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Archimedes Death Ray 584

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."
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Archimedes Death Ray

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  • MIT numbering... (Score:5, Informative)

    by Anonymous Coward on Wednesday October 12, 2005 @09:50PM (#13778803)
    For the unitiated, 2.009 at MIT is a class in course 2 (mechanical engineering), called Product Engineering Processes.
    • by Anonymous Coward
      called Product Engineering Processes

      So that would make class lectures PEP talks? *ducks*
    • MIT numbering... (Score:4, Informative)

      by dachshund ( 300733 ) on Thursday October 13, 2005 @09:43AM (#13781646)
      For the unitiated, 2.009 at MIT is a class in course 2 (mechanical engineering), called Product Engineering Processes.

      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.

      • by porcupine8 ( 816071 ) on Thursday October 13, 2005 @10:10AM (#13781872) Journal
        As an MIT person, I can honestly say I have no idea why anyone would include a course number in their submission and expect it to make any sense to anyone else. But then, people often include random acronyms or other jargon in their submissions that require explanation in the comments - so I don't think it's an MIT-only problem. Just in general, /.ers who either think "Oh, this is common knowledge!" when it's not, or "Hey, I'll show how extra-special I am by using terminology nobody else knows!"
  • by patio11 ( 857072 ) on Wednesday October 12, 2005 @09:51PM (#13778807)
    ... and the server is a smoking husk before the first comment is posted.
  • Glass? (Score:2, Informative)

    by rossdee ( 243626 )
    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.
    • Re:Glass? (Score:5, Funny)

      by rpj1288 ( 698823 ) on Wednesday October 12, 2005 @11:03PM (#13779161)
      A mirror can also prevent the server from burning up.
    • by MoreDruid ( 584251 ) <moredruid@noSpaM.gmail.com> on Wednesday October 12, 2005 @11:34PM (#13779319) Journal
      Maybe he devised a combination of the two. A conical mirror to catch the sunrays and aim them, then a lens to bundle them even more.

      I remember a Mythbuster episode where Adam & Jamie try to reproduce this myth/story. They were not able to set a boat hull on fire (they built a replica-piece of boat hull from that age). Stronger still they barely managed to get the temperature higher up... iirc it was only a few degrees higher in the focused center of the beam.

      • 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.
      • by Scrameustache ( 459504 ) on Thursday October 13, 2005 @08:41AM (#13781133) Homepage Journal
        I remember a Mythbuster episode where Adam & Jamie try to reproduce this myth/story. They were not able to set a boat hull on fire (they built a replica

        I remember that episode, they couldn't set their replica on fire even when they poured gasoline on it and set that on fire!

        Adam's credibility was busted, not Archimedes'.
      • by Svartalf ( 2997 ) on Thursday October 13, 2005 @10:04AM (#13781814) Homepage
        There's things about what Adam and Jamie does to "bust" myths that end up being "wrong" and they
        bust myths that aren't myths. The chicken gun story is a prime example. They'd "proven" that
        it was not possible to have what was described in the chicken gun- but what they did was miss
        what the conditions were and didn't test the actual story's premise. When re-done in a recap
        story trying to revisit the whole idea, they more closely duplicated the whole set of conditions
        and ended up reversing the decision they'd come to on it. The cell-phone story was debunked
        but it wasn't debunked appropriately- again they didn't reproduce the conditions. They used
        a non flip-phone cell-phone with capacitive operated buttons. No way for the phone to EVER
        introduce a spark into an environment. I'm of their opinon on that one- it's a myth, but to
        claim that it is off of their test on the subject is bad science.

        Don't get me wrong, Mythbusters' is a great show and the bulk of the stuff they do is highly
        accurate; but they should never ever be held as a final authority because they're a much
        about showmanship as they're about mythbusting and miss many things. The MIT project apparently
        shows this situation to be another one of those, "they didn't get the conditions right to
        properly test and prove/disprove anything" situations they're guilty of on a periodic basis.
  • by bcat24 ( 914105 ) on Wednesday October 12, 2005 @09:54PM (#13778829) Homepage Journal
    The server seems really slow right now, try this [nyud.net].
    • by Tripman ( 88428 ) <tripmanic.gmail@com> on Wednesday October 12, 2005 @10:08PM (#13778905)
      Mirrordot is proving more reliable for me:

      http://www.mirrordot.org/stories/90e7777b89ad9e538 15d479865f65c52/index.html [mirrordot.org]

      • by cluckshot ( 658931 ) on Wednesday October 12, 2005 @10:22PM (#13778976)

        I don't suppose that reminding the crowd that Archamedes had quite a history building some pretty massive things and doing so using some pretty cute tricks with some really high math is in order. I am quite sure that Archamedes was aware of the solar reflection and other issues. It is my understanding that he used bronze mirrors of very large size that were essentially slightly parabolic with a focal range about 1 mile. I do know he possessed the math, and architectural skills to do this. This is typical of ratio projection used in buildings.

        I do know the results in history of this man's work are pretty well established. He pretty much set about and did whatever he intended to do. As a scientist he was neither politically correct nor foolish. He was the best of his time and frankly would have been pretty good today.

        The Mythbusters assumed that some things were too big to do. This would not have been a problem for a man who engineered the roofing of big Greek buildings.

        • Two possibilities (Score:5, Interesting)

          by jd ( 1658 ) <<moc.oohay> <ta> <kapimi>> on Thursday October 13, 2005 @01:34AM (#13779758) Homepage Journal
          It depends on how large an area the mirrors would have been placed, whether they were flat or parabolic, etc. If we assume relatively narrow, flat mirrors then the problem becomes slightly different. All you'd then need is for each mirror to be on a pole.


          Since the Greeks had gears [wikipedia.org] and ropes, it would have been possible to build a mechanism whereby one person could rotate many mirrors. I'm not saying it would have been easy, or even that it was done this way, only that they had all of the required technology to do it.


          A second possibility would have been similar to the sighting mechanism used very successfully by the Dambusters in their attacks in World War II on German dams. They needed to know when they were at a certain height above the water, level, and at a certain distance from the dams. They achieved this by angling the searchlights to cross over at the right height and strike the dam at the right distance. To know if they were level, they used pieces of wood at different distances, which would line up when the aircraft was level.


          To line the mirrors up with the ship, you'd need to know when the light from the sun would strike the ship at the right height. Angle of incidence equals angle of reflection, so as the sun moves through the sky, you'd need to shift the mirrors both horizontally and vertically to keep the light on the right spot.


          If you had a hole in the mirror and stood behind it, you could swivel the mirror to face the ship. Since the ship would be at water level and the mirror would probably have been much higher, the mirror would have to have pointed at the tallest mast. It would be the only thing visible. To ensure all mirrors pointed the right way, each mirror would need behind it a stick that needed to line up with the mast, but set at an angle such that each mirror would line up differently along a crude parabolic curve. Shouldn't have been hard, with the Greek knowledge of geometry, which they were exceptionally good at.


          If the action was brief enough and at the right time of day and at a predictable distance, the vertical angle would be unimportant. If it had to be ready for ANY time of day OR at ANY distance, then you'd need to have the poles on which the mirrors were attached themselves movable.


          If you mounted the pole on one end of a see-saw, then added weights to the other end, you would be able to adjust the vertical angle of the mirror to whatever was required. The line of the see-saw would be parallel to the normal of the mirror. You can tilt the mirror such that the reflected light will intersect the ship at the same point that the line along the see-saw intersects the ship. This would guarantee all mirrors get identical vertical alignment.


          We now have a guaranteed way of aligning a great many mirrors onto an identical point on a ship at any distance at any time of day, using nothing more than geometry, alignments and pivots. Again, this is NOT to say that this is how it was done - we don't know HOW it was done, or even IF it was done. What this is saying is that the arguments against have largely been based on sophistication, but that the required level of sophistication was certainly achievable had anyone wanted to achieve it.

  • Mythbusters (Score:4, Informative)

    by fimbulvetr ( 598306 ) on Wednesday October 12, 2005 @09:54PM (#13778832)
    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).

    Mythbusters: http://dsc.discovery.com/fansites/mythbusters/myth busters.html [discovery.com]
    • Re:Mythbusters (Score:5, Informative)

      by pete-classic ( 75983 ) <hutnick@gmail.com> on Wednesday October 12, 2005 @10:06PM (#13778895) Homepage Journal
      I like mythbusters, but they missed the boat, so to speak, on this one.

      I build a Death Ray [hutnick.com] and it works great.

      -Peter
      • Re:Mythbusters (Score:5, Interesting)

        by HermanAB ( 661181 ) on Wednesday October 12, 2005 @11:47PM (#13779381)
        Nice project - though since you had a properly shaped parabolic reflector already, you could simply have coated it with aluminium foil - no need for glass, as the mirror stuff on the back of the glass is aluminium. I once saw a documentary showing that some people in the desert areas of China cook food with 1.5m parabolic reflectors and they easily bring a pot or a kettle to the boil with it.
    • by Anonymous Coward on Wednesday October 12, 2005 @10:07PM (#13778902)
      If you check out the application [discovery.com] to develop a better death ray experiment, you see that one of the criteria for participation is:

      You must not be a candidate for elected public office, and if selected as a participant, you will not become a candidate for elected public office until 12 months after the initial broadcast of the last episode of the series in which you appear.

      I'm wondering if their logic is "If you can build a death ray, you can't run for office, since it would give you an unfair advantage. Who the hell is going to vote against the guy with the death ray?"
      • Re:Mythbusters (Score:5, Informative)

        by skiflyer ( 716312 ) on Wednesday October 12, 2005 @10:58PM (#13779119)
        In case you're serious, it's because of airtime laws and public elections. If they put this person on TV and their a political candidate, then they must also allow equal airtime to their opponents.

        I like your idea better though.
    • Re:Mythbusters (Score:4, Interesting)

      by blackcoot ( 124938 ) on Wednesday October 12, 2005 @10:10PM (#13778913)
      i saw that episode (as did the folks who did that project, if you read the article). the mythbusters folks didn't really build a parabolic mirror so much as a poor approximation thereof and they didn't really do a good job of focussing it, so it makes sense that they had problems making it work.
    • Re:Mythbusters (Score:5, Informative)

      by LnxAddct ( 679316 ) <sgk25@drexel.edu> on Wednesday October 12, 2005 @10:14PM (#13778936)
      Not to argue that the mythbusters are always wrong, but they were wrong this time. Not only does the number of mirrors count, but they must be lined along a parabolic path, must be "perfectly" flat (in this case) and as the article stated, the point of focus changes at 36 feet per hour so you have to keep the mirrors "up to date". There are a lot of factors to take into account, and optical physics to solve. You can clearly see MIT's results, setting the ship on fire, and it was made out of wood stronger than what would have been used by the Romans. The ship hit over 1100 degrees and burnt pretty well. Moral of the story: Myth Buster's results no longer matter because a contradiction to them was proven to exist.
      Regards,
      Steve
      • Re:Mythbusters (Score:5, Interesting)

        by Wavicle ( 181176 ) on Wednesday October 12, 2005 @10:56PM (#13779111)
        Okay, if we're going to use this argument...

        In the MIT experiment, the boat was arguably a very poor replica of a trireme. It was painted black to optimize the energy transfer (which in the end didn't matter). The target was not moving, only the sun. The target was not in water. Highly polished silver on a superflat surface would have been the closest thing that the ancient greeks could have had to simulate those mirrors, and if such a thing were possible, it would have been enormously expensive. The greeks would have had people holding the mirrors, not tables and stands.

        At 100 feet, your each soldier's heartbeat would have defocused the weapon, even if he could otherwise hold perfectly still (which he couldn't). To protect the soldiers from archers, Archimedes' weapon would have to hold focus at a much greater distance.

        All these things the MythBusters got much close to right and the MIT folks avoided.

        Nobody is arguing that focusing the sun on something won't result in transfer of lots and lots of energy. That would be just silly (the web page says they wanted to see if it was at least possible - damn, they had to go to MIT to figure out a finite amount of energy will cause wood to burn?!). The question is could such a thing have been constructed and put into use by the Greeks. And that's something the MIT folks answered far less effectively.
        • Re:Mythbusters (Score:5, Insightful)

          by dangitman ( 862676 ) on Thursday October 13, 2005 @05:52AM (#13780370)
          In the MIT experiment, the boat was arguably a very poor replica of a trireme. It was painted black to optimize the energy transfer (which in the end didn't matter).

          Why would the greeks have tried to set fire to the wood? It would me much easier to target the sails, and they would burn much more quickly. Once the sails are burning, the wood follows. I don't understand why modern people have such problems following logic, and instead have such faith in modern products, and complex solutions rather than simple ones.

        • Re:Mythbusters (Score:4, Interesting)

          by 99BottlesOfBeerInMyF ( 813746 ) on Thursday October 13, 2005 @08:23AM (#13780981)

          In the MIT experiment, the boat was arguably a very poor replica of a trireme. It was painted black to optimize the energy transfer (which in the end didn't matter).

          Actually a lot of the boats of the time were black. In any case, they would probably have targeted the sails if they were unfurled, being higher and easier targets.

          Highly polished silver on a superflat surface would have been the closest thing that the ancient greeks could have had

          I think bronze, or white bronze seems a lot more likely.

          The greeks would have had people holding the mirrors, not tables and stands.

          Because the greeks had not yet invented tables or stands?

          At 100 feet, your each soldier's heartbeat would have defocused the weapon, even if he could otherwise hold perfectly still...

          Again, because they had not invented stands yet?

          To protect the soldiers from archers, Archimedes' weapon would have to hold focus at a much greater distance.

          Or they could be standing behind big sheets of bronze.

          All these things the MythBusters got much close to right and the MIT folks avoided.

          I seriously doubt that. Now I'll be the first to admit, I'm no expert on light, reflection, or focal instruments. Similarly, I'm not an expert on Greek history and technology or Archimedes. I do, however, have my aptitudes, some of which have been touched upon by other Mythbusters episodes. It makes you want to cry when you see them making fundamental mistake after fundamental mistake, applying constants that are wrong by three orders of magnitude, and basically making all sorts of assumptions without any real research. Mythbusters are entertainers. They blow things up and make stuff that looks neat on TV, while trying simultaneously trying to address various topics in a very informal, half-assed sort of way. To assume that these jokers can "bust the myth" that a genius figured out how to do something that they are unable to in their five days of quickly throwing crap together without any real expertise or research is the real joke.

          Note, I'm not saying this legend is true, but I am saying I'd never believe that it is not based upon the posturing of these twits.

    • Re:Mythbusters (Score:5, Insightful)

      by Shamashmuddamiq ( 588220 ) on Wednesday October 12, 2005 @10:18PM (#13778950)
      With all due respect, I don't think the Mythbusters are as smart as Archimedes was. You shouldn't impugn someone just because they lived a long time ago.
    • Re:Mythbusters (Score:5, Insightful)

      by scdeimos ( 632778 ) on Wednesday October 12, 2005 @10:27PM (#13778997)
      Not to argue that the mythbusters are always right, but they've disproved this in one of thier episodes.

      Actually, they only disproved their own design and construction methods on this one. A properly-designed and -constructed working model was demonstrated on BBC Two's practical archeology programme, What The Ancients Did For Us [bbc.co.uk]

  • AHH (Score:3, Informative)

    by 42Penguins ( 861511 ) on Wednesday October 12, 2005 @09:54PM (#13778833)
    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 [wikipedia.org] Quite the inventor!
  • by Anonymous Coward on Wednesday October 12, 2005 @09:55PM (#13778834)
    That's an Archimedes Death Ray, now banned from all commercial airline flights. Lame.
  • I'm still waiting for an explanation of who built the Antikythera Mechanism. Was it Archimedes or not?
    • Re:Fire good! (Score:5, Insightful)

      by jericho4.0 ( 565125 ) on Wednesday October 12, 2005 @10:51PM (#13779095)
      Doughtfull at best. The Antikythera Mechanism [wikipedia.org] is probably only one of hudereds or thousands of devices that existed at the time, and many people could have been making, buying and useing similar items. Our knowledge of how the ancient Greeks (and others) actually lived is so fragmentary, and we tend to fill in all the blanks with the lowest common denominator answer, ie; we see no evidence of clockwork, therefore they had no clocks. Before the discovery of the Antikythera Mechanism, the suggestion that the Greeks had clockwork would have been met with scorn.

      Yes, Archimedes was a very smart cookie, but he was surrounded by other smart cookies, who were also geting up to interesting things. IMO, ancient Greece was pretty much as technologicly advanced as 15th century Europe. Why we ended up having the industrial revolution, and the Greeks did not, becomes a very interesting question.

  • by Steve1952 ( 651150 ) on Wednesday October 12, 2005 @09:57PM (#13778845)
    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.
  • Solar Death Ray (Score:5, Informative)

    by bobgoatcheese ( 455695 ) on Wednesday October 12, 2005 @10:00PM (#13778866)
    Not exactly the same concept, but the Solar Death Ray [solardeathray.com] always reminded me of this.
  • by fprog ( 552772 ) on Wednesday October 12, 2005 @10:00PM (#13778868)
    No wonder why the webpage says:
    "Click on image thumbnails to see a larger images. Video clips will be online next week"...

    Why next week?
    Can't we just take down the entire MIT web server! =P

    So, those poor students in mid-session won't be able
    to access to their course material and similar! =)

    That's nice a new excuse just came out!
    "Sir, I couldn't do my assignment, because the MIT web server was slashdotted,
    so I couldn't access the course material, can I get an extension.... PLEASE!!!!"

    So, next time, you guys have a hard deadline assignment,
    please just post an article on slashdot and there you go.

    For everyone else, please use the Mirror...

    http://www.mirrordot.org/stories/90e7777b89ad9e538 15d479865f65c52/index.html [mirrordot.org]
  • No tin foil (Score:5, Funny)

    by complexmath ( 449417 ) * on Wednesday October 12, 2005 @10:07PM (#13778898)
    as tin foil hadn't been invented yet, his enemies would have had no viable defense against this weapon. Devastating!
  • Hm? (Score:3, Interesting)

    by TX297 ( 861307 ) on Wednesday October 12, 2005 @10:09PM (#13778908) Homepage
    I never could quite figure out if this was a hoax or not... but I still wanted to build one anyway. I don't see why not, though.

    Solar Death Ray [solardeathray.com]

    Looks like the renewable energy people are in on it, too [renewablee...access.com]

    I also remember seeing one in my chemistry book last year... it was in france or somewhere (theoretically temperatures could get high enough to ignite something with a low flashpoint like wood or paper). The mythbusters' argument was that copper wasn't shiny enough and that even with mirrors, the soldiers wouldn't have enough precision to focus on a point for long enough.

    -TX297

  • by complexmath ( 449417 ) * on Wednesday October 12, 2005 @10:24PM (#13778987)
    in 212 BC, Archimedes (a notably smart person) constructed a burning glass to set the Roman warships, anchored within bow and arrow range, afire.

    If the enemy ships were anchored within bow and arrow range, I suspect that while Archimedes was fiddling with his mirrors, a few archers dipped their arrows in pitch and fired them at the fleet. Eventually, when Archimedes finished aiming his master weapon he was overjoyed to discover the fleet in flames. Archimedes reported his success to the king, and went down in history as the oldest recorded example of a horribly over-engineered solution to a simple problem.
    • Re:He was duped (Score:5, Informative)

      by TGK ( 262438 ) on Wednesday October 12, 2005 @10:54PM (#13779105) Homepage Journal
      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.
      • Re:He was duped (Score:4, Interesting)

        by Galvatron ( 115029 ) on Thursday October 13, 2005 @01:37AM (#13779770)
        The Romans didn't have anything more flammable than olive oil

        Huh, that surprises me. Wasn't pine sap one of the more common incendiaries during the Middle Ages? I suppose that there probably aren't a lot of pine trees in Italy, but presumably they existed somewhere in the Empire, and I imagine that other saps would work alright as well.

      • Re:He was duped (Score:3, Informative)

        by perrin ( 891 )
        Yes, the Romans did not have Napalm. However, the Greeks had "Greek Fire" [wikipedia.org], which is somewhat similar. So this kind of knowledge did exist in ancient times.
  • Lost Technology (Score:3, Interesting)

    by fm6 ( 162816 ) on Wednesday October 12, 2005 @10:30PM (#13779009) Homepage Journal
    Technologists from the classical era did a lot of stuff that's never been reproduced. For example, reports of Alexander the Great's funeral claim that vehicle carrying his body had fairly good shock absorbers. Nothing special by today's standards — but a modern engineer has much better materials to work with. How were they able to build such an item with the materials available in 323 BC? Nobody knows.

    This, of course, is where the "Gods From Space" crowd chimes in. Works on TV [wikipedia.org], but in real life, there's a much more satisfying answer: people are damned fucking clever.

  • by TummyX ( 84871 ) on Wednesday October 12, 2005 @11:47PM (#13779383)
    They run these unscientific experiments (most involving explosions or decaying corpses) and then "conclusively bust" myths. Some experiments are fun and interesting, but most don't deserve the hard conclusions they assign.

    It's really annoying when people take accept their "proofs" as proofs.
    • Oh ye ghods yes (Score:3, Insightful)

      by Medievalist ( 16032 )

      Thanks for the breath of fresh air, Tum.

      WWF (aka All Georgia Pro Wrestling) = entertainment
      Penn & Teller's "Bullshit" = acerbic entertainment
      Mythbusters = geeky entertainment

      Nothing on any of these shows is any more true than anything you'd see in Archie Comic Books. It's supposed to be fun, people, not a freakin' belief system!

    • MythBusters is what it is. The show is not infallable, but, quite honestly, what do you expect from a mainstream television show? It's a fun hour of TV - the MythBusters have resources available to them that are far beyond what a typical person could expect to have. Where else are you going to see rockets attached to a car, a cement truck blown up with mining explosives, or a giant slingshot?

      Don't take it too seriously. I know that the MythBusters don't.
  • by alanw ( 1822 ) * <alan@wylie.me.uk> on Thursday October 13, 2005 @01:32AM (#13779746) Homepage
    In 1973, a Greek scientist, Dr. Ioannis Sakkas performed the same experiment. There is a discussion at this web site [mlahanas.de], and a link to this one. [editorialbitacora.com]

    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 [mit.edu] (also forbidden).

  • by MichaelKaiserProScri ( 691448 ) on Thursday October 13, 2005 @02:21AM (#13779902)

    Something like only needs to be used once to be effective. After that, the mere idea that it exists is a deterrent. Two other examples of this working:

    1) The ancient Israelites carried a large gilded box called the Ark of the Covenant in front of them into battle. They believed it could summon up the wrath of God on their enemies. Their enemies were not 100% sure that the Israelites weren't right. There is no evidence that the Ark ever actually did summon up the wrath of God, but boths sides beleived it and the Israelites beat enemies who had superior numbers on a number of occasions.

    2) How many atomic bombs were actually ever used? Two. But the mere thought that a country has nuclear weapons gives them a bargaining position. And the the fact that the wrong country even MIGHT be trying to obtain them is reason to go to war.

    In the ancient world, this "death ray" would have struck fear in the enemies hearts and minds, despite the fact that it might have serious limitations, or may not even work at all except in controlled situations. And one or two prominant demonstrations of such a weapon would go a long way toward keeping this fear going.

  • by AgeOfUnreason ( 889145 ) on Thursday October 13, 2005 @04:21AM (#13780164)
    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.
  • 1000 KW "death ray" (Score:5, Interesting)

    by PhilipPeake ( 711883 ) on Thursday October 13, 2005 @09:10AM (#13781376)
    General technical specifications

    The parabolic reflector gaves at the focal point a maximum flux of 1000 W/cm2. The experimentations takes place at the focal zone (18 m in front of the paraboloid. The range of available temperature is from 800 to 2500 C (the maximum reachable temperature is 3800 C) for a maximum thermal power of 1000 kW.

    http://www.imp.cnrs.fr/foursol/1000_en.shtml [imp.cnrs.fr]

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