Is this "Quantum Handshake" something that lets Mach Effect allow inertial changes to manifest themselves in realtime, rather than having to interact with the distant universe under the limits of lightspeed?
The thing to understand is that advanced waves coming back from the future never propagate farther into the past than the rock hitting the water that initiated all of the waves.
Quote from: flux_capacitor on 04/24/2017 09:42 amThe thing to understand is that advanced waves coming back from the future never propagate farther into the past than the rock hitting the water that initiated all of the waves.This is not exactly true. In fact, as I have understood, advanced waves coming back from the future do propagate farther into the past than the rock hitting ... But then they cancel with the advanced waves produced by the rock hitting event ...This cancellation is perfect in an overall flat space, but things may be different in a curved space and this is an open question which could challenge the law of causality. We must stay tune to this strange eventuallity !!
Quote from: sanman on 04/23/2017 09:27 pmIs this "Quantum Handshake" something that lets Mach Effect allow inertial changes to manifest themselves in realtime, rather than having to interact with the distant universe under the limits of lightspeed?The transactional interpretation of quantum mechanics and Machian relativity theory both share the same "action-at-a-distance" concept described by the Wheeler-Feynman absorber theory. But there is no recognized quantum gravity theory yet: the absorber theory is the only thing they have in common.According to general relativity with Mach's principle (= gravitational absorber theory) the interaction between an object "here" and the distant matter in the rest of the universe is indeed limited by the speed of light. However, inertial reaction forces are instantaneous. How could that be? The waves themselves in absorber theory are not superluminal, but the retarded+advanced solutions give a result that appears as being instantaneous. As said earlier, Jim Woodward gave a didactic image how Wheeler-Feynman advanced waves work when applied to gravity and inertia:A first image to understand would be filming a sequence where a rock is thrown in the middle of a pond, making concentric ripples on the water propagating towards the shore. Running the sequence backwards (thinking it as seeing events running backward in time) we then observe concentric waves propagating from the shore towards the center of the pond, where a rock emerges. The thing to understand is that advanced waves coming back from the future never propagate farther into the past than the rock hitting the water that initiated all of the waves.So when you push on a heavy object, this generates "retarded" inertial reaction waves that propagate forward in time at a limited velocity, interacting with the distant matter in the universe. But a similar "advanced" back reaction field propagates backward in time and reach the object the very instant you touch it, giving its property known as inertia. The retarded and advanced waves are two faces of the same coin, they are connected and time-symmetric like the propagating concentric ripples in the movie of the water pond.
Suppose the Mach Effect proves real and a viable space propulsion mechanism. Let's say it can eventually provide continuous thrust of 1G over the duration of an interstellar voyage - say to Alpha Centauri.Let's further say that it comes into regular use, and hundreds or even thousands of MET drive ships are in operation by mankind. So, you have ships continously accelerating up to say 95% the speed of light and then beginning a deceleration halfway into the voyage, in order to arrive at their destinations at a dead stop.Now, what happens when the Thruster breaks down on a particular ship halfway into its return journey to Earth, meaning the ship can no longer decelerate, leaving it travelling to its destination at 95% the speed of light. The idea being that you now have a relativistic missile heading straight for the Earth. If the ship is say several hundred meters across, weighing thousands of tons, well, you get the idea.My concern being, could the achievement of such a space drive be a kind of answer to the Fermi paradox? Meaning you only need one such ship to malfunction and strike your home planet to create a catastrophic outcome?And given this danger, are there some standard safety mechanisms that can be adopted if such a technology is in widespread use, to minimize this risk? Like self destruct mechanisms, or perhaps protocols to never head straight to a destination, but instead only change course directly for your destination planet once you have reached the inner solar system, and your velocity is significantly lower?Else the Mach Effect could prove an existential threat to our species, if proven true.
Else the Mach Effect could prove an existential threat to our species, if proven true.
Quote from: M.E.T. on 04/29/2017 02:41 pmElse the Mach Effect could prove an existential threat to our species, if proven true.I'm more concerned about someone intentionally aiming a piece of junk with a MET attached without anyone noticing. There is no shortage of disgruntled, unhappy or crazy people around, and any of them can one day decide life is not worth living, deciding to turn the lights off for everyone else too; sending out an improvised kinetic missile or subverting an existing one (like a ship, as some pilots have unfortunately done) and then bring it back to Earth at full steam for a date with history.METs (and Emdrives, any space drive really) would make very easy to make terrifying kinetic impactors.If they exist, they would really need to be regulated more than nuclear weapons.
Quote from: tchernik on 04/29/2017 03:59 pmQuote from: M.E.T. on 04/29/2017 02:41 pmElse the Mach Effect could prove an existential threat to our species, if proven true.I'm more concerned about someone intentionally aiming a piece of junk with a MET attached without anyone noticing. There is no shortage of disgruntled, unhappy or crazy people around, and any of them can one day decide life is not worth living, deciding to turn the lights off for everyone else too; sending out an improvised kinetic missile or subverting an existing one (like a ship, as some pilots have unfortunately done) and then bring it back to Earth at full steam for a date with history.METs (and Emdrives, any space drive really) would make very easy to make terrifying kinetic impactors.If they exist, they would really need to be regulated more than nuclear weapons.This is true and, I think, completely underapprecciated today. If Mach drives exist, everybody having their hands on one will also have the possibility, in principle, of inflicting a nuclear-explosion-level damage (even much more) on any point on the Earth's (or any other planets, moons or asteroids) surface. Nothing would keep, e.g., Kim Jong-Un to hide a few impactors somewhere in the Kuiper belt, ready to accelerate and strike any point in the US whenever needed (they might need a few weeks to reach Earth, but that wouldn't reduce much the damage they could do once unleashed). To mitigate against that type of threat, it might (eventually) become necessary to constantly scan the vicinity of the Earth for relativistic impactors, and have a fleet of ultra-fast accelerating Mach drive missiles ready to intercept (remember that at ~c, a kinetic impactor would cross the Earth-Moon distance in 1 sec... So this would require scanning for sub-meter-sized objects several light-seconds out or even further - difficult, but probably not impossible). Lasers won't help here either because you have to make sure the bulk mass of the impactor doesn't hit the atmosphere - whether it reaches the atmosphere in a solid, molten or vaporized state makes (almost) no difference. Alternatively, you just have to make sure you live in a place where your future position cannot easily be determined. I.e., if we all lived in space colonies attached to randomly firing Mach drives, the threat of such impactors might be mitigated, too. So yes, I see this outcome as a possible solution to the Fermi paradox: Only those civilizations who do not yet know of the terror of relativistic impactors freely share their position with others...
This is true and, I think, completely underapprecciated today. If Mach drives exist, everybody having their hands on one will also have the possibility, in principle, of inflicting a nuclear-explosion-level damage (even much more) on any point on the Earth's (or any other planets, moons or asteroids) surface. Nothing would keep, e.g., Kim Jong-Un to hide a few impactors somewhere in the Kuiper belt, ready to accelerate and strike any point in the US whenever needed (they might need a few weeks to reach Earth, but that wouldn't reduce much the damage they could do once unleashed). To mitigate against that type of threat, it might (eventually) become necessary to constantly scan the vicinity of the Earth for relativistic impactors, and have a fleet of ultra-fast accelerating Mach drive missiles ready to intercept (remember that at ~c, a kinetic impactor would cross the Earth-Moon distance in 1 sec... So this would require scanning for sub-meter-sized objects several light-seconds out or even further - difficult, but probably not impossible). Lasers won't help here either because you have to make sure the bulk mass of the impactor doesn't hit the atmosphere - whether it reaches the atmosphere in a solid, molten or vaporized state makes (almost) no difference. Alternatively, you just have to make sure you live in a place where your future position cannot easily be determined. I.e., if we all lived in space colonies attached to randomly firing Mach drives, the threat of such impactors might be mitigated, too. So yes, I see this outcome as a possible solution to the Fermi paradox: Only those civilizations who do not yet know of the terror of relativistic impactors freely share their position with others...
Oh yeah, most of the damage you guys are talking about can be had by simply putting kinetic impactors in orbit.
But how does humanity gain access to a MET capable of heavy lift (constant 1g+) and remain prisoner to the idiots around us.
If position and visibility become a risk, the solution is to hide, make backups and expand.
Of course, it is doubtful Earth could never be fully evacuated in any meaningful time frame, therefore a parallel state machinery of surveillance and tight regulation of the METs would emerge (the same as with nuclear power), where every single private MET thruster is accounted for, tracked and could be remotely disabled. And probably within some radius of Earth, no object would be allowed to move above certain speeds or follow an accelerating trajectory of more than certain fractions of G.
First this: Quote from: birchoffOh yeah, most of the damage you guys are talking about can be had by simply putting kinetic impactors in orbit.Nope. In orbit, kinetic energy is 60 Megajoules per kg. A relativistic kinetic impactor can easily get 60 Megatons per kg...QuoteBut how does humanity gain access to a MET capable of heavy lift (constant 1g+) and remain prisoner to the idiots around us.Well, how did humanity get access to fusion bombs and remain prisoner to the same idiots? Humans will always be humans, regardless of technology.All the technological developments you mention would probably happen, but wouldn't defuse the threat of relativistic weaponry. Just having telescopes looking out for relativistic kinetic impactors (RKIs) will not protect the Earth alone - as mentioned, you need some kind of interceptor which can build up in very short time the kinetic energy needed to divert the RKI from its collision path (or at least deviate it such that it doesn't hit a city and impacts over the ocean instead - if that is enough...). To do that, you need to find the approaching RKI, calculate its trajectory, notify a battery of interceptors, launch them and have them reach the RKI in time, all in the matter of a few seconds...One limitation to the RKI threat is probably that the acceleration to relativistic speeds is energy-limited, and therefore you would also need a very powerful energy source to build an RKI (also, as a consequence the RKI would probably glow brightly - at least in infrared - on approach, which makes it easier to identify - unless you accelerate it from very far away so it has time to cool down again). But in a future where both Mach drives and compact nuclear fusion are commonplace, at least state actors should have no problem setting up a fleet of RKIs in the Kuiper belt or beyond.Quote from: tchernikIf position and visibility become a risk, the solution is to hide, make backups and expand.Exactly. QuoteOf course, it is doubtful Earth could never be fully evacuated in any meaningful time frame, therefore a parallel state machinery of surveillance and tight regulation of the METs would emerge (the same as with nuclear power), where every single private MET thruster is accounted for, tracked and could be remotely disabled. And probably within some radius of Earth, no object would be allowed to move above certain speeds or follow an accelerating trajectory of more than certain fractions of G.That radius would have to be very big (probably encompass the solar system or so) to make sure any rogue Mach drives could be intercepted in time. But then, how would you track those who do not want to be tracked? As long as you have different states with different interests, surveillance / regulation will always serve the needs of these interests. So I agree - the diaspora would be likely to happen. On these ships going into hiding/riding, you can even have a comfy 1 Ge - just accelerate constantly with your Mach drive (but not in a fully deterministic fashion). Go see the universe. All you need is something to feed your fusion reactor with, but that, you can get from everywhere. And hey, at 1 Ge acceleration, the next star system is only a few years of travel away. That's certainly doable, right? And while we're at it: the galactic center is only 30 years away, 60 if you want to stop...
Quote from: Bynaus on 05/02/2017 06:30 amFirst this: Quote from: birchoffOh yeah, most of the damage you guys are talking about can be had by simply putting kinetic impactors in orbit.Nope. In orbit, kinetic energy is 60 Megajoules per kg. A relativistic kinetic impactor can easily get 60 Megatons per kg...QuoteBut how does humanity gain access to a MET capable of heavy lift (constant 1g+) and remain prisoner to the idiots around us.Well, how did humanity get access to fusion bombs and remain prisoner to the same idiots? Humans will always be humans, regardless of technology.All the technological developments you mention would probably happen, but wouldn't defuse the threat of relativistic weaponry. Just having telescopes looking out for relativistic kinetic impactors (RKIs) will not protect the Earth alone - as mentioned, you need some kind of interceptor which can build up in very short time the kinetic energy needed to divert the RKI from its collision path (or at least deviate it such that it doesn't hit a city and impacts over the ocean instead - if that is enough...). To do that, you need to find the approaching RKI, calculate its trajectory, notify a battery of interceptors, launch them and have them reach the RKI in time, all in the matter of a few seconds...One limitation to the RKI threat is probably that the acceleration to relativistic speeds is energy-limited, and therefore you would also need a very powerful energy source to build an RKI (also, as a consequence the RKI would probably glow brightly - at least in infrared - on approach, which makes it easier to identify - unless you accelerate it from very far away so it has time to cool down again). But in a future where both Mach drives and compact nuclear fusion are commonplace, at least state actors should have no problem setting up a fleet of RKIs in the Kuiper belt or beyond.Quote from: tchernikIf position and visibility become a risk, the solution is to hide, make backups and expand.Exactly. QuoteOf course, it is doubtful Earth could never be fully evacuated in any meaningful time frame, therefore a parallel state machinery of surveillance and tight regulation of the METs would emerge (the same as with nuclear power), where every single private MET thruster is accounted for, tracked and could be remotely disabled. And probably within some radius of Earth, no object would be allowed to move above certain speeds or follow an accelerating trajectory of more than certain fractions of G.That radius would have to be very big (probably encompass the solar system or so) to make sure any rogue Mach drives could be intercepted in time. But then, how would you track those who do not want to be tracked? As long as you have different states with different interests, surveillance / regulation will always serve the needs of these interests. So I agree - the diaspora would be likely to happen. On these ships going into hiding/riding, you can even have a comfy 1 Ge - just accelerate constantly with your Mach drive (but not in a fully deterministic fashion). Go see the universe. All you need is something to feed your fusion reactor with, but that, you can get from everywhere. And hey, at 1 Ge acceleration, the next star system is only a few years of travel away. That's certainly doable, right? And while we're at it: the galactic center is only 30 years away, 60 if you want to stop...your missing my point. The reason we have to restrict access to fusion/fission bombs is because WE HAVE BUT ONE PLANET. and that weaponry can destroy the one planet we have. Heavy Lift MET's basically remove the biggest barrier to humanity only having a single planet it can live on. Heavy Lift MET's will basically lead us to moving off planet. There are other technologies we need. but it is my position that those technologies do not see alot of investment because the market doesnt believe there is a need. heavy lift MET's would automatically generate a market need while providing the buyers with a variety of business opportunities to fund development/procurement of that need. That means at most their would be a short term threat. but long term humanity would be sufficiently spread out across the inner and possibly outer solar system than relativistic impactors just become a nice way to piss off people. instead of being the end of humanity scenario it is today.One other thing I forgot to mention. heavy lift met's also provide you with a protection system. if you have complete coverage of the sky to detect them. then you just need a drone pulling many many G's of constant acceleration to pull up along side and alter its course. Or take the SPS system and use it to power a GW Laser. again relativistic impactors are not a great concern here
I'm not so sure about easily stopping RKV threats.How far out could you detect a 1m diameter ball of iron traveling at 95% the speed of light? How about a 10cm diameter ball of iron. And at that speed, your response time would likely be in minutes only, maybe hours at most.And furthermore, it seems that even Mach Thrusters would take months to get such a device up to 95% the speed of light. To achieve the same speed from rest in a few hours seems unlikely. Yet that would be required to have any hope of intercepting the incoming projectile.
Lasers are also of no good use here, because even if you vaporize the RKI with a laser, the ion velocities in the resulting plasma will still be very small compared to the relativistic forward velocity, and thus this will not make much of a difference (as builder of the RKI, you could even help this by using very heavy building materials which are difficult to accelerate, like tungsten). It doesn't really matter if the Earth is hit by a lob or tungsten or a cloud of tungsten atoms of the same mass, if it is at relativistic velocities. Also, it is by no means given that the approaching RKI would agree to be a passive target on a deterministic course. In the last section of its flight, it might accelerate and slightly change course at random, which - given the dimensions involved - would probably make it impossible to hit with a laser.