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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.
Welcome our Death Ray weilding overlords
... and the server is a smoking husk before the first comment is posted.
Help poke pirates in the eyepatch, arr.
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.
The server seems really slow right now, try this.
And Mythbusters is LAW!
The Tech Terminal
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!
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?
Ignore Alien Orders
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.
Sounds interesting. Unfortunetly their has smoke comeing out of it. I would have expected more from MIT! Oh well
google.slashdot
I personally thought that they didn't do a very good job at testing it and they could have definitely gotten it to work if they did a better job setting up the mirrors. (of course they like to claim they "busted" something even when it was inconclusive or mostly true)
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.
What was the "death ray" attached to? Oooh. I know. Fricken sharks!
Flash ignition!
In an instant there is a large, open flame. The volatiles liberated from the wood ignite at roughly 1100 F.
Open, sustaining flame occurred less than 10 minutes after the sun was in a clear patch of sky!
You can also clearly see that there are still 3 mirrors not aimed correctly.
Now that Mythbusters is wrong, are there other myths that could be true?
if the ships were within arrow range... wouldn't a flaming arrow have done the job just as well... why the over engineering?
Not exactly the same concept, but the Solar Death Ray always reminded me of this.
How's my typing? Call 1-800-eta-shut
No wonder why the webpage says:
8 15d479865f65c52/index.html
"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/90e7777b89ad9e53
-er *no carrier*
"Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
For what it's worth, the MIT folks said they couldn't unequivocally rule it out. They didn't say it happened. One of the main points on Mythbusters was that it seemed like it might work, but the fleet would have had to remain essentially motionless for the wood to get hot enough for ignition. The MIT folks did nothing to answer that as they the mirrors and the "ship" were motionless until ignition.
If Nalgene water bottles are outlawed, only outlaws will have Nalgene water bottles.
as tin foil hadn't been invented yet, his enemies would have had no viable defense against this weapon. Devastating!
Oh for fuck's sake. It's in the fucking article that their experiment was inspired by the MythBuster's episode. They felt the Mythbusters didn't do it very well, and wanted to try it themselves. Based on the experiment, it's possible that the "Death Ray" existed, but they do point out that their experiment is rough, and also doesn't prove that it was used.
Solar Death Ray
Looks like the renewable energy people are in on it, too
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
Doesn't pick too many targets that I consider interesting (it's mostly meant to amuse)... but it is a pretty neat device that they've built.
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The mythbusters set up a more realisitc scenario to test with, they had a real wooden boat that was harder to combust due to the protective resin that was coating the boat, their test was more true to the original myth then what the MIT trial was I think.
MIT's boat wasn't even in the water, they were just pointing mirrors at dry wood.
A boat would have also been damp which would have also made it harder to combust.
http://www-personal.umich.edu/~bclee/lens.html /. last year. This is the one that came to my mind when reading this title.
Covered on
Fly me to the moon Let me sing among those stars Let me see what spring is like On jupiter and mars
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.
Take into account the strength of the Grecian Sun and I have a reasonable degree of confidence this could be achieved. To me the question is whether the mirrors we use today are unfairly superior, but a polished metal mirror can be surprisingly good, the only draw back is oxidation. A benefit of a metal mirror is that a slight curvature is easily accomplished.
I dont think the resin would be all that protective. It was pitch - a long chained hydrocarbon that would burn like buggery once it was hot enough to vaporise.
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.
Yes the Mythbusters rig was flawed, but pretty cool given the time frame it was made in. But the practical considerations in their conclusion are still true. It's got to be a perfectly sunny day and they have to show up at exactly the right time. You've got to be able to aim the mirrors, which is hard enough to do at a fixed target, that isn't loaded with people who would like to kill you. And if it takes 10 minutes for iginition at 100 ft, well after 10 minutes the invaders are already raping and pillaging in the town after killing all the funny guys holding up mirrors.
This, of course, is where the "Gods From Space" crowd chimes in. Works on TV, but in real life, there's a much more satisfying answer: people are damned fucking clever.
He was doing geometry in the sand with a stick when a Roman soldier slew him after saying that..
.Romans were very anti-G{r}eek
I'll swear there was a MST3K featuring a truly awful film of which the premise was Archimedes had built a death ray. I can't remember the precise name, but god it was awful...
Igniting sails, or burning/blinding people is much easier than setting fire to wood (especially a hull that could be wet). I've always thought that the victory was due to the psychological effects of the weapon on morale more than the outright destruction of vessels.
A number of mirror devices have been built to generate electricity on a commercial scale. So burning/blinding a ship using carefully positioned mirrors certainly was within Archimedes' capability. A handful of Mythbusters simply don't have the resources that a city state can throw at a problem. http://www.aerospacesoftware.com/archimedes.html
Oh well, what the hell...
I'll bet Archimedes as a child liked to burn ants with a magnifying glass, too. ;-)
A story about boats that shoot rays and no one has yet mentioned sharks with frickin laser beams?
mythebusters clearly cut part of the card throwing episode. Measurements were taken for metal cards, you can see it in a tivo slomo. It was wither cut for time, or the fact that it was found that the metal cards would cause major damage.
well they did a very good job. Compared to what people would have used some thousand year s ago. Do you think they could have made hundrets of 100% identical mirrors. Well, actual they had no mirrors (they sayed that in Myth Busters, as I remember). They would have used brass or something similar.
So in my opinion the myth was correctly busted.
"Freiheit ist immer auch die Freiheit des Andersdenkenden" - Rosa Luxemburg, 1871 - 1919
I doubt. Ships are not motionless. They move up/down, left/right, forward/backward. You have constantly adept the aim of your sunbeam. Thats really hard, even with technology nowadays. In my opinion its not doable, this is not a spyglass vs paper or bug ...
"Freiheit ist immer auch die Freiheit des Andersdenkenden" - Rosa Luxemburg, 1871 - 1919
"Mythubusters" doesn't account for the FACT that the ships using the "death ray" ARE MOVING.
And thuis can't account for the TEN MINUTES needed for ignition.
Lame.
No gods, no demons, and no masters. Secular Humanism!
Seems to match the historical description dead-on.
Based on the experiment, it's possible that the "Death Ray" existed, but they do point out that their experiment is rough, and also doesn't prove that it was used.
Which is particularly interesting because that's just what the MythBusters said... Only the MythBusters did a better job recreating the conditions the weapon would have been used under. I think everyone is just bitter because the MythBusters didn't ignite their ship (again, due to the improved realism of their experiment).
Education is a better safeguard of liberty than a standing army.
Edward Everett (1794 - 1865)
I recently saw a documentary on Australian TV where an Italian Professor in the 70s lined up a fair number of troops on the shore with polished METAL shields and set fire to a wooden boat below. Did it a couple of times. Seemed pretty straight forward although I'm sure someone who hasn't actually SEEN the film will comeback with a reason why this never actually occurred.
Myth Plausible.
[This space is NotForRent]
Seems like a great trick, and I think Archimedes would have been smart enough to be able to engineer it to work, but it doesn't seem very practical. Yeah, it's intimidating to burn a ship at a great distance from shore...
Until the enemy attacks at dawn, or night, or on a cloudy day, or foggy...
And what if there are too many ships approaching to burn them all?
Given the ease of countermeasures, I doubt that they would have bothered to develop this novelty.
It's still a neat idea though.
You see? You see? Your stupid minds! Stupid! Stupid!
Actually if you read the article or even looked the Death Ray up, Archimedes supposedly used his death ray from land to target ships anchored within bow and arrow distance.
Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo!
"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?
-----
PGP Key ID 0xCB8FF658
Everything is subject to change.
Did Mythbusters have a large enough mirror ?
Did MIT utilise better aiming of their mirror ?
Did the boats that Archimedes tried to destroy sit perfectly still on a cloud-less day waiting to be burnt to a crisp ?
enquiring minds want to know.
AAAAHHHH!! It burns us, my precious!!
This sig is neither interesting, nor humorous. Including meta-humor.
You aren't, perchance, related to MacGyver, are you?
#include <disclaimer.h>
#include <beer.h>
Whether it really happened or not, what I wonder is where the idea came from? It seems strangely anachronistic, even though ancient Greek sceintific knowledge was more advanced than most people think. For example, they knew the earth was round - they found that out by observing lunar eclipses (which shows how backwards later Europeans actually were, rather than the norm as we consider them). So how did Achimedes come up with an idea like that? What sceintific knowledge did he have that his fellow Greeks didn't? Too bad we don't have more writings about him.
I dream of a better world... one in which chickens can cross roads without their motives being questioned.
The Mythbusters said it was busted (if memory serves) because they couldn't reproduce the results in a way that the original death-ray could have been constructed. The MIT geeks concluded that it COULD have been possible IF there was sufficient mirrors EXACTLY focused for an EXTENED period of time WHILE there was no clouds...
:) )
Here are my issues, in no particular order.
Mirrors in that day and age would have been average, to say the least.
It has been shown that trying to get people to aim at the same time is virtually impossible.
For the soldiers to be able to aim this thing, they must have been quite far away (otherwise previous comments about bows and flaming arrows would apply..) and therefore the quality of the mirrors combined with the distance would make focusing almost immposible (diffusion etc).
It is pretty clear that while it is POSSIBLE it is highly improbable. Kinda like cold fusion.... (not sure wether that last comment helped my cause or not..
Still a moving target. Ever been to the ocean?
No gods, no demons, and no masters. Secular Humanism!
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.
The best weapon of a dictatorship is secrecy, but the best weapon of a democracy should be the weapon of openness.
Yes I have as a matter of fact, and I've lived on a 200 foor yacht for upwards of a week in Greece, not to mention easily the 10 100-120 footers I've been on for vacations. I realize it's a moving target, however in a harbor the amount of motion is fairly small. Ever been on a boat?
Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo!
This was built in mini-form on a show called screensavers. It use to aire on G4 a year or so ago before it go turned into Attack of the Show. They proved that it worked by placing an object infront of the mirror (about 2 feet away) and just about instantly set it on fire.
The problem with mythbusters, and they do this often, is they only did one test to see if it would work in one way. They only aligned the mirrors in one direction, every single one of them at the same degree, meaning that the light that hit the center mirrors wouldnt reflect on the same spot the top mirrors did. If you watch the show they did, you can clearly see the reflection of the mirrors all across the 'boat' from 3 to 6 feet, not on a single point. That means that the mirrors didnt concentrate the light energy in one spot and were only able to get the spot to around 200 degree's.
Wouldn't it be easier to just instantly blind half the crew with a swoosh of that array, rather than focus it on the hull for ten minutes?
It's also possible that the ships were a lot more flammable than the mockups used in the tests, if they were caulked with pitch (it is not known if they were or not).
may bounce
In Soviet Washington the swamp drains you.
The Delta Knights already found Archimedes' death ray.
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.
I posted this a week ago too, linking to Boing Boing of course.
The dangers of knowledge trigger emotional distress in human beings.
The Archimedes Mirror is considered a myth because there was not enough technology by that time.
To concentrate the needed amount of sun light at that distance it is needed a fairly high precision in defining the right flexure of the mirror surface and its polishness.
Historians and engineers believe that it was out of reach for that time technology.
Even by "clustering" mirrors, the constraint of precision in the flexure remains with some more problems.
Maybe Computers will never be as intelligent as Humans.
For sure they won't ever become so stupid. [VR-1988]
Also, besides greek fire, hurling burning balls of pitch was common in the day.
(Nothing wrong with Tesla; i've always said he was a remarkably brillant man and have great admiration for what he did. He just lost a few screws in the last part of his life it seems...)
This might be handy time to mention the trick for lighting a fire with a coke can and a piece of chocolate:
c hocolatebar/index.html
http://www.trackertrail.com/survival/fire/cokeand
"You can justify anything by putting it in quotes, adding a famous name and making it a sig" - Albert Einstein
The enemy ship would have to attack on a cloudless sunny day, when the sun was in the right position... Presumably too early in the morning or too late in the afternoon and the mirror(s) would be between the sun and the enemy ship - no good.
Even then, the enemy captain has to park his ship at the focal point. Not very practical I am afraid. Polished metal mirrors tend to tarnish rapidly, which is one reason why large telescopes used mirrors made from metal evaporated onto glass as soon as the technology became available.
I would be more likely to believe Archimedes cooked his lamb chops over a mirror stove than to believe it ever made for a practical weapon.
My rights don't need management.
Oh, so that was YOU! Dude, for next time please note: wear more than just a string, breath-mints are for your other end, and as for your unbending will, well, it WAS kinda cold outside...
Don't use the Troll mod just because you disagree with me.
One thing not quoted yet is that unlike the other Archimedes invetions, the 'Death ray' was never mentioned by any of the ancient historians. It was (IIRC) a full 800 years later it first appeared. That was mentioned in the Mythbusters episode.
Mythbusters did use a pretty large array of mirrors, perhaps 10 meters across the wooden frame, which was quite unhandy :) They managed to melt the tar, but never got a temperature anywhere close to setting the ship on fire. On a sunny day, ship lying still in the water, and the crew handling the mirror well within an arrow's range.
I'd say that myth is *BUSTED* :)
-Henrik
I'm in a Unix state of mind.
... maybe the greeks just used short-range arrows for the calculation. Or maybe the romans were flirting with building boats out of paper that day. Or maybe ...
Remember, this was a siege defense weapon. Archimedes would've had acess to Syracuse's best mason's and smiths to construct his Death-Ray, and the King's coffers to fund it.
It would not be inconceivable for him to have started by carefully sculpting large clay molds to very precise tolerances, using the molds to cast the bronze dish, polishing it, and then coating the dish with a clear or white glaze to increase its reflectance (and thus efficienncy/output power).
Such a scenario would require several skilled craftsmen, but presumably such were available. MIT and Mythbusters both went for the quick&easy way, and not surprisingly encountered difficulties.
Not really all that interesting of a story in my opinion.
Mathematics is made of 50 percent formulas, 50 percent proofs, and 50 percent imagination.
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.
This is before bow 'n' arrows, back in a time when lasers were the weapon of choice.
I remember when legal used to mean lawful, now it means some kind of loophole. - Leo Kessler
Since the Greeks had gears 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.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Wow, boat nerdfight!
You seem to assume that a greek city had a large factory, capable of cranking up 500 parabolic mirrors just like that.
In practice, they'd have one smith with maybe a couple of apprentices, and I very much doubt that they'd even have the ore supply ready in the warehouses for that kind of a task. We're not talking about going to your local factory and asking them to run some sheet metal through the big press 500 times, we're talking about someone hammering and polishing all those by hand. It would have taken many months there.
Add to that the question if a smith was even qualified enough to make a parabolic mirror with the right focal distance. Then produce 500 with the same focal distance. Yeah, a smart guy like Archimedes could have done it, with lots of tuning and experimentation. The local weaponsmith and a couple of almost untrained apprentices? Yeah, right. So you're proposing, what? That Archimedes himself, and maybe a couple of other smart guys, polishes and tunes 500 bronze mirrors by hand? That would take _years_.
Basically _that_ is the whole problem. We're not talking if it could be done with a modern factory, and a warehouse full of materials at that. We're talking about an ancient town. Those weren't even too large.
A polar bear is a cartesian bear after a coordinate transform.
Read your link. Greek fire was invented in 673 AD.
The ancient Greeks were not stupid. When they wanted unusual materials, they just ordered them on eBay.
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.
One common criticism of this theory is that coordination and aiming would be too difficult to be practicable.
It might be possible to engineer a simple method to coordinate the aiming of many mirrors. First assume that your soldiers are standing in a fixed formation and distance relative to their target. (i.e. a straight line)
Each soldier is holding a mirror which is joined at the base to a board, at an angle of 90 degrees. Put a tiny hole in the mirror, so that a point of light falls on the board to which the mirror is attached. Each soldier now has an indicator of the orientation of the mirror. On each board, an ancient geometer has inscribed a grid. (intersecting parabolic arcs, in the case of a straight line of soldiers) If each grid is drawn appropriately (different for each board), then a commander may call out a row and column and each soldier orients their mirror so that the pinpoint of light falls on the appropriate point.
Implemented as simply as I describe, I doubt this arrangement would be suitably precise, but with a larger (possibly two-person) apparatus and provisions for increased stability, it might be possible to quickly focus the hundreds mirrors required to achieve combustion. The only skill required of the solders would be the ability to stand in a straight line and know the alphabet.
Don't forget Archimedes acquired a reputation in his lifetime that has lasted more than two thousand years. That is, he was not only considered the smartest man in his generation, but one of the smartest men ever to live for another hundred lifetimes of men, all over the Western world. He was very probably the ancient world's equivalent of Newton, Einstein and Fermi all rolled into one.
Further, given that he was at the time of his supposed feat a powerful figure in Syracuse, and the fact that the fate of a conquered ancient city was dire -- the city leaders would be paraded and killed, and everyone else sold into slavery -- Archimedes probably had access to all the material wealth of the city, and as much willing -- nay eager -- manpower as he could wish.
Given those facts I would hesitate to scoff at the myth on the basis of what can be achieved, or not, by a mere dozen modern men, of average intelligence* and creativity, working with trivial amounts of money, and not nearly as motivated as men facing enslavement, an ugly death, or in many cases both.
-------------
* Yes, I know the MIT students are no doubt above average in intelligence. But the odds that their number includes someone so clever and inventive that his name and accomplishments will still be common knowledge twenty centuries from now seems remote, to say the least.
That is, if you use mirrors that are mirrored on both sides, and have a hole in the middle. See, then all you have to do is hold the mirror up to the sun in such a way that the mirror casts a shadow on your own body. Then, looking at your reflection in the back of the mirror, simply line up the the reflected hole in the shadow with the hole in the actual mirror, while you can see the target through the hole.
The mirror is then at the proper angle. Keep using the hole to aim, and keep the shadow lined up, and you can easily track the target.
I saw a diagram of the geometry on-line somewhere, but I can't seem to find it now. It would make it a little easier to understand, if you can't parse my description.
It is worth noting that the source for the story of Archimedes "death ray" was written by a Roman almost five-hundred years after the event (if memory serves). There is no first-hand description of the construction or event, and it is more than likely a myth that was developed from his other (less ridiculous) weapons. Unfortunately I have had no luck tracking down this source, as most articles on Archimedes I can quickly find simply say "he was said to have..." and "the story is that..." (Any help or clarification is appreciated)
I find it increadibly annoying that people accept their "proofs".
Sorry, but they are idiots compared to the intelligence of Arhimedes. Not only that, but if they had done some research they would have found that this experiement has been done many times before, in many variation, some of which have been very successful.
It's easier to just use many not too large mirrors.
The main issue is to coordinate the mirrors.
You can aim them all in one spot and then wait till a ship passes that spot and holds still, no wind and all that, but that doesn't look very practical.
So I'd put the main challenge as how to make an aiming device for the mirrors so the people who held the mirrors could keep them adjusted.
If you think about that, it's simple too to make such a device.
Could Archimedes have done it? Sure.
Did he have a feasible plan? Maybe.
Did he actually try it ? Who knows.
Did he get the chance to try it several times and succeed ? Don't ask me...
Maybe he tried and it worked, but the men on the boats kept putting out the flames faster than that and no boat was sunk.
That's the NSA trying to prevent widespread knowledge about the creation of Death Rays. Just imagine what happens if terrorists get to read that!
The Tao of math: The numbers you can count are not the real numbers.
Two points I haven't seen anybody raise.
First, the ship would be constantly moving because of waves. This makes it a tad harder to heat up one spot to igniting and means that the spot would have to be fairly large for this to work. Bigger spot means that we need more mirror surface to heat it enough to ignite.
Second, solid mirror would have fixed focal distance. That means such weapon would have fairly limited range.
"It's a sailboat you idiot!"
remember, this was supposedly used against ships trying to either get near sea walls or drop off soldiers onto walls / quays / seafronts... it would have been fairly easy for archimedes to ensure that the roman ships had to pass through restricted spaces (sinking boats round the harbour, laying chains, dropping piles of boulders etc etc); it may even have been the case that there were only a few places where the roman ships could get close to land simply because of the layout of the place. in which case, you wouldn't need lots of people trying to aim lots of moving mirrors at moving targets- a few pre-aimed ones covering strategic spots could be used whenever a ship was in the right place. if the ships where disgorging soldiers, they'd have to keep still for several minutes at least.
if i was archimedes and trying to attack moving targets with a weapon that was best used on stationary targets, my first thought would be to hamper the targets' movement.
it's a basic principle of fortification and defense - ensure the enemy has to pass through or in front of a concentration of your best firepower to get to you. it's why castles have gatehouses, un-aligned entrances, and towers with arrow-slits covering the area immediately in front of the walls. you don't need to attack the enemy while they're a hundred yards away - they'll come right up to you. if they retreat out of range, it means you're winning.
Hah, I was born on the boat built by my great great grandfather who was replacing the boat inhabited by generations of our ancestors, the boat my great grandfather and grandfather and father were also born and lived on until their dying days. I have sailed to every port in every every continent and can count the amount of hours I have spent ashore on the fingers of one hand ( in binary ) so there is nothing I do not know about the motion of boats.
I can't RTFA, so i have no idea what MIT did, but from what others are saying it's not possible because of the difficulty aiming the mirrors. What people seem to forget is that there would have been thousands of trained mirror aimers available to make something like that work.
As a real test I suggest someone hand out 30,000 mirrors at a football game and at halftime tell everyone to just try to aim at a target. I'd bet it would work, but the game will probably be canceled due to blinded/vaporised players.
-John Fenley
How come this is called a death ray? It's more like a death cone, isn't it?
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.
You are ALL missing one very important fact. Back in Greek times, the earth was 1000x closer to the sun, and the sun was 100x hotter. So only one small mirror was needed, and a lot of Coppertone Suntan Lotion. Why do I have to teach you important scientific facts time after time after time?? You Earthmen are stupid, STUPID!! No wonder Xangargo will conquer you.
"How about using the polished insides of bronze shields? Presumably the greeks would have had plenty of those at hand, considering the situation."
The idea is ingenious, but unfortunately it's not realistic either.
The greek round shields, also (incorrectly) known as Hoplon were made of _wood_. (As a side-note, most shields ever used were wood. Roman shields, for example, were literally made plywood.)
So, well, you're telling me they'd focus light with a polished _wooden_ shield? That seems... a little improbable.
Additionally, we're talking about shields that were too deeply curved anyway. Even if you covered a shield's inside with silver and polished it (and that too would take time and a lot of silver), you'd be left with something that's maybe good for sorta almost focusing the light at maybe 1 to 2 meter distance, not "at bow and arrow range".
So, yeah, they had plenty of... something completely useless.
A polar bear is a cartesian bear after a coordinate transform.
Over here in England, we have a guy called Adam Heart-Davis who runs a series called "What the [insert period in British history here] did for us" on BBC 2
He actually did a test of this idea with a series of highly-polished Roman soldiers' shields directing the suns light at a small boat at a quay side and the boat did indeed begin to smolder and subsequently burst into flames.
However, with the inclement British weather being what it is, this process did take some time, but I'm sure Mediterranean weather was much more affordable...
For one, they do *many* more experiments than they show on air. Check out their website for details - basically, for every one experiment that makes it to air, they did 5. In reference to this episode in particular, you can be sure they tried many different cell models with many different levels of gas. These guys have quite a large budget to work with, they aren't going to skimp out on one cell phone.
For two, in reference to this particular episode, they did bust the myth that a cell phone can cause an explosion *through normal useage*. What they ended up saying, is in all likelihood the reported explosions were not coming from cell phones, but were a result of static electricity buildup at the scene. This is entirely plauseable. In my last car, depnding on the clothes I was wearing, I would often get actual blue sparks coming from my fingers to the door handle if I touched the car in the wrong way while getting out of it.
An explosion from a spark caused by static is much more likely than anything caused by a cell phone. How could useing a cell phone or having it ring *possibly* be any ore dangerous than a car radio? The car radio operates simmilar electronics, and hell, old ones even have rotary contact-based resistors for the volumne, which would be an ample source of spark potential. Any cell phone whose batter is sparking is not going to work properly because the battery is not making proper contact with the battery, so your calls would be constantly dropping. No one would use it.
The downfall of the Greeks is similar to ours, they had slaves, we outsource. (Fred Phelps claims other similarities)
True. But i think in this case they are probably right. Mythbusters is a great show, its cool, and they do generally have a more real world situation than a scientist would set up in an experiment. But a (good) scientist is thorough, and at least tries to check every possible variation and discern the exact cause from these. Then they dont (or shouldnt) give a 100% conclusive result. Mythbusters on the other hand, sets up a real live situation, tests that particular situation rarely gives any thought to any variations (well sometimes) and then gives pretty much a 100% conclusive result, as if they are all mighty and all knowing. Anyways, as i said, its a great show, for blowing up cement trucks. Though the actual experiment to go with that i dont think was very conclusive. They didnt try different positions for the explosive, such as on the outside to deform the barrel. Anyway, just my thoughts.
"Although many of the images of the death ray depict Archimedes with a parabolic mirror, it seemed like a bunch of individual flat mirrors positioned by 'the troops' would be a fast, more practical implementation of the concept."
0 4.jpg
This reminds me of the Death Star's weapon in ROTJ, the configuration of the light beams firing upon a single ship.
See: http://www.theforce.net/swtc/Pix/cards/wide/rotj1
He who knows best knows how little he knows. - Thomas Jefferson
"Death ray, fiddlesticks! Why it doesn't even slow them up." -- Charles Addams
There is nothing so silly as other peoples traditions, and nothing so sacred as our own.
Its like watching a slasher movie shouting "-Nooo! Don't go naked into the dark alley!!!11 The killer is in the alley!!!!" I suspect the show to be cut and scripted for that effect. The whole team cant be so unimaginative and under educated, most sollutions are high school level science.
First, the Greeks didn't have mirrors. There was no glass at that time. Good so they need bronze, highly polished. First you need to get enough of that. They probably used most they could find (there was no deep core mining then) for armour and weapons. So, first you need to make it totaly flat, highly polished and then aim it correct.
please try it out, with just 120 0.33 m^2 plates. I am sure, 100% sure, you will not succeed. Not even a motionless dry wood.
"Freiheit ist immer auch die Freiheit des Andersdenkenden" - Rosa Luxemburg, 1871 - 1919
(a notably smart person)??
You'd have to do better than that!
It's thanks to him alone, and his "ships that spewed fire" that the Persian throne didn't conquer the Western world at the time. (They had many other tries. This invention helped the Greeks even after he was gone, that is the lords recognized his genius even though most of them didn't even knew who Archimedes was.)
In addition, he did the batthub thingie, which should grant any man the status of genius.
Defining Statistics and Social Research
No historian is 100% why its Western Europe that had the Industrial Revolution and the advent of capitalism. Many historians and historical economists debate this left and right with no conclusive answer. Argubly, Western Europe was pretty backwater compared to the rest of the world until the Rennesscense(sp?). The Ottomans, India, China all had larger more powerful economies. That fact is the basis of some historians that the other empires and civilizations of the time didn't need one since they were already doing quite well so they became complacent. For an excellent history (and future predictions) of our sociological and economic system, check out Immanuel Wallerstein's "The End of the World as we know it." Its a scholarly work, a bit hard to follow at times, but a very, very interesting read that will change the way you think about how things were and are.
With a name like "MythBusters" would anyone expect the experiment to be successfull? Their whole aim in life is to prove things not to be possible or to be wrong, so that's what they did.
I don't watch their programs (are they on TV or something), but I'm curious, have they ever proved a myth to be true? Or are they just into hopelessly beingsceptical and debunking anything that moves.
We all know Archimedes was just Nikolai Tesla using his time machine so he could go back and test his magnificent death ray.
Wait, let me guess: You're pirates?
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.
The problem is that you were expeccting something different than what Mythbusters sets out to do. Yes, they try to prove/disporve thing, but by experiment, not through rigerous theory. I believe that both of the host are Hollywood stunt persons by trade, so mostly they know how do blow things up.
As far as dialogue and mistakes, that's supposed to show that the show is real. It is supposed to be unrehearsed, not staged.
All in all, I find the show interesting, and sometimes they surprise me with things I don't know about, but it is not scientifically insightful (nor is it supposed to be.)
Doesn't Any other Geeks Here Watch Myth Busters on the Discovery Channel?!?! They Busted this myth in season 2. The even built a boat out of wood, tar, and cloth as they did in the old days to try and make it catch fire. An I would imagine they could re-produce the mirrors and test much better then some one hundreds of years ago?
A lot of VERY brilliant ppl lived long before modern civilization .
Da Vinci, Archimedes, and Tesla .
Tesla alone was close to a break thru on harnessing the power
of lightning world wide .
There are many other brilliant men we do and do not know .
Our modern world tends to mock these ppl in regards to some
of what they claimed to do, and this is just another example
of how the modern age is sometimes wrong .
Score another one for Archimedes .
google "32 trillion offshore needs IRS attention"
Sure quite a few turn out to be true, some cool ones too.
They don't really try to disprove myths, they try VERY HARD to make them happen. Especially when there's explosions involved.
SYS 64738 NO CARRIER
The experiments are just as bad. The biggest problem I have is that they seem to have no awareness of significance testing. Without an evaluation of the statistical significance of their results, they can't claim to have proved or disproved anything... A negative result ("busted") could simply mean that their sample size was too small.
I love the show, but it would never pass peer review :-)
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
Really, really, really smart people 2000 years ago were probibally really, really smarter than most people now. Additionally Archimedes was very familiar with the materials available. It is very possible that the best and brightest of today would fail because they couldn't believe that a technology of the day would have been able to make sufficiently reflective mirrors etc.
I saw a show on TLC last week (I have no idea what it was called... caught it channel surfing while it was already started) where they were building devices by following the drawings of Leonardo daVinci.
That was one of the most fascinating hour of TV I've ever seen.
Anyway, I caught it when they were about to try the giant crossbow, and they had strayed from the design to use modern techniques which they were reffering to as much more efficient and superior to what Leonardo had access to. And they could barely move the projectile.
Then someone on the team forced them to do it right, and the thing flew out.
I could tell that the modern way was weaker than the original just by looking at it. The only thing that the modern way had going for it was that it was easier to do.
The lesson is: Newer != Better.
Just because a lot was invented since doesn't mean that they couldn't do anything with what they had.
You can't take the sky from me...
Probably Archimedis built the thing well in advance so that any ship that came into the harbor could be targeted. That would give him the time to build big enough to do the job, also it will allow a very limited traverse a plus when engineering the thing. When not in use the mirrors could be covered.
"It's so convenient to have a system where everyone is a criminal" - A. Hitler
You've got to have respect for a guy who can jump out of a bath, run out into the street and yell "I've found it!"...
They show fuck ups and dialog that any self-respecting director would yell "cut" and redo.
The point is to show them try to recreate the myths. The process is part of the show as much as the explosions and (eventually) the cute redhead.
You can't take the sky from me...
Terror is a possibility. To the uneducated it may very well have seemed like sorcery.
#!
I have two gripes with the experiment of both MIT and Mythbusters.
1. Mythbusters assumed one large array of mirrors. MIT got it right here, IMO, because it would be more likely that the ancient Greeks would use mirrors attached to the shields of the ranks of a Greek Phalanx. Highly disciplined, ordered, and trained to act as a coordinated unit - they could aim the beam quite easily I'd imagine.
2. Both MIT and Mythbusters assumes they would aim for the wooden hull. I would aim for the sails, which would be easier to ignite. Even given that the ships were rowed galleys, they still relied on sail to a certain extent. The burning sails would deliver a significant psychological blow to the enemy, not to mention rain burning canvass down on their heads.
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.
Of course, this presumes that this whole story isn't just a load of horseshit propagnda in the first place. And that's presuming a lot.
-Eric
SJW: Someone who has run out of real oppression, and has to fake it.
I'd like to know what the difference in latitude and altitude, and effects of global dimming would have on this experiment. I didn't see those items in the FAQ.
Rucker
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!
Yeah, I know, the hull is black and the sails were white or some other color (red, blue, whatever they painted them). But the hull is constantly cooled by water splashing on it. It's also a relatively small target over a mile away (most of the hull is under water?).
The whole point of fire arrows and stuff like that is to set the sails and the upper deck on fire. Once that's burning, it's hard to keep rowing and ignore it.
"If you could only see what I've seen with your eyes..." - Roy Batty
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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I bet Archimedes could have easily got 1000-5000 soldiers. Or maybe even archers - who'd be good at this thing (decent eyesight, steady hands etc). Whether he was able to get enough flat bronze mirrors is another issue, but I won't be surprised if he was able to do that - Syracuse wasn't that poor.
It's not that difficult to aim the sun's reflection at a target. As some people have already mention, some methods would involve putting a hole in the flat bronze mirror and using the hole to aim.
I'm sure Archimedes would have figured out many other ways of doing it, possibly more practical given the circumstances. He definitely was smart enough.
So yeah, on a clear sunny day (not uncommon in that part of the world), if you see 1000 people each with a large flat bronze mirror reflecting sunlight to you, I think it'd be best to make a quick retreat and come on a cloudy day.
BTW, Archimedes also had other defenses against ships attacking the city walls by night.
I guess the persistence of the Romans worked in the end.
IBM has a traveling museum exhibit of models of Leonardo daVinci's work. Its worth seeing if you get the chance.
It may be too late in this discussion to explain the difference between the Mythbusters and the MIT experiments, but...
Basic thermo applied to optics means that no purely optical system can increase the surface brightness of an extended object. Old important optics theorem. Check any introductory textbook for the proof.
What this means is that, from the target's point of view, no part of the lens/mirror/whatever system is going to be any brighter or hotter or provide more energy per square degree than the sun does. Instead, the mirrors or lenses or whatnot only make it seem as if, from the targer's point of view, there are more suns covering more of the field of view.
Therefore, the limiting factors in the temperature the target will reach are the size of the optical system and how far away it is. If it's small enough or far enough that it appears, to the target, about the same size as the sun in the sky, it will provide about as much energy as the sun does, and the target temperature should roughly double. The weapon can't do any more, because it can't be any brighter than the sun itself.
On the other hand, a strong magnifying glass held near a twig covers at least half the sky from the twig's prospective, and all that area can provide as many watts per square degree as the surface of the sun. The sun, taking up something like a ten-thousandth of our sky, provides almost all the heat energy that keeps us and our planet alive. It's not hard to imagine what happens when, from a specific prospective, it suddenly seems to cover a tenth, or a half. Nearly-instant campfire. Or fried eyeball if the prospective happens to be yours.
This in mind, a quick look at the experimental setups from Mythbusters and MIT explains the difference in their results. The TV crew used a moderate sized cluster of mirrors at some distance from the target. Probably covered a few square degrees, or 8 or so sun areas. The collection of MIT students was fairly large and quite a bit closer, and covered far, far more of the target's 'sky' with sun image. It's no surprise that their target got quite a bit hotter. Personally, I'm not at all convinced that the MIT scheme could have been used during an actual battle. To duplicate their results would have required that either the soldiers move very close, or that they have a very large number of them.
For anyone who's interested, this ratio between the size, or _aperture_, of an optical system and the distance at which it brings light to a focus (the _focal_length_) is a common parameter used to describe the system known as the focal ratio or f-number. This is why two camera lenses of the same focal lengths but different f-numbers will require different exposure times to properly expose a piece of film or a CCD sensor.
And yes, for those who've checked, this explanation does directly contradict the FAQ from the MIT experiment's site. The professor argues that the distance isn't relevant to the results they got, because the light energy from their mirror system can be focused arbitrarily tight. That would be the case only if the sun was a point source rather than an extended object. If they had actually tried the experiment at more realistic distances they would have found that their mirrors projected images of the sun on the ship that were too large and blurred to heat it much, unless they added more students with mirrors to fill up more aperture and compensate.
The MIT class appears to have been an introduction prototyping and product validation. It intrigues me that, by misunderstanding the underlying theory, they ended up modifying a parameter that was actually crucial to their results and validating a scheme that would be, at best, cumbersome in the real world. What this implies for the design and test process is, ah, left as an exercise for the student.
fast mirror:
u lt.html
http://deathray.bootnetworks.com/10_ArchimedesRes
you may be basicaly correct by I might argue that
so basicy I'm argueing that Archimedes didn't specificaly build a death-ray burning glass, but more probably they discovered the technic by accident.
Apocalypse Cancelled, Sorry, No Ticket Refunds
Actually, the 3rd rail episode is one of the ones I consider to have been done poorly. If I recall correctly, they never actually did anything to verify whether an actual urine stream breaks up like that in all cases. They only established that the pressurised stream going through the plastic tube did so. They didn't even address my favorite version of the myth, which is that a drunk guy wet his pants. By wetting his pants and drunkenly walking onto the rail, they would almost certainly have had it. Also, at lower oressure and flow rates, it seems less likely that the stream would have broken up in that manner. given that biological systems are wierdly efficient, it wouldn't surprise me at all if real urine would be a less turbulent flow. This was never investigated...
I meant 2000, not 200.
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Swim out and start fires on an entire naval fleet? And you are trying to debunk a myth? What, did they carry along some waterproof matches or did they hold the burning torches aloft?
Perhaps they used Greek fire?
This sig has absolutely no significance and serves only to take up screen space and waste the time of the reader.
Do anyone really, in the least bit, want to suggest that pissing on the 3rd rail is safe even though they found it safe under one trial? This is a setup for a Darwin award nomination.
I have found photographic proof of such an event at 8^)
Science is the Real TRUTH!
They don't really try to disprove myths, they try VERY HARD to make them happen. Especially when there's explosions involved.
Not only that, but they will resport to absolute brute force methods to try and duplicate the results that the myth supposedly purports. Probably the best example of this was the "Exploding Scuba Tank". They tried to "encourage" an aluminum scuba tank to explode by shooting it with a high-powered rifle. The best they could achieve with this method was to put a bullet-sized hole in the tank and let the 3000 or so psi "leak" out and blast the tank around the test chamber like a rocket. They finally got the tank to explode by using a bit of C-4. The devastation caused by the C-4 in conjunction with the 3000 psi tank exploding was quite impressive...
TODO: Insert witty sig
2) Unless the ocean was glass-smooth, actual boats would have been rocking/bobbing up and down in the waves. It looks like light needed to be focused on the same spot for 10 minutes to acheive ignition. This would seem to be impossible given a rocking boat and manually aimed mirrors.
That being said, shields polished to mirror smoothness would have been effective for something: blinding the eyes of the guys shooting arrows at you. Setting a ship on fire probably could actually be accomplished, but that would require an array of mirrors in a parabolic configuration all attached to a single frame, and this would only work at a single fixed distance.
I've abandoned my search for truth; now I'm just looking for some useful delusions.
Right you are. My bias is towards the physicists, 'cause I understand what they did better. But both Gauss and Euler awe me, ayup.
Guys, if you wanna have fun, just take an old satellite dish and cover the inside with reflective tape. Be careful where you point it, though. For added pleasure, mount a lens - the parameters of which are dependent on the dish and are left as an exercise to the reader - into the focal point, using the receiver mount. Then be REALLY careful where you point it...
This comment does not exist.
But you have to admit, turning on "enhanced" physics in CS:S and DOD:S is perhaps the most hilarious good times I've had in a while... and yes, I'm married.
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.
See the Pictures of the Flood of '08
You would also stow away as much of the sails and lines as possible for at least two reasons: to prevent your own people from stumbling over them, and to prevent anybody from damaging them. Either way, sails wouldn't be available as a target for any notional death ray.
Hmmm. Your ideas are intriguing to me and I wish to subscribe to your newsletter.
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.
Really? Could be, they're next to each other on my TV...
You wouldn't happen to know the name of the show by any chance?
They also built a working glider from Leonardo's drawings... I'd pay to see that thing fly again!
You can't take the sky from me...
Hey look, an anonymous shitbrick with a not-so-witty retort, devoid of any actual substance, of course.
3 slashdot
Why Yes I do.
Leonardo's Dream MachinesThe world's leading experts boldly attempt to build, for the first time ever, two of Leonardo da Vinci's machines to the exact specifications that he designed 500 years ago. The first is a giant crossbow, with arms nearly 70 feet across, and the second is a glider that predated flight by 400 years. This two-part special reveals whether the inventor's ideas were flights of fancy or revolutionary designs hundreds of years ahead of their time.
It is presented in 2 parts which -atleast in my area were aired one right after the other. --- It should be on next on Wednesday October 19th In my area anyway
And we all know how much PBS likes money... for $29.99 you can buy it from their website. Will not be released until 11/15/2005. They are offering 20% off too.
See the Pictures of the Flood of '08
@1) like a previous poster said, their shields were not maid out of bronze or any metal. so that cuts it out.
@2) see 1)
3) I still think there were more pratical ways to burn down a fleat than using some non existend bronze shields and some well trained solders and tons of luck.
"Freiheit ist immer auch die Freiheit des Andersdenkenden" - Rosa Luxemburg, 1871 - 1919
hey used bronze for everything. That's why it is known as the bronze age. If they were short of available bronze they could always have melted down some coins. Just because they used it for everything doesn't mean they had enough of it. You need a bit more of bronze than just some coins. Why are you so sure that it never happened? Because in the given situation at the given time it is more than unlikely that it would have ever succeeded.
"Freiheit ist immer auch die Freiheit des Andersdenkenden" - Rosa Luxemburg, 1871 - 1919
The Romans may not have used flaming arrows, but the Greeks sure as hell knew about them. Hell Athens was supposedly burned down by flaming arrows way back during the Persian War, and then there were descriptions of the use of a flamethrower-like device in the Battle of Delium.
Mathematics is made of 50 percent formulas, 50 percent proofs, and 50 percent imagination.
Neither of those examples had anything to do with the 7th century invention known as "Greek Fire".
Mathematics is made of 50 percent formulas, 50 percent proofs, and 50 percent imagination.
On similar lines there was a show that build one of his tanks.
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Um, did you just question the construction ability of the Ancient Greeks?
We are all just people.
It's all just smoke and mirrors...
If I recall correctly it took them four setups to test the chicken myth:
They kept one of the glass targets that was shot with a frozen chicken, because it had a very nice round hole in the center all the way through. It's part of their "backdrop of crazy crap" and you can see it when they are sitting around their table with the blueprints.
On similar lines there was a show that build one of his tanks.
Yeah, I saw that too, I think they're the same people.
They made a tank, and then a diving suit, which turned out to work only if you knew which line to move in the drawing... that clever Leo drew his plans with failure-inducing design deviations so his inventions would fall into the wrong hands.
You can't take the sky from me...
A lot of things that might have been done in the past are exegerated or made up. Thats how history works. Thats why I would be double careful to believe it. It might be doable nowadays, but I really doubt it was doable then.
"Freiheit ist immer auch die Freiheit des Andersdenkenden" - Rosa Luxemburg, 1871 - 1919
Is that the one where the cork needed less holes?
And the tank had some problems with the gears?
My Transformation Website
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Sorry folks but I am sorry to inform you that Dr. Wallace's team came second as far as the the proof of Archimedes death ray is concerned. The feasibility of Archimedes feat has already been proved on 6th November 1976 in Skaramangas (near Athens), Greece by J. Sakas a civil engineer. A brief report and a photo of this have been published in the greek version of Encyclopaedia Britannica (article Archimedes, published in 1981, Volume 11, p. 266 see at http://alevantis.com/archimedes.jpg) and a copy of the full works were sent to the editors of the English version of Britannica at the time.
I know this because I was at the time Editor for Science and Technology of the Encyclopaedia Papyros-Larousse-Britannica
For one, they do *many* more experiments than they show on air. Check out their website for details - basically, for every one experiment that makes it to air, they did 5.
I have ordered at least a dozen hard drives over the last five years, and not one has arrived that was DOA. Therefore, no one ever recieves a hard drive that does not work, and DOA's from manufacturers is a myth.
In reference to this episode in particular, you can be sure they tried many different cell models with many different levels of gas.
Say Samsung sells 10 million cell phones a year, and this problem only occurs on 1% of them. The chances of Myth Busters getting an exploding cell phone are very remote, and yet there's still 100,000 cell phones out that that could potentially explode.
For two, in reference to this particular episode, they did bust the myth that a cell phone can cause an explosion *through normal useage*.
"Normal usage" is a complete red herring. Showing that something doesn't "normally happen" does squat to prove that it *doesn't happen.*
What they ended up saying, is in all likelihood the reported explosions were not coming from cell phones, but were a result of static electricity buildup at the scene.
Quite possible, and it sounds like an interesting lab experiment. But you'd have to try more than five times before you threw up your hands and said, "it's not possible."
Sometime in the early 1970's, I read an account in either Time or Newsweek of the Greek navy performing an experiment to see if this could be done. They used highly-polished aluminum shields, about 1x1.5 meters, and they made a wooden rowboat burst into flames.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
It might be easier to get a quick deployment using a fresnel type of pattern rather than a parabolic arc, more compact, easier to adjust as a result. Might have taken more reflectors though.
If the reflectors were relatively tall and narrow, the focused beam could effectively clear an area of deck (at least the part above the sides) before the hull would catch fire. Sails also may have been a more easily ignitable target.
Umm, the MITers were disproving the MythBusters, not the other way around. For a show with a little more credibility, check out PBS where they actually get real scientists and engineers to see if they can replicate ancient technological feats on Secrets of Lost Empires. Conclusion: Not so simple.
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)
Though I understand it works just fine on an electric fence. (Dosen't reliably fragment in the short distance.)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
There's one problem, sails are often white.
Take an old classroom projector, and hold a black paper in front of the lens. Have something close by with which to extinguish the paper. Now try a white paper.
steve
Oh, you're not stuck, you're just unable to let go of the onion rings.
Why no one modded the parent INSIGHTFUL is yet another /. mystery, but I'll offer a verbal (or is it written) accolade as a consolation prize.
Ignorance is curable, stupid is forever.
I would have focused on the sails or the people on the decks, they are easier to set on fire or would cause havoc on the decks. Focusing on the hull is a mistake, you don't start a fire with a big log, you start with the kindling.
There was an unknown error in the submission.
Hmnnnnn..... didn't you already say this HERE
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http://science.slashdot.org/comments.pl?sid=16512
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