Idea for sci-fi/fantasy worldbuilding: (Similar to the shields from Dune)
Suppose there is a device, about the size of a small car, that produces energy (consuming some fuel, of course) with overall characteristics superior to modern gasoline engines (so e.g. produces 3x as much energy per kg of device, using fuel that weighs 1/3rd as much as gasoline per unit of energy it produces)
Suppose further—and this is the important part—that a byproduct of this device is the creation of a special “inertial field” that slows down incoming matter to about 50m/s. It doesn’t block small stuff, but any massive chunk of matter (e.g. anything the size of a pinhead or greater) that approaches the boundary of the field from the outside going faster than 50m/s gets slowed to 50m/s. The ‘missing’ kinetic energy is evenly distributed across the matter within the field. So if one of these devices is powered on and gets hit by a cannonball, the cannonball will slow down to a leisurely pace of 50m/s (about 100mph) and therefore possibly just bounce off whatever armor the device has—but (if the cannonball was initially travelling very fast) the device will jolt backwards in response to the ‘virtual impact’ a split second prior to the actual impact.T
his also applies to matter within the field. So e.g. if a bomb goes off inside the device, the sphere of expanding gas/plasma/etc. will only expand at 50m/s. W
hen an inertial field generator absorbs hits like this, it drains the energy produced (and converts it into waste heat within the device). So if a device is pummeled by enough cannonballs—or even enough bullets—it will eventually run out of fuel, and probably before then it will overheat unless it has an excellent cooling system.Fi
nally, the inertial field can be extended to cover larger areas. Perhaps some ceramic or metal or metamaterial works as a sort of extender, such that a field nearby will bulge out to encompass said material. Thus, a vehicle powered by one of these devices can also be built with this material lining the walls and structure, and therefore have the inertial field extend to protect the whole vehicle.Wh
at would be the implications of this tech, if technology is otherwise roughly where it was in the year 2010? (Not sure it is even coherent, but hopefully it is...)..
.First of all, you could make really tough airplanes and helicopters, so long as they fly slow. If they fly above 50m/s, they’ll start to overheat / drain fuel rapidly due to the inertial field slowing down all the air particles. So possibly biplanes would make a comeback and definitely helicopters (though in both cases the props/blades would need to be outside the field, which would render them vulnerable to conventional ranged weaponry… perhaps orinthopters would be the way to go then! Dune was right after all!)Se
condly, long-range weaponry would in general be much less effective. Any high-value target (e.g. an enemy vehicle or bunker) would have its own inertial field + light armor coating, and thus would be effectively immune. You’d have to hit it with a shell so big that sheer weight alone causes damage basically. So there might be a comeback of melee—but in vehicular form! I’m thinking mechsuits. Awesome mechsuits with giant hammers. A giant hammer that hits at ‘only’ 50m/s can still do a lot of damage, and moreover in a few seconds it’ll hit again, and then again...Po
ssibly spears too. Possibly warfare would look like pre-gunpowder infantry combat all over again—formations of humanoid mechs with melee weapons bashing into other such formations. (Would mechsuits be optimal though? Maybe the legs should be replaced by treads. Maybe the arms should be replaced with a single bigger arm, so that the thing looks kinda like an excavator. I think the latter change is fairly inconsequential, but the former might matter a lot—depends on whether legs or treads are generally more maneuverable across typical kinds of terrain. My guess is that legs would be. They’d sink into soft ground of course but then that’s no different from walking in sand or snow—slows you down but doesn’t stop you. Whereas treads would be able to go fast on soft ground but then might get completely stuck in actual mud. Treads would also be more energy-efficient but in this world energy-efficiency is less of a bottleneck due to our 3x better engines, 3x better fuel, and reduced need for superheavy armor (just a light armor coating will do, to extend the inertial field and protect against the slow-moving projectiles that come through)
I think the counter to shielded tanks would not be “use an attack that goes slow enough not to be slowed by the shield”, but rather one of
Deliver enough cumulative kinetic energy to overwhelm the shield, or
Deliver enough kinetic energy in a single strike that spreading it out over the entire body of the tank does not meaningfully affect the result.
Both of these ideas point towards heavy high-explosive shells. If a 1000 pound bomb explodes right on top of your tank, the shield will either fail to absorb the whole blast, or turn the tank into smithereens trying to disperse the energy.
This doesn’t mean that shields are useless for tanks! They genuinely would protect them from smaller shells, and in particular from the sorts of man-portable anti-tank missiles that have been so effective in Ukraine. Shields would make ground vehicles much stronger relative to infantry and air assets. But I think they would be shelling each other with giant bombs, not bopping each other on the head.
Against shielded infantry, you might see stuff that just bypasses the shield’s defenses, like napalm or poison gas.
Re 1, we worldbuilders can tune the strength of the shield to be resistant to 1000 pound bombs probably.
Re 2, I’m not sure, can you explain more? If a bomb goes off right next to the tank, but the shockwave only propagates at 100m/s, and only contains something like 300lbs of mass (because most of the mass is exploding away from the tank) then won’t that just bounce off the armor? I haven’t done any calculations.
The ‘missing’ kinetic energy is evenly distributed across the matter within the field. So if one of these devices is powered on and gets hit by a cannonball, the cannonball will slow down to a leisurely pace of 50m/s (about 100mph) and therefore possibly just bounce off whatever armor the device has—but (if the cannonball was initially travelling very fast) the device will jolt backwards in response to the ‘virtual impact’ a split second prior to the actual impact.
With sufficient kinetic energy input, the “jolt backwards” gets strong enough to destroy the entire vehicle or at least damage some critical component and/or the humans inside.
A worldbuilder could, of course, get rid of this part too, and have the energy just get deleted. But that makes the device even more physics-violating than it already was.
Kinetic energy distributed evenly across the whole volume of the field does not change the relative positions of the atoms in the field. Consider: Suppose I am in a 10,000lb vehicle that is driving on a road that cuts along the side of a cliff, and then a 10,000lb bomb explodes right beside, hurling the vehicle into the cliff. The vehicle and its occupants will be unharmed. Because the vast majority of the energy will be evenly distributed across the vehicle, causing it to move uniformly towards the cliff wall; then, when it impacts the cliff wall, the cliff wall will be “slowed down” and the energy transferred to pushing the vehicle back towards the explosion. So the net effect will be that the explosive energy will be transferred straight to the cliff through the vehicle as medium, except for the energy associated with a ~300lb shockwave moving only 50m/s hitting the vehicle and a cliff wall moving only 50m/s hitting the vehicle on the other side. (OK, the latter will be pretty painful, but only about as bad as a regular car accident.) And that’s for a 10,000 lb bomb.
We could experiment with tuning the constants of this world, such that the threshold is only 20m/s perhaps. That might be too radical though.
Idea for sci-fi/fantasy worldbuilding: (Similar to the shields from Dune)
Suppose there is a device, about the size of a small car, that produces energy (consuming some fuel, of course) with overall characteristics superior to modern gasoline engines (so e.g. produces 3x as much energy per kg of device, using fuel that weighs 1/3rd as much as gasoline per unit of energy it produces)
Suppose further—and this is the important part—that a byproduct of this device is the creation of a special “inertial field” that slows down incoming matter to about 50m/s. It doesn’t block small stuff, but any massive chunk of matter (e.g. anything the size of a pinhead or greater) that approaches the boundary of the field from the outside going faster than 50m/s gets slowed to 50m/s. The ‘missing’ kinetic energy is evenly distributed across the matter within the field. So if one of these devices is powered on and gets hit by a cannonball, the cannonball will slow down to a leisurely pace of 50m/s (about 100mph) and therefore possibly just bounce off whatever armor the device has—but (if the cannonball was initially travelling very fast) the device will jolt backwards in response to the ‘virtual impact’ a split second prior to the actual impact.T
his also applies to matter within the field. So e.g. if a bomb goes off inside the device, the sphere of expanding gas/plasma/etc. will only expand at 50m/s. W
hen an inertial field generator absorbs hits like this, it drains the energy produced (and converts it into waste heat within the device). So if a device is pummeled by enough cannonballs—or even enough bullets—it will eventually run out of fuel, and probably before then it will overheat unless it has an excellent cooling system.Fi
nally, the inertial field can be extended to cover larger areas. Perhaps some ceramic or metal or metamaterial works as a sort of extender, such that a field nearby will bulge out to encompass said material. Thus, a vehicle powered by one of these devices can also be built with this material lining the walls and structure, and therefore have the inertial field extend to protect the whole vehicle.Wh
at would be the implications of this tech, if technology is otherwise roughly where it was in the year 2010? (Not sure it is even coherent, but hopefully it is...)..
.First of all, you could make really tough airplanes and helicopters, so long as they fly slow. If they fly above 50m/s, they’ll start to overheat / drain fuel rapidly due to the inertial field slowing down all the air particles. So possibly biplanes would make a comeback and definitely helicopters (though in both cases the props/blades would need to be outside the field, which would render them vulnerable to conventional ranged weaponry… perhaps orinthopters would be the way to go then! Dune was right after all!)Se
condly, long-range weaponry would in general be much less effective. Any high-value target (e.g. an enemy vehicle or bunker) would have its own inertial field + light armor coating, and thus would be effectively immune. You’d have to hit it with a shell so big that sheer weight alone causes damage basically. So there might be a comeback of melee—but in vehicular form! I’m thinking mechsuits. Awesome mechsuits with giant hammers. A giant hammer that hits at ‘only’ 50m/s can still do a lot of damage, and moreover in a few seconds it’ll hit again, and then again...Po
ssibly spears too. Possibly warfare would look like pre-gunpowder infantry combat all over again—formations of humanoid mechs with melee weapons bashing into other such formations. (Would mechsuits be optimal though? Maybe the legs should be replaced by treads. Maybe the arms should be replaced with a single bigger arm, so that the thing looks kinda like an excavator. I think the latter change is fairly inconsequential, but the former might matter a lot—depends on whether legs or treads are generally more maneuverable across typical kinds of terrain. My guess is that legs would be. They’d sink into soft ground of course but then that’s no different from walking in sand or snow—slows you down but doesn’t stop you. Whereas treads would be able to go fast on soft ground but then might get completely stuck in actual mud. Treads would also be more energy-efficient but in this world energy-efficiency is less of a bottleneck due to our 3x better engines, 3x better fuel, and reduced need for superheavy armor (just a light armor coating will do, to extend the inertial field and protect against the slow-moving projectiles that come through)
I think the counter to shielded tanks would not be “use an attack that goes slow enough not to be slowed by the shield”, but rather one of
Deliver enough cumulative kinetic energy to overwhelm the shield, or
Deliver enough kinetic energy in a single strike that spreading it out over the entire body of the tank does not meaningfully affect the result.
Both of these ideas point towards heavy high-explosive shells. If a 1000 pound bomb explodes right on top of your tank, the shield will either fail to absorb the whole blast, or turn the tank into smithereens trying to disperse the energy.
This doesn’t mean that shields are useless for tanks! They genuinely would protect them from smaller shells, and in particular from the sorts of man-portable anti-tank missiles that have been so effective in Ukraine. Shields would make ground vehicles much stronger relative to infantry and air assets. But I think they would be shelling each other with giant bombs, not bopping each other on the head.
Against shielded infantry, you might see stuff that just bypasses the shield’s defenses, like napalm or poison gas.
Re 1, we worldbuilders can tune the strength of the shield to be resistant to 1000 pound bombs probably.
Re 2, I’m not sure, can you explain more? If a bomb goes off right next to the tank, but the shockwave only propagates at 100m/s, and only contains something like 300lbs of mass (because most of the mass is exploding away from the tank) then won’t that just bounce off the armor? I haven’t done any calculations.
2 is based on
With sufficient kinetic energy input, the “jolt backwards” gets strong enough to destroy the entire vehicle or at least damage some critical component and/or the humans inside.
A worldbuilder could, of course, get rid of this part too, and have the energy just get deleted. But that makes the device even more physics-violating than it already was.
Kinetic energy distributed evenly across the whole volume of the field does not change the relative positions of the atoms in the field. Consider: Suppose I am in a 10,000lb vehicle that is driving on a road that cuts along the side of a cliff, and then a 10,000lb bomb explodes right beside, hurling the vehicle into the cliff. The vehicle and its occupants will be unharmed. Because the vast majority of the energy will be evenly distributed across the vehicle, causing it to move uniformly towards the cliff wall; then, when it impacts the cliff wall, the cliff wall will be “slowed down” and the energy transferred to pushing the vehicle back towards the explosion. So the net effect will be that the explosive energy will be transferred straight to the cliff through the vehicle as medium, except for the energy associated with a ~300lb shockwave moving only 50m/s hitting the vehicle and a cliff wall moving only 50m/s hitting the vehicle on the other side. (OK, the latter will be pretty painful, but only about as bad as a regular car accident.) And that’s for a 10,000 lb bomb.
We could experiment with tuning the constants of this world, such that the threshold is only 20m/s perhaps. That might be too radical though.