Archimedes Death Ray in San Francisco

Monkey-Man2000 writes "Following the recent demonstration by MIT students that Archimedes' death ray could have been used to burn Roman ships, the producers of the Discovery Channel's Myth Busters invited the MIT team to San Francisco to try their death ray on an 80-year old fishing boat. This time, even with perfect weather, they were unable to set the boat afire. From the article, "Peter Rees, executive producer of "Myth Busters," said the experiment at the Hunters Point Shipyard showed that Archimedes' death ray was most likely a myth.""

It would have worked...

[Black Parrot (19622)]

...if they had properly powered it with cold nuclear fission.

Pants on fire ...

[kedar_85 (828932)]

Looks like getting someone's pants on fire was not the pastime in Archimedes's day.

So tell me

[elmegil (12001)]

Why are they trying to burn the wood, when it seems like the rigging should be easier to torch and just as debilitating?

Re:So tell me

[oO0OoO0Oo (548702)]

See their FAQ here:

http://web.mit.edu/2.009/www/lectures/10_Archimede sFAQ.html#FAQi [mit.edu]

Re:So tell me

[zippthorne (748122)]

iv) Does the intensity of the reflected light not decrease the with square of the distance.
The reflected light does not decrease in intensity with the square of the distance from the mirror. If this were the case, there would be no hope whatsoever for the myth (or a laser pointer) to work, even in modern times. The attenuation of the reflected light from a flat mirror is only related to how much the beam disperses geometrically before it hits the target (e.g., our 1 ft square tile's reflection spread to an

Re:So tell me

[gunnk (463227)]

A flat mirror has negligible dispersion when reflecting sunlight. Sunlight striking a small portion of the Earth's surface can be treated as truly parallel rays unless you are reflecting it to astronomical distances. That's why a mirror from a make-up compact makes such an effective signalling device: even at large distances it is still extremely bright. Dispersion of light sources is more aptly applied to point sources where the rays radiate outward in all directions. Far enough from a point source, h

Re:So tell me

[kalidasa (577403)]

The Romans used quadriremes at Syracuse. They were at anchor for quite some time, as it was a blockade/siege, rather than merely a naval battle. Most likely the attack with the "death ray" would have taken place well after the start of the siege. My question is why the "death ray" couldn't have been aimed at the stowed sails - I don't think the sails would have been put belowdecks (but I don't know much about Roman naval technology: the best source would no doubt be Lionel Casson's book Ships and Seamanship in the Ancient World ISBN 0801851300 ) - I haven't read it, but Casson's very good on travel in the ancient world, and he knows his ancient ships. On Syracuse itself, I imagine there's stuff in Polybius, but from what I remember, the "death ray" story is late (Plutarch, maybe? Maybe even later?) and we don't know for sure if there's a reliable source lying behind the story. Regardless, Archimedes did engineer various kinds of engines that were used in the siege (cranes, etc.).

Re:So tell me

[elmegil (12001)]

Why should anyone study history? Indulge their curiousity? I mean we know everything, right?

What a Scientific Conclusion!

[robbyjo (315601)]

Having failed to do the experiments once and declare the thing as "most likely a myth"! Even today, many, if not most, of the experiments are non-replicable. Well, for most cases they are probably myths or hoaxes, but some of them are genuinely very hard to replicate. The reason can range from precision requirements to hazy details. The latter is the usual suspect, which, I believe, applies in this case as well.

Re:What a Scientific Conclusion!

[FatBear (835919)]

Yes. The old Roman ships were planked in cedar (very flammable wood) and sealed/coated with tar and pitch. The fishing boat may have been cedar planked, but was certainly painted, not pitch sealed and coated in tar. And these are just the obvious differences.

Re:What a Scientific Conclusion!

[Peyna (14792)]

I think most people with any kind of scientific background that watch Mythbusters realize that all they are really proving is that the particular way of doing things that they chose does not work. They rarely if ever prove something is impossible, but they have proven many things to be possible. Given the perfect set of conditions, a lot of things that they say are myths could probably actually have occurred.

News flash--pyramids a myth

[Urusai (865560)]

After attempting and failing to reconstruct the pyramid of Cheops, experimenters conclude that "the fabled Pyramids of Egypt are likely just a myth, there's no way they could have built such a huge pile of stone slabs when we with our mighty technologies cannot do so today."

Re:What a Scientific Conclusion!

[david duncan scott (206421)]

Yeah, well, I used to say that Jamie and Adam are engineers playing at science, but in fact they are mechanics playing at science. Their positive results are usually reasonable (it happened here so it might have happened before,) but their negative results are completely meaningless.

MythBusters [discovery.com] is a bit smarter than Brainiac [skyone.co.uk], but the girls, while undeniably [discovery.com] pretty, [discovery.com] aren't, well, like this [skyone.co.uk].

Re:What a Scientific Conclusion!

[Kesh (65890)]

Unless they happen to have an authentic ship of the type used in the siege ... which is impossible, given those ships will have rotted away many centuries ago. Perhaps you meant, "Unless they happen to build an authentic replica..."

Then again, even a replica won't satisfy some folks, so there's no way to 100% prove or disprove the concept.

Re:What a Scientific Conclusion!

[einhverfr (238914)]

Then again, even a replica won't satisfy some folks, so there's no way to 100% prove or disprove the concept.

Correct. Although a replica created by historians and naval engineers working together would carry a lot more weight than an old fishing boat.

Good thing they had Archimedes

[melikamp (631205)]

I take it as a sign that if Syracuse had the entire MIT instead of one Archimedes, we would not be hearing the story at all. Go Greeks.

A brilliant but unreliable weapon

[KiloByte (825081)]

So... it sometimes works, but is generally not reliable enough for anyone to bother reusing it. The Greeks lost that battle, too -- if the death ray worked well, they could have just burned everything (at least until the evening came).

The story sounds plausible. Archimedes invented something that managed to set one or two ships on fire (and most likely the fire was extinguished in no time), but was unable to have any strategic meaning.

flammability differences

[G4from128k (686170)]

I wonder if Roman ships may have been innately more flammable than that 80 year old boat. The use of tar or pitch to seal rough-hewn planks on the sides of the Roman ships would have made them more susceptible to fire. Any oiled cloth would also have made these ancient boats more flammable.

Roman navies.

[Savage-Rabbit (308260)]

Early Roman navys were often temporary entities although there were also permanent squadrons even during the later empire. By then it seems their main function was to combat pirates and smugglers since the Romans had by then eliminated all serious naval challengers. A large standing navy only reappeared during the very late imperial and Byzantine period when various barbarian and large moslem naval forces reappered as the Western and then the Eastern Roman Empire collapsed. The temporary fleets, built on campaign or to deal with some sudden maratime threat, were often built of unseasoned or low quality wood and intended to last no more than a few of campaigning seasons before they were either scrapped as unseaworthty or had been lost to bad weather. While it is probably possible to torch a Roman war galley at ancor on a calm cloudless day using some sort of mirror array I don't think such a weapon would have scored more than a couple of sucesses at best and it would have been practically useless against a fast moving and maneuvering target. It would have been most useful against relatively immobile targets such as floating siege towers or catapults that would have been mounted on platforms made by lashing several galleys together. If anything the psychological effect of this 'death ray' would have been far greater than the practical destructive effect, sort of like the effect that rockets had the first time Chinese armies deployed them in combat. At first they probably scared the hell out of the barbarians but after a short while barbarians got wise to the fact that unless they were really big and carried exploding warheads Chinese rockets were not terribly destructive and made sure their forces knew it and that the horses were acclimatized to the alien noises the rockets made. I would not expect a force that achieved the very high degree of professionalism the Roman army did to have been impressed by this sort of a weapon for very long even if the weapon worked under ideal conditions.

Re:flammability differences

[toddestan (632714)]

Unlikely - setting ships on fire was an obvious and common strategy back then, so boats would have to have been at least somewhat fireproofed. If they were really floating fire hazards, they wouldn't have lasted long.

Ahh... but maybe setting ships on fire was such a common, effective strategy because the ships were so flammable?

Myth busted?

[FatBear (835919)]

"I couldn't do it, therefore it cannot be done"? These guys need to go back to logic 101.

Re:Myth busted?

[winwar (114053)]

"The complete lack of peer review in their show is sickening."

FYI,I see better science and logic in their show that in a lot of scientific papers that were peer reviewed.

Of course when people complain about scientific literacy who obviously lack reading comprehension it kind of undermines their argument. Especially the quote this is "most likely a myth" in both the summary and article. Remember, the "myth" is about torching a bunch of ships, not starting a fire with a large mirror....

Re:Myth busted?

[FireFury03 (653718)]

They have succeeded in dumbing down science and engineering enough for the average Phil and Sally to understand. Of course, then your average Phil and Sally understand nothing, yet think they are masters in such fields.

I think they've got a good balance - true, they don't perform rigorous scientific experiments, but clearly they never intended the show to do that (and have you any idea how long and potentially boring it would be for them to do the experiments properly?).

I mainly watch it to see the interest

"Mythbusters" should become the "Mythtesters"

[CyricZ (887944)]

Perhaps they should call themselves the "Mythtesters", rather than the "Mythbusters". The process they use does not lend itself to definite conclusions. They merely test the plausibility of such myths. As such, I don't think they should make the claim that they "bust" the myths.

variables

[Quixote (154172)]

There are just too many variables here that must be taken into account before you can write it off as myth (and, unfortunately, the ever popular quest on American TV to sensationalize stuff does not lend itself to accurate scientific pursuits).

As others have mentioned, we don't know what the Roman boats were exactly made of. Was it pine? Balsa? And the tar/pitch used to seal them is very flammable.

The time of day is important; the amount of solar energy hitting the mirrors is highest at noon.

They could have lit the sails, which is good enough when you're trying to set fire to a wooden boat.

Modern boats have paint and all sorts of other goodness on them, which is reflective.

This boat that they tried this experiment on was 80 years old. What does years of sitting in water do to the wood, in terms of flammability? We don't know. How old were the ships that Archimedes set on fire? We don't know.

Re:variables

[stubear (130454)]

I saw the original Mythbusters episode where they tested Archimedes death ray and they tried fairly hard to replicate the design components of a roman ship of the time. The conclusion of their tests was that it would be nearly impossible to focus enough mirrors in one spot for a long enough time to be able to generate enough heat to set wood and pitch on fire. Were they able to make Archimedes death ray? No, because no plans exist of the device, hence it being a myth. They did, however, make a fairly pl

The preoccupation with BURNING is getting tiresome

[by Anonymous Coward]

The anti-personnel aspects of the Archimedes Heatray were probably more important.

Imagine being a rower and this intolerable heat builds up on your back.
Or a steersman or bowman? Sighting in the glare?

Burning the rigging would be a plus, but disabling the enemy crew would be better. In fact it would be the equivalent of a neutron bomb, leaving the boats to be used by the Greeks at a later date whilst killing off the enemy!

There's more than one way to skin a cat!

That's probably underestimating it quite a bit

[vadim_t (324782)]

In those times, it must have been something quite scary.

Let's see, you're on a boat, going into battle. Everybody's naturally quite nervous already. And suddenly there's this really awful light that sets fire the sail, sets somebody's hair on fire, burns another one's face, blinds several people... The Greeks would probably not get it perfectly right on the first try, but could in the process manage to freak everybody out even before getting any practical results.

I bet that even without burning anything you

That's what made it a great weapon of peace

[Radical Rad (138892)]

"Like all good myths, just because we disproved it doesn't mean that people will not believe it," Rees said. "A good story is a good story even if it isn't true."

Spreading rumours about Archimede's marvelous machines must have been a pretty good deterrent to invasion.

MythBusters, not Myth Busters!

[antdude (79039)]

As a picky guy, I noticed a space. It is "MythBusters". See the official Web site [discovery.com]. No space! Also, no Mythbusters.

This doesn't mean it never happened.

[Xarius (691264)]

We cannot build something that compares to the size and accuracy of the pyramids in Egypt, using only the materials and tools they had available at the time. Although we know for a fact they managed it somehow.

Just because we can't replicate it, doesn't mean it can't be done.

Re:This doesn't mean it never happened.

[Minna Kirai (624281)]

We cannot build something that compares to the size and accuracy of the pyramids in Egypt,

We cannot land on the moon either.

It's not a matter of misunderstood technology- just an unwillingness to spend 10% of the national GDP on something completely useless. Convince 20,000 men to work at it for 50 years, and they'll build you your pyramid.

Re:This doesn't mean it never happened.

[Jesus 2.0 (701858)]

We cannot build something that compares to the size and accuracy of the pyramids in Egypt, using only the materials and tools they had available at the time.

Of course we can. It would just be utterly immoral.

Do you honestly doubt that if a team of engineers, construction experts, and master masons had access to and complete command over tens of thousands of slaves and/or peons, and put aside all questions of morality, they would be incapable of building a pyramid using ancient methods?

Re:This doesn't mean it never happened.

[nathanh (1214)]

We cannot build something that compares to the size and accuracy of the pyramids in Egypt, using only the materials and tools they had available at the time. Although we know for a fact they managed it somehow.

There have been numerous shows - on Discovery and similar channels - where Egyptologists demonstrate various methods that the Egyptians might have used. In the last show I watched a bunch of 50-60 year old unfit British scientists, working in the midday Sun of Egypt, in the middle of a desert, managed to move gigantic stones several hundred yards and stack them on top of each other. They demonstrated about a half dozen techniques, including their favourite which was sliding the rocks on sleds over wet sand.

I have no idea where you got the idea we "cannot build something" like the Pyramids. If a bunch of old bastards like that could do it using ancient techniques, I have no doubt that it can be done.

The other thing to remember

[jgmaynard (925073)]

Hi.... It's my first post here..... I really like this site! Now.... The other thing to remember is that at the time of Archimedes, good quality glass was not discovered yet - most mirrors at the time were made from malachite. Such a mirror would not have reflected nearly the amount of light that a modern glass mirror would have done. Good quality glass did not come into Rome until about 250 years after Archimedes. I actually looked into this pretty carefully for my book "The Light of Alexandria" - http://www.lightofalexandria.com/ [lightofalexandria.com] . Some of the other inventions that Archimedes made for the defense of Syracuse were pretty amazing, though........ JM

National Solar Thermal Test Facility

[cavehoark (521731)]

When completed in 1978, the National Solar Thermal Test Facility cost just over $21 million. The NSTTF is an array of 222 focusable mirrors, or heliostats, covering 8 acres (7 football fields), located on the grounds of Sandia National Laboratory at the edge of Albuquerque, New Mexico.

The mirrors (facets) are focused onto a receiver or target mounted on a tower. The NSTTF tower is 200 feet tall, and its 8-foot-thick foundation is 50 feet below ground. The mirrors can direct up to 5 megawatts of solar radiation onto the receiver or other experimental objects. An uncooled object placed in the beam can be quickly raised to temperatures of over 4000 degrees F.

The mirrors are mounted on individual frames that are tipped up and down and rotated east to west by small motors much like those used in electric clocks. The motors are controlled by a computer which determines how to position each heliostat so that its reflection hits the receiver at any time of the day and any day of the year. The mirrors are made of two layers of glass with reflective silver between the glass layers. The quality of the glass is like that in your windows at home. The silver in one heliostat (25 mirrors-in one frame) weighs only about 1 ounce. Rain, snow, and other natural forms of moisture actually help keep the mirrors clean by washing away accumulated dust. Hail and dust storms have not harmed the mirrors. Only hail over 1 inch in diameter is likely to break the mirrors.

Re:What is their background?

[iLogiK (878892)]

"Hyneman has a degree in Russian language and literature. He has had a variety of careers, including scuba diver, wilderness survival expert, boat captain, linguist, pet shop owner, animal wrangler, machinist and chef."

"Adam Savage: Before becoming a TV host, he spent 10 years as an artisan in special effects, specifically modelmaking for companies such as Industrial Light and Magic, Warner Bros. and Disney. He worked on such films as Star Wars Episodes I and II, The Matrix sequels, Bicentennial Man, A.I., Space Cowboys, and others.

He has also been an animator, graphic designer, carpenter, set designer, toy designer, rigger, and has many sculptures on display in museums across the country."

http://en.wikipedia.org/wiki/Adam_Savage [wikipedia.org]
http://en.wikipedia.org/wiki/Jamie_Hyneman [wikipedia.org]

Re:What is their background?

[CapnRob (137862)]

Remember that 7-Up commercial from a couple'a years back? The one that features a 7-Up machine on treads that rolled around and fired cans of soda at people?

Jamie built that.

His company, M5 Industries Inc., specializes in robotic designs for visual effects. He's got a lot of experience building, you know, robots. He's designed or been involved in designing things that are required to do a huge variety of bizarre and wacky things - from the aforementioned surly soda-firing vending machine robot to a motorized shoe-cycle to a articulated giant hand (as seen in the film Monkeybone).

And, to remind those of you who watched Battlebots when it was on:

He built Blendo.

So, yes, he's got engineering experience. He's got a lot of engineering experience. And, yes, special and visual effects work *does* require a lot of skill and talent - and the ability to judge whether something is practicable in the field.

(I'd also recommend that you look at the career of one James "The Amazing" Randi before commenting further. Take an especially close look at how often people claim that a stage magician shouldn't be trying to debunk so-called "real" paranormal events.)

Go to his home page!

[antdude (79039)]

Click here [m5industries.com]!

True believers are true believers?

[po8 (187055)]

"If you investigate paranormal events with the mindset that it's all fake, then you're just as bad as the `true believers' you're trying to discredit. Scientific exploration of anything requires an open mind."

Oops! Mind the deep philosophical waters there. Now you've splashed truth all over yourself; let's try to dry you out a bit.

The history of the philosophy of science (a mouthful were there ever one) is complicated, and I think that it's fair to say that there's no widespread agreement on the exact

Re:What is their background?

[luna69 (529007)]

The fact is that the mythbusters guys often engage in poorly constructed 'experiments' which a scientifically literate person would recognize as being inadequate for the purposes in question. Many of their efforts are laughably incomplete or rely on misunderstandings of the phenomena that contibute to whatever they're testing.

Re:What is their background?

[deglr6328 (150198)]

Such as? I think Mythbusters is one of the best science-related programs on tv today. No not because all of the shows are done with an exacting precision and logical rigorousness reminiscent of the Cavendish lab, but rather because it shows the core of the scientific method IN ACTION. They have an idea that needs testing, they make a guess at what might happen if they try X, they build an experiment to actually try X, then they run the experiment and draw some conclutions from the results. I can not recall a more apt application of the Baconian method ever being shown on any TV show (save for perhaps Bill Nye or Mr. Wizard or something). Who cares if thier guesses about how precisely the experiment should be set up are wrong, that's (a HUGE) part of science! At the end of the show they usually even discuss where thier experiments could've gone wrong or what might be done better if they tried it again. What more could you ask for in a tv show?! I think it is an especially excellent show for kids to watch. Numerous scientific principals are explained in an accessable and interesting manner (bouyancy, properties of heat and light, mechanical levers and mech. advantage, electrical circuts, flamability of vapours vs. liquids, properties of density, inertia, and on and on). The show can do a great job of keeping them simultaneously entertained with the odd explosion but also teaching the rigorous and logical thought processes necessary for the foundation of a scientific mindset. I really can't say enough good about it.

Re:300 SQFT??

[KiloByte (825081)]

Now we know that SQ of distance effects the power

No, dissipation of light in air is negligible on such distances, so the power itself is roughly constant. The effect of distance is all in targetting inaccuracies -- having a number of soldiers pinpoint a distant object exactly is not really feasible.

Re:it does work

[Aeiri (713218)]

Right, that thing will set a boat on fire... maybe a small fire from 2 feet away...

I remember that there was an episode that they did this with, way before the MIT thing, and they took into consideration the materials the boats were made from, the fact that Arcimedes used bronze shields to do it, with the soldiers as the individual mirrors, and they couldn't successfully set the boat on fire because it was just too damn hard to get everyone to aim it correctly. So they made a giant thing that was alrea

Re:it does work

[by Anonymous Coward]

If you bothered to read the FAQ [solardeathray.com], you would see that he agrees with the MythBusters conclusion. The mirrors need to be aligned VERY precisely AND the device needs to be within A FEW FEET of the object to be destroyed. Yes, the device works, but it is not a ship destroyer.

Although the LEGO pirate ship [solardeathray.com] managed to last just 16 minutes...

Re:The sail

[Locke2005 (849178)]

Screw the sails.. real triremes would have been covered in hemp rope. And from the experiments I performed in college, I can attest that hemp burns very well!

Re:The sail

[Deadstick (535032)]

I imagine it certainly could be possible to actually, permanently BLIND the people on the boats,

Yul Brynner did that trick in Solomon and Sheba (1959), having his troops polish their shields before an expected sunrise attack. The enemy weren't blinded, just dazzled, but he had positioned his men behind a convenient chasm...

rj

Re:is it really a "myth"?

[DoctorHibbert (610548)]

5 second rule? What are you a barbarian? Where I come from it's 3 seconds. 5 seconds is just insane.

Re:I'm shocked, shocked

[grumpygrodyguy (603716)]

This is why you don't put your faith in freshmen (or 1/3 of the stuff in medical journals, but that's a separate issue).

Fair enough but the MIT team did achieve ignition using fixed mirror placements and just 127 flat 1 square foot mirrors.

The 'freshmen' failed because there was no visual reference point for aiming. When 100 other 'bright spots' are aiming at the same target you, there is no way of telling which bright spot is yours so it's impossible to make the proper adjustments to focus your beam onto the target.

So, the only real constraint is providing a means of manually aiming the mirror properly. I'm not an optics expert...but if there's a way to design a sighting device, perhaps like a sextant, then the myth of 3000 soldiers with 5'-square bronze shields incinerating a ship could easily be true.

(1 square foot)X127=127(MIT achieved ignition with this, roughly 1100 F)
vs.
(5 square feet)X3000=15,000(Grecian army w/ bronze shields)

That's a massive magnification factor of about 120X. 120X the ignition luminance(cd/m2) could vaporize the target instead of igniting it.

Re:I'm shocked, shocked

[irc.goatse.cx troll (593289)]

My first thought back when watching the originalepisode was pretty simple: Hold something (preferably colored glass) infront of your mirror. Your bright dot will be the colored one. Bonus points for a unique stained glass design you can use so multiple people can aim at once, but once you start coloring them you can fix your aim and move on to the next guy within 30seconds.