# Best way to blow up the Pyramids? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [August 23, 2017, 3:53pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469 "2017-08-23T15:53:27Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [August 23, 2017, 5:48pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/21 "2017-08-23T17:48:00Z")
> [@Richard\_Parker](#): > > Each cubic foot of tungsten traveling at fast-meteorite speed (100km/s) has a kinetic energy of roughly 2.5 terajoules. A sub-orbital payload doesn’t travel at “fast meteorite” speeds, a sub-orbital payload travels at sub-orbital speeds. Even [launched from an orbiting spacecraft](https://en.wikipedia.org/wiki/Kinetic_bombardment) and not an ICBM-type situation: [QUOTE=Wikipedia] In the case of the system mentioned in the 2003 Air Force report above, a 6.1 m × 0.3 m tungsten cylinder impacting at Mach 10 has a kinetic energy equivalent to approximately 11.5 tons of TNT (or 7.2 tons of dynamite). The mass of such a cylinder is itself greater than 9 tons, so the practical applications of such a system are limited to those situations where its other characteristics provide a clear and decisive advantage—a conventional bomb/warhead of similar weight to the tungsten rod, delivered by conventional means, provides similar destructive capability and is far more practical and cost effective. [/QUOTE] You’re gonna need a much, much, much, much bigger ship. ---
**Author:** ![Richard\_Parker](https://avatars.discourse-cdn.com/v4/letter/r/35a633/32.png) [@Richard\_Parker](https://boards.straightdope.com/u/Richard_Parker)\ **Post date:** [August 23, 2017, 5:52pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/22 "2017-08-23T17:52:59Z")
> [@Darren\_Garrison](#): > > A sub-orbital payload doesn’t travel at “fast meteorite” speeds, a sub-orbital payload travels at sub-orbital speeds. What does that restriction follow from? My use of the word “missile”? If so, abandon that restriction, if you like. We build a space weapon. It accelerates itself around the sun before looping back to strike the pyramids. Revenge of Ra! ---
**Author:** ![silenus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/silenus/32/166_2.png) [@silenus](https://boards.straightdope.com/u/silenus)\ **Post date:** [August 23, 2017, 6:00pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/23 "2017-08-23T18:00:29Z")
2 five-year-olds, a plastic hammer and a puppy. Pyramid to pile of rubble in 15 minutes. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [August 23, 2017, 6:06pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/24 "2017-08-23T18:06:44Z")
> [@Richard\_Parker](#): > > Each cubic foot of tungsten traveling at fast-meteorite speed (100km/s) has a kinetic energy of roughly 2.5 terajoules. Where did _that_ number come from??? The [fastest meteor ever recorded](http://www.nature.com/news/us-meteorite-was-fastest-on-record-1.12095#/b1) is 26.8 km/s. Most meteorites aren’t much faster than 11 km/s (escape velocity). Sub-orbital missiles are near orbital speed at most (7 km/s). ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [August 23, 2017, 6:09pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/25 "2017-08-23T18:09:33Z")
Forget bombs. [This](http://www.popsci.com/bagger-288-facts) is the tool you want. ---
**Author:** ![Richard\_Parker](https://avatars.discourse-cdn.com/v4/letter/r/35a633/32.png) [@Richard\_Parker](https://boards.straightdope.com/u/Richard_Parker)\ **Post date:** [August 23, 2017, 6:13pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/26 "2017-08-23T18:13:37Z")
> [@scr4](#): > > Where did _that_ number come from??? The [fastest meteor ever recorded](http://www.nature.com/news/us-meteorite-was-fastest-on-record-1.12095#/b1) is 26.8 km/s. Most meteorites aren’t much faster than 11 km/s (escape velocity). Sub-orbital missiles are near orbital speed at most (7 km/s). It came from googling “meteorite speed” and rounding up from 72km/s. IS THAT NOT RIGOROUS ENOUGH FOR YOU??? ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [August 23, 2017, 6:14pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/27 "2017-08-23T18:14:53Z")
> [@Richard\_Parker](#): > > What does that restriction follow from? My use of the word “missile”? From physics. If something is traveling at a speed higher than orbital velocity, then you have just launched an interplanetary or interstellar missile, not a intercontinental one. > [@](#): > > If so, abandon that restriction, if you like. We build a space weapon. It accelerates itself around the sun before looping back to strike the pyramids. Revenge of Ra! Okay, say that the projectile was traveling at Earth orbital velocity. A quick estimate looking at a Google maps image is that the width covering the three main pyramids at Giza is around 1500 meters. Which is a bit larger than Meteor Crater in Arizona. For the sake of argument, let’s say an object the same size as the one that made Meteor Crater would be the right size to wipe out the pyramids. That nickel-iron meteorite is estimated to be in the range of 50 meters across, weighing in the range of a billion kilograms. So you’d need that. ---
**Author:** ![cochrane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cochrane/32/10441_2.png) [@cochrane](https://boards.straightdope.com/u/cochrane)\ **Post date:** [August 23, 2017, 6:20pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/28 "2017-08-23T18:20:25Z")
> [@Darren\_Garrison](#): > > It is interesting that most photos of the pyramids (even modern ones) are framed to make it look like they are located deep in a sweeping desert, possibly with a few Bedouin and camels in the photo to imply the long and arduous journey that you have to take to reach them. Then there is [this](https://photos.smugmug.com/Travel/Egypt-and-Jordan-ERM/Egypt/i-qnpttkX/0/ca84a841/X2/IMG_0096-2-X2.jpg), showing that now, they are basically a theme park in the middle of a city. So Cairo is basically Las Vegas without the roulette and blackjack? ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [August 23, 2017, 6:22pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/29 "2017-08-23T18:22:24Z")
> [@Richard\_Parker](#): > > It came from googling “meteorite speed” and rounding up from 72km/s. IS THAT NOT RIGOROUS ENOUGH FOR YOU??? BTW, the difference between a fast meteoroid and a slow meteoroid is the direction that they are coming from–a car going 60 miles per hour and a car going 50 mph hitting head on has a combined velocity of 110 mph. A car going 60 mph hitting a car going 50 mph from behind has a combined velocity of 10 mph. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [August 23, 2017, 6:25pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/30 "2017-08-23T18:25:50Z")
To be clear, when I say “Earth orbital velocity” in post #27, I mean the velocity of Earth’s orbit around the sun, not the velocity of something orbiting the Earth. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [August 23, 2017, 6:29pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/31 "2017-08-23T18:29:08Z")
> [@Richard\_Parker](#): > > It came from googling “meteorite speed” and rounding up from 72km/s. IS THAT NOT RIGOROUS ENOUGH FOR YOU??? Even if we accept 72 km/s, multiplying by two (in terms of energy) goes a bit beyond “rounding up.” ---
**Author:** ![Arrogance\_Ex\_Machina](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/arrogance_ex_machina/32/192_2.png) [@Arrogance\_Ex\_Machina](https://boards.straightdope.com/u/Arrogance_Ex_Machina)\ **Post date:** [August 23, 2017, 6:36pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/32 "2017-08-23T18:36:44Z")
> [@Richard\_Parker](#): > > What does that restriction follow from? My use of the word “missile”? > > If so, abandon that restriction, if you like. We build a space weapon. **It accelerates itself around the sun** before looping back to strike the pyramids. Revenge of Ra! (bolding mine) I think you need to play more Kerbal Space Program before we’ll take space weapon ideas from you. ---
**Author:** ![Richard\_Parker](https://avatars.discourse-cdn.com/v4/letter/r/35a633/32.png) [@Richard\_Parker](https://boards.straightdope.com/u/Richard_Parker)\ **Post date:** [August 23, 2017, 6:40pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/33 "2017-08-23T18:40:40Z")
> [@Darren\_Garrison](#): > > From physics. If something is traveling at a speed higher than orbital velocity, then you have just launched an interplanetary or interstellar missile, not a intercontinental one. Who said anything about intercontinental? Again, if you are somehow taking that from my post, feel free to reject that limitation. > [@Darren\_Garrison](#): > > Okay, say that the projectile was traveling at Earth orbital velocity. A quick estimate looking at a Google maps image is that the width covering the three main pyramids at Giza is around 1500 meters. Which is a bit larger than Meteor Crater in Arizona. For the sake of argument, let’s say an object the same size as the one that made Meteor Crater would be the right size to wipe out the pyramids. That nickel-iron meteorite is estimated to be in the range of 50 meters across, weighing in the range of a billion kilograms. So you’d need that. Seems like overkill. We can use three of these interstellar tungsten projectiles, if you like. But also…is there some reason they have to travel as slow as that meteorite did? Suppose we accelerate them on a Project Orion style spacecraft, and that humanity is content to wait an arbitrarily long time for them to strike. What keeps them from traveling at, say, 200m/s instead of 100m/s? Gotta think big if you wanna blow up the pyramids. > [@scr4](#): > > Even if we accept 72 km/s, multiplying by two (in terms of energy) goes a bit beyond “rounding up.” LOL. Yeah. I think there may be one or two other problems with the rigor of the method. Please, feel free to provide a more rigorous approach to how to blow up the pyramids using a kinetic strike from outerspace. ---
**Author:** ![Richard\_Parker](https://avatars.discourse-cdn.com/v4/letter/r/35a633/32.png) [@Richard\_Parker](https://boards.straightdope.com/u/Richard_Parker)\ **Post date:** [August 23, 2017, 6:42pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/34 "2017-08-23T18:42:36Z")
> [@Arrogance\_Ex\_Machina](#): > > (bolding mine) > > I think you need to play more Kerbal Space Program before we’ll take space weapon ideas from you. If you’re taking space weapons ideas from me, something has gone terribly wrong. I agree. What’s the problem with the sun? Too hot? ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [August 23, 2017, 7:16pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/35 "2017-08-23T19:16:23Z")
> [@Richard\_Parker](#): > > But also…is there some reason they have to travel as slow as that meteorite did? Suppose we accelerate them on a Project Orion style spacecraft, and that humanity is content to wait an arbitrarily long time for them to strike. Well, I was working under the assumption that there was an unstated implication of the destruction being done using currently existing technologies. If you want to go exotic, you could go with a [sun gun](https://en.wikipedia.org/wiki/Sun_gun). There is also the concept (which I’m not successfully googling up at the moment) of surrounding a star with a Dyson shell of mirrors and using those to focus a large percentage of that star’s energy on a single target, possibly using it as an interstellar weapon to vaporize planets in nearby solar systems. That would do the job, too. ---
**Author:** ![UncleRojelio](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/unclerojelio/32/3160_2.png) [@UncleRojelio](https://boards.straightdope.com/u/UncleRojelio)\ **Post date:** [August 23, 2017, 7:20pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/36 "2017-08-23T19:20:20Z")
> [@Arrogance\_Ex\_Machina](#): > > (bolding mine) > > I think you need to play more Kerbal Space Program before we’ll take space weapon ideas from you. I wish we had had a “Thumbs up” button here. ---
**Author:** ![Richard\_Parker](https://avatars.discourse-cdn.com/v4/letter/r/35a633/32.png) [@Richard\_Parker](https://boards.straightdope.com/u/Richard_Parker)\ **Post date:** [August 23, 2017, 7:23pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/37 "2017-08-23T19:23:35Z")
> [@Darren\_Garrison](#): > > Well, I was working under the assumption that there was an unstated implication of the destruction being done using currently existing technologies. If you want to go exotic, you could go with a [sun gun](https://en.wikipedia.org/wiki/Sun_gun). There is also the concept (which I’m not successfully googling up at the moment) of surrounding a star with a Dyson shell of mirrors and using those to focus a large percentage of that star’s energy on a single target, possibly using it as an interstellar weapon to vaporize planets in nearby solar systems. That would do the job, too. Sun gun is perfect. Get the scientists working on the technology! But is the tungsten meteor outside our current prowess? We can certainly shoot a rocket at the moon and have it come back at the Earth at well over 200m/s. Is it a matter of having it go much faster than that in order to have that velocity after traveling through the atmosphere? The precision of the targeting? ---
**Author:** ![UncleRojelio](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/unclerojelio/32/3160_2.png) [@UncleRojelio](https://boards.straightdope.com/u/UncleRojelio)\ **Post date:** [August 23, 2017, 7:29pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/38 "2017-08-23T19:29:24Z")
> [@Richard\_Parker](#): > > But is the tungsten meteor outside our current prowess? We can certainly shoot a rocket at the moon and have it come back at the Earth at well over 200m/s. Is it a matter of having it go much faster than that in order to have that velocity after traveling through the atmosphere? The precision of the targeting? Just because no one has posted it yet, the wikipedia page on [Kinetic Bombardment](https://en.wikipedia.org/wiki/Kinetic_bombardment) ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [August 23, 2017, 7:32pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/39 "2017-08-23T19:32:56Z")
A giant magnifying glass to focus the sun’s rays on a pyramid and melt it. ---
**Author:** ![Mr.Nylock](https://avatars.discourse-cdn.com/v4/letter/m/77aa72/32.png) [@Mr.Nylock](https://boards.straightdope.com/u/Mr.Nylock)\ **Post date:** [August 23, 2017, 7:49pm UTC](https://boards.straightdope.com/t/best-way-to-blow-up-the-pyramids/794469/40 "2017-08-23T19:49:07Z")
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