Slashdot Mirror

http://www.solardeathray.com/ another one. They like to burn stuff.

Line it with mylar and make a solar death ray.

Use it to build a solar concentrator to melt stuff.

http://www.solardeathray.com/

You can use the CDs to focus the sun's energy to a point and make a solar death ray! It's fun- all you need is a little epoxy!

If you want to put your lunch in front of something, try this: http://www.solardeathray.com/

The Solar Death Ray!
http://www.solardeathray.com/

Shame on me for saying without supporting link, but iirc if a person is rendered suddenly unconscious while standing, or is shot dead instantly (etc) they will fall "forward" instead of backwards, though most of the momentum is downward.

But while we're at nitpicking the nitpickers... The purpose of Mythbusters isn't science itself, but to engage people in science. To entertain foremost, but there's a background hope your 8 to 18 year old kid will say "Waittaminute" at something, look at it, and do their own analysis at some level. No I don't mean load the back yard up with bottle rockets and send the beanie baby to the neighbors (IE the raccoon myth) but they actually have lots of things where you can look and say "I think I can make a better device than that" or "But what happens if THIS factor is accounted for?" or or or.... For a kid, that can be a career deciding moment. And at worst, it makes them more aware and willing to research. How many of us haven't seen the death ray links both from the show and hobbyists (linked from /. articles, of course!! Like http://www.solardeathray.com/ ) and said "Hrmmmm...."?? I know I'd like to try building my own (but knowing my glue skills, I'll set me on fire, and the Britney Spears plush will survive. If we ever want ET life to touch down here, I'd best not do that.)

Also, I must agree, 90% of the time the scope of their intentions is misunderstood either through us not looking, or them not presenting. Or both. I'm not praising their science, I'm praising their intentions. And to be honest, I'd be honored to meet EITHER of the hosts, or even "The Build Crew" (KARI!!! but the rest are neat too) and engage in a 5 minute(+) discusion.. I suspect there's lots to these guys we don't get to see on TV.

He must ave been inspired by the ex-ex-Xbox-box-box.

It didn't take MIT to prove the Death Ray was possible. I think it's unlikely Archimedes constructed such a large device (or had an army of highly coorinated mirror handlers--not to mention modern mirror manufacturing techniques) and was able to focus and guide it with the precision necessary to set a ship to flames.

The technology of yesterday, today!

If you bothered to read the FAQ, you would see that he agrees with the MythBusters conclusion. The mirrors need to be aligned VERY precisely AND the device needs to be within A FEW FEET of the object to be destroyed. Yes, the device works, but it is not a ship destroyer.

Although the LEGO pirate ship managed to last just 16 minutes...

If you bothered to read the FAQ, you would see that he agrees with the MythBusters conclusion. The mirrors need to be aligned VERY precisely AND the device needs to be within A FEW FEET of the object to be destroyed. Yes, the device works, but it is not a ship destroyer.

Although the LEGO pirate ship managed to last just 16 minutes...

mythbusters just did it wrong. http://www.solardeathray.com/

I have found photographic proof of such an event at 8^)

I found a site one day ( pictures and everything ) of a guy who built a mirror 'sun ray'. The only way he got it to work, however, was to have the target about a foot in front of the mirrors.
 
I believe you are looking for the Solar Death Ray...
 
Hey, didn't MythBusters do this and declare it busted? I guess Adam and Jamie didn't go to MIT!

I'm guessing this is the site you're looking for...at least it's the one I've looked at in the past:

http://www.solardeathray.com/

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.

Didn't they already hear about it here or maybe even here?? Don't they read /. ?

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

Not exactly the same concept, but the Solar Death Ray always reminded me of this.

Not only can you find one of those on the net, you can find one that also uses "green" power to do it. Now you just have to get them all to stand in the same spot long enough...

death ray?

Here's a low-budget version of said project:

http://www.solardeathray.com/

Igniting toy soldiers is more fun than hydrogen, and more colorful too.

Just to clarify... this plastic changes shape in response to various wavelengths of light... not the quantity, as has been previously done. (Note - the older technology has been adapted for cell phones, too)

Just to clarify... this plastic changes shape in response to various wavelengths of light... not the quantity, as has been previously done. (Note - the older technology has been adapted for cell phones, too)

You have two options

No. You have a lot more than two options; there are dozens of types of welding. Just because you only know of two doesn't make it the case that there are only two.

gas

"gas" welding typically refers to either gas-arc or plasma-arc welding. Both involve strong electric currents; you need a ground, and have to deal with electrostatic attraction of dust (regardless of whether or not you have a stream of gas). As for "solar welding", they did a much simpler task on mythbusters a while back - the notion of a "solar death ray". They couldn't even ignite a boat covered in tar and doused in accelerants with a focused mirror. Somebody built a 4' by 6' solar "death ray", but it's really only good for burning flammable objects from close up and melting plastic. At a distance (like the mythbusters), more problems crop up: in addition to the simple fact that the sun doesn't contain that much power per square meter, your focal point gets larger, and it's hard to keep it focused where you want it to. In short, to do solar welding on the moon, you'd need something like a 30 foot parabolic (or array of smaller mirrors) that you can focus precisely. It's not a realistic proposition for the moon.

as for air

Air was only cited because the powder press that ran into was pneumatic. Find your own hydraulic press, but I can bet you it won't be any lighter. Are you ignoring the fact that the press weighed almost a metric ton, to produce 3 centimeter parts?

Your heat solution involves bringing a huge drill to the moon so you can install your heat sink, in addition to lots of copper pipe which you have to install. You just keep ratchetting up the mass of what you have to bring, you know that?

Lastly, you only dealt with about half of the issues I mentioned concerning welding; you especially avoided safety issues. Welding on earth regularly causes burns. A burn on the moon can mean death. Experience on earth will be little applicable, as everything involved in the process will behave differently in low gravity and almost no pressure, working on top of a huge thermal and electrical insulator (basically, you're standing on statically-charged powdered glass).

Cars are pressurized vehicles

I got a very good laugh when I read this one. Do you even know what "pressurized" means? It means that it *holds pressure*. If you slam a car door, do your ears *stay* popped? Of course not. You can feel the pressure when you shut a door in my study too, but it's clearly not "pressurized" - there's a half-inch crack below the door. A pressurized vehicle *doesn't leak*. Period. If it leaks, it is, at best, a "broken pressurized vehicle". How many survivor stories have you heard where someone who drove off a bridge said, "Well, we didn't roll down the windows or open the door, so no water came into the car...."? Even the brief feeling of pressure is due to a minor artifact - unless your ears are popping (and I've never heard of anyone's ears popping from closing a car door), you're looking at a tenth of one atmosphere or less.

steel and iron are different, yes, but being mostly the same thing (iron + carbon = steel) they share many properties

How about I say "coal and diamond are diffent, yes, but being mostly the same thing (carbon) they share many properties" - sound reasonable to you? Of course not.

Iron and steel are *very* different, property-wise. Pure iron has less than a tenth the yield strength of a good steel (note: cast iron and grey iron are actually low carbon steels). Pure iron is a "soft" metal - softer than aluminum, and quite the opposite from steel. Pure iron is many times more reactive than steel, and will form a white (note: white, not red, like from steel) coating of iron hydroxide (note: not iron oxide, like steel) from the oxygen and water in the air in hours to days (note: not years to decades, like steel).

The best way is to not worry about returning the drives under warranty, just buy a new one.

And as for the old one, a sledgehammer and a horseshoe magnet should do the trick. Beat the HE-double-hockeysticks out of the drive (or maybe just the removed platters, if you want to save some energy by unscrewing the case), and then pass a magnet over the fragments a few times in the hope that anything still left might be scrambled.

A solar death ray should be able to handle a hard disk too. 600 degrees Celsius should cut it, eh? Of course, it's cheaper just to shatter the platter with a sledgehammer.

(Disclaimer: I am not a lawyer, engineer, physicist, chemist, biologist, or healthcare professional, nor do I play any of the above on TV. By acting upon any suggestions contained herein, which do not constitute expert advice, you agree implicitly to this contract. I am not responsible for injury, death, destruction, dismemberment, liability, or prosecution such as may ensue from your actions. Use at your own risk, contains no CFCs, Barbie(R) dolls do not talk or move by themselves. Do not eat iPod shuffle)

Provided the nanites with reflective skin don't go to www.solardeathray.com. The we would be in teh shit.

this is definitely not as cool as the solar death ray slashdot article

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.

No, he did kill some something: Army men. Okay, maybe they are made of plastic, but they're still men.

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.

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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Wired article as proof

the animation. The speed of light is different for each particle after they bounce off the mirror. How can that be achieved? Doesn't the mirror have to be one continuous parabolic mirror to achieve phase synchronization?

Hmmm, judging by his short writeup it seems he's doing everything right.

...someone puts that damn Rock and Roll music to good use!