Slashdot Mirror
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...
The article talks about constant linear velocity (used in the original audio standard) and constant angular velocity drives. It comments how manufacturers like to have CAV drives to quote impressive speeds compared to the CD (audio) standard, but doesn't mention a much more important reason for using CAV: if you used CLV you'd need to wait for a long time (probably seconds) for the spin rate to change and stabalize whenever you seeked from one part of the disk to another.
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
Contrary to popular belief, plastic doesn't last forever.
:)
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.
Aw, fuck it. Let's go bowling. - The Big Lebowski
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!
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 $25 heat gun.
"Face it, a nation that maintains a 72% approval rating on George W. Bush is a nation with a very loose grip on reality.
A fun experiment is to put a polished, hardened steel rod through the spindle hole, then hit it with a jet of compressed air. If you get the bearing effect just right the CD will spin up to a 10-20krpm and will occasionally disintegrate on the spindle. Mostly though if you let it slip off the spindle it'll hit the ground, stand due to gyroscope effect while the edge melts against the ground enough to get traction, then take off across the room and explode on impact with the opposite wall.
You can also make an air bearing with an orange by cupping your hand just right and blowing compressed air between your hand and the orange. Oranges explode good.
It is possible for a point to be wrong, flat out.
for instance:(these are just examples, because I don't want to dig up the article)
Linux doesn't have any graphical interface.
No company has ever released a game for Linux.
Not one piece of Windows software runs well enough under WINE to consider using day-to-day.(rather subjective -- until you see that some programs run identically to their windows counterparts, such as Quake II, which makes this flat-out wrong.)
Linux users are forced to use Netscape 4 if they want to surf the internet.
Linux has no way of changing the IP address of an interface without resorting to the command prompt.
No company would ever consider deploying Linux.
No hardware company would ever release drivers for Linux.
If I recall, he did make points such as the above(not the exact ones, mind you). There's nothing subjective about saying "$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...
It's been a long time.
1)The vast majority of statements imply the usage of linux as a platform. Therefore, it is generally good form to accept the common usage.
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.
It's been a long time.