[Pc_Support] x-ray + laptop

[Phil Barnett]

On Friday 11 March 2005 04:03 pm, Justin M. Keyes wrote:
> Hi guys,
>
> Is there a significant chance that an airport security x-ray may
> corrupt a laptop's hard-drive or anything else?

Probably not. Way back when, they used much stronger magnetic fields to excite 
the x-ray tube and lots of people lost data on unprotected disks, such as 
floppy disks and even occasionally a hard drive. But about 20 years ago, they 
got much more efficient and the fields generated are very very small compared 
to what it takes to wipe data from a drive.

Technically, we are subject to cosmic forces every day that can cause this 
kind of damage. Chance change of molecules, cosmic radiation and other low 
energy phenomena can toggle bits in memory and can change bits in hard 
drives. For hard drives, we have ECC bits protecting data that decays. 
Expensive servers also have ECC memory to counter this effect.

It's difficult to say how much this effect has on average use, but chances are 
very high that at some point a crash has been due to this very low level 
stuff. Maybe even to someone you know...

-- 

"The significant problems we face cannot be solved at the same level of
thinking we were at when we created them"

Albert Einstein