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Archimedes Death Ray
Werner Heuser writes "Ancient Greek and Roman historians recorded that during the siege of Syracuse in 212 BC, Archimedes (a notably smart person) constructed a burning glass to set the Roman warships, anchored within bow and arrow range, afire. The story has been much debated and oft dismissed as myth ... Intrigued by the idea and an intuitive belief that it could work, MIT's 2.009ers decided to apply the early product development 'sketch or soft modeling' process to the problem."
For the unitiated, 2.009 at MIT is a class in course 2 (mechanical engineering), called Product Engineering Processes.
I always thought it was a mirror he used. A mirror can at least be aimed whereas with a lens you could only butn a target directly in front of you (with the sun behind you.
I want to kick you in the tits. Then I want to punch you in the catcher's mitt.
Then I want to make sweet anal love to you.
That is all.
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Not to argue that the mythbusters are always right, but they've disproved this in one of thier episodes. They did some pretty good convincing after building a trireme and using a few hundred mirrors and only reaching a couple of hundred degrees (F).
h busters.html
Mythbusters: http://dsc.discovery.com/fansites/mythbusters/myt
IT BURRRRRNS! The same Archimedes whose last words were "Do not disturb my circles!" at Syracuse. The Wikipedia article links to the same story at MIT. http://en.wikipedia.org/wiki/Archimedes Quite the inventor!
This sort of demonstration has been done before. I remember reading an article in Time magazine in the 1960's or 70's that reported on one such earlier experiment. Many men held polished flat "shields" in the sun at the right angle, and confirmed that they could cause charring in a simulated boat target.
Not exactly the same concept, but the Solar Death Ray always reminded me of this.
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Yes, but IIRC the show also pointed out that an earlier generation of mythbusters had demonstated it is possible to set a wooden boat on fire using soldiers holding large mirrors. Each soldier directs an individual mirror onto the boat, use enough mirrors and it will start smoking.
I don't belive the ancient greeks had the technology to make a glass lense large enough to fry a boat, let alone focus on a moving target. However it is certainly possible using multiple mirrors, even the crude ones made from polished metal like Archimedies would have had access to.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
It's worth pointing out that the availability of really useful materials for incendiary warfare was notably lacking in the ancient world at this time. Even the Romans, with their much more sophisticated war machine never managed to deploy fire based weapons of any magnitude.
Dr Lendon of the University of Virginia and a leading expert on combat in the ancient world is oft quoted in reference to the opening scenes of Gladiator as saying this:
"The opening battle is remarkably accurate for a Hollywood depiction of Roman warfare... if you think away the Napalm. The Romans didn't have anything more flammable than olive oil"
Flaming arrows, while they make good cinematography, weren't in the Greek arsenal at the time.
Killfile(TGK)
No trees were killed in the creation of this post. However, many electrons were inconvenienced.
"Carbon in the wood is burning, which means the surface is at least 750 degrees F. "
So what's that in units that the rest of the world uses?
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I saw that too, but I also saw a BBC program where they used a smarter design using metal mirrors, and they managed to burn the ship allright. So the principle works.
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It's in Spanish, but it does have a photograph of about 40 of the 70 man-sized mirrors they used. He managed to ignite a tarred wooden boat in about 3 minutes.
I am now seeing "Forbidden" when trying to access the original MIT web page, however Google claims there is mention of the Sakkis experiment on this one (also forbidden).
Heron of Alexandria invented a kind of steam engine. He was mathematician, physicist, and an engineer who lived between 10 and 70 AD.
Yes, the Romans did not have Napalm. However, the Greeks had "Greek Fire", which is somewhat similar. So this kind of knowledge did exist in ancient times.
Read your link. Greek fire was invented in 673 AD.
Andam Hart Davis has a programme on the BBC at the moment and in it he created the experiment at a smaller scale. He used a round disc with a lot of small flat mirrors that could be tilted to focus a beam of light onto a boat. With in a few seconds smoke started coming out. It worked and was shown on tv recently.
So i got to read it...
Looks like they calculated how much energy it would take, then upped that by a bit, then carefully aimed their mirrors to achieve the required flux. It worked. If they were able to get smoke from 129 self-aimed, 1ft. mirrors, get a few thousand soldiers on a hill, and see what they can do.
btw... the math on the power of the mirrors is wrong. if the mirrors are flat (and you can think of a curved mirror as many small flat ones), then the mirrors effectively apear to be another sun. from the targets point of view a mirror(or part of one) is either reflecting the sun or not. The total flux at any point comes from how big (angular) the total surface of all the reflecting mirrors apears to the target. That's why a small, close, shaped reflector (or lens) can burn things, and why it's harder to scale up.
-John Fenley
Actually this is almost entirely incorrect.
They used spot lights to determine altitude only, the normal aircraft instruments indicated whether they were level and they used a bomb sight calibrated against the postion of towers on the dam to determine distance (basically a Y shaped stick with some nails in it. With the bomb aimer's eye at one end the marks at the other two aligned with the towers when the aircraft was at the correct distance to drop the bomb).
I learned in boyscouts a very simple way to aim the reflection of the sun from a mirror at a distant object. You need a mirror that is reflective on both sides with a hole in it. Look through the hole at the target. There should be a spot of sunlight on the ground or your body from the sun shining through the hole in the mirror. Angle the mirror such that the reflection in the back of the mirror of this spot of light lines up with hole in the mirror. The suns rays will now be directed at the target. Many outdoor provisions companies sell small mirrors of this type for signalling purposes in emergencies.
I can only assume you were misinformed or made the wrong assumption about the show. Perhaps you are missing out on what Mythbusters is about. It's this funny little thing called "entertainment".
It is not an "Educational" program. It's about 2 guys who used to do FX work for Hollywood using their skills with "getting close" to the right thing trying to see if they can replicate urban legends.
The funny thing is, you probably missed the episodes where they revisit old myths they worked on. If the show receives enough requests from the audience or they decide they didn't do something justice, they give it another go. They did the "chicken gun" myth a couple times because they kept doubting their setup. I didn't get to catch the final conclusion, but I would say that by the time they were done, they had tried everything available to them to see what would happen.
Other examples of where they've done things incredibly right include hanging a pig carcass from a hook on a pivot and shooting it with various guns to prove that no, taking a gunshot does not make you fly back and do cartwheels, and using a ballistics gel dummy (with a pig backbone to simulate the human one) to determine if you could be injured by a ceiling fan (even the high-powered ones didn't do much until they sharpened the blades).
Yes, most people who have shot guns would understand that Hollywood fakes it, but for the average Joe who just watches movies and TV, with no physics background, it was probably something neat to see.
Yes, they blow stuff up. They put a crash test dummy through hell. Yes, they keep fuck-ups on the film, because that makes the show more approachable to the target audience- it isn't a dry, we-just-provide-the-facts-ma'am-only-the-facts show. It is supposed to feel like you and you buddies could be right there with them. You know what, though? It's entertaining. And for a channel that brings us 5 variations on "hey, we're going to destroy a room in your house by letting a half-assed decorator come in and ruin your happiness", it's a damn good show.
Many of their conclusions are valid. They've shown that pissing on the "live" rail of a 3-rail train system will not shock you (urine stream is too fragmented by the time it hits the rail for electricity to travel), exactly how many bug bombs you would have to set off in a room with an ignition source before the gas was concentrated enough to explode, and that you cannot get sucked into the intake on one of those firefighting helicopters while wearing scuba gear, only to be dumped into the fire and die.
I respect the fact that MIT has its own unique course numbering system, and curricula are referred to by numbers rather than by name. However, it does bug me that MIT folks expect their bizarre internal numbering to make sense to outsiders. If one didn't know better, one might even see it as some sort of bizarre exclusionary "in group" code. But I suspect that it's just cluelessness, combined with intense isolation.
There is a technique for aiming the mirrors easily and quickly, provided that one person holds each mirror and the mirrors are reflective on both sides. Make a hole in the center of the mirror. Open only one eye. Position the mirror so that you see the target in the hole and the sun shines through the hole onto your face. Tilt the mirror so that the image of the spot of sun on your face is centered on the hole.
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You were watching PBS... just giving credit where credit is due. It was excellent. I had to double check that I still didn't have cable or satellite.
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