On 4/23/02 at 7:26 PM -0500, Jeremy Derr wrote:
> On Tuesday, April 23, 2002, at 06:21 PM, [EMAIL PROTECTED] > wrote: > > > There are many opinions on this matter, but starting and shutting down > > a computer causes it to heat up and cool down. materials expand and > > contract with temperature differences which can lead to small cracks or > > breaks and that is all it takes > > This is one of the more original explanations I've heard. Have any > proof? or is this anecdotal? You're kidding here, right? The coefficient of thermal expansion for materials is a fundamental engineering consideration when you build anything. In general, an increase in temperature causes an increase in size (there are a few wxceptions -- shrink wrap comes to mind). A thermostat takes advantage of the phenomena. Two materials, each with a different expansion coefficient, are bonded together. When the temperature changes, one side expands more than the other, and the strip bends forcibly toward the side having the lower coefficient to make (or break) an electrical contact. You can design to allow for or minimize movement, but you can't ignore it. Leaving the machine on doesn't eliminate thermal changes, but the temperature swings between "on" and "stand-by" are smaller than between "on" and "off". Smaller temperature swings = smaller movements. John at Wood-n-Shavings, Inc. -- The iMac List is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | - Epson Stylus Color 580 Printers - new at $69 | & CDRWs on Sale! | SPECIAL LIST PRICES - Apple iMac CDROMs from $79.99, iMac DVD CDROMs from $99.99 3 port USB Hub $14.99, 40GB Hard Drive Upgrades $119 <mailto:[EMAIL PROTECTED]> Support Low End Mac <http://lowendmac.com/lists/support.html> iMac List info: <http://lowendmac.com/imac/list.shtml> Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/imac-list%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
