When Spun Really Fast, CDs Explode 464
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...
better way (Score:4, Funny)
Re:better way - another way (Score:5, Interesting)
You can also make an air bearing with an orange by cupping your hand just right and blowing compressed air between your hand and the orange. Oranges explode good.
52X (Score:2, Interesting)
also you can always just put more data on the disk. I mean maybe you could never read a 100GB disk faster than 52X, but thats still like 100GB of data read in a minute or two
Re:52X (Score:2, Informative)
dvds are the same thing... a 1x dvd player is enough to stream the dvd onto a tv but a 8x/16x or whatever is better for ripping... a 8x dvd reader will actually transfer many times faster than an 8x cdrom becuase of the dvd format in which more data is read at the same time...
Re:52X (Score:2, Offtopic)
You forgot to kiss. You insensitive, inconsiderate bastard.
Pah! (Score:5, Funny)
Al.
REPOST (Score:3, Offtopic)
Exploding CDs? (Score:4, Funny)
It depends on the age of the CD... (Score:3, Interesting)
Since CD is made up of two layers of clear plastic, sandwitching a thin wafer of metal media inside, the more the CD is aged, the weaker the plastics of the CD become.
And so, the maximum spinning speed for a CD depends on how old the CD is.
I do have some pretty old CDs from the early 80's, and I will NOT put them in my 52X CDROM drive. Unless of course, I want to scrap bits and pieces out of my machine.
Re:It depends on the age of the CD... (Score:2)
Anyone have info on changes in manufacturing od CD's over the years that might explain this?
Re:It depends on the age of the CD... (Score:3, Funny)
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..."
Re:It depends on the age of the CD... (Score:2)
Re:It depends on the age of the CD... (Score:2)
Nero Burning Rom [nero.com] comes with utility to change the speed too.
now they know how to make hard drives explode... (Score:2, Funny)
slashdotted in _under_ a minute (Score:2)
Duplicate (Score:5, Informative)
Re:Duplicate (Score:5, Funny)
Slashdot staff has appearently been spinning in their chairs so fast that their memories centrifigully left their container.
This is getting ridiculous (Score:3, Insightful)
OK. The staff can't be perfect, but this is not even close to being all that unique. I remember this story as well.
I suggest the department headings be changed from frivolous titles to useful ones, to help with categorisation. I'd also like to see duplication URLs recorded, as Sircus suggests.
Someone here noted that Slashdot has an option to show all sections. Perhaps editors should have this as a mandatory condition on their own logged-in sessions.
Re:This is getting ridiculous (Score:3, Interesting)
for instance:(these are just examples, because I don't want to dig up the article)
Linux doesn't have any graphical interface.
No company has ever released a game for Linux.
Not one piece of Windows software runs well enough under WINE to consider using day-to-day.(rather subjective -- until you see that some programs run identically to their windows counterparts, such as Quake II, which makes this flat-out wrong.)
Linux users are forced to use Netscape 4 if they want to surf the internet.
Linux has no way of changing the IP address of an interface without resorting to the command prompt.
No company would ever consider deploying Linux.
No hardware company would ever release drivers for Linux.
If I recall, he did make points such as the above(not the exact ones, mind you). There's nothing subjective about saying "$X doesn't exist under linux", or "linux doesn't have $Y", when it does exist. Saying "I don't like $Z" is a completely different matter...
Re:This is getting ridiculous (Score:3, Interesting)
2)Quake is a game which was released under linux. So are Quake III and UT(the former as a boxed item one could buy off the store shelf sans windows version). You'd have to get pretty narrow on your definition of "game" to subjectively say that no company has ever released a game for it. In such a case, the new, narrower definition of "game" would allow the new statement to be correct, but the sweeping generalization "no company has ever released a game for Linux" remains incorrect.
3)dosemu used to be a biatch to install, I'll admit that, but because you didn't use it, you can't subjectively or objectively say anything about it's functionality as a DOS emulator, merely that you failed to install it. Objectively, the program emulates DOS well enough to run those games, regardless of your own experiences trying to install it.
4)Narrowing the field to only mainstream software, both Opera and later versions of netscape are available. Objectively, there's nothing stopping an individual from using non-mainstream software in terms of functionallity, so in this case, it's not the linux platform which is forcing the user to use netscape 4, but their own stubbornness. Once again, narrowing the definition makes the new statement correct, but the original sweeping "users are forced to use netscape 4" statement is still false.
5)and I grimace because I mentioned that these were mere examples. This very example came up yesterday in a chat I was having regarding the user freindlyness of linux. Sometimes trying to use an OS means spending five minutes just clicking around the interface just exploring, but that's another matter.
6)Just another example. One that many people like the echo. You'd be suprised how many people(on slashdot) believe that no company would ever consider using linux as either a back-end or a desktop. This is, of course, wrong. Short of narrowing the definition(which makes that narrow definition correct, but the original statement still false), companies and governments the world over are considering Linux.
7) I think you'd be suprised at the number of companies which are releasing drivers. Many winmodems have drivers for Linux now for instance.(oddly enough, my rockwell modem works far better under Linux than under Windows, as does my Geforce 4)
8) the subjectivity of the language doesn't mean that vast overgeneralizations are correct when they are narrowed later.
Re:Way offtopic (Score:3, Insightful)
Get back to me(in another thread, I give up here, the "nuke this thread" defense is almost as hard to counter as the chewbacca defense) when your mind learns that a straight line is not always the most productive way to reach point C from point A(ie. life, like this conversation, is full of interesting detours, don't shut them out just because it strays from the path).
Being a pseudo-intellectual is fun!
Re:Duplicate (Score:2, Funny)
(j/k)
Re:Duplicate (Score:2)
Old version was better (Score:2)
The real reason for the limited speeds that can be reached with CD-ROM drives is the vibrations in the CD resulting from motion in that speeds. If the CD moves too much, the laster can't read it properly. Hence, the reason why caddy drives used to be popular - the caddy helped keep the CD still, thus allowing the drive to spin it faster.
If you want a faster CD-ROM drive, you'll have to do what they did in this experiment - tighten the CD down so that it is always perfectly coplanar with the plane of rotation.
Ooh, new copy protection idea... (Score:5, Funny)
oh boy.
Wonder what happens if you spin a floppy at 30,000 rpm?
portables (Score:2)
Cheap and geeky way to overclock dremel tools (Score:3, Funny)
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!
Re:Cheap and geeky way to overclock dremel tools (Score:3, Interesting)
I wonder what would happen if you used a heat gun to soften up the outer tracks as it spins fast. I wonder if these CDs would stretch to the size of pizza dishes (extremely warped dishes of course). Since you've already got the spinner made, you only need a $25 heat gun.
Re:Cheap and geeky way to overclock dremel tools (Score:2)
Oh the Irony (Score:2)
More Explosions! (Score:5, Funny)
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! (Score:4, Funny)
Check it out at http://www.fiftythree.org/etherkiller/ [fiftythree.org](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! (Score:3, Funny)
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! (Score:2)
Re:More Explosions! (Score:3, Funny)
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.
Bannage target? (Score:5, Funny)
Re:Bannage target? (Score:2)
Re:Bannage target? (Score:2, Funny)
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.
... OR for you geeks out there, for your delta, I can always find a more dangerous epsilon.
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.
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.
Re:Bannage (BONDAGE) target? (Score:2)
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.
Hmm... the passengers naked & chained to their seats. Welcome to Bondage Air where the Second Class is REALLY Second Class and the First Class gets deal out discipline to those naughty naughty Second Class riders.
I see a market for this somehow.
Re:Bannage target? (Score:2)
Re:compact discs banned from airlines (Score:2)
I've known a few women who have nails more dangerous than the clippers. Will they make them wear gloves and a gag?
Re:compact discs banned from airlines (Score:2)
Or maybe just handcuff everyone stronger than a 1 year old.
Or, really radical idea - encourage citizens to actually defend themselves, instead of acting like subjects like a dictatorship and doing whatever the thugs want until the gov't thugs show up...
Mirror (Score:2)
[wustl.edu]
http://wuarchive.wustl.edu/users/tom/mirrors/cd
other ways to do this with normal CD drives... (Score:2, Funny)
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
Re:other ways to do this with normal CD drives... (Score:2)
CLV and CAV (Score:5, Interesting)
Spin laser instead? (Score:2)
Would it be possible to leave the CD stationary, and spin the laser instead?
Re:Spin laser instead? (Score:5, Funny)
Re:Spin laser instead? (Score:5, Funny)
Yeah, right. Next you're gonna tell me that CDs are flat and if you read too far you'll fall off the edge.
Re:Spin laser instead? (Score:3, Funny)
Re:Spin laser instead? (Score:2)
Re:Spin laser instead? (Score:2, Funny)
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:Spin laser instead? (Score:2, Interesting)
But, if you work through the equations of general relativity for a universe rotating around a fixed body, you'll find that the motions of those distant galaxies generate forces on the body - outward forces exactly balancing the centripetal ones!
So a spinning CD is exactly equivalent to a fixed CD with the universe spinning around it - no experiment can tell them apart.
Re:Spin laser instead? (Score:2, Interesting)
Besides which, because the CD spinning and the universe staying still is exactly equivalent to the universe spinning and the CD staying still, everybody would just think you were spinning the CD anyway.
"Dammit Scotty, I need faster data!" (Score:2, Funny)
Maximum Velocity? (Not Spin) (Score:3, Funny)
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:Maximum Velocity? (Not Spin) (Score:2)
Problem with high speed spinning (Score:2)
aol.yoyo.com (Score:3, Funny)
The next breakthrough... (Score:5, Insightful)
1. The CD will be spun at 64x or so clockwise. Under that will be a second counter-rotating plane that will contain the laser. With the platters rotating in opposite directions you can break the 30K RPM physical limitations of the media. You can build the mechanism strong enough to do 300x normal CD speed I'd guess. 300 * 64 = 6,000x or ( 2.5GB/s). I wouldn't be surprised to start seeing such a mechanism in hard drives either. The disks i
2. What I think will truely be the big breakthrough will be to not spin the disk or reader mechanism at all. Instead, the drive will use a scanner like method to read the entire CD in to a 700MB buffer in a few seconds. The disk will then sit idle while all requests are served from the buffer. I see this used in a slot loading scheme, so as the disk is drawn in it is read.
The nifty thing about this would be that you could create a CD image in the buffer, change the bugger copy just like a normal disk drive, then eject the physical master and burn the buffer to a new CDR(/CDRW disk.
Re:The next breakthrough... (Score:2)
I'm not so sure you could spin a mechanism at such a rate without making it impossible to seek the laser back and forth. If the forces involved can cause a CD to fragment, then you'd need a hell of a drive to move the laser inwards and outwards; and a mechanism strong enough to do it probably wouldn't operate quickly enough to match that 300X speed.
I suppose there are other ways to make the laser scan, and it might work. It's still a neat idea.
Re:The next breakthrough... (Score:2)
Also, we could use another trick VCR's use: they scan the media at a high rate, while it actually passes through very slowly. While we already have high speeds from the CD, we could use multiple heads and borrow a technique from the VCR that it uses to reassemble the two signals it gets.
For the VCR, two heads take turns during each half of a revolution scanning the tape at a high speed near sideways motion to get the high frequencies required from the heads. The VCR has the problem that each half revolution, one head leaves and one head starts passing the media, leaving a gap in playtime. A clever means of injecting the signal into a quartz delay line for reassembling the signal is used.
To double the CD's bandwidth (or any multiple speed increase,) we could place more IR pickups in parallel next to each other. This would read multiple groves during each pass. You can reassemble digitally, or just use the cheap quartz delay line hack like the VCR's use.
Re:The next breakthrough... (Score:2)
You mean, data storage like that planned by IBM's Millipede Project? [slashdot.org] No wonder they're quitting the hard drive business... rotating media might be a thing of the past.
Re:The next breakthrough... (Score:2)
If my PC has 700mb memory to play with, I hope that it wouldn't be isolated in the CD-rom reader subsystem. Expect to see this only after average PC RAM installed tops several Gb, and allocating that 700Mb of cache to one component isn't a very skewed allocation.
I like the idea mentioned by the other poster: multiple read heads.
Re:The next breakthrough... (Score:2)
Re:The next breakthrough... (Score:2)
Re:The next breakthrough... (Score:2)
When we start thinking that a 52x DVD readers is too slow, THEN I'll start wondering when the stronger materials will arrive.
Re:The next breakthrough... (Score:2)
All the more reason for someone to develop one. The drive would still work for round (or square or triangle) shaped media. I just don't see the point in going to a new CD format when DVD and DVD-R is already available.
As seen by my initial post's math error, my brain is in sleep mode, not accurate math posting mode so I won't attempt to calculate the percentage gain in storage by going 12cm square and loosing the hole while keeping density the same.
Re:Why not 2 heads or 3 or 4? (Score:2)
Or 7, like kenwood did three years ago [active-hardware.com]. Though, I think that they are using only one laser and beam splitter and mirrors and stuff instead of multiple lasers.
RC Propellers as well (Score:2)
Anyone with a passing interest in radio controlled airplanes already knows this fact:
Plastic propellers disintegrate at high rpm.
So they use wooden ones. The document (the cached version, sans photos) did not go into great detail about the nature of the material failures, which they claim will be investigated with SEMs, but it would be interesting to use their same setup with same-size components made of other materials. A wooden CD-sized disc, an aluminum one, etc.
Not that CDs should be made of wood, but certainly plastic at high rpms is a compromise between cost and durability.
merry-go-round (Score:3, Funny)
A faster way (2,466X) (Score:5, Funny)
An obvious suggestion? (Score:2)
This took me all of 5 seconds to check. This
wasn't something about Microsoft that would be buried 10 pages back, no. This shows up at the upper half of the upper quarter of the list of responses to a simple 10 second (I wonder if we did this before) check.
I know dupes are going to happen from time to time. With several editors, its impossible for all of them to know off the top of their heads if the article has been posted before. Even if it were only one person, I still wouldn't hold it against them that much. But some modicum of effort should be taken to at least avoid looking like a complete moron. This means, make sure its not still on the front page somewhere (this includes the older stuff links), make sure you can't find it in the search list with one or two
of the common topics of the article, and perhaps,
if possible, do a quick check on the URL to see if its been mentioned before.
-Restil
If Intel made CD-ROM drives... (Score:4, Funny)
- A giant fan aimed at a heat sink attached to the spindle that grips the CD
- Pressurized CD-ROM drives
- 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.Multiple beams - alternative to ridiculous RPMs (Score:4, Informative)
It has been licensed by several companies including Kenwood that used it to produce an amazing 72x drive [kenwoodtech.com].
Yeah, I know... (Score:2)
The second, and not so obvious solution is to spin the player in the opposite direction of the cd. Then both can rotate at their maximum angular speed, and the effective angular speed will be the sum of the CD-speed and the player speed. I'm not sure how fast you can spin a cd-player before moving the heads precisely will become a problem, but if you throw enough money at it, I'm sure it's probably close to the speed you can spin a CD at.
On the other hand, I'm relatively happy with my 40x burner. 2-3 minutes for burning a full CD is about as tolerable as floppies used to be. If I want something more from CDs now, it must be safety (never loose data), storage capacity, and being able to use them as a real read-write medium, not something that needs to be "blanked".
Google cache here (Score:2, Redundant)
Gamecube... (Score:2)
I've seen two CDs explode in 50x drives (Score:2, Interesting)
Dangerous if you ask me - if you have a tower case, make sure the CD drive isn't at eye level!
Re:I've seen two CDs explode in 50x drives (Score:2)
Are you kidding? Just a little eye damage for a law suit that'll keep you set for life. This is a legal gold mine!
A bunch of materials scientists, I see... (Score:2)
Hey, Einstein! What doesn't break when spun fast enough? This is news?!?!
Happened here (Score:2, Interesting)
install a feature of MS Office from her CD-ROM. She stuck the thing in and after about 5 seconds there was a loud bang from the computer. She nearly hit the ceiling when she jumped.
After checking signs of smoke and what not, we opened the CD tray and there was nothing but a shards. It had completely disintegrated into pieces no more than a couple cenitmeters long.
Of course the drive was completely hosed after that. It just made a jingling noise with all the shards in the unit.
Yet another fine M$ product - exploding CD's.
Re:oops (Score:4, Informative)
I Know what DEPARTMENT its from... (Score:2)
Some people seem to be missing the point on CD's DVD's and other forms of optical storage. Speed is nice... but cheap is better If you need insane speed buy a hard drive. If you want compact and rewritable use flash memory... I got several negative comments about not liking new disc sizes in optical storage a couple days ago...
Re:and hard drives? (Score:2, Interesting)
I do know that I had some fun with an old 5 1/4" Full Height HDD and a 3-phase grinder once.
Did you know that you can spin hard drives like that up fast enough (mostly safely) to actually make the centripetal force cause the drive to stand up on a corner for a bit! FUN FUN FUN! More fun than jumping off a moving bike to see how far it will go before it falls over (or hits something). Even more fun than trying to roll a quarter completely down the college hallway during late hours!
(and no, even with the stress the grinder put on the platters and the high speeds nothing "exploded"... but someone did mention to me I should have worn protective gear anyways.)
Re:and hard drives? (Score:2)
The platters in 5.25 inch drives were aluminum, which is relatively soft and fairly ductile. I suspect that before the centrifugal force got high enough to cause the platter to fly apart, the spindle hole would stretch enough that the motor would no longer drive the platter
The high strength materials used in the smaller drives would, IMHO, be MUCH more likey to hold together long enough to "explode."
Just my US$0.02
Re:and hard drives? (Score:2)
The speed of sound is about 1130 (depends on temp) feet/second. a 5.25-inch disc's outer edge would be spinning at around 1282 feet/second - in excess of the speed of sound. I'm not well versed of the physics of the equation, but it seems that the disc's outer edge, having broken the speed of sound, would be the recipient of some extreme air pressure and turbulence that would cause the edges to break, and the uneven weight distribution would do the rest.
Of course, I'm just taking a stab - could be wrong.
Re:and hard drives? (Score:2)
Actually, because of centrifugal force and gyroscopic forces a spinning disk is inherently stable, and resistant to any turbulence or wobble. Likewise, the aerodynamic crossection of a hardrive platter is pretty negligle. Flywheels [us-flywheel.com]often spin at several times the speed of sound, often well over 60,000 rpm using disks measured in feet. Most operate in a vacuum condition, where there is nothing to turbulate. If a flywheel breaks vacuum suddenly the efffects might be catastrophic, The energy released during the failure of a 1 kW-h flywheel is enough to lift a mid-size car 100 feet into the air [rqriley.com]
Could Jesus microwave a burrito so hot, that he himeself could not eat it? HS
Truth as Activator for Fiction (Score:2)
The truth of this, however, is strange in and of itself. It was indeed possible to drop a platter stack in crooked, such that when you removed the clamp, closed the lid and spun them up the drive housing would start banging around like an out-of-balance washing machine. It was also possible to design seek programs for the step motor (the one that moves the head across the platter) such that you could cause the drive housing to move. With a properly designed progam and a near-felonious disregard for the equipment, you could move a drive housing several feet. I was privy to a contest some time ago where several programmers competed to try to get the drive housing to move to certain places in the lab (using an old, blown-out platter pack, of course, since we really didn't want to be wiping out a good one).
Virg
Re:i call rehash (Score:2)
Suffice it to say that this is indeed a repeat. An amusing one, true.
Re:Older technology saves the day? (Score:2)
OTOH, the fastest drive Plextor makes operates at 40x CAV. And I've fed many, many messed up (cracked, deeply scratched, off-balance) CDs into my 32x Plextor, without ever having one disintegrate, even when they're spinning at high speed for 12 hours or more.
So, personally, I'm not too worried about the safety aspects. But if you want to slow down a CD-ROM for whatever reason, Plextor is a very sure route to follow.
Re:Quit humping the laser.... (Score:2, Funny)
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...
Re:Holding back CD speed? (Score:2)
A 7200RPM hard drive today may be able to sustain 40MB/s transfer rate, but that comes from at least four read heads. Each head is only transfering about 10MB/s. That roughly equates to 60X in a CD burner.
So a single read head of a hard disk at 7200 RPM is roughly equivilent to CDROM at 22,000RPM(avg).
And that shows us that the HD data density is much greater than that of a CD. The reason: CDs are a portable media. The have to remain compatible for long periods of time. You can't just arbitrarily shrink the size of a bit or change the encoding scheme. If this happened you'd need to purchase new CD players and CDRW drives every six months to keep up with technology. HDs are non-portable. The media is treated as a black box. You never need anyone to be able to read the media, just send the proper commands to the interface to the black box, so you can do whatever you like to the medium's format.
Re:Holding back CD speed? (Score:5, Informative)
If things are consistantly and violently exploding at a little over twice that speed, would it not make sense that there is a very real safety issue in making things faster than this?
One might theorize that off-balance discs, cracked/scored/otherwise-damaged media, and just plain bad luck might cause things to go dangerously amiss even at current speeds.
Current high-end SCSI hard drives spin at 15,000RPM, but do so using extremely well-balanced, carefully-produced, expensive solid aluminum platters and motors. And, besides, they're also encased in heavy metal boxes, and don't have a soft plastic face through which to fire shrapnel into the chest of the user.
Consider that a CD-ROM has a much larger diameter than a typical hard disk platter, and is thus exposed to far greater centrifugal force and linear velocity. Consider also that a CD-ROM drive only costs a few dollars to make, and that CDs are down to a couple of cents each in large volume.
Given this information and that contained in the article, I doubt it would take much effort to make a CD explode in a current 56x drive, thus presenting a very real bottleneck, indeed.
Re:"Spinning" laser beams (Score:2)
You can probably spin a mirror much faster than a CD disc or the laser itself...:-)
Re:"Spinning" laser beams (Score:3, Insightful)
The "ring" could work much like a phone cord detangler - bars at extend each to a different ring. The other problems you have here:
Synchronization: Getting the laser at one spot on a CD is a complex process (so much so that a buffer underrun can cause a misalignment in a burnt CD, making coasters). If you spin the CD and the laser at different variable speeds, you would need some great hardware calculating that would be able to put the two speeds to gather as they vary.
Communication: Getting power is pretty easy, but what about returning data? You could use the same spinning wire-on-ring system, but I think it would limit the communications bandwidth.
I think a better system would be to have 2+ read heads on a CD-ROM. Two or four read heads could more quickly access data if they were fully independant. Drive access time could be halved, as could seek time. Two heads could "stripe" data, allowing the transfers to be even faster.
Well, I'll stop.
Re:A NEW LOW for Slashdot.org (Score:2)
When you get some READING COMPREHENSION SKILLS, get back to us.
They wrapped some KEVLAR WIRE around the CD to reinforce it. They could have easily made it COPPER REINFORCED by wrapping copper wire around the CD too. Goodness sakes, I hate WILLFULLY STUPID PEOPLE.
I think it has been tried... (Score:2)
Re:AOL+RIAA - 2 Birds, 1 Stone (Score:2)
It really sucked when I started getting about 3 CDs a month from them, though.
Re:AOL+RIAA - 2 Birds, 1 Stone (Score:2)