How can antimatter be weaponized?
Antimatter could in principle be used to make an explosive weapon. The idea of explosive weapons is that you release large amount of energy very quickly close to your target, producing effects like heat and shock wave, that destroy the target. For best effects you'd like your explosive to be as small as possible, because it is easier to deliver and there is less chance that enemy can intercept it before it reaches the target.Antimatter could in principle be the ultimate explosive, because if you deliver a certain amount of it to the target and let it contact and annihilate with matter around the target, you'll release the amount of energy equivalent to twice the mass of that antimatter. A gram of antimatter would produce 43 kiloton explosion - like a small nuke. Fortunately with our present technology weaponizing antimatter this way is completely impossible. First, antimatter is very difficult to produce. The Fermilab antiproton source, the most powerful "antimatter factory" in the world has produced during its entire lifetime of abut 25 years just 17 nanograms of antiprotons. And of course we never had this amount "at once", antiprotons have been usually stored for at most a couple of days. Second, storage of antimatter is very difficult, because you have to keep it from contact with matter. Devices that allow that are bulky. Either you have to deliver your antimatter together with such device to your target (that would completely negate the advantage of "small amount"), or you'd have to form your antimatter into a beam and shoot it towards the target - but devices that can accelerate such beams are even more bulky and unsuited for the battlefield. Thus, without some very serious technology improvements using antimatter as a weapon will remain domain of SF.
Could a gamma-ray laser make an effective weapon, or are gamma rays too penetrating to weaponize into a practical armament?
Simple answer… weapon, probably. Effective, probably not.Gamma ray lasers have come a long way from the Star Wars days, when gamma ray lasers [then given the hip, trendy name “grasers”] could only be set off by an actual nuclear explosion. It was theorized that they could deposit enough energy into an incoming warhead to destroy it by ablating a hole at the point of contact of the gamma ray beam. The point was often made at the time that setting off an actual nuclear explosion just to pump a laser was a bit like using a gasoline engine to throw a rock at somebody. Gamma ray lasers do not currently require such drastic measures.There is a minor allusion made to gamma ray laser weapons at Induced gamma emission, but it’s quite short and generic. I know a lot of people fantasize about this stuff, of course.Most of the time, “Never say Never” is a very good idea, but I personally don’t see them any time in the future. For one, thing, I think lasers far closer to the visible spectrum [energies in the single-digit eV or low double-digit eV range - consistent with air transmission] are likely to get very powerful very fast. For another, gamma rays don’t penetrate air very well, either… the 1/e distance for 10 MeV gammas, for example, is only about 80 meters.To me, gamma ray laser weapons sound like the stuff of permanent syfy - kinda like EMP weapons.
How feasible would X-Rays be as a murder weapon, given sufficient time?
It's plausible. However it would be a very difficult, inefficient, and uncertain way to reach your desired goal.First of all you would need to acquire an x-ray machine and rig it in such a way so as to direct it's beam at the target, undetected. This requires electricity and a little skill, but could be done by housing it in an adjacent room. But also, unless you didn't care who you zapped, you would need to sit your target in place in such a position or with shielding so as the beam didn't expose anyone else on the other side of them. Then after you have achieved all of that, you would have to get them to sit tight whilst you expose them with enough radiation to cause acute radiation syndrome and kill them. The LD 100 or the dose of radiation that will certainly kill them, is 10 Gray or 10 Sieverts. A typical chest x-ray is 0.1 millisievert. So you would have to give them the equivalent of about 10,000 chest x-rays in a short period of time.Then, after you have achieved that, forensics would not have a hard time determining the cause of death, finding out where the victim has been recently, finding your murder weapon, and sending you up the river.If you want to kill someone with radiation, get your hands on some alpha emitters such as polonium-210. A very small amount of this ingested or inhaled will lead to a rapid and painful death as demonstrated by the alleged assassination of Alexander Litvinenko in 2006.Poisoning of Alexander Litvinenko
Could humans weaponize gamma rays to kill enemies?
You are thinking of one of two things:A gamma-ray laser (or something else that produces a beam of gamma rays) or a dirty bomb.Gamma lasers are not in the cards at the moment - we can’t even make x-ray lasers without setting off a nuclear bomb. We can generate high-energy photons with a linear accelerator - as they do for cancer therapy - but as Stephen said, it’s a horribly inefficient way to make a weapon. Not only that, but the beam spreads out with distance so, even if it’s deadly at, say, 100 meters it’s going to be 1/4 the strength at 200 meters and down to 1% of the deadly level at 1 km.Or you can strew a lot of cobalt-60 or cesium-137 on top of your enemy and let the gamma radiation make them sick. At least, if you can arrange for them to stay put long enough to collect a harmful dose. And congratulations! You’ve made a dirty bomb.So - realistically - no.
Have any governments weaponized satellites yet?
In the 1960s there was a program called BAMBI to put interceptors on satellites orbiting over the Soviet Union.[1]In 1988, there was another program to do essentially the same thing called SBI.[2]Also in the 1980s, there was work done to develop a nuclear explosion-powered space based x-ray laser called Project Excalibur.[3]In the late 1990s there was a program to put a high energy laser on a satellite called Space Based Laser - Integrated Flight Experiment.[4]It has widely been reported that the former Soviet Union and China have experimented with “hunter-killer satellites.” [5] [6]There are numerous videos describing the war in space that has been going on since the late 1950s. [7] [8] [9] [10]Footnotes[1] United States national missile defense - Wikipedia[2] Strategic Defense Initiative - Wikipedia[3] Project Excalibur - Wikipedia[4] The History of Space Based Laser[5] Russia’s ‘Killer Satellites’ Re-Awaken[6] U.S. Air Force Has a Plan to Counter China's Super Lethal 'Satellite-Killer' Weapons[7] 60 Minutes The battle above[8] War In Space - The Next Battlefield - CNN[9] BBC Panorama The Real War in Space 1977[10] The Real War in Space II We are entering a post nuclear era 1978 from BBC
What are the chances the United States already has weaponized satellites in space?
I am not aware of what the point of weaponized satellites in space would be. If you wanted to destroy some satellite, the best way to do that would be to launch an anti-satellite missile from the ground or from an aircraft. The best way to attack a target on the ground is the same.Aside from the GPS satellites, the primary military use of satellites is for recording various types of electromagnetic signals, and for communications.In the 1980’s it was proposed that X-ray lasers on satellites could be used as an anti-ballistic missile system. After a significant amount of money was spend on trying to develop such X-ray lasers, the idea was abandoned as unfeasible. The only types of ABM systems which are known to exist use missiles which are launched from the ground, or from ships in the ocean.