Tests of Fabled Archimedes Death Ray Fail

[Fire Fly]

Link

Tests of Fabled Archimedes Death Ray Fail

SAN FRANCISCO - It wasn't exactly the ancient siege of Syracuse, but rather a curious quest for scientific validation. According to sparse historical writings, the Greek mathematician Archimedes torched a fleet of invading Roman ships by reflecting the sun's powerful rays with a mirrored device made of glass or bronze.
ADVERTISEMENT

More than 2,000 years later, researchers from the Massachusetts Institute of Technology and the University of Arizona set out to recreate Archimedes' fabled death ray Saturday in an experiment sponsored by the Discovery Channel program "MythBusters." Their attempts to set fire to an 80-year-old fishing boat using their own versions of the device, however, failed to either prove or dispel the myth of the solar death ray.

The MIT team's first attempt with their contraption made of 300 square feet of bronze and glass failed to ignite a fire from 150 feet away. It produced smoldering on the boat's wooden surface but no open flame. A second attempt from about 75 feet away lit only a small fire that burned itself out.

Mike Bushroe of the University of Arizona's Lunar and Planetary Laboratory tried a mirrored system shaped like flower petals, but it failed to produce either smoke or flames.

Peter Rees, executive producer of "MythBusters," said the experiment showed Archimedes' death ray was most likely a myth.

"We're not saying it can't be done," Rees said. "We're just saying it's extremely impractical as a weapon of war."

The experiment showed it may be technically possible, but didn't answer whether Archimedes used it to destroy enemy ships, MIT professor David Wallace said.

"Who can say whether Archimedes did it or not?" he said. "He's one of the great mathematical minds in history. I wouldn't want to underestimate his intelligence or ability."

Historical text describes Archimedes defeating a Roman fleet using the ray.

In "Epitome ton Istorion," John Zonaras wrote: "At last in an incredible manner he burned up the whole Roman fleet. For by tilting a kind of mirror toward the sun he concentrated the sun's beam upon it; and owing to the thickness and smoothness of the mirror he ignited the air from this beam and kindled a great flame, the whole of which he directed upon the ships that lay at anchor in the path of the fire, until he consumed them all."

"MythBusters" also tried to recreate the ray last year, and after failing, declared the story a myth.

"If this weapon had worked, it would have been the equivalent of a nuclear weapon in the ancient world," Rees said.

Well, I guess this story has been permanently put to sleep now. I always thought that the likelihood of the weapon working was too demanding on the prerequisite conditions.

[LordShaithis]

Wait, they actually managed to produce smoke and even a small temporary fire with such a device? Couldn't a genius with time on his hands maybe do better then?

[Xon]

The Archimedes Death Ray worked.

Some guys in the 1930s replicated it with a few hundred of highly polished fullbody shields arranged in a horizontal array all aimed at the same target which was a much better replicate of the ships at the time. There was a documentary on the Australian ABC about it a few months ago.

Some guys over at MIT managed to replicate it too linky.

[Xon]

Whoops. Way off target.

~150 mirrors and in 1747

Comte de Buffon, in 1747. Buffon recognized that the real problem was the one of having a variable focal length and so the mirror must be an array of individual adjustable elements. What does such an array do to the image quality? The answer is "surprisingly little". Let us look at Buffon's own numbers. He assumed a mirror of 400 feet radius of curvature and a diameter of 10 feet. Such a spherical mirror will produce an image of the Sun about two feet in diameter. if the mirror is made of plane elements of diameter d, then the image is increased in size by about d.

If the elements are six inches in diameter then the two foot image is smeared out to two and one half feet

Buffon assembled 168 mirrors 8 in. by 10 in adjusted to produce the smallest image 150 feet away. The array turned out to be a formidable weapon. At 66 feet 40 mirrors ignited a creosoted plank and at 150 feet, 128 mirrors ignited a pine plank instantly. in another experiment 45 mirrors melted six pounds of tin at 20 feet.

[Xon]

linky

And the linky for that source.

[Admiral Valdemar]

The concept is sound, but it does suffer from relying on ideal conditions and many mirror arrays directed at one point. Shouldn't be a problem in the Med where it's pretty much always sunny and for a guy with the brain of, well, Archimedes. They always had their version of napalm too: Greek fire.

[Steven Snyder]

The Archimedes Death Ray worked.[/url].

The article doesn't deny it can work, but it states (Correctly IMHO) that it was an impractical weapon.

[Prozac the Robert]

The article doesn't deny it can work, but it states (Correctly IMHO) that it was an impractical weapon.

Hmm, maybe if the Romans were involved in some sort of blocade then you'd be able to wait for ideal conditions before using the mirror.

It also occurs to me that ancient boats might have been more flamable than semi-modern ones. All the pitch and whatnot could easily catch fire.

[Setesh]

:ahem:

http://www.solardeathray.com/

[kheegster]

It seems that even if Archimedes managed to build something that could set fire to ships, all the evidence shown here suggests that it would only be effective inside a couple of hundred feet, which is well within arrow range.

[Xon]

It also occurs to me that ancient boats might have been more flamable than semi-modern ones. All the pitch and whatnot could easily catch fire.

The way ancient ships were made water proof involved lots of flamable materials. And sails would be worse.

It seems that even if Archimedes managed to build something that could set fire to ships, all the evidence shown here suggests that it would only be effective inside a couple of hundred feet, which is well within arrow range.

Polished shields were used as mirrors

Just have another rank of men behind the front rank holding shields over the top. What were the Romans going todo, flank the men on the harbor?

[Braedley]

I'm just wondering if they'll do a myth revisited for this on Myth Busters. I still think it is/was an impractical weapon, even if you do consider the discipline of the Roman army.

[drachefly]

300 square feet of bronze and glass. Hmm... I would have made it bigger if I were trying to prove implausibility.

Also, I would expect that the power would not be terribly adversely affected by range (provided targeting went right), since: the sun provides very good collimation, and it's not hard to make a decently flat mirror.

Also of note is that Greece is considerably closer to the equator than Boston.

[Braedley]

Also of note is that Greece is considerably closer to the equator than Boston.

Yes, but there isn't much difference between Greece and San Fran

[Faram]

Well I have a solar deathray!



Perfect to start a fire with, just some paper or easely cumbustable wood on top.

Boght from http://www.raymears.com/ if anyone wants it, and the pic is stolen from that site.

[Illuminatus Primus]

The article doesn't deny it can work, but it states (Correctly IMHO) that it was an impractical weapon.

Hmm, maybe if the Romans were involved in some sort of blocade then you'd be able to wait for ideal conditions before using the mirror.

It also occurs to me that ancient boats might have been more flamable than semi-modern ones. All the pitch and whatnot could easily catch fire.

Didn't the Roman ships have sails? Wouldn't aiming the mirror arrays at the sails, rolled or otherwise be more simple?

[Darth Wong]

Even if this device worked, it would require co-ordination between all of these mirrors, and I doubt they could have pulled it off. They certainly couldn't have pulled it off quickly enough to switch rapidly from target to target, so they couldn't have "torched an invading fleet" with it. At best, they could maybe ignite a ship or two unless the enemy just conveniently sits there for days without moving.

Besides, the description in the original text (which is the only real source for this claim) does not describe an array of mirrors; it describes a single great mirror which not only ignites faraway ships but also creates a column of flame in the air: an absurd description which is obviously inaccurate. So you have no idea how much embellishment or exaggeration was involved in this highly questionable account.

[Admiral Valdemar]

I'd have expected a rig with many parabolic mirrors on it to aid in co-ordination. I never saw it as a superweapon, more of a terror weapon since your ship's sails suddenly bursting into flame and nary a flaming arrow in sight is somewhat troubling. Anything to take an enemy vessel out prior to getting to closer ranged fighting is worth a shot.

[Braedley]

The article doesn't deny it can work, but it states (Correctly IMHO) that it was an impractical weapon.

Hmm, maybe if the Romans were involved in some sort of blocade then you'd be able to wait for ideal conditions before using the mirror.

It also occurs to me that ancient boats might have been more flamable than semi-modern ones. All the pitch and whatnot could easily catch fire.

Didn't the Roman ships have sails? Wouldn't aiming the mirror arrays at the sails, rolled or otherwise be more simple?

IIRC, only one, maybe two (jeeze I have a test on this stuff on Friday, and I still can't give a solid answer), and it would only be up for travel, not for combat. All tactical manauvers were done by oarsmen (which basically involved trying to ram the other ship or get close enough to board).

[Mange]

IIRC, the Mythbusters "busted" this myth in one of the early episodes.

[Setesh]

I've always thought that they cheated and dumped loads of greek fire in the water than the 'mirror trick' lit a single ship on one end of the line, sweeping the mirror across the line quickly will still result in a blinding flash and the illusion of the effects described. After 5 or 6 retellings the greek fire got eliminated from the story. Hell the mirror may have just been to blind thoose ship board so they wouldn't see a guy touching it off with an arrow.

[Kettch]

I agree w/ Valdemar's asertion that the mirror was more of a "terror weapon" than anything else. Archimedes inventions seem to have a bit of that German V weapon ring to them. Ingenious, but deriving much of their effect via their unusualness. i.e. the 'death ray' could have only burnt a few ships, but under the mysterious circumstances, the fleet was driven off & later became that the whole fleet was sunk by the 'death ray.'

Massed mirror hypothesis:
Mike, I think you're underselling the responiveness of the Greek soldier, who was trained to work in highly disiplined massed formations. If we make the resonable assumption that the city fathers allowed Archimedes to go through w/ another one of his successful inventions, they'd let him have plenty of training time to perfect the mass aiming of the mirrors.

The other thing that struck me about both the MIT & mythbusters experiments is, well, how small they are. 129 One ft mirrors? (Well that was what the hardware store had in stock...) I don't know what the greek mirror production rates were, but Archimedes probably got the full production rate of Syracus's mirror industry & any imports as well... I have the feeling that he would have been able to aquire much more than 129 sq ft of mirrors. If we go w/ the contraption idea, mythbuster's rig, as impressive as it seems, still is on the small/ low medium scale of greek & roman seige weapons.

Did it work?
Well..... Unlike every one rushing to build ballistic missles during & after WWII, the very practical romans (who'd steal most any idea) never took up the mirror death ray for their costal defense in the Med. I'm leaning towards, yes it did work, but the constraints on its use were such that it worked to scare off Roman fleets a few times, but once it was a known qunatity.... it became ineffective. Kind of like mustard gas.

[The Duchess of Zeon]

The man invented calculus and the screw pump, he doesn't exactly need to have invented this to be one of the greatest geniuses in world history, so I'm not sure why people bother.

Frankly, the best use of the mirror might have been to blind the crews of the ships, or create a false sun or generally obscure their vision. That would, if the ships were operating close to the harbour of Syracuse, knowing the typography there, easily lead to the grounding of some ships on the rocks off the entrance.

[Admiral Valdemar]

That'd be a good tactic, actually. Hot enough to smolder cloth at a few hundred metres is more than enough to blind or burn a marine or sailor. If they're hunkering down for cover, they can't really fight. Then you just get your archers ready and begin artillery volleys into their vessel.

[Master of Ossus]

The Death Ray lives!

In Eritrea, of all places.

By Ed Harris

KEREN, Eritrea (Reuters) - Seyoum Goitom, inventor and father of six, stood in his workshop in Eritrea, explaining his passion for mechanics, while young girls herded goats outside and butterflies wobbled in the warmth.

Goitom has so far built a biscuit maker, welding machine and lawnmower from recycled parts. Now he is looking at a much bigger and possibly more significant project.

The 38-year-old is turning his creative energies to deforestation around Keren, his home and one of Eritrea's most attractive towns, where the forest is slowly disappearing.

He is working on an enormous, solar-powered stove based on a satellite dish which he believes could drastically cut the need for firewood among his compatriots in the Red Sea state.

Some 95 percent of Eritrea's forests have been lost in the past century because of drought, a growing population and -- to a lesser extent -- the war for independence from Ethiopia when many trees were cut to deny hiding places to combatants.

"When I was young, we could find big, old trees in the mountains and a small stream at the bottom all year round," Goitom said, standing on a dry slope.

"Now the river is dry, and there are almost no trees. They have been cut for fuel and building," he added, as two young boys ambled past, looking for firewood with axes in their hands.

Deforestation is a major threat to Africa's vulnerable communities. An international report said earlier this year that desertification, caused in part by widespread deforestation, threatens to drive millions from their homes.

Goitom thinks he can make a difference.

"Our country is becoming a desert," he said. "If we use solar (power), the environment will be OK. My children will be healthy and happy and better."

The inventor has received some financial support from the Dutch Embassy and is hoping to win backing from other groups in order to make his solar-powered stove available to schools and other public organizations.

"I'm using this old satellite dish, and converting it to a cooker," he said. "The schools use wood for cooking. If they have a solar cooker, then we can save on wood."

The satellite dish measures 6-1/2 feet in diameter.

Running his hands over the tin foil that covers the dish, Goitom explains how the direction and angle can be adjusted to cook wherever the sun is shining.

"We are trying a pilot project. If it is successful, then we will produce more (solar-powered cookers)," he said.

Necessity is the mother of invention in Eritrea, where roughly two-thirds of the population of 3.6 million require food aid this year. Like Goitom, many people learn to harvest what they can from the harsh environment to survive.

In Arberebo, in the mountains outside Asmara, children pick succulent prickly pears, or beles, from cactuses and sell them.

The fruit can grow in harsh climates and even on dry stone walls, making it well-suited to Eritrea's drought-prone climate.

Perhaps more importantly, the beles season runs from June to October, the hunger season when the previous year's harvest has run out and the next one is not due for several months.

SELLING BELES FOR BOOKS

"We sell it," says Marta Deriba, 15, smothering the kiwi-shaped fruit with an old tin can on the end of a stick. With a flick of her wrist, she twists the stick and tears the beles off the cactus.

"Then with the money, we buy our clothes and our shoes. We also buy pens and exercise books, and we also help our parents."

Donkeys and camels shuffle into Asmara's Medeba market every morning bearing wooden boxes full of beles. Idris Ali, 16, gets up at 3 a.m. every morning for the three-hour trek to the market.

"(The fruit) creates job opportunities for the kids, who cannot otherwise find any work especially during summer," he said. "I don't have to depend on my parents. I can buy anything I need for myself."

Goitom, the inventor, recognizes this need to improvise and

use what is available to improve one's life.

"When there are no spare parts, you have to be more clever," he said. "(You become) more interested in modification."

Looking around at his tools, old generators, engines, and motorbike parts strewn randomly on his workshop's dirty floor, he recalls how he developed his passion for gadgets.

"I used to go to my father's workshop every day to help him," he said, describing his first attempts as a 10-year-old to repair broken radios and water pumps. "Little by little, I became more and more interested in technical things."

Okay, so it's not vaporizing approaching enemy warships, but it's still pretty cool. A good start, given that he started with an old satellite dish and some tin foil.