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Post by samchiu2000 on Jun 19, 2017 11:49:55 GMT
could you mod this game to model planetary collisions like the Universe sandbox? then you could actually fire a relativistic planet at another planet and see what happens. Sounds good. So, anyone with Universe sandbox in his/her hard-disk?
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Post by Kerr on Jun 19, 2017 11:57:05 GMT
could you mod this game to model planetary collisions like the Universe sandbox? then you could actually fire a relativistic planet at another planet and see what happens. Last time I checked Universe Sandbox doesn't have relativistic physics.
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Post by samchiu2000 on Jun 19, 2017 13:31:41 GMT
could you mod this game to model planetary collisions like the Universe sandbox? then you could actually fire a relativistic planet at another planet and see what happens. Last time I checked Universe Sandbox doesn't have relativistic physics. At 0.3c the relativistic effects isn't really significant actually.
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Post by Kerr on Jun 19, 2017 13:34:54 GMT
Last time I checked Universe Sandbox doesn't have relativistic physics. At 0.3c the relativistic effects isn't really significant actually. Well then, is there even an object ingame with a mass of 2kton?
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Post by samchiu2000 on Jun 19, 2017 13:36:43 GMT
At 0.3c the relativistic effects isn't really significant actually. Well then, is there even an object ingame with a mass of 2kton? Don't have this game so IDK.
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Post by The Astronomer on Jun 19, 2017 14:35:42 GMT
Objects in US2 range from a pool ball to a supermassive black hole. You can edit that pool ball's properties and make it larger than Earth or hotter than the Sun or wahtever you want to do with it. Still no 2D temperature (a planned feature) map as for now, though.
Also, my new computer cannot run it...
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Post by Kerr on Jun 19, 2017 14:51:37 GMT
Objects in US 2 range from a pool ball to a supermassive black hole. You can edit that pool ball's properties and make it larger than Earth or hotter than the Sun or wahtever you want to do with it. Still no 2D temperature (a planned feature) map as for now, though. Also, my new computer cannot run it... Why tho? Incompatibility?
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Post by The Astronomer on Jun 19, 2017 15:00:50 GMT
Objects in US 2 range from a pool ball to a supermassive black hole. You can edit that pool ball's properties and make it larger than Earth or hotter than the Sun or wahtever you want to do with it. Still no 2D temperature (a planned feature) map as for now, though. Also, my new computer cannot run it... Why tho? Incompatibility? Yeah, I guess.
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Post by Kerr on Jun 19, 2017 15:04:31 GMT
Why tho? Incompatibility? Yeah, I guess. Tried everything? Using older windows version compatibilities modes and running it as administrator? Or do you have Linux?
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Post by The Astronomer on Jun 19, 2017 16:00:49 GMT
Tried everything? Using older windows version compatibilities modes and running it as administrator? Or do you have Linux? Nah, and I don't think I'll need US 2 soon anyways. Have fun.
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Post by Kerr on Jun 19, 2017 16:42:13 GMT
Well then, what do you think is the best way of achieving an RKKV? Normal rockets with high isp fuels like D-HeΒ³?
Or Track-rockets which escape the tyranny of the rocket equation? But require an immense infrastructure.
Or Laser sails? With special materials they can easily reach 0.99c, giving them the ability to penetrate atmosphere without any damage. And creating relatively small and efficient explosions on ground.
For both Laser and Track RKKV's I propose an 330TW Coilgun/Laser system. The coilgun system with 90% efficiency launches 1kg D-HeΒ³ at 0.08c in the target direction. Problem is this requires the fuel being launched several years before the spacecraft even started. But they usually reach cruising velocity before the photons even reach the other system in the first place. The Laser system uses a different path, instead of giant rkkv's it uses very light 1kg Beam Sails. At 165TW Laser output 33x 0.995c sails can launched daily. With only 50 AU Acceleration distance. Instead of one 90 Teratons (Chicxulub had 100 teratons) the laser rkkv system launched multiple hundred thousand of small rkkvs. Each B-RKKV yields at about 200MT, at their velocity they just pass through the atmosphere and create a cone shaped explosion. Arbitrary to a normal nuke it also produces much more Gamma-rays and other high energy radiation. Because of the shape of the explosion most energy is coupled to the ground. Creating an giant crater. Lifting multiple hundred tons soil into the atmosphere. In order to produce 330TW Energy one would need to use a D-HeΒ³ fusion reactors with a low efficiency of 62% (energy can be directly converted to electricity because of charged particles.) which fuses 1,5kg of D-HeΒ³ per second.
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Post by thorneel on Jun 19, 2017 23:56:07 GMT
Given how much energy is required to accelerate a large RKV, chances are that you are energy-limited first. So better use a high-efficiency propulsion. External propulsion seems the best, otherwise the rocket equation is going to club your mass ratio to infinity. A laser sail and a very high-power continuous laser is the obvious answer, but acceleration may not be high enough, depending on what you want to do. OTOH, laser ablation or laser thermal would bring back the rocket equation club to bear. Antimatter can be used as pure AM drive (so no AM-triggered fusion or AM-thermal, just directly use annihilation products as propellant), but getting a high enough mass ratio despite the mass of antimatter storage is a big challenge. Micro-black-hole drive is another choice for massive RKV, but is an even bigger challenge, if possible at all.
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Post by Kerr on Jun 20, 2017 13:41:20 GMT
Given how much energy is required to accelerate a large RKV, chances are that you are energy-limited first. So better use a high-efficiency propulsion. External propulsion seems the best, otherwise the rocket equation is going to club your mass ratio to infinity. A laser sail and a very high-power continuous laser is the obvious answer, but acceleration may not be high enough, depending on what you want to do. OTOH, laser ablation or laser thermal would bring back the rocket equation club to bear. Antimatter can be used as pure AM drive (so no AM-triggered fusion or AM-thermal, just directly use annihilation products as propellant), but getting a high enough mass ratio despite the mass of antimatter storage is a big challenge. Micro-black-hole drive is another choice for massive RKV, but is an even bigger challenge, if possible at all. -Laser Acceleration: It is actually pretty good. With 100TW Beam power and 50AU acceleration distance an Laser sail can reach 0.995c. While weighting 3kg. Based on the Breakthrough starshot probe. Which is build to withstand 100 GW of Power. We scale it up from that point. At 100TW the probe needs an 1-2kg Sail made out of same graphene-composite that Starshot uses. The rest 1kg equipment can be used for an Photonic Thruster, electronics and a battery. With an 75g RTG an 500KW Photonic Thruster can be powered, 500W Input. Producing 3,5mN of thrust (this was actually an tested photon thruster from NASA) Giving the RKKV an acceleration of 10,5cm/s or 37,8m/day. Considering that this ship needs 4 years from Sol to Trappist that enough to target an city or something like that. Thanks to it's massive it's to fast to fuse with the atmosphere. On impact with the solid ground the 2.5e18 Joules (roughly) produce an 600MT explosion. Different from normal nuclear weapons this explosion isn't spherical but cone shaped. Means this is a 600MT Bunker buster. Probably producing an dozen kilometer deep crater on impact. 100x per month. For years to come by. Antimatter: If we had an near perfect gamma-ray mirror we could use Positron annihilation to power ship to extreme relativistic velocities. An 300TW Antimatter photon Core rocket could produce one giganewtons of thrust, but only if 100% of gamma-rays reach the chamber. And can be reflected 1000x.
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Post by Dhan on Jun 20, 2017 18:27:43 GMT
Assuming you can build 300 TW reactors to power your lasers or guns, how would you even get rid of the ridiculous amount of waste heat?
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Post by Kerr on Jun 20, 2017 18:51:27 GMT
Assuming you can build 300 TW reactors to power your lasers or guns, how would you even get rid of the ridiculous amount of waste heat? With radiators? Building a single 300TW Coilgun/Laser is beyond idiotic. As for lasers you could build 1 million 300MW Lasers throughout the system which can be focused through a Laser Web and a giant lens. As for Power: Using current tech D-HeΒ³ reactors can achieve 50% Fusion-electric energy conversion efficiency. Meaning you need to fuse 2kg/s D-HeΒ³ every second. And before someone says that this is too expensive to be practical or something Non-track fusion rkkv needs even more D-HeΒ³ per megaton than a laser rkkv.
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