Alt-BEAM Archive
Message #07334
To: beam@sgiblab.sgi.com
From: "Ben Hitchcock" beh01@uow.edu.au
Date: Wed, 03 Nov 1999 23:05:00 +1100
Subject: [alt-beam] Re: magnets
>From: "Timothy Flytcher"
>Wow Bob!
>True perpetual motion!!! something that can induce energy and change on
>something ells and still retain 100% of it energy!!! Were can I buy those!!!
tsk tsk tsk.
It's not inducing any energy at all. The extra 'energy' on the fridge door
is created by:
a) thermal vibration
b) mechanical vibration.
Think of the door as having lots of little compass-needles on it, that are
all stuck in whatever direction they want to be in.
When you put a magnet onto the door, the needles try to move - but are
stuck. Hitting the door will 'unstick' the needles, and then they will all
point more or less in the direction of the original magnet. Now when you
take the magnet off the door, the needles will still be pointing in the same
direction - towards where the magnet was.
That's all that's happening.
Ben
>
>> > >A magnet stuck to the front of your refrigerator does not loose any
>> > >strenght
>> > >in the process of sticking there, for months or years.
>> >
>> > Yes it dose... try running a guise meter over a refrigerator door after
>>you
>> > have removed them...
>>
>>This is getting off topic, but a magnet hanging on the refrigerator does
>>not
>>loose
>>any energy at all. A magnet floating over a supercondutor also does not
>>loose
>>any energy while levitating.
>>
>>In fact, when a bit of metal is drawn to a magnet, say a paperclip being
>>picked
>>up off a desk, is not taking any energy from the magnet at all. Thats
>>simply
>>not
>>how the physics of magnetic fields works. (in fact, the magnetized
>>paperclip
>>hanging from the magnet is in a lower energy state than when it was sitting
>>on
>>the desk!)
>>
>>All the energy the magnet appears to use in drawing up the paperclip is
>>payed
>>back, with interest, when you remove that paperclip. The same is true when
>>you
>>remove
>>the magnet from the refridgerator.
>>
>>You can also make magnets (like the spot where your fridge magnet hung)
>>without
>>'taking' any energy or magnetism from the original magnet used to make the
>>second magnet. So just because your fridge has a magnetic spot left behind
>>does
>>not mean that 'energy' was taken from the magnet, or that it 'used' any
>>energy
>>while it hung there.
>>
>>To do this, you simply place a bit of iron next to your magnet pole, and
>>hammer
>>on the iron bit. Viberation from the hammering will realign the magnetic
>>moments
>>in the iron, and they will move into alignment with the field of your
>>magnet.
>>In this case the energy used to magnetize the bit of iron came from the
>>hammering, not from the magnet. Thermal viberations will also do this over
>>time, depending on how long you let your fridge magnet hang, so will the
>>motor
>>viberations, etc.
>>
>> > >PM motors will loose efficiency if the armature becomes magnetized,
>>which
>> > >happens much quicker if the motor overheats, and then cools again (this
>>is
>> > >how
>> > >many mangets are made in the first place).
>> >
>> > This is how a few magnets are made...very few! it is simply too
>>expensive!
>>
>>Not according to many manufactuers. As most modern magnets are ceramic
>>based rare earth magnets, they have to be formed above their curie points
>>anyway.
>>A huge zap from a capacitor is dumped into a copper sheet around the form
>>as its
>>quenched, and there you go...one supermagnet, ready to ship.
>>
>> > Only end product magnets are shipped magnetized...I once worked for EB
>> > making guitar pickups. I can't remember the composition of the material
>>but
>> > its qurie point was 530' a little high for the card stock that we used
>>to
>> > mount the windings...And yes guitar pick-ups loose there strength with
>>time
>> > and use... some say they mellow... I can and have reproduced this upon
>> > request... :)
>>
>>Maybe pickups do age, I have no idea, but the reason why they age may not
>>be
>>what you think it is. Bucking magnetic fields can also depoloarize
>>magnetic
>>materials, and other materials can easily become saturated (like Mu metal).
>>
>
>______________________________________________________
>
>------------------------------------------------------------------------
>-- Talk to your group with your own voice!
>-- http://www.egroups.com/VoiceChatPage?listName=alt-beam&m=1
>
7335 Wed, 03 Nov 1999 07:04:36 -0500 [alt-beam] Re: MWT on PBS tonight - don't forget! beam@sgiblab.sgi.com Bob Shannon The only BEAM device shown was a quick shot of the Rubic's Brain.
On the other hand, Cog sure did not look like it was about to beat itself
to death!
Richard Piotter wrote:
> I didn't see Tilden on Sci Am Frontiers??? You sure he was on that one.
> It was called natural born robots. They had a giant cockroach, robo
> tuna/pike/cog/the little facial expresions head deal (I forgot it's
> name), some tour guide robot with virtual emotion response, the honda
> humanoid, Aibo robot dogs, robotic "ducklings", and some socker bots. I
> didn't remember spotting any BEAM or Mark...
>
> Dave Hrynkiw wrote:
> >
> > If it isn't too late, check out PBS's "Scientific American Frontiers"
> > tonight. Robots, with a segment with our own MWT.
> >
> > Later,
> > Dave
> > ---------------------------------------------------------------
> > "Um, no - that's H,R,Y,N,K,I,W. No, not K,I,U,U, K,I,_W_. Yes,
> > that's right. Yes, I know it looks like "HOCKYRINK." Yup, only
> > 2 vowels. Pronounciation? _SMITH_".
> > http://www.solarbotics.com
>
> --
>
> Richard Piotter
> richfile@rconnect.com
>
> The Richfiles Robotics & TI web page:
> http://richfiles.calc.org
>
> For the BEAM Robotics list:
> BEAM Robotics Tek FAQ
> http://people.ne.mediaone.net/bushbo/beam/FAQ.html
Home