Paris gun (courtesy

In the video below RealLifeLore ask What’s the Biggest Gun We Could Possibly Build? Personally, I couldn’t “build” a BIC pen spitball gun. But I know enough to know that RLL’s missed a trick . . .

I watched a science program (whose name I’ve forgotten, along with the names of everyone I’ve ever met casually) where some science fiction-loving scientists dreamed-up ways to repel an alien invasion.

One of the participants suggested digging a massive hole in the ground, topping it with an enormous piece of flat metal, then setting off a nuclear bomb in the hole. Ba-BAM!

I don’t know about targeting, but that would be the world’s biggest possible gun, right? Now about those tanks . . .


  1. The old NASA Project Orion from the late 1950s proposed a space ship with a BIG hunk of steel under it. Set off an atom bomb under the steel plate and the ship moves up at a very high velocity. Repeat as necessary to get you where you want to go. The Sf novel Footfall written in 1985 by Larry Niven and Jerry Pournelle used this technique to oppose an alien invasion. Its a good read and the technology is very possible if you accept the idea of setting off nuclear explosions in the atmosphere to propel a space ship. The bomb propulsion system is a lesser evil than an invasion by very nasty and hostile space aliens, although I’m sure that today’s snowflakes wouldn’t see it that way.

    • In addition to footfall there is one by jerry pournell (i think) called king davids spaceship. slightly different premise, and it uses conventional explosives instead of atomics, but same general design

    • If you read into the science behind it, its a lot more plausible than you’d think. they were able to design small bomb launching charges that were optimized through charge type and moderating materials etc to produce propulsion with no significant amount of fallout. They had actually contracted with coca-cola to produce the feeding mechanism to launch the series of small bombs out of the center of the base-plate (due to their experience with vending machines). the really neat part is that a lot of what we consider the fundamentals of space travel are turned on their head. Unlike conventional chemical rockets, additional weight is not only not nearly as big a negative, its actually a POSITIVE in many ways. Helps damp out the shock impulse of the propulsion system and a thicker baseplate extends the range (as a certain thickness of the steel was ablated away with each blast). It was planned out, to a very high level of detail, to have a GIGANTIC spaceship built (I’m talking size of several city blocks) that would have been capable of travel to Proxima Centauri fast enough to get there and back within a decade or three (you can accelerate to a signifcant percentage of C aka speed of light with this propulsion system). So in the 60s, we had the technology to send a few thousand people to another star and back. The only reason we didn’t is the “optics” of using nuclear propulsion (it’s not nearly as damaging/harmful as you’d think, but try convincing the public of that). Kinda amazing/sad.

  2. Realistically speaking, nukes are about our only hope if any alien race decides to invade. An all out nuclear strike would probably be our only way to cause such a race significant enough damage to abandon the effort, while also trashing the planet enough to where they decide a radioactive wasteland isn’t an ideal place to colonize. We’d have to live in a radioactive wasteland, then, however. But, that could prove rather exciting.

    • “Realistically speaking, nukes are about our only hope if any alien race decides to invade.”

      Look, I know we have a problem at the southern border, but maybe we should try the wall first before we nuke Mexico.

      • I been thinking about our borders and walls. I think the wall should extend up before it hits the Pacific, say at Kalifornia and Arizona. It could then follow Kalifornia border up who knows how far. Persons wanting to migrate to the right side (good side) would have to show weapons they own and pledge allegiance to Trump. Bet Trump could get a travel ban passed for people wanting to come across that border! I know there are good people on the wrong side of that line but they need to move now before wall is built. If only it was that easy. This is a plan that needs more thought.

    • Project thor. Kinetic bombardment weapons. Drop a crowbar with a basic steering package from orbit. Okay it’s actually slightly bigger than your crowbar, but you get the point. Chunk of inner metal, basic steering, guidance, and targeting package. the bigger the piece of metal the bigger the impact. Force equals mass times acceleration. and you can get things to go really fast when you drop them from orbit. first conceived of in the fifties if I remember right. if you’re telling me some super Secret Squirrel government agency hasn’t put a few of these in orbit and just not told anybody about it I’m going to believe that you’re an optimist

  3. Ballistic weapons aren’t the standard anymore for terrestrial warfare for a reason. Our largest guns, those on battleships and two-track rail cars, have been made obsolete by missiles. Explosive ordnance with the ability to penetrate bunkers exists within autonomously piloted cruise missiles like the Tomahawk, that can be launched from bombers, ships, subs, or even trucks if there was any advantage. Instead of setting off an atomic reaction to propel a ballistic projectile, we would just send the atomic reaction onboard a sneaky, adaptable vehicle. No ballistic projectile can deliver even an atomic payload better than a missile.

    Now, if you’re asking “why not?”, then I’m totally on board anyway, and the limit is probably due to our level of manufacturing of material strong enough to hold the propellant charge’s energy. We could send a heavier projectile slower, or a lighter one faster, but just like any gun, you can’t send a heavier projectile faster without risking tearing off half your face over it. So we forge a barrel out of the strongest material we can produce, and load it with a given projectile and charge until it cracks, and that’s our answer, until we invent a stronger material.

      • It is my more recent understanding that EMPs don’t damage as much stuff as people like Mr. Forstchen suggest it will in their books. Power grids yes, every electronic device no. Probably not even most cars. Yes it would be a huge wrench in the monkey works but not all would be lost.
        I still liked On Second After though.

        • Good book BTW. Hopefully we will never know just how bad an EMP is. But the power grid failing would be a “game over” deal.

        • “It is my more recent understanding that EMPs don’t damage as much stuff as people like Mr. Forstchen suggest it will in their books. Power grids yes, every electronic device no. Probably not even most cars.”

          I disagree, a high-altitude detonation will produce a *massive* voltage spike, in the order of thousands of volts per meter, at ground level for a thousand + miles.

          It’s real. The consequences for dismissing the possibility are catastrophic for the nation.

          Here is a near-field simulation on a Ford Taurus :

        • Geoff, I concede that you may be correct, but since reading One Second After, did quite a of reading on the subject and was left thinking yeah the grids will be gone and some running circuits but it was doubtful that most electronic circuits would be damaged. As dumb as it sounds I was mostly wondering about electronic weapon sights. There have been plenty of tests done on vehicles under Marx generators as in that video and often they do not end with the car or airplane being disabled. Future Weapons was known for exaggerating things to make it more exciting. There are many variables, not the least of which is the length of the wires running to the ICs, no? As far as I could tell the areas of most intense pulse strength from likely NEMPS are way smaller than the US mainland. I did read about the Starfish Prime test and its results. As for discounting the effects of an NEMP strike, I used to keep some things in a Faraday cage when I was not using them and the home I am building this summer will be one big cage with one of my cars inside it. It’s greatest EMP protection is from it’s ferrocement exterior with a several fine and one large wire mesh. The screens over my few windows will be conductive and the shutters sheet steel. The 3 doors are similar. For right now I still don’t believe most electronic circuits will be damaged but that doesn’t mean I am not taking steps to minimize the risk. Just because I doubt something doesn’t mean I discount it, especially when it is fairly easy to add protection – I was going to use a ferrocement exterior finish over insulated concrete form construction anyway.

        • The length of the wire leading into the chip is critical, you are correct. That’s why cars are vulnerable, wires 10 feet long are leading into the ECU. The red dot *may* be OK, the circuit leads are very short, but LEDs *are* diodes and sensitive to zaps.

          Rather than a garage Faraday cage, have you considered simply acquiring junkyard used (and tested by you) ECUs, coil packs, and other sensitive bits and storing them in a galvanized trash can as an improvised cage? If the big zap happens, install the sealed-away ones. Put some cardboard between the goodies and the inside wall of the metal can.

          The Starfish Prime shot was the warning. 1,600 miles away it blew out street lights and telephone gear…

    • The one advantage of tube guns over modern missiles is that gun technology is well understood and far cheaper to field.

      The downside is that you’ll need forward spotters to put the cheap, dumb tube arty rounds on target as well as modern guided missiles.

      • “The downside is that you’ll need forward spotters to put the cheap, dumb tube arty rounds on target as well as modern guided missiles.”

        True, but drones are fulfilling that role nowadays at a lot lower risk to personnel…

  4. Schwerer Gustav. 31.5″ railway gun, WWII. Max range 30 mi. with HE shells weighing over 5 tons, but also fired an AP round weighing nearly 8 tons with a range of 24 mi.

  5. The narrator of that video is terrible. He’s not quite monotone bad, but it’s close. He lacks normal intonation or passion. I had to consciously force myself to sit through it.

  6. For *once*, I’ll be on-topic for this thread. *cough* 😉

    1 – It’s pretty much known who killed Bull. He was visited by people who didn’t want the gun built, and told him it would be a good idea to drop the project.

    He didn’t, so they dropped him. The folks who dropped him were reputedly the Mossad.

    2 – The steel plate atom-bomb thing.

    There’s a large grain of truth there. Back in the days of US underground nuclear testing in Nevada, they were conducting an underground nuke test where they placed a 4-inch thick cast-iron plate over the test hole and set up a high-speed camera to record the launch velocity.

    It exceed *all* test expectations :

    “Brownlee replicated the first experiment, but the column in Pascal-B was deeper at 500 feet deep. They also recorded the experiment with a camera that shot 1 frame per millisecond. On August 27, 1957, the “manhole cover” cap flew off the column with the force of the nuclear explosion. The iron cover was only partially visible in one frame, Brownlee said.”

    “When he used this information to find out how fast the cap was going, Brownlee calculated it was traveling at five times the escape velocity of the Earth — or about 125,000 miles per hour.”

    More on the test shot series :

    • EDIT – In my non-humble opinion, if the plate were traveling *that* fast, compression heating of the lower atmosphere would heat that thing to iridescence, and no one reported a reverse shooting-star…

  7. Project Metal Storm. Theoretical fire rate of 1 million rounds per minute. Yes 1 million rounds per minute.

    Now Define biggest. our current limitations on rail gun technology are Material Sciences for the conducting coils and Material Sciences for the capacitors and energy storage And generation systems. Rail guns, also occasionally referred to as gauze rifles, provide the most kinetic punch per pound. U.s. military has been testing them out for deployment on Naval vessels for years now. You can theoretically get anti-Armor weapon. down to a size that would be able to fit in a Humvee. Man portable is still a few years off, again due to limitations in Material Sciences and energy storage.

    I’m going to leave directed energy weapons out of this discussion because gun implies a projectile, not directed energy.

    • “Man portable is still a few years off, again due to limitations in Material Sciences and energy storage.”

      To say nothing about what would happen to the operator if the ‘energy storage’ (capacitor bank) ‘device’ were to be pierced by flying metal projectiles called ‘bullets’ quite common on modern battlefields.

      Probably something along the lines of these :

      • i was sent to investigate an outage on a 345kv transmission line. one of the (10ft) tall lightning arrestors had obviously exploded (we refer to these scientifically as “self locating” faults). this equipment exits the now defunct fisk coal generating sta11 directly across 22nd st (cermak) from where the local pilsen residents celebrate a gala fiesta del sol.
        they would have all been impressed.

    • Metal Storm? The BK’d company? The long discontinued research, except maybe the Chinese projects?

      I would love to see a “gauze” rifle though…

      • It’s actually Gaus rifle. Gaus is the unit of measure for magnetic fields. A ‘gauze’ rifle would tend to burn up the projectile. 🙂

        • It’s actually a Gauss rifle, and I’m quite aware of the fact that (Carl Friedrich’s) Gauss is the unit of measurement it is named for. Hence the post….

  8. Just a weird hunch, but I think the far-ish future will be rife with ‘gravity’ / ‘anti-gravity’ weapons.

    If you AG-nuke a city and it throws the whole city up into the air 180′ (20′ of dirt and all), the results would be Armageddon-like, without the fallout. If you G-nuke it, you could do some serious damage and pin moving objects / vehicles / personnel to the ground.

    How do you accomplish this? What, you want me to tell you everything?

  9. Meh. Bigger is not always better – that’s why we don’t have 200 ton tanks, our guided missile destroyers are not 1500 feet long, and nobody concealed-carries a bofors 40mm cannon.

    We technically CAN build huge guns – have done so long ago. The Germans did it in WWII with rail guns, which had very little impact on the war because they weren’t very mobile.

    The Japanese 18″ cannons on the Yamato were inferior to the American 16″ cannons on the New Jersey class battleships.

    As for the gun vs missile argument posed by the article’s author, its “horses for courses”. Guns are far superior to missiles for some applications.

    • If the dinochrome brigade shows up its time to go home. Also even they can be beaten. Eventually simple attrition won (ok everyone lost, but still) against the bolos

  10. where some science fiction-loving scientists dreamed-up ways to repel an alien invasion.

    IF a hostile race wanted us out of the way a simple asteroid nudge would solve all their problems. So I have a tough time reconciling a great Independence Day win.

  11. Schwerer Gustav, the Paris Gun and the V-3 Cannon showed what really big guns can do — which is not much. At “best,” they’re terror weapons. At worst, they’re massive money sinkholes.

    Besides, as we saw in “Independence Day: Resurgence,” the only way to kill an alien is to get behind him and chop off his head with a BFK (Big Kukri).


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