Slashdot Mirror
The Solar Death Ray
Ant writes the "Solar Death Ray is made of 112 mirrors mounted on a platform 4 feet wide and 6 feet tall. Each mirror is a square roughly 3.5 inches on edge. All these mirrors focus the sun to a single spot 5 feet, 6 inches from the mirror platform. A wooden fork extends from the mirror base to the area near the focus and serves as a mounting point for Solar Death Ray targets. The mirror platform is mounted to the support frame on a pivot that allows the platform to be angled. The whole system is mounted on a set of wheels. The goal of the Web site was to show the results of the targeted items when the solar death ray was used."
And Batman & Robin wasn't very good.
How I squandered my youth and why I didn't get laid.
"I'd rather be a lightning rod than a seismometer." -Ken Kesey
Use the Coralized link here!
If Tyranny and Oppression come to this land,
it will be in the guise of fighting a foreign enemy. -James Madison
Solar Death Ray Guy's next News entry should be fun.
Trolling is a art,
Yeah, it is pretty cool to burn something with mirrors alone, but why not throw in magnification? Or does anyone know anything that has been designed similar using magnification?
Proceed with Format (Y/N)? Y
...on the old Atlantis movie.
Sheesh, evil *and* a jerk. -- Jade
...is batman and robin and a you're a super villian!
Kent! Where'd you put the giant bag of popcorn at?
I want to build one of these now... Except I'm in Northern England. I'd be lucky if it could melt marshmallows :p
It's really only a "death ray" if you're really really tiny. Mythbusters did a great job of blowing the myth apart, with a much larger mirror array arranged in a proper fresnel configuration. It douldn't set fire to much of anything, even when they put gasoline on the target.
...someone puts that damn Rock and Roll music to good use!
Get your Unix fortune now!
Dantooine. I mean Alderan. I don't understand the question.
The ace of spades, teh hootie and the blow fish tape, and his pants. IMO these are the bes ones that caught fire.
Wasn't something like this on MythBusters on Discovery Channel a while back?
It sounds like something David Letterman would do.
Wonder how much juice you could generate if you were to mount a stirling engine at the end of this sucker. Seems like it'd be a lot cheaper/easier to implement than normal high efficiancy solar cells if you could work out a reasonable and reliable sun tracking system.
Every year during my review, I just pray the words "slashdot.org" aren't mentioned.
This toy kinda reminds me of what I used to do as a kid with a magnifying glass. It was an easy way to set leaves on fire, among other things...
Rosco: "If brains were gunpowder, Enos couldn't blow his nose."
On Hackaday today. Check it out. http://www.hackaday.com
This is another way of starting a sig with this and ending it with that.
Yeah, but can you mount it on the head of a friggin shark?
Don't blame Durga. I voted for Centauri.
when you can just point Slashdot at a server?
Don't look at mirrors with remaining... er... head...
I'm a bloodsucking fiend! Look at my outfit!
Isn't that how they got all that pop corn popping?
Rosco: "If brains were gunpowder, Enos couldn't blow his nose."
I must now go into my parents basement and build a replica, then steal the neighbor's plants for "science experiments" Of course, "staring at the sun" by offspring will be playing the entire time.
This myth was busted on Discovery Channel's Mythbusters in episode 16:
http://dsc.discovery.com/fansites/mythbusters/ep isode/episode_03.html
Aside from making a giant palette of mirrors (and unsucessfully attempting to ignite a small boat), they tried to no avail to be sprayed by a skunk.
That show is classic.
Warning!
The slashdot is bright. Don't look at the slashdot or you will damage your eyes. Anything that focuses the slashdot will only make it more dangerous. The Slashdot.org is dangerous. Don't build one.
I'm surprised I haven't burnt or blinded myself yet. The fumes from molten trolls can't be good either. Don't play with flames.
(And he thinks that 120,000 pageviews is a lot...)
--
Vote for your hopes, not for your fears - Vote Third Party
Looking at the picture, with paved roads and suburban atmosphere, it's interesting to note that even places like Doom Mountain are not immune to gentrification.
THIS is a solar death ray: 10 metres of high-precision parabolic polished aluminium. (And there are bigger ones out there in the world too.)
I've observed there. Because it is radio astronomy, we could observe before sunset and after sunrise, but for some reason we had strict instructions to never let the sun fall on the dish. (That includes the back, but that was to do with thermal distortion of the dish, rather than frying the focus.)
I also used my HP48SX calculator (running a terminal emulator) to command the telescope to slew. Because of this, I claim the CSO as world's the largest and most expensive peripheral for a pocket calculator.
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
Larry Niven invented the "flashmob" years ago. Now, it looks like someone has come up with something similar to his Ringworld "Sunflowers", which consisted of petal-ringed mirrors which could focus on prey and turn it into ash fertilizer.
Don't blame Durga. I voted for Centauri.
FTB...
Given that it's winter in Seattle, it might be
a while [before I can test this out]. I should have built a rain-powered death ray or a death ray
powered by granola.
Rule #1 -- Politics always trumps technology.
Yes.
The claim was that Archimedes thought up having 1000+ soldiers use their reflective bronze shields to shine sunlight on enemy ships. Thus igniting and incinerating them.
They tried this on MythBusters and it didn't work. But they don't always do a perfect job on that show, and since armies were huge back in the day....I wouldn't be surprized if it worked.
The government has a defect: it's potentially democratic. Corporations have no defect: they're pure tyrannies. -Chomsky
This is how the Death Star got started.
No, because they would get very HOT, and the efficiency goes down dramatically with increasing temperature.
Actually the Mythbusters were trying to take out a wooden boat that was a couple hundred meters (that part I'm not sure of). They wanted it to catch fire. This guy is concentrating the energy and melting stuff, not actually setting anything on fire (except the clue board). Setting fire to a wooden boat far away is a lot tougher than melting a rubber ducky.
Better patent that idea before someone else makes use of it.
Government of the people, by corporate executives, for corporate profits.
I hope they post it again. /just kidding
--Gentoo Baby!
Build a copy of this solar death ray, then point them at each other. Mutually-assured destruction kicks ass!
This one is a bit bigger!
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.
(Did someone just say holy fucking shit?)
Picture of the Odeillo Solar Furnace
1q2w3e4r5t6y7u8i9o0pqawsedrftgthyjukilo;p'azsxdcf
Although I found the justification for the Hootie and the Blowfish tape hilarious, he should be flogged with a bamboo cane for burning that tetris disk. That thing was a fucking museum piece!
You are such a nerd. We will have to make you king of the winter carnival.
10 metres of high-precision parabolic polished aluminium
Why aluminum? Is it the most reflective substance on earth?
we had strict instructions to never let the sun fall on the dish
No matter where you point it, you are pointing it somewhere.
And make sure to not leave it pointing in the direction of the only all-black fraternity house on campus. That could start up those nasty black versus nerd wars again. Instead, point it at the Sigma Chi house, those bastards are always burning down their own house... nobody will suspect anything.
Rosco: "If brains were gunpowder, Enos couldn't blow his nose."
I'd suggest an ant, but then PETA would be all over their case and people would mod me, uh, flamebait.
Hmm...
A feeling of having made the same mistake before: Deja Foobar
Mu, uhh, death ray is bigger than your death ray
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.
Picture of the Odeillo Solar Furnace
1q2w3e4r5t6y7u8i9o0pqawsedrftgthyjukilo;p'azsxdcf
I'd like to see a beowulf cluster of those...
What if you made one of those that was roughly 50 times the size (or N times, I guess), and put it in Death Valley, or something?
(Ever read "The Crystal Shard")
Then aim it into a high-powered, highly resistant solar panel.
I suppose if something like this were mass-produced, and constructed with computerized calculations of mirror angles, we might have a highly efficient energy system!
Or even if we made smaller solar death rays. We would need a less resistant solar panel to absorb the energy. They could be calibrated to maximize solar energy efficiency!
Although maybe mirrors would be too expensive...perhaps some highly lustrous and cheap metal.
Crap man, I'm starting to feel like John Travola in Phenomenon.
Better stop.
http://augustwestproducts.i8.com
This is right out of Gundam 0083: Stardust Memories sick little minds trying to fry us like ants .
Given that he was able to set a rag on fire, I'm guessing that the Mythbusters team did something incorrectly regarding the focusing of their mirrors. And your link says they used a circular configuration which is only good in limited cases since the light is focused in a line (which isn't really focus) rather than a point. This was parabolic setup which is why he was able to melt plastic and set a rose on fire.
--
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Or try a free Nintendo DS, GC, PS2, Xbox. (you only need 4 referrals)
Wired article as proof
Maybe not igniting them directly, but...
How about blinding the sailors on board, who then run around in a panic and knock over the pot of charcoals used for igniting the flaming arrows? Carcoals ignite the ship's deck instead, or someone's clothes, the fire spreads, voila. No more battleship.
Let's just say that they're using the ray model of light, and split the rays into dots to make it more visible.
Grampa: What the hell is that?
Frink: Why, it's a death ray my good man, behold.
(Frink fires death ray)
Grampa: Hey, feels warm, kinda nice.
Frink: Well it's just a prototype, with proper funding I'm
confident this little baby could destroy an area the
size of New York City.
Grampa: But I want to help people, not kill 'em.
Frink: Oh, well to be honest, the ray only has evil
applications. You know my wife will be happy,
she's hated this whole death ray thing from day
one.
http://www.snpp.com/guides/prof.frink.html
Proof: Take a microscope and set it to 500X. Point the objective at the sun. Do you death rays spewing from the eyepiece? (Answer: no). To find out why, read the first paragraph or ask someone that *really* knows. (Hopefully someone that took some optics (physics) or astronomy)
"He came back with a golf ball and said "Here, try this." This guy was in his forties and was wearing the orange and reflective outfit I associate with road construction, so I'm not sure why/how he had a golf ball."
;) ...or for that matter how much those union workers get paid...
Obviously he has no idea just how FAR you can hit a golf ball on a stretch of new road
- Adam L. Beberg - The Cosm Project - http://www.mithral.com/
I hate to be the one to point this out, but um. They haven't actually killed anything. This more accurately should be called a Solar Plastic-Melting Ray.
a more useful target would be a sterling engine connected to a generator.
noon today (Tuesday), and I was shocked to see that there
had been about 80,000 page views that day.
That was yesterday. I bet he's in for a suprise when he looks at the logs today.
— darco
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
You forgot libstdcpp.
No no, if we're stuck with trying to get a moontan and welcoming spring with moonlight savings time then the terriorists will have already won!
Want to improve your life? This guy will show you how!
I, for one, welcome our Solar Death Ray overlords.
I surrender.
Under perfect conditions, you should be able to reach the surface temperature of the sun - about 5600 C. This will be reduced by atmospheric absorption, imperfect reflectivity of your mirrors, etc.
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
...die now and save the world from idiot pollution.
A message delivered on behalf of all living things
but what if we threw something like this together on a (pulling number out of ass) 1000x scale, put it in orbit, and pointed it at something on earth. would that work?
"Kindergarten Solar-powered Death Squad
Take a large crowd of children out into the sunshine and give each one a 20cm square mirror. Show them how to aim all of their little spots of sunlight at the same distant object, then stand back and see what they do. Better yet, run away.
FAST!"
And another one here...
Is anyone else noticing that there are a lot more people ready to jump on anything that doesn't have the "This is a joke - look, here is the smily.... :)" smily on it?
Get your own free personal location tracker
There are historical accounts of Archimedes using a similar system, though likely much larger to set ships on fire.
Same idea but with a big Fresnel lens: Remember?
~Someday, I hope to be an aspiring author.
No offense here to Larry Niven (big SF fan here) but Archimedes has prior art for them since 2200 years or so.
"Slashdot Death Ray is made of 1 website and no mirrors of the target site mounted on a platform of linux, perl, and horribly mangled html. Each user is a square (ed. note: update to modern parlance, ie "geek"). All these mirrors focus the slashdot to a single web server. A wooden fork is stuck into the web server after it melts to signify that it is "done". The mirror platform is often asked for and often denied by CmdrTaco, who mounted his stock answer on an FAQ somewhere. The whole system is mounted on a stack of open protocols dating back to the early days of DARPA. The goal of the Web site was to show the results of the targeted items when the slashdot death ray was used."
You see? You see? Your stupid minds! Stupid! Stupid!
Thanks - you just made my day. :-).
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
...they should just burn them after they sing that "I Only Wanna Be With You" song again. I can imagine them singing "I only wanna beGAHHHHH!!1!--nah, just joking, I like Hootie. Though cassettes are old enough to burn; hard drives and even CDs* just seem much better and space-efficient to me.
*esp. when they're put in thinner cases and not those 1/2cm monstrocities.
You can hold down the "B" button for continuous firing.
I always wanted to round up a kindergarten class worth of children to act as my solar death squad. Here's how it would work:
1. Give each kid their own shiny little mirror with a post-it note stuck on it to block the shiny part
2. One at a time, have them remove the post-it, aim their mirror to reflect the sun upon some point, then re-post-it.
3. Once everyone is aimed (30 kids or so), have them all remove their post-its at once, instantly creating a plasma-hot ball of fire at the point of focus, incinerating your enemies with the might of a kindergarten class.
Has anyone else had this idea too, or am I the only weirdo around here?
As a matter of fact these guys built something kind of like that, and seem to be producing all sorts of concepts for cheap, clean, solar energy. I think they were featured in Discover in August of 2003. (The year might be wrong though.)
I just can't wait until they get into mass production, because the metric they seem to be using throws out traditional physical efficiency and relies on power per unit cost rather than conversion efficiencies.
It's also been implemented on a much larger scale in molten salt power towers which iirc use high temp (200-500C) salt to make steam to turn turbines. Yes, it's a solar plant that can work at night if it has to.
-Holmes.
I wonder how long it took to orientate each individual mirror so that they're all focusing on the one spot.
Not sure I'd have the patience to do that!
Don't look at mirrors with remaining... er... head...
Don't worry, the mirrors are fine. It's the real server that we're wor--what, the ray's mirrors? Whoops.
You can hold down the "B" button for continuous firing.
ERROR
The requested URL could not be retrieved
While trying to retrieve the URL: http://www.solardeathray.com.nyud.net:8090/
The following error was encountered:
* Access Denied.
Access control configuration prevents your request from being allowed at this time. Please contact your service provider if you feel this is incorrect.
My physics teacher let me borrow a 3x4ft Fresnel lens. It would focus that 12sq.ft. of incoming sunlight down to a about a square inch. It melted pennies into the concrete walkway.
Unfortunately, I did not get to use it twice, as I set a passer-by's shoe on fire, and she complained.
See this website for a similar story.
... so I can use it on people who burn ants. [grin] :)
Ant(Dude) @ Quality Foraged Links (AQFL.net) & The Ant Farm (antfarm.ma.cx / antfarm.home.dhs.org).
7 MW maximal thermal poer in the receiver. 7 times bigger than your tiny little French toy.
...a very large array?
You can hold down the "B" button for continuous firing.
Then whoever took the picture on the page you linked to never got the memo.
What sort of lame museum exhibits things you can buy for $5 on ebay?
Tetris the Classic PC Puzzle Video Game 5.25" 3.5"
My amazing wife - Artist, Author, Philosopher - Laurie M
No, Mister Duck. I expect you to die!
"Anyone that has ever gotten an idea based on any of my work and done something better with it-good for you."--J.Carmack
Get a 12" frensel lens and try that. It can burn thru plate metal.
---- Booth was a patriot ----
Not to ruin your "all things are influenced by Ringworld" fantasy, but the solar death ray guy(s) were directly influenced by Rob Cockerham over at cockeyed.com.
Will it float?
You can hold down the "B" button for continuous firing.
I read an article about http://www.amasci.com/amateur/mirror.htmlthis solar array quite a while ago, I thought it had been posted hear. 112 mirrors doesn't really sound like a lot.. if you covered a 4 by 8 sheet of plywood with 1 inch mirrors, you'd be able to get 4608 mirrors in your array, not allowing for clearance. if you use the same number and make the mirros 3/4 inch, you would end up with a target spot around that size at 4608 times the power of the sun. I think that would do some considerable damage.
Stuff burns when it gets real hot.
Heh. heh. heh. Actually, Archimedes beat them both too it by a long time, as the other guy pointed out. I don't know about the Cockeyed guy. I did, however, find Nigerian penpals on his site.
Don't blame Durga. I voted for Centauri.
An Army testing lab in Natick, MA used an enormous array of mirrors to simulate the thermal flash pulse of a thermonuclear detonation, for the purpose of testing a sunscreen that the labs were developing for GIs in a nuclear battlefield. Best part is, they tested using pigs! Sound like some loony conspiracy to you?
Check it out.
It's real-world stuff like this that keeps sci-fi writers going.
Supposedly the inventor Archimedes during the siege of Syracuse by the Romans used large mirrors that focused/concentrated sun light into an intense enough laser beam that it burned invading Roman ships. There was an episode of Myth Busters on this subject (Season 2 Episode 4).
Here's what the Myth Busters guys did to test the theory:
- The crew build half a trireme and balanced it in the water.
- The crew built 400 sq ft mirror built from 300 individual mirrors. They were arranged in a cicle and were all focused at the same point.
- They aimed the giant mirror such that the focal point of the indvidual mirrors was directly on the trireme.
- They were only able to get the temperate up to 280 degrees even with all of their efforts.
- They just couldn't get the ship to burn, so they used Molotov cocktails instead just so they could destroy something.
Simply put, this is a myth. It is very unlikely it happened.
Pankaj Arora
Homepage
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maybe its been modded redundant cos the parent is mentioning the Mythbusters link for, like, the 50th time?
Mongrel News all the news that fits and froths
This is a solar furnace, of which there are many in use today. The biggest one in the world is the Odeillo Solar Furnace located in Odeillo, France. The top 3 in use in the United States are at Sandia National Labs, Georgia Tech and the White Sands Missile Test Range. Awesome stuff!
One amusing side note is that Frank Gehry's popular postmodern buildings have been noted to act as solar collectors, effectively frying people passing by on the sidewalk.
Slashdot's first reaction to VMware
Maxim burns when it gets real hot, too.
You'd be right if there were no atmosphere.
I can see Microsoft making a Solar Death Star and targeting the Apple HQ from outer space. Perhaps this could be a new era in OS wars?
They cannot be beat for simplicity: google for giant fresnel lens
If by magnification you mean with a lense, by golly it has been done before..... in fact it was even mentioned on slashdot. Fresnel lenses are really useful for totally obliterating innocent inanimate objects.
Gundam had this in 1979, we're already past the year 2000 giant robots will just blow it up. Whats the point?
I like muppets.
"The goal of the Web site was to show the results of the targeted items when the solar death ray was used."
No, the goal of this site is to solicit money from while having fun destroying stuff. An admirable goal, mind you.
You need a FREE iPod Nano
They tried to build a fixed arrangement of mirrors (with a fixed focal length) ... and then aim it at a point not at the focal point. A much better test would be to make several hundred flat mirrors with a hole in the middle (signal mirrors... but bigger, to make aiming at the same point easier). Then teach several hundred volunteers how to aim a signal mirror, and tell them all to aim at the same point on a boat.
Now make a reflector on one side of the moon and cook cities!!!
(If at first you don't succeed, do it different next time!)
polished aluminum is used because its sub-mm but not extremely sub-mm (ie, optical).
its been awhile, so i forget the exact formula, but basically your surface can be as rough as some fraction of the wavelength you're trying to focus. Hence, wide waves can use dirty and/or rough surfaces (such as arecibo, which is just a hole in the ground and some perforated aluminum panels) and still work just fine, even when soiled as a huge bowl in the ground is bound to become.
-
I remember reading a Sci-Fi story ( at least 30 years old) where a guy goes to a soccer game in a South American country.
He notices the program for the game (given to everyone who attends) has a very shiny white back to it.
Into the game the referee makes a decission against the home team. In reply the crowd all hold up their programs, focus the sun onto the ref and vaporize him.
"To stay awake all night adds a day to your life" - Stilgar | eMT.
But this makes me wonder how much electricity could be produced by a series of parabolic mirrors heating water to turn a turbine, and whether this would be economically worth it in areas with a great deal of sunlight.
(And don't talk to me about google... I'm lazy this evening.)
That green slime had it coming.
Are we talking seconds, minutes, days?
printf($randomline(sigs.txt) \n "-- "$randomline(authors.txt));
-- myself
...but he can't make a properly formatted webpage.
Someone ought to mirror this (pardon the pun); the site is getting sluggish already and I have a feeling it'll be going down in the next 45 minutes.
Sounds like Archimedes and the Greeks knew enough math to make piecewise parabolic mirrors that could focus on a point.
Did they have the technology to make reasonably flat GLASS mirrors?
IIRC glassblowing was not known then, and it was quite hard to make flat glass panels.
Also the legend seems unclear as to whether they were using glass mirrors or shields. Bronze shields, whether flat or curved might have much poorer reflective properties than a mirror.
It would only fry the focus if you pointed it directly at the sun. Otherwise, the light would focus at some other point. Thermal distortion does make sense however. Pretty sweet though.
SIGSEGV caught, terminating
wait... not that kind of sig.
Finally something I can contribute to slashdot!(says the optical engineer working late): The collection of mirrors used here is actually a piecewise-flat approximation to a large magnifying mirror, and does magnify the sun, within a margin of error. Augustin Fresnel invented this concept in 1822 for use in lighthouses. http://www.lanternroom.com/misc/freslens.htm If you look at the array of mirrors used here, the outer ones curve increasingly inward, just as as if it were a sigle curved mirror that had been cut up and rearranged to fit on a flat board. Any small part of a large curved lense is approximately flat anyway. It is not generally called "magnification" because that is used to talk about enlarging images, and this type of lense, being approximate and cheap, yields pretty blurry images. Still, works great for spotlights and solar concentrators. Here is another example: http://ravenrocks.org/Mook/
"I love his boyish charm, but I hate his childishness" - Leela
There is no way that would fit on the head of a dolphin.
So what use is it to me?
the death ray is 4 feet mirror is 4 feet by 6 feet. It looks to have a bout 50% of its area covered with cheap mirrors, which I'll assume are about 80% refelective. that makes it about a square meter of effective reflectivity. the solar flux near the equator is about 1 kilowatt per sq meter. This is focused down to an area of about 6 inches square or about the size of a stove burner. A typical stove burner probably runs at about 1.5 KW. so basically this thing has the heat delivery of a burner. Actually a bit less since the object itself may be reflective over a large part of the spectrum. So call it maybe half a stove burner. Still plenty to fry plastic, your hand, or even start a fire.
Some drink at the fountain of knowledge. Others just gargle.
> I surrender.
Wait a minute; isn't this backwards?
hawk
This mirror is layed out in concentric rings for some dumb reason. He should've just done lots of solid rows of mirrors. There's no reason they have to be in circles. He'd have gotten nearly double the power out of it for the same sized board.
I'd guess that they wanted a publicity photo, and took appropriate precautions:
(1) Ensure the desired dish position and sun position cause the focal point to be somewhere harmless.
(2) Slew to desired position with shutters closed
(3) Open shutters
(4) Take photo
(5) close shutters.
However this is speculation on my part. As a visiting astronomer, if I'd tried this, I expect they would have been Not Impressed.
The rainbow does, however suggest a certain spontineity/opportunism in the taking of the photo.
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
I have had INCREADIBLE success wearing the copyleft shirts.
:P
Don't be afraid to nerd out a bit but keep it in moderation, women like men who are into politics especially if they don't already have an oppinion (especially a contrary one) since most haven't heard of DRM or IP they'll listen to you complain for a while and think you're a friggin genius about it.
Picking up girls the copyleft way, can't find the shirts I have 2 of the DECSS crossed out and the green one which says my shirt is illegal, girls love that
No info on prices for a Stirling engine suitable to put in front of this toy, can't find the reference to the individual who built a backyard concentrator in a 7' satellite dish, nothing on materials for a refractory crystal capable of creating a real beam at the focal point, now my head is spinning around the idea of adding a cylinder internally mirrored from just shy of the focal point to several inches beyond it containing at its center a laser-capable crystal or substance container (Who needs expensive xenon pumping flash tubes? we've got ~3kw of sunlight!) - and no, the resulting assembly would NOT fit on the head of a shark - want mobility, buy a truck.
But thanks for the ideas.
Take the 90-Day Challenge! http://rwmurker.bodybyvi.com/
Imagine a beowulf cluster... never mind.
The Weizmann Institude has a large scale version of this. A large lot is covered by computer controlled mirrors that can be aimes to reflect sunlight into one of three floors of an opposing building.
Each floor has one wall that can be opened up, as a garage door, to let the sun shine in, and supposedly they can reach tempratures of several thousand degrees in a controlled space there.
One of these doors has a large black spot on it, supposedly from not opening it on time.
Since the target is so close, why bother to actually use an optical system that focuses the light? Why not just use nonimaging optics that concentrate the light at the target. Such systems can generate phenomenal temperatures, which would probably produce much more interesting results.
Signatures are a waste of bandwi (buffering...)
"Bwaaahaaaha, Finally I nailed that ant that didn't succumb to my Cracker Jack magnifier when I was 8. Whose your Daddy now, insect breath!"
Table-ized A.I.
who notices this guy's web layout, solardeathray.com watermarked animated gif's, and rather lame attmept at Dave Berry style humor as an utter maddox rip?
seen it before, but this stiff is always fun. There's just something cool about melting stuff with the power of the sun. Although you can get better focus and higher heat from a bug fresnel lense, this definately has style.
Remind me to submit my UV (hydrogen) pumped cyanine dye laser if I ever finish it. Just need some more 6KV capacitors, a good vacuum pump and and a lot of Tide(TM).
A Call For A New Slashdot Moderation Level!
All he needs now is a tropical hideaway to stash his "goodies" and maybe a cat with a diamond collar. Henchman with metal teeth and bad case of acromegaly optional...
This sounds a lot like a minature version of the French solar furnace.
Since most anything French seems to be unknown in this country (US) this story would be news.
Telescopes have wide aperatures for two reasons. Angular resolution and light intensification. At high magnification, the light is more 'spread out' so it is *less* intense.. or would be if the aperature of the telescope was the same as your iris. It is not. The larger aperature area of the telescope can collect much more light, and this is why you must not look at the celestial object without filters. Under high enough magnification (which would probably be well beyond the diffraction limit for most telescopes) you would not need the filter anymore.
Can you be Even More Awesome?!
It's a heck of a lot easier to get an old 4' radio dish (example) and cover it with a reflective mylar. It works GREAT! No fine-tuning mirrors - this is MUCH less work.
I did this with kids at a small science museum - they loved it. We boiled water and lit cardbord on fire.
If you're not outraged, you're not paying attention!
Wasn't this a Myth Busters topic. They couldn't get it to do anything.
It's a hoax. A fresnel array (and what this guy built is a fresnel array not a parabola) of this size cannot generate the heat to burn anything. BTW, one of the experiments done by the Mythbusters was essentially the same thing. They explained why this approach doesn't work and their explanation was essentially correct. You can't focus a significant amount of light from flat mirrors on a focal point. Most of the radiant energy is wasted.
That's funny.
Change the B to A and you get Fry.
C doesn't do anything.
It's late.
The rest of the alphabet is left as an exercize for the readership.
When I was growing up I made a 17" Dobsonian telescope. At the time it was considered quite the light bucket. We would take it out just before dusk so that it would cool down properly for a midnight viewing. One of my buddies did the classic, "Oh let's point it at the moon," thing thinking that because it was still light out, it would be safe to look at without stopping down the aperture. Notta good idea: a few feet away his *hand* lit up like a halogen bulb and that was the end of that "bright" idea. Lucky it was only his hand.
But this makes me wonder, the brightness of the light at the focal point would be: L[f] = L[a]*r*A[a]/A[f]
where A[a] is the area of the aperture, A[f] is the area of the focal point, and L[a] is the brightness at the aperature, and r is the percentage of light that gets reflected.
Now, in the article he says that the solar death ray uses 112 normal mirrors, and they're all flat, so r*A[a]/A[f] is likely to be .85*112 ~= 95, which gets him a temperature of 500 degrees C. Now, my telescope can bring the light cone down to an area of, say 1/4" diameter, and the reflective coating I use on my mirror can get 90% transmission no problem. So, r*A[a]/A[f] for my 17 inch aperture is likely to be .90*4900 ~= 4410. Ok, the moon's average albedo (measure of reflectivity) is 0.12, and the moon and the sun have the same apparent size in the sky (ie solar eclipse is close match in size). So, does that mean I should be getting 0.12*4410/95 ~= 4.5 the light intensity from my lunar death ray as he does from his solar one?
Hey I could fry ants with the moon! Or on second thought, maybe not.
It's sometimes sad that simple devices like this are not used on a large scale to generate electricity. Focusing the light on a tank of water would generate a lot of steam, and, if the steam passed through a simple closed circuit where the water could condense and flow back into the tank, you'd have a minimal maintenance generator for all those sunny days. And you could use large ones to power pumps to push water uphill into dams to generate electricty during cold months and the proverbial rainy day.
I could have put that to some good use, damnit!
a slut did tulsa
Actually I was only second (last I checked) and the other fellah only beat me by four minutes.
/. of late has been shoddy at best, meta-moderation be damned...
Heaven forbid I work a job and perhaps can't hit "submit" as fast as I like whilst CTRL+TAB'ing between Firefox tabs... or wait, if this is the boss then I mean of course debugging our monolithic application for the benefit of future generations of lawyers.
And I extend many thanks the parent AC; "moderation" on
crazy dynamite monkey
No, the original poster was only mentioning it for the fourth time. And they posted it no more than 2 minutes after the original mention of Mythbusters.
I agree with the grandparent - the post really didn't need to be moderated redundant. Some moderators seem to be under the delusion that just because a post is 3/4 of the way down the page that it was posted *after* all the comments above it, and somehow the poster must have submitted despite all the references that already existed.
Read the posting times, and cut the guy some slack.
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Actually, in a major part it depends on the mirrors. Specifically, on glass. Most of glass (at least the cheaper kind used in common mirrors) is infrared-opaque. Sure the spot will be lit brightly. So what, if all the light is in visible range, and no infrared ever gets there, dissipated in the mirrors?
If they used mirrors i.e. from polished metal, that could work. Each such mirror can raise the temperature by a few degrees. This won't get you far beyond 100C and would hardly be able to set things ablaze, but could possibly melt a plastic bottle or explode an egg.
Anagram("United States of America") == "Dine out, taste a Mac, fries"
he'd rigged all those mirrors to be computer controlled so that he could drive the focus spot around using a joystick...
Donald 'Duck' Dunn: We had a band powerful enough to turn goat piss into gasoline.
Sorta, anyway. This is a link to the UNLV Solar Project, a project playing with new ideas in solar energy such as focus the light to a specific point (roughly, of course) to increase the uptake of energy by the receptors. I drive by these bad boys everyday. UNLV Solar
What is your penile percentile?
I've always wondered why my Braun electric shavers came with little mirrors.
Niven's Ringowrld "sunflowers" in man-made form. Cool.
There are lies, damned lies, and statistics.
If it reflects twice less light, then you simply need twice as much men with mirrors..
Lemony Snicket's A Series of Unfortunate Events (2004)
This is a game? for real? for honest?
lick the cancle button (at least thats what our Chinese QA says)
Why aluminum? Is it the most reflective substance on earth?
Yes. Strictly speaking, freshly applied silver is more reflective, however silver tarnishes very rapidly, and after about a week, an aluminium coated mirror is a better relector than a silver coated one.
done since 1970 in the pyrénées, much bigger, and by Archimede way before
I have to wonder how such tech could be being used in grid-less nations, for example, to promote industry?
I mean, is it possible to create such a system that could be used to fire a kiln, for example, or keep a high-temperature oven maintained long enough to do glass?
As a tech-nerd who longs to get off the grid, this sort of thinking appeals to me. How can small, light industry, be brought to the DIY scale
; -- the corruption of government starts with its secrets. a truly free people keep no secrets. --
I can't believe nobody has jumped on the obvious ObPost. Dude! You should burn a DELL! ;-)
Resistance is futile. Reactance buggers it up.
At least half their experiments have been organized so poorly that they failed when its well documented something works, and that was a prime example.
Its entertainment, not science. Don't watch it to learn anything about the reality of the "myths", watch it because its freakin' hot to see Kari bound up in the water torture episode.
(Oops, did I just say too much?)
Energy Innovations has a device called the Sunflower that uses a similar concept of focusing the sun's energy for heating purposes... on a sterling engine! They use it to generate electricity. They're also working on a newer model which, IIRC, is about 4 feet by 6 feet in a rectangular array (easier to orrient the mirrors, they said).
That is well within the range of archers and spearmen aboard the ships. I'd like to see this shown possible 400 yards out with plausible Greek tech. We aren't talking about firing a derelict. These are supposed to be ships full of armed sailers and marines.
Just for the fun of it, would he gain much by using parabolic mirrors that would concentrate solar rays even more ?
Of course you must be able to find a lot of cheap parabolic mirrors of the right curvature (ideally they would have slightly different curvatures, being at different distances from the target focal point, but hey that would still be better than flat mirrors).
But still, I wonder how much power he could get from this.
Thomas-
I wonder if this was an extention to a science fair project... Maybe he lost and he thought "I'll show them. This will work!" This is way better than the project that won - "How to get a strange dog to bite you"
...made that...over 20 *years* ago for a high school science fair.
GET FREE APPLE STUFF!
Myth Busters tried this one too to duplicate something Pythagoras (I think) was supposed to have done.
Lost at C:>. Found at C.
Oh Dear... I hope this does not add up ...
If we point them at the Sun itself, I wonder how much mirrors we need to blow it up ?
I remember one History's Mysteries episode where they tried to debunk if Archimedese could build a death ray in ancient Greece using mirrors. They showed that the amount of mirrors needed to make it more than just "really hot" was physically implausible.
click me
Finally! George Hamilton can get that tan he's always dreamed of.
For another thing that needed doing, read Catapult: Harry and I Build a Siege Engine. Sorry, I don't remember the author's name.
"Who controls the past controls the future. Who controls the present controls the past." -- George Orwell
If your Maxim gets hot enough to burn, you obviously need more water in the water jacket.
Duh.
No, no, no. I'm sure he meant Maxim, the men's magazine, not Maxim, the water-cooled machinegun.
25 years ago in middle school, my brother did a science project. He took a large umbrella and covered the inside with alluminum foil. He clamped a grate of some sort onto the handle near the focal point, set it out in the yard facing the sun, and cooked a hotdog on it. I don't think it took nearly the effort this "deathray" geek put into mounting all those mirrors....
so now it is both glass and fur. Very Hollywood.
Mein MG-08 ist wunderbar!
Viral software licensing is not freedom, it is in fact GNU/Socialism.
About the light go faster than c, well, it appears to be here already http://www.aip.org/pnu/2000/split/pnu495-2.htm, although not exactly faster than c :). There is also this blurb about a negative index of refraction, which might also be interresting. http://www.aip.org/pnu/2001/split/534-2.html
What the resonant frequency of those mirrors is...
If you scale the whole thing up to about the size of the Buckhouse, you'll be fine.