite element modeling and optimization for field configurations requiring less energy than that, improving other properties and such. (FEM modeling to search the irrotational sector of the Hamiltonian constraint...) They mentioned this with a fair amount of enthusiasm - sounding like there may be room to optimize. I wonder what the gradients look like.
ginko 5y ago
The Sun has a mass of about 2x10^30 kg. 4 orders of magnitude smaller would be 2x10^26 kg which is somewhere between the mass of Saturn and Neptune. So turn one of those into energy and you're good to go.

perl4ever 5y ago

I think that's like 1/10th of Jupiter. Wasn't there a space drive that needed negative mass of about one Jupiter?

akiselev 5y ago

The first paper detailing the Alcubierre drive required exotic particles with negative mass to achieve a spacetime bubble (soliton) which is an issue since particles with negative mass have never been observed. The next big paper figured out how to do it with regular matter and it brought the requirements down to the energy equivalent of four solar masses. That would put it squarely into the realm of a type II or III civilization (1 solar mass worth of energy is in the same ballpark as the amount a star puts out over its entire lifetime). If this paper is correct, it brings the requirements down to a tenth of Jupiter's mass, which is probably somewhat achievable for a type I civilization. The Enterprise would be the size of a small gas giant to hold an equivalent amount of matter and antimatter. It'd be able to enter warp once.

TrevorJ 5y ago
Would be interesting if paired with the harvesting of energy from a black hole. It is theorized that you can do this 'remotely' by slingshotting a laser around a black hole. This functions the same way a normal gravity assist does, except in this case it's photons, and not spacecraft. Shoot a laser around one side of a black hole, it returns to you around the other side, but at a higher energy wavelength. In this way, perhaps you would not need to store the energy needed 'in' your spacecraft, but instead in a black hole that is some safe distance away.
- AnimalMuppet 5y ago
  If your laser beam doesn't spread so far that you can't harvest enough energy to be net positive, then the black hole is not going to be a safe distance away.
  - TrevorJ 5y ago
    I supposed the term 'safe' is pretty relative in this case.
samplatt 5y ago
>It'd be able to enter warp once. ...why once? Are you assuming all matter+antimatter is destroyed in the single trip? If you have x amount of critical material, could you not warp for half the distance of the "fuel" in your "tank" and then come back? IANAPhyicist. I'm assuming that if we have the ability to contain and harvest energy from a matter/antimatter reaction then we also have the ability to stop it & start it at will.
- emeraldd 5y ago
  IANAPhyicist but if I understand what’s being said correctly the amount of energy necessary to create the warp bubble in the first place, would require converting something roughly the mass of Jupiter. So you’d twice that to “come back”. It sounds much more like surfing a wave that something that get’s turned on or off.
- akiselev 5y ago
  The way I said it is misleading for the sake of brevity. That's a small gas giant worth of matter and antimatter to power a warp drive for a ship so small that it's not even worth calculating its mass relative to the fuel. The entire mass of Mount Everest is something like 0.00000000001% of the mass you'd need to create the warp bubble. If the ship was in the center of the fuel, it'd be crushed into something so dense it'd resemble the earth's core. Best case scenario we're talking a mass effect style planetary megastructure that forms a warp bubble around a ship and shoots it with just enough "momentum" for the warp bubble to fail right at the destination.
ClumsyPilot 5y ago
The scale is all wrong. A type 1 civilisation is, rougly, civilisation that covered earth with solar panels. This drive needs a planet's mass in the form of pure energy, that's a totally different league. Also you dint have a planet to live on after that. This is a major stretch for even a type 2

beervirus 5y ago

> 4 orders of magnitude less than the sun's mass does sound like a positive development - still a lot but less than before, right? That’s something like 10^43 joules. Still not achievable anytime soon.

XorNot 5y ago
Progress in warp field research though has resulted in significant energy reductions though - everytime a more efficient formulation is found its a step on the way to a possible practical system. After all, if it was easy then everyone would be doing it.
- TrevorJ 5y ago
  We've definitely achieved progress on this sort of scale with transistor density. Not that it's at all similar, but it's interesting to observe that we do seem to be able to occasionally bring things within our grasp that would have sounded absolutely silly a lifetime ago.
  - WJW 5y ago
    Did we though? From milli- to nanometers is "only" 9 orders of magnitude. 10^43 J is about 30 order of magnitude from practical application than the first transistor was. Also, warp bubble generation might be more like electric motors, which have gone from ~2% to ~95% efficiency and will never ever surpass 100%.
- mcswell 5y ago
  "if it was easy then everyone would be doing it": And, I suppose, we'd see them. Little green men, I mean.
  - mathw 5y ago
    Well that supposes that they currently exist, that they're close enough and that they want to come here. Maybe it is feasible to build an FTL engine, but maybe it can only feasibly go at like 4c. That doesn't make it very easy to drop by our solar system and have a look at what all that radio noise means, even if anybody's heard it.

tobmlt 5y ago

The paper also gives recommendation for a starting point for some finite element modeling and optimization for field configurations requiring less energy than that, improving other properties and such. (FEM modeling to search the irrotational sector of the Hamiltonian constraint...) They mentioned this with a fair amount of enthusiasm - sounding like there may be room to optimize. I wonder what the gradients look like.

ginko 5y ago

The Sun has a mass of about 2x10^30 kg. 4 orders of magnitude smaller would be 2x10^26 kg which is somewhere between the mass of Saturn and Neptune. So turn one of those into energy and you're good to go.