When Spun Really Fast, CDs Explode

Anonymous Coward writes: "Ever wonder why cd-rom/cd-rw drives are not getting any faster? Wonder why they heat up? This page has a rather amusing experiment where they put various CD's into something that can spin up to 30,000RPM and found that most cd's explode at just around 28,000RPM. Oh and they seem to like using Corel CD-ROM discs for their experiment." Update: Yep, it's a dupe...

Comments

better way

[xero_sign]

I prefer to just microwave mine..

Pah!

[popeydotcom]

They should at least have chosen AOL CDs to destroy. Sheesh.

Al.

Exploding CDs?

[kitzilla]

A lot of bands might consider exploding CDs a feature. :-)

now they know how to make hard drives explode...

[yuri82]

just a post a link to it on slashdot and BOOM, there goes your hard drive...

Ooh, new copy protection idea...

[silverhalide]

I can see it now, the RIAA manufacturing discs that experience structural failure when you spin them faster than 1X to rip them....

oh boy.

Wonder what happens if you spin a floppy at 30,000 rpm? :-)

More Explosions!

[Inexile2002]

I want to see more of this kind of story!

I want to see what else can explode in my box. I want to see what happens (with big color pictures) to to a hard drive at 20000 atmospheres of pressure. I want to see ASUS vs ABit mobo's head to head for resisting g-forces. I want to see what happens when you force 100,000 volts through a cat-5 cable.

Isn't this what the internet is all about, pictures of stuff exploding, videos of people endangering their lives for my tittlation while discovering what happens if you fill a case with gasoline and run it as a server. Get cracking people.

Re:More Explosions!

[kwishot]

What happens when guys in IT departments get bored or "fed up" with hardware? Try hooking up common computer cables and connectors to 110vac for the purpose of destruction =) I especially like VGA killer and the "powered" hub!
Check it out at http://www.fiftythree.org/etherkiller/ (I've actually had the honor of seeing these things up close, and they're every bit as cool as you'd think! =)

Re:More Explosions!

[TheConfusedOne]

Well, I can't give you 20,000 atmospheres, but I can give you a tank driving over a hard drive.

http://homepage.cc/harddisk/

Enjoy. Personally, I think it would be more fun if they used the main gun to "partition" the disk.

Re:More Explosions!

[Lumpy]

I want to see what happens when you force 100,000 volts through a cat-5 cable.

i cant tell you about 100,00 voles but I can tell you about what happens when you shove 2-4 million volts down a cat-3 cable that is 400 foot in length.

I ran a cat-3 cable from my parent home to their deck in lake michigan for a telephone extension. I had aquired for them an old police call box, modified it to have the ability to be locked with a combination. (Jerks walking the Lake Michigan shoreline will happily make long distance or 1-900-nasty-sex calls on your phone for you if you dont.) so I ran some cheapo regular cat-3 wire out there for the 2 phone lines they have at the house and mounted a cheapo 2 line phone in the call box. (later changed it to a 2.4Ghz Cordless with custome antennas out the top... that's another story)

WEll we had a lightning storm. and silly/stupid me didn't think of these things and GROUND things at the phone box end on the beach. so we had a direct hit to the tree next to the phone box... It did the following.. The cat 3 cable was completely vaporized for 20 feet. It was gone, nothing NADA, as if aliens came and beamed it to their mothership with charring effects. the rest of the cable length had interesting things done to it.. From the charred point to the house where the first ground point was available (outside) it was broken every 1 foot, the every 2 foot and os on until it was up to every 10 feet had a section broken/burned out.. on close look you could see exit wound pinholes near the break point as the voltage found a weak point and escaped. My only explination was that the voltage continued to drop as it made it's way toward the good ground (or the rest of the house) and this was what was causing the increase in distance between breaks/burnout points.

Oh yeah, of the wires in the cat 3 cable... 4 were phone, 3 were alarm indicator from the house,1 for house is alarming, 1 for reporting to the house that someone opened the phone box wrong, and one was grounded at the house.

The alarm was blown up.. completely it was dead, circuit board fried, I stuck a fork in it and handed it to the insurance man.

3 of the 5 phones in the house were dead (electronic or cordless) the 2 old mechanical bell phones worked.

Re:Duplicate

[Tablizer]

This story (with the same URL) was [already] posted here [slashdot.org].

Slashdot staff has appearently been spinning in their chairs so fast that their memories centrifigully left their container.

Bannage target?

[Tablizer]

Oh great. Now CD players will be banned from planes.

Re:Bannage target?

[Anonymous Coward]

actually I agree. you are correct CDs could be dangerous. lets lets look closely at what it will take to make our skies secure:

I think we should ban hands because we can choke the stewardesses. cut em off or chain em down.

I think we should ban long sleeve shirts. A sleeve can be used to choke too. I could easily choke someone with a cotton sleeve.

I think we should ban toothbrushes. they could easily be rounded to a point and used to poke holes in the jugular.

hard sole shoes are also a no no. you could knock someone out with a really hard sole.

paper is a big risk too. with lots of paper, and the one allowed lighter (now) it's pretty easy to start a big fire on a plane. then everyone is fscked.

they have absolutely NO idea if my shampoo is flammable or volatile.

nix those headsets they hand out. those have to go. a wire cord could easily tie the (still live, but squirming) hostages.

I often travel with wire coat hangars. a nice titanium hangar with a sharp point could easily stab someone in the heart, the eye or the genital.

feet are nasty weapons too. I once saw a Korean kick-boxer break another mans leg with a single kick. I think it was a video on the Internet. clearly a terrorist risk.

I had a friend named Kip who weighed about 380 pounds and subsisted entirely on canned cheese, hotdogs and pizza. he could fart so much that people literally passed out. fat farters are no longer allowed. (unless they buy two seats).

my grandfather had a key that was actually a screwdriver on the end. prisoners sharpen keys and kill each other often. I guess we can't have keys with us any more.

4 laptop batteries if modified and connected in series, put passed through a step up voltage transformer, could produce a shock large enough to (with high probability) produce a heart attack. no more batteries which means no more laptops.

carry-on suitcase are never weighed. I've carried a carry on with a 28 volume set of encyclopedias which weighed close to 130 pounds. a big arsh terrorist with a 130 pound carry-on over your head in cramped quarters == not your friend. no more heavy bags.

this doesn't even talk about the UNBELIEVABLE TWENTY-FIVE PERCENT failure rate at catching fake guns, bombs, knives, chemical maloderants, and other dangerous stuff passed through security. In the future we will have only 3 passengers per plane to reduce this risk.

belts are nasty. people kill themselves all the time with belts. shoelaces too. when I was in jail in Houston nobody had belts or shoelaces. and nobody died! dress ties fall into this category too. I guess it's low riders, no ties, and sandals for everyone!

I recently transported a piece of lead crystal in my carry on. drove the security people bonko. made me EMPTY the whole suitcase. couldn't see through it on xray. I also had a set on 1950's glasses that belonged to my grandfather, each wrapped in paper. they didn't care I had 12 1-lb breakable projectiles that could be heaved or tubing shot at high speed through the cabin -- let alone a 6 pound chunk of lead crystal. nothing heavy AND nothing breakable. (security screens don't see surgical tubing as a threat).

see that aluminum mag light he has in his ha*WACK* *omg, the floor is approaching my face really fast*

head butt, elbows, body check, high falls, knee in the groin, the face? "I'm sorry sir if the chains and shackles are tight, but we'll be landing soon. It's for your own good."

I'd bet a food cart full of books pushed by the expanding gases from oxygen canisters would blow right through a reinforced cabin door.

I wonder if they can tell the steel shanks in my packed boots are actually removable and cut into strips and sharpened into knife blades. I'd bet not.

The list could go on and on and on and on and on

_______________________________________

THE POINT:

SO... TO MAKE OUR SKIES SAFE: only 3 at a time, naked and with hand and feet chained fast to your seat; nothing else in tow. that would about do it.

PEOPLE CANNOT CONTROL EVERYTHING. IT IS A BIG LIE TO OURSELVES THAT AIRPLANES ARE SAFE. THE MORE WE SQUEEZE, THE MORE SLIPS THROUGH OUR FINGERS. ... OR for you geeks out there, for your delta, I can always find a more dangerous epsilon.

MAYBE, WE SHOULD CREATE A WORLD WHERE PEOPLE DON'T WANT TO KILL US.

-

I really really did not want to post this anonymously. I don't want the hassle of some ignorant fsck from law enforcement to think I would actually do any of this and come give me static. I won't. But given the way we all act, there are those who will.

In other news.....

[Anonymous Coward]

It seems slashdot has uncovered the perfect Denial of service attack. The first step involves linking to the site on slashdot's homepage, then millions of unsuspecting geeks, click the link simultaneously, overloading the webserver. One geek was quoted as mumbling something about being a couple seconds to late to see all the l33t stuff the site was supposed to contain. Then the attack continues, by reposting the link in another story, a dupe so to speak, that ensnares even more geeks. But alas, when will this slashdotting criminals be brought to justice.

other ways to do this with normal CD drives...

[H3XA]

Find yourself an old 40x (or so) drive that you no longer need and get ready for some fun (tested on tray load drives only so far).

Grab an AOL or old magazine CD and make a few small cracks (so they don't go into the data area) about 1cm long on the inner edge of the CD (aka the hole in the middle of the CD). Then put it in your high speed CD reader and start reading data - with luck after a minute or so (maybe longer) you will hear a loud BANG and the CD will no longer be spinning :)

Sometimes you tray will eject still but more often than not you will have to take the drive out and shake the bits out. When you are shaking you may find other bits like the small CD laser lens and small pieces of metal - in which case you drive is probably fux0red now....

I did this to my work PC drives.... old Diamond Data and Fujitsu drives that use to piff me off for various reasons :)

You look around hardware review sites you will come across readers stories of similar experiences where the CD structural integrity has failed and tried to spread itself over the insides of the PC case.

- HeXa

"Dammit Scotty, I need faster data!"

[Hawthorne01]

"I'm givin' the CD-ROM drive all it ken handle, Captain, anymore and the discs will explode!"

Maximum Velocity? (Not Spin)

[Skevin]

I'm in the process of converting a WGP Autococker into a CD/DVD Launcher - specially flattened barrel, tightened on one side to impart a spin - to launch Compact Disks with a burst of CO2. Although the CD's needed to be loaded by hand, one at a time (up until recently), I can reliably attain ~550 ft/s. This is enough to cleave thick pieces of styrofoam/cardboard or aluminum cans in half... or embed itself into soft wood like Eucalyptus trees. Against harder targets, such as rocks, the rounds simply undergo fragmentation and splinter into tiny plastic chunks. I don't know the effects against animal matter yet, because the contraption is notoriously inaccurate and squirrels are annoyingly fast.
At higher velocities (~700 ft/s) the rounds begin to fragment in the "barrel". I'm currently examining other alternatives to increase the velocity, but I guess now I have to take spin to account. :)

Other notes: I've put together a rudimentary feeder/hopper that now lets me use my CD Launcher in a semiautomatic fashion (and wastes more CO2 per shot)

Solomon

PS: I'm slapping together a solenoid-actuated electric trigger frame (similar to a Sandridge) to convert my paintball^H^H^H^H^H^H^H^H^H CD gun to a fully automatic weapon. I don't know if it will work... yet. (I have given thought to converting an Angel, but I'm not willing to futz with $1300 gun, and I've been doing my own custom internals on 'Cockers for years now.)
I estimate a potential ROF of ~13 CDs/second. (maybe *now* I'll be able to hit that pesky squirrel) My anticipation is that it still won't do any damage to brick walls, bronze statues, and masonry of quality craftsmanship, but will absolutely *shred* old wooden fences, thrown-out sofas, and squirrels.
BTW, I once thought of calling it my Assault Ordnance Launcher, or AOL for short... the idea being that people would soon become afraid of my AOL CDs...

Re:Duplicate

[jsse]

I was going to copy-n-paste high score comments from them for karma whoring. I earned my karma all the way up to max this way.

(j/k)

Re:Spin laser instead?

[Myco]

Actually, it's a little-known fact that all CD-ROMs do keep the CD stationary, and simply spin the rest of the universe around it. True fact. ;)

aol.yoyo.com

[Tablizer]

There goes my plans to turn all those free AOL disks into yoyo's to sell on ebay.

merry-go-round

[charlie763]

At what angular velocity would a child (~30kg) explod on a merry-go-round? What would happen if they were to have a CD in their pocket?

Re:Spin laser instead?

[cybermage]

Actually, it's a little-known fact that all CD-ROMs do keep the CD stationary, and simply spin the rest of the universe around it. True fact. ;)

Yeah, right. Next you're gonna tell me that CDs are flat and if you read too far you'll fall off the edge.

A faster way (2,466X)

[carambola5]

I take no credit for this, but I remembered reading an interesting comment on the last time slashdot posted something like this. All credit should go to labradore:

This is a good way to get a fast CDROM drive:

1. Buy a 10,000x10,000 dpi scanner with firewire interfeace
2. Write cdrom image analysis algorithm.
3. Scan cdrom image into temp hard drive space and analyse, extracting data

This is based on these rough figures:

• A cdrom is approximately ( PI*5^2 - PI*0.75^2 )= 76.75 sq. inches of data surface
• If a cdrom has about 5.6 billion bits on that surface then the density is roughly 76 million bits per square inch.
• That works out to about 8,800 bits per linear inch. Assume you will need a little better resolution than that because there is some empty space between the dots on a cd surface. 10,000dpi aught(sic) to be good enough.

Assuming that the scanner is faster than the firewire (400Mbps) and 10% overhead for the data transfer, each cd image will be approx. 7.3 billion bits, taking just over 20 seconds to transfer. This device is a 2,466x speed CDROM "drive". Put that in your Pentium and smoke it! Scanner and algorithm design left as an excercise for the reader.

Re:Spin laser instead?

[shepd]

Don't forget that CDs spin backwards in Australia.

Re:Quit humping the laser....

[Waffle Iron]

Maybe if they spun the laser it would be faster, since the disk seems to have more mass. Or better yet the spin the laser in the other direction of the disk so they are both spining.

There'd be no need to spin anything if you took CD drives to the ultimate extreme. Just integrate 700 million microscopic lasers onto a 4-inch wafer. Hold it next to the CD and, Bam! Read the entire disk in 10ns.

Let's see-- that's about a 420,000,000,000-X drive. That's the kind of product spec that makes for a sure-fire winner in the marketplace. Might need to consider upgrading to a somewhat faster IDE interface version, though...

Cheap and geeky way to overclock dremel tools

[dattaway]

Dremels can spin much faster than 30,000rpm. Those motors have a field winding and an armature winding. If you decrease the field current, it causes the armature current to go through the roof. This is called "field weakening" and is a common method to get motors to spin faster. The motor's speed can be expressed as a ratio of armature/field current. The motor's speed is that ratio.

AC motors are tricky to do that with, but one sure way to overclock a dremel motor is by "overclocking" one of those 120VAC inverters. Look for an opamp that generates the clock frequency and the resistor for that RC circuit can be replaced with a potentiometer. You can vary the frequency from 0 to about 400Hz. Higher the frequency, the higher AC motors will sync. Don't go to high on the frequency or the inverter's mosfets will exceed their slew rate. That means most of the energy they are trying to switch will be disapated inside themselves, because they can only switch between the voltage rails so fast. Another resistor on the opamps will adjust the voltage for charging the storage capacitor. This one will have the greatest effect. You can get most inverters to pump out over 200 volts. Use an oscilloscope to track down the inverter's signal generator.

I found a non-overclocked dremel will easily cause the cd's outer tracks to skew. Extreme vibration will be the result as the cd warps quickly. Speed will drop quickly due to this imbalance. Solution: turn up the power!

If Intel made CD-ROM drives...

[guttentag]

If Intel made CD-ROM drives, we would start seeing the following in 95% of new PCs:

1. A giant fan aimed at a heat sink attached to the spindle that grips the CD
2. Pressurized CD-ROM drives
3. A sticker on the "5x-the-speed-of-sound" drive stating that by using this CD-ROM drive, you agree that the speed of sound is one-tenth the speed the rest of the world claims.

One of the above would be appended to what we know today as a 24x CD-ROM drive.

Re:Spin laser instead?

[cappadocius]

Actually, it's a little-known fact that all CD-ROMs do keep the CD stationary, and simply spin the rest of the universe around it. True fact.

In fact it was this fact which lead us to discover the shape of the universe. It is the only one which will simultaniously spin around thousands CDs in different drives.

Re:It depends on the age of the CD...

[MooseGuy529]

Anyone have info on changes in manufacturing od CD's over the years that might explain this?

Well of course, the newer it is the crappier LOL... like in the Simpsons episode where Bart meets Buck McCoy:

Bart: "What's this lunch box made of?" ::tap tap tap::

Buck: "Oh, back in our day, we had a thing called metal!"

Bart: "Me-tal... hmmmm..."