MythBusters season 2

  • Thread starter cronxeh
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  • #26
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cyrusabdollahi said:
Thats not likely zooby. making a large mirror is a veryyyyy hard thing to do. He would need a mirror that is almost perfectly parabolic to focus the light if he wanted one big one. It HAD to be small mirrors.
That's why I want to find the original wording. Did he build a large mirror from many small mirrors, in which case it's quite possible to set a boat on fire from a distance? If he did it this way and had the focal point set to a distance he knew the boats would have to approach, then it's perfectly plausible.

As far as an army of men holding mirrors goes, I would like to see this tried with some substantial mirrors. A foot square per man is lame. An authentic army of men holding shield sized mirrors might do some real damage.
 
  • #27
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An authentic army of men holding shield sized mirrors might do some real damage.
Not unless its they are all trying to focus the energy in one spot, which is very hard to do on with a moving ship. If its so far away it seems to be still, then its too far. If its so close that the beams will work effectively, then the ship will be moving to fast. Your screwed either way.
 
  • #28
enigma
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I watched an episode this weekend where they determined that a human's mouth is dirtier than a dog's mouth. They took samples and incubated at 98.6 degrees. Lo and behold... the dog's sample had fewer colonies.

Big shocker.

A dog's body temperature isn't 98.6 degrees; it's around 101. Canine bacteria wouldn't have evolved to thrive at human temperatures...

We get fevers to kill bacterial infections. 101 degrees is pretty sick for a human. It goes the other way, too.
 
  • #29
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cyrusabdollahi said:
Not unless its they are all trying to focus the energy in one spot, which is very hard to do on with a moving ship. If its so far away it seems to be still, then its too far. If its so close that the beams will work effectively, then the ship will be moving to fast. Your screwed either way.
That's why I'd like to find the original myth. Were the men on shore and the ships in a harbor? If so, the ships would have been anchoring and the men taking to small boats to get to shore and invade. Also, how many men is an "army"? If it's enough, there migh always be a large enough percentage of them hitting the side of the ship with their refections to heat it past combustion temperature.

Fixed arrays of flat reflecting mirrors can reach temperatures of 1000 degrees at a hundred feet.

The other thing that occured to me is that these old wooden sailing vessels are still built by hand in various places around the red sea and they oil them heavily to make them more water proof. If the ancients did the same that might make them more combustable.
 
  • #30
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Fixed arrays of flat reflecting mirrors can reach temperatures of 1000 degrees at a hundred feet.
At 100 feet, you might as well shoot arrows of fire and save yourself the agony....eh?
 
  • #31
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"Splitting arrows" bothered me a bit in the failure to find some of the tricks used by arrowsmiths for straightening arrow shafts, that is, forming shafts with continuous grain parallel to the axis; they depended instead on milled dowels.
 
  • #32
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Thats true. But I still say until someone can do it, im going to have to say BUSTED.
 
  • #33
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cronxeh said:
I cant believe they've never been injured with so many flaws in experiments :eek:
Jamie and Adam are relatively ok with safety.
In the episode about the rocket vacuum cleaner, Tory's rig for supplying propane to an experiment was just insane. He put the propane tank on the other side of experiment, so if something went wrong he would be unable to turn off the propane (which was in a fairly large tank).
 
  • #34
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http://www.math.nyu.edu/~crorres/Archimedes/Mirrors/Tzetzes.html" [Broken]of the burning mirror story.
 
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  • #35
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Just yesterday I was watching something on the history channel and they had the mirror story thing. It worked... (not hard to believe really, if you have so many mirrors, even half decent)


EDIT: During the test to see if a person could be sucked out of a window in an airplane. They only payed attention to difference in pressures, but they didn't even care about how fast the plane was flying (air flying past it...quickly)...

EDIT2: The guy who tested the myth about the mirrors, I forgot who he was, but he even went to essentially the original spot and burned down a small fake ship...
 
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  • #36
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Was the ship moving?
 
  • #37
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Integral said:
http://www.math.nyu.edu/~crorres/Archimedes/Mirrors/Tzetzes.html" [Broken]of the burning mirror story.
And http://www.solardeathray.com/" is one of those Solar Death Ray's. Which is awesomely cool by the way :biggrin: :biggrin: :biggrin:
I gotta get me one of those. Read the one about the honey bear :rofl:
 
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  • #38
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Integral said:
http://www.math.nyu.edu/~crorres/Archimedes/Mirrors/Tzetzes.html" [Broken]of the burning mirror story.
Thanks for finding that, Integral.

It sounds like the beams from many small mirrors were aimed at the large mirror which was then aimed at a ship.
 
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