Archimdes' 2,200 year-old death ray!

[Phreddie]

Originally Posted by Hill-Shatar

*sigh* I am currently reading up on the wonders of the Ishial Tuberosity...

sounds exciting, but if you want some real entertainment, try reading the book of job (the bible, jewish or christian) with out fall asleep, i dont tihnk it can be done.

[Hill-Shatar]

Originally Posted by Phreddie

sounds exciting, but if you want some real entertainment, try reading the book of job (the bible, jewish or christian) with out fall asleep, i dont tihnk it can be done.

Pst* I find anatomy of the hip and lower spine much more interesting then Religion. Unfortunately, half of the disucssion threads turn out to be, well... religious discussions.

Trying to remember if a certain part of the hip is a Fossa or an intercondyle thingy-mic-jigger. I always make the mistake, even though it is so obvious.

CE! HELP!

[Aegis]

Originally Posted by Phreddie

sounds exciting, but if you want some real entertainment, try reading the book of job (the bible, jewish or christian) with out fall asleep, i dont tihnk it can be done.

Job's easy. Horribly dull, but easy. I've read the bible through, and am currently working on translating the Koran. Now, that's a challenge.

[Hill-Shatar]

Ok, I think it is time to bust this a little.

Number one. These people had multiple mirrors from multiple angles focused on one point, whereas the picture depicted one man using it.

Number two. It took several minutes for any effect on one area; the boat would have been moving.

Number three. Wood? Why would you aim for the wood? It isnt exactly flammable (compared to the power of the light).

Number four. They are aiming below water. Right, where the wood is wet... perfect...

Feel free to add. This is just preliminary thoughts. On the other hand...

If the mirror in the picture was not exactly a mirror. What if it was a lens more shaped like a satellite dish, to get as mauch light in as possible, with another concave item behind it, the actual mirror, would focus it and send it back though the lens refocused. That may work... if the mirro and lens were large enough.

The operator would have to be behind the mirror, of course... the materials of the time are available. But the weight may be too much fopr a boat... or it may be some sort of alloy.

The deck would be a target, if I didn't know for a fact it was oiled (not with the flammable ground stuff, mind you, the good stuff) and therefore permanently non-flammable. Therefore, aim for the place that has the best flint, ect, which was on the boats at the time. Although, those piles were usually protected... what about the canvas? Or the rope? Both would be good targets.

Of course, all of this is open to interpretation... my skill in physics are not the best. Mostly because anything similar to that was removed from my life when I same into my current line of work, except for the really annoying parts of it that will follow my work for the rest of my life (molecular weights of drugs. YAY!)

Look at the wood, it is barely scarred!

[Aegis]

Damnit, Hill. You took a perfectly good thread of spam, and put it back on course. Shame on you, shame!

[Kipi]

Originally Posted by Aegis

Damnit, Hill. You took a perfectly good thread of spam, and put it back on course. Shame on you, shame!

Hill adopted your job too well

About ship movig, well, you can always move/turn the mirror
Which, I admit, would be very hard, especially to keep the spot in same location. But if the ship is coming towards you, the it would be another matter...

And also, like Hill said, they had many mirrors...

[Cuchulain82]

Yeah, but having one mirror that was large and properly crafted would potentially increase the power of the beam, right? Also, like the site says, the fact that the boat caught on fire proves it is possible, not probabile. Don't forget that archimedes was in Greece, where the sun is in much greater supply than in upstate NY.

The cool thing about this is considering it from the point of view of someone on a boat. Imagine this: you're the captain of a boat or admiral of a fleet that is poised to invade Archimedes' city. Maybe you're moored a hundred yards or so beyond the city's port, cutting off all sea traffic. There you are, in the middle of the day, waiting to attack... and your boat(s) start bursting into flames!!! You don't know why, or really how it's happening. You can see somone on shore with a big lens, but other than that you're at a loss. Isn't that wacky?

Now, feel free to continue spamming. In fact, I'll even get you started- Hill, did you say that reading the Bible about lower back anatomy was better than shooting Greek Fire out of an ancient cannon? Discuss...

[Dottie]

Originally Posted by Hill-Shatar

Ok, I think it is time to bust this a little.

Number one. These people had multiple mirrors from multiple angles focused on one point, whereas the picture depicted one man using it.

Number two. It took several minutes for any effect on one area; the boat would have been moving.

Number three. Wood? Why would you aim for the wood? It isnt exactly flammable (compared to the power of the light).

Number four. They are aiming below water. Right, where the wood is wet... perfect...

-snip-

If the mirror in the picture was not exactly a mirror. What if it was a lens more shaped like a satellite dish, to get as mauch light in as possible, with another concave item behind it, the actual mirror, would focus it and send it back though the lens refocused. That may work... if the mirro and lens were large enough.

Most of these questions are answered by the article or by the FAQ. Shame on you Hill.

Personally I fail to se the extraordinary quality in this. With enough mirrors you could set fire to something... Wow, how suprising.

[Xandax]

To expand on Hills list:

I would think that the flawlessness of the mirrors/lenses would be the first large obstecle with this "theory".
To much unevenness and it would be difficult to aim the ray, let alone get it focused enough to generate enough heat.

Secondly for this to take place over a distance it would requier massive coordination in aiming the rays. The experiements as I see them on the linked page has a range of 100feet with stationary targets and stationary mirrors
100 feet - which isn't excatly any large distance when talking about naval combat, not even in a siege of a city. Ships would likely have been a great deal father away, and within that distrance - 100feet, I'd say archers with fire-arrows would be much much more effective. If the ships where ancored, other weapons exists which would have been much more practical to use, which also begs the question - why would somebody make this weapon when better weapons existed.

Also - as Hill says - ships have a tendencey to ... well move. And combine this with the coordination requiered, and the actual time before seeing just any kind of result - and I'd say a snowball has a greater chance in Hell at a chilie bbq then for this to actually have taken place.

Perhaps it is plausible that using "mirrors" you can get wood to catch on fire from a (larger) distance. But I strongly doubt it would be practical let alone possible, especially in the time of Archimedes.

(Also - if I recall correct, wasn't it polished shields which supposedly was used? Which makes it just a fairytale in my book.)

I need to see concrete evidence of this working in a pratical manner over a distance of greater then 100 feet against a moving target before I'd even say it is plausible. These extreemly conditional tests shows nothing. It has to be practical for somebody 2000 years ago, not for somebody with "all the time in the world" with current techonology levels.
No way. I think we'll see Elvis again before this is proven practical for Archimedes.

[Hill-Shatar]

Originally Posted by Aegis

Damnit, Hill. You took a perfectly good thread of spam, and put it back on course. Shame on you, shame!

Some of us are under caffeinated.

Originally Posted by Cuch

In fact, I'll even get you started- Hill, did you say that reading the Bible about lower back anatomy was better than shooting Greek Fire out of an ancient cannon? Discuss...

Are you having some probl;ems with Ouzo too?

Originally Posted by From that ever-so-useful article

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.

Oops, they have already differed from the plan! That's not how they did in the past. Tsk, tsk, at least try and follow the historical possibilities instead of incorporating your own ideas right away!

However, the picture seems to depict a seige, so if several of these instruments were lined along a wall... well, they may not all hit at the same place at the same time, but hit the right area and it heats up. the heat would not entirely dissipate, right?

Just taking the view from two sides.

The article also mentioned something about the mirrors being slightly concave. I would have made a larger mirror, or more larger mirrors, of increased amounts of concaveness (sp?) for this project myself, perhaps with a concave lens in front as well, to collect and focus enough light to refocus in the angles of the mirror and send it back though the center (path of least resistance and least disruptuion and "spraying" of light).

Originally Posted by More from the article

In addition to reducing the available power, each mirror made a very diffuse image on the ship, making aiming more difficult, as evidenced by the size of the bright spot.

Who would have thought that Archimedes had a bullhorn (or would be on the Roman ship)?


Only wisps of smoke were observed.

At the time, it would have been worse, as the mirrors and lenses may not have been as refined, as was mentioned by Xandax.

However, if this Archimedes was as intelligent as they claim, then most likely hwe had some way to target them all... these devices seemd much larger and more thought out, so they most likely had a scope, and had a system for targeting certain ships, and where.

Anyways, the last would be a Duh. they mentioend that clouds had popped up overhead...

Originally Posted by the article again...

The Roman ships are believed to have been painted with colored wax. Ours was stained with ‘minwax’. While it was thought that these materials would help with energy absorption and possibly act as accelerants, in the end it seemed that the stain did not matter… ignition occurred evenly over an area involving both raw wood and stained wood. The stain volatiles had boiled off and the region was evenly charred well before open flame was achieved.

OPh yes, use ore of todays tools. they also forgot to cover the deck and ship in oil. As you all know, wood rots, and at the time., it was one of the best ways to stop that from happening. They seem to have forgotten the fact that Roman and Greek ships all had multiple layers of substances on their decks. Already the amount of ariables has made this test mostly pointless.

Time to debunk the FAQ.

Setting the sails on fire would probably easier, but at anchor they would be furled. Also, I believe that in battle they would be furled since otherwise they are a great target for other types of projectiles.

Actually, at the time one of the majopr weapons in battle was the ships themselves. Ciovered in the front of the ship with metal, such as brass, they would charge and ram other ships.

Again, they are moving... and from the test, you can see that it really did not work all the fast, nor could they all track witrh the mirrors effectively.

Anyways, the saisl dont disapear when furled. they are rolled up wioth rope, and make a fairly good fire trap.

ii ) Archimedes would only have access to bronze or silver plated mirrors.
Yes, my impression is that Archimedes would certainly have had access to polished bronze at this time. It is not clear if they would have had silver mirrors. If silver was available, silver mirrors would be about as good as the mirrors we used. Bronze would not be as good but polished, it is actually a fairly good reflector. Its lower reflectivity can be compensated for by increasing the collector area.

Considering the reflectivity of polished brass/bronze, my initial estimate is that we would need to increase the size of the array 1.4 to 1.5 times for bronze reflectors to work. It would be fun to try it again in bronze (but more expensive)!

They did have access to silver at the time. In fact, glass was almost in use for some finer instruments, such as the hour glass. A lens of large proportions perhaps could be made, but it would be easy to damage.

iii) A bowshot is easily greater than 100 feet. Are greater distances a problem?
A bow shot can definitely be more than 100 feet, but this is actually not a huge deal assuming that the air is clear. 100 feet was the biggest space we had.

The number of 'perfectly flat' mirrors needed with increasing distance will go up because the beam from a flat mirror reflecting sunlight will disperse slightly with distance. In fact, the amount of dispersion from a flat mirror is almost exactly what we observed in our test (1 square ft mirror projects a 3 square ft area at 100 feet), meaning the mirrors we used probably really were very flat. This is because the sun is not a true point source, and actually is about 0.5 degrees wide in the sky. This leads leads to the dispersion that we observed from a flat mirror. However, a quick experiment flexing the mirror tiles by hand (done by one of my colleagues) indicated that it is not too hard to make the mirror slightly concave to compensate for this effect. So, with slightly concave mirrors one would not need to increase the collector area for greater target distances. To understand this last statement more, please see FAQ iv).

Again, they limit the test. You can not do that and recieve feasable results.

The rest, well... I think this has been argued.


Ill just answer number 4. Pretty much, these mirrors would eventually disperse the light in different directions, but these mirrors were concave. they can hit a point. Still, they use inadequate tools for the task.

vi) The approaching boat would have to be completely stationary for a few minutes. Could anchors at the time achieve this?

My instinct is that if the ship was anchored it would actually be still enough. If it was say 70-100 feet long (that's the size historians seem to cite) and it was fairly calm, the boat would be almost completely still in the vertical direction (irrespective of the anchor). Given that the city was in a bay, I would surmise that the waves there are typically not too big, and the Mediterranean is somewhat calm.

The mythbuster rig in the original show was very small (guessing ~10 feet?) and thus would be much more sensitive to wave action. Consider the difference between riding on a cruise ship vs. a 14 ft Boston whaler. So, that covers vertical motion.

I am not aware of a reason why their anchors could not keep the boat stationary in a horizontal direction.

Additionally the boat can bob around some. For example, in our test the hot spot was roughly 3 feet in diameter, so the boat could bob around roughly +/-1.5 feet and still keep at least some common area in the heat all the time. The bigger the hot spot, the less sensitive to boat movement the death ray will be. The bigger the hot spot, the bigger the collector area needed.

This would still take invariably a huge amount of time. If they were bobbing, they would bob more than 1 and a half feet. This is the medditareanian, not some inland lake system, and its a sea for a reason. there is a reason the lakes are lakes, here in Canada, and one of them is lake wave size.

The medditareanian isnot the same one as today. Wave size has recently decreased. Still, it can bob some fairly large boats up to three feet, and some areas much higher, suich as in the currents of the straioghts of Gibraltar.

Finally, the boats anchor will not keep it from moving, rotating, or moving that nice shiny brass to the front.

[Hill-Shatar]

Continuation from above, and another below. Wow, I wrote little... I suppose I could go into more detail, if anyone requires it...

vii) The device would only be capable of its peak burning power at midday on a cloudless day.

Yes, the position of the target and time of day does matter, but at least the geometry of the region is about right (so the boat would be roughly between the sun and the mirrors).

One needs to size the collector for the worst case for which you want it to work. The effective area of the mirror is a function of the position of both the target and the sun. This notion is considered in the order of magnitude estimate on the 2.009 page (you need to load the big image of the hand written estimate to read it).

The time of day can be compensated for by adding more mirrors. Of course, at some point the scale gets so big it does not make sense. But, say between 10 AM and 3-4 PM at this time of year in Boston (early October), I feel we could get it to work at a reasonable scale.

We found our 'death ray' was very sensitive to even light cloud between the mirror array and the sun because of how the clouds diffused the sunlight. However, even on our successful day, you can see a lot of cloud in the picture. All we needed was a bit of time between clouds. So cloudless is a bit too strict. On the up side, my Greek graduate student tells me it is sunny there much of the time!

The weapon would be very tempermental to sun. ALthough none of you may have been to Greece, I hjave and it is fairly sunny. However, angles of the sun and the like alter so much that any thing like this could be fairly difficult to manuever into happening. Greece has a low angle sun, nothing can change this, not even badly performed tests.

The rest is pretty much stating the obvious. Clouds may effect the weapon. Oh dear, we could not have figured that out on our own!

viii) The target would have to be directly below the sun on the horizon for maximum effectiveness.

This is more or less the same issue as discussed in FAQ vi). The position of the sun and the target matter since that determines how the mirror needs to be oriented, and thus the effective area of sunlight it reflects. The less perpendicular the mirror is to an imaginary line from the center of the mirror to the sun, the lower its effective area. One just has to account for this and design for the range of conditions you want it to work in.

Maximum/peak burn power is not required for the death ray to work. For greater reliability, the death ray should be designed to work over a reasonable range of conditions (for example, between the hours of 10AM-3PM). We also need to know the time of year, latitude and where the ships are most likely to be relative to the collector to decide a reasonable time range and appropriate number of mirrors/collector size. Using the 2.009 approach is is very easy to employ more or fewer mirrors.

If designed to have enough area to work at 10 AM, the death ray would be very effective (much bigger than needed) in ideal conditions, but still be sufficiently effective for a larger range of conditions. In product design speak (i.e., in our 2.009 class), you need to design for the worst case scenarios.

No argument from me here.

ix) The weapon would only work on targets to the east, south and west as the sun shifted through the day.

Feasibility is site specific. Looking at a map, and assuming that the modern Syracuse is in exactly the same location (I don't know if it is), a naval attack would have only been possible from roughly ESE to SW, which is pretty ideal.

Again, this is more geogrpahical. Lucky foiir many Greek cities, they could have implemented this somewhat slow and mostly useless defence.

x) The planking of the boat would have had a high moisture content after possibly years in the water.

Yes, below and near the water line the ship would probably be dependent on the wood being swollen with moisture just to keep the joints tight and not leak. However, I suspect that well above the water line, the wood would have a much lower moisture content. One would certainly want to aim for the driest parts to reduce the amount of time to achieve a sustaining flame. Growing up, my family had a cedar strip boat that stayed in the water for extended periods and the wood above the chines was reasonably dry.

From the small amount of reading I have done on the subject, my impression is that setting the ships on fire (along with ramming) was a common battle strategy. Also, wikipedia suggests that the ships may have been taken out of the water to prevent them from becoming water logged, which would cause them to ride lower in the water and become more difficult to propel and maneuver.

Again, aiming for the wood consistnely. Althpough multiple devices aiming from mulitple angles may make this work, the most likely could not, in this modern day experiement. The fact that there is a lower mositure content means nothing. Does it matter that when you douse a campfire with one bucket of water or twelve? Thisa is the same thing; you are trying to set on fire wood which will be constantly wet, and nothing will change that. Water will stay around, as it is encased in the wood. It will be replaced by the sea they are sitting on.

xi) Weren't those ships caulked with pitch, which would increase their flammability?

This is not my area of expertise. There seems to be a fair bit of inconsistent information, but the planking may have been covered with pitch or wax coatings. Dark pitch would increase the surfaces' absorption of energy from the death ray. In our experiment, the fire started in a region with both raw wood and wood coated with an oil-based stain. We had wax in the joints and this boiled off well before ignition. Therefore, coated or not, it seems possible to set the wood on fire.

Pitch was used under a coat of oil in the keel areas, closer to the fore, to reduce friction. they were aiming aft.

However, the painting of the ship was made with some what pitchy substances, and would absorb a lot of light. The wax is different, as it is made from plants, and therefore is harder to melt, especially with something like light.

All the rest was inside to reduce the amount of humidity the crew would have to deal with if they were below decks.

xii) Why bother with all of this when powerful weapons like the Palintonon or Ballista were available?

They work in all weather conditions and can be accurately and repeatedly targeted.
True, they did have these options, and given the dependence on weather I personally would not want the death ray as my only choice! Aside from weather dependency, I think that (using the technique of the 2.009 attempt) we could accurately and repeatedly target objects to achieve the desired outcome (although there was a definite learning curve).

On the rationale side, it is fun to speculate. Does it hurt to increase one's options? With appropriate mirrors it might be possible to target ships at significant range. Also, one might simply benefit from the element of surprise. Would the Romans understand enough about optics to realize what was happening and react quickly? Using the ray does not consume any materials. Why haul all those heavy rocks to use as projectiles when you can just aim a beam of light! (kidding) ...

Yes, giving that it isnt rainingg, clouded, and the sun is at the right angle. Targeting would be slow and close to useless. Repition would be diffiuclt, and would require a high level of coordination to get it to all work together.

I personally, would rather rely on other devices of distuction at the time, as well, and give this a try only if the enmey is still far out and there is little to no danger to my city.

Yes,... surprise: Look, a light is shining at the boat! Lets sit here and watch it
! Oooh... shiny... oops, I cant see it anymore, itmuch be targeted at the boat. CVause you know, we can see the light reflected of a mirror not directed at us. Lets move five feet forward and, whhops! All that hard work for nothing!

no matwerials? You made a bunch of huge mirrors out of silver!

If he did not say kidding at the end I would have got on a rant for a while...

xiii) Did it really happen?
We're not historians and cannot answer this question. Overall, there are a number of special conditions and important details that need to be considered to get the death ray to start a fire. However, given the location of the city, the local conditions, the ease of implementing the idea once one has worked out the sensitivities, and the brilliance of Archimedes, my own opinion is that I personally can't rule it out all together (can't say it happened either). However, our goal was to use Mythbusters to motivate doing a quantitative estimation of feasibility, to demonstrate the possibility using a sketch model experiment, and to have some fun in the process.

Neither can I rule out either way.

However, it has been repeatedly documented that people in ancient times would take such things like the Death Ray and the Byzantine Flamethrower and say that it is the holy power of god.

This may be something else, and they may have refered to it as channeling the light of Zeus, or something along those lines. Yopu never really know.

[Hill-Shatar]

Originally Posted by Dottie

Most of these questions are answered by the article or by the FAQ. Shame on you Hill.

Personally I fail to se the extraordinary quality in this. With enough mirrors you could set fire to something... Wow, how suprising.

Read above, Dottie. Last night I was to tired to pay attention to bias... Also, I needed caffiene, something I dop not have. Luckily, I am at home today, as they convinced me that workjing over 120 hours a week was not good for my health, and I dont feel like bar hopping...

I agree...its not like you havent heard of this before. Of course, naming it after a ray of power from a sci fi movie with a death star kind of lowers my opinion of it, consiering I could write just as long about the impossibilities of rays of light that you can target, see and do mass damage with.

Originally Posted by Xandax

I would think that the flawlessness of the mirrors/lenses would be the first large obstecle with this "theory".
To much unevenness and it would be difficult to aim the ray, let alone get it focused enough to generate enough heat.

actually, they could make concave lenses of the time in extreme proportions, its just that the rate of success was low. If they tried a hundred times and made one, it would be possible.

sorry, I woulde comment more on what Xandax said, but my fingers hurt. Ill just say I agree with him and we can all walk away happy.

And toss some Ouza to Aegis for entertainment.

[Lestat]

Stop mentioning Greece!
Though Archimedes was a Greek, Syracuse is in Sicily (Southern Italy & Sicily were colonised centuries earlier by Greeks and several Greek city states existed there).
Syracuse's latitude is around 37. Boston is in the low forties I think, so the difference in intensity of sunlight would not be that high.

[Cuchulain82]

Good golly Hill. Whatever your dayjob is, I think you should apply for government work- you can kill time with the best of us!

Why is it that we can all extend plausability to our own personal fantasies (rpgs, games, crack-pot personal theories) but can't imagine that Archimedes might have made a big lens to burn ships?

[Hill-Shatar]

Originally Posted by Lestat

Stop mentioning Greece!
Though Archimedes was a Greek, Syracuse is in Sicily (Southern Italy & Sicily were colonised centuries earlier by Greeks and several Greek city states existed there).
Syracuse's latitude is around 37. Boston is in the low forties I think, so the difference in intensity of sunlight would not be that high.

I think I mentioned the angles of the sun somewhere above, perhaps repeatedly.

Anyways, the Greeks were invading Syracuse... meaning that any Greek ship would be stopped by Syracuse weaponry... I said nothing above, I believe, to displace that fact.

Good golly Hill. Whatever your dayjob is, I think you should apply for government work- you can kill time with the best of us!

Why is it that we can all extend plausability to our own personal fantasies (rpgs, games, crack-pot personal theories) but can't imagine that Archimedes might have made a big lens to burn ships?

Thanks, but you obviously didnt read my answer to dottie in post number 3.

Anyways, it may be possible. Unfortunately, many variables have leasd to the fact that the weapon may either be extremely weak, powerless or useless in the first place.