# magnets and degaussing



## garsh (Apr 4, 2016)

Kizzy said:


> Do magnetic media survive with data intact after travel in the car? (Cabin or trunks.)


----------



## Akilae (Jan 16, 2017)

garsh said:


>


Well at least in IT magnetic media are still a thing (hard disks, tapes). So a very valid question, although I really can't think of a possibility where Tesla wouldn't have thought about that and it wouldn't be safe for transportation.


----------



## Thomas Mikl (Jun 26, 2017)

You actually need a pretty strong magnet do de-gauss a harddisk or tape. Anything that strong will possibly destroy the chip on any NFC card in your wallet including all your credit cards. So I guess you will be safe.


----------



## Akilae (Jan 16, 2017)

Thomas Mikl said:


> You actually need a pretty strong magnet do de-gauss a harddisk or tape


Exactly


----------



## garsh (Apr 4, 2016)

Thomas Mikl said:


> You actually need a pretty strong magnet do de-gauss a harddisk or tape.


The electric motors certainly are strong enough. But a degausser requires physical contact with the media to work. This is because magnetic field strength decreases _exponentially_ with distance. So your floppy disks will be fine (or at least, they won't degrade any faster - you really should switch to solid state ASAP).

http://www.instructables.com/id/Evaluate-magnetic-field-variation-with-distance/


----------



## Thomas Mikl (Jun 26, 2017)

Actually it does not need physical contact, as the magnet just has to be strong enough, but trust me you do not want to be in the presence of such a magnet (if you could build one that is not the LHC).

Also a fun useless fact: Physical contact is an illusion by your sensor nerve system. You never have touched anything in your life as technically the atoms in your fingers never "touch" any surface you think you touched. If they would you would have to push REALLY hard (like internal forces of the sun hard) and that would result in spontaneus fusion reactions.... So all you feel is the quantum field of your finger getting in contact with the quantum field of the surface and slightly compressing your molecules to create a sensoric reaction in your cells.
Sorry but sometimes physicists have to make stupid knowlegde available


----------



## garsh (Apr 4, 2016)

Thomas Mikl said:


> Actually it does not need physical contact, as the magnet just has to be strong enough


...and making it strong enough requires a lot of electricity, therefore degaussers are made just strong enough to work when the media is touching it, because it would waste a lot of power otherwise.


----------



## garsh (Apr 4, 2016)

Thomas Mikl said:


> Also a fun useless fact: Physical contact is an illusion by your sensor nerve system. You never have touched anything in your life as technically the atoms in your fingers never "touch" any surface you think you touched. If they would you would have to push REALLY hard (like internal forces of the sun hard) and that would result in spontaneus fusion reactions.... So all you feel is the quantum field of your finger getting in contact with the quantum field of the surface and slightly compressing your molecules to create a sensoric reaction in your cells.
> Sorry but sometimes physicists have to make stupid knowlegde available


----------



## Topher (May 11, 2016)

Thomas Mikl said:


> Physical contact is an illusion by your sensor nerve system. You never have touched anything in your life as technically the atoms in your fingers never "touch" any surface you think you touched.


Nonsense. "Touch" is what we *mean* when we get electron repulsion between atoms in our body, and atoms in another object. If you want to invent a new word for bringing atomic nuclei together, be me guest, but don't expect a lot of people to use it (not even particle physicists use "touch" that way).

Thank you kindly.


----------



## SSonnentag (Mar 30, 2017)




----------



## Thomas Mikl (Jun 26, 2017)

Topher said:


> Nonsense. "Touch" is what we *mean* when we get electron repulsion between atoms in our body, and atoms in another object. If you want to invent a new word for bringing atomic nuclei together, be me guest, but don't expect a lot of people to use it (not even particle physicists use "touch" that way).
> 
> Thank you kindly.


Buddy I know, it was a fun thing more of a phylosophical view on it. Inspired by this:


----------

