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Everything Sticks Together

by Paperweight
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Paperweight
#1
Jan8-14, 03:52 PM
P: 5
Take two objects and put them close together, but not touching.
Induction will cause some opposite charges to move across the gap from one another, and away from each other in an alternating fashion.
Make the gap r small enough and since the electrostatic force is inversely proportional to r squared the attraction between these opposite charges will overcome all repulsion forces between slightly more distantly separated similar charges.
Thus anything will attract something if it's only close enough, just using electrostatics. No matter what the net charges on the objects are.
Problem?
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fuddyduddy
#2
Jan8-14, 05:12 PM
P: 6
Quote Quote by Paperweight View Post
Make the gap r small enough and since the electrostatic force is inversely proportional to r squared the attraction between these opposite charges will overcome all repulsion forces between slightly more distantly separated similar charges.
Problem?
I'm confused about this part. Let's say we're looking at two individual particles - the electrons are closer to the other electrons than they are to the nuclei, so I don't see how the similar charges are slightly more distantly separated. Maybe if you are only accounting for the protons, but the electrons are closer to each other.
Student100
#3
Jan8-14, 05:15 PM
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Quote Quote by fuddyduddy View Post
I'm confused about
I'm confused by most of it, since it's nonsensical what he's (I think) trying to suggest.

Paperweight
#4
Jan8-14, 07:00 PM
P: 5
Everything Sticks Together

It's a thought experiment. Consider two conducting plates that have unequal, but both positive, charges. If you hold them close enough together, won't they induce an electric dipole in each other that will actually cause them to attract each other, even though they are both positively charged overall?
ZapperZ
#5
Jan8-14, 07:12 PM
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Quote Quote by Paperweight View Post
It's a thought experiment. Consider two conducting plates that have unequal, but both positive, charges. If you hold them close enough together, won't they induce an electric dipole in each other that will actually cause them to attract each other, even though they are both positively charged overall?
Note that in your original post, you said "anything"! You were given at least one example (2 electrons) where your proposition broke down.

So what are you trying to argue for now?

Zz.
Paperweight
#6
Jan8-14, 07:30 PM
P: 5
Hey, man, I'm not trying to argue. I didn't say "anything". I meant "two objects" as in macroscopic objects.

Fine. Here's experimental evidence of my "proposition": http://rspa.royalsocietypublishing.o.../468/2145/2829
Student100
#7
Jan8-14, 08:15 PM
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Quote Quote by Paperweight View Post
Hey, man, I'm not trying to argue. I didn't say "anything". I meant "two objects" as in macroscopic objects.

Fine. Here's experimental evidence of my "proposition": http://rspa.royalsocietypublishing.o.../468/2145/2829
two charged conducting
Makes all the difference in that experiment and is a far cry from any Marco objects.
fuddyduddy
#8
Jan8-14, 08:16 PM
P: 6
If you knew it was experimentally proven why did you come here acting like you came up with the experiment? Trying to get brownie points with strangers? If you wanted to discuss the phenomenon you should have just posted that link right off the bat.
Nugatory
#9
Jan8-14, 08:17 PM
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It's an overstatement to say that "everything sticks together"... but if you can get all the conditions exactly right, perfectly clean dead-flat surfaces with no air or contaminants between them, most solids can be made to adhere. Google for "gauge blocks".
Paperweight
#10
Jan8-14, 08:41 PM
P: 5
"Everything sticks together" was a joke!
Jeez you guys. I was just wondering about it and thought there might be people here who knew more about it or wanted to talk about it.
All that I "came up with", wrongly assuming that speculating for the sake of discussion was allowed here, is that maybe the same effect could happen with objects other than metal spheres. Like maybe metal plates would experience the effect much more strongly. I couldn't find much about it in my textbooks or on the internet.
What the hell do you expect? I'm supposed to submit a thesis to get a discussion going or something?
fuddyduddy
#11
Jan8-14, 08:43 PM
P: 6
I overreacted, for which I apologize.
Student100
#12
Jan8-14, 09:57 PM
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It's not spheres that are important, it's what I quoted from the paper above. I don't know where to begin any discussion with you because I can't gauge were you're at other than being mistaken about electrostatic induction/electrostatics in general.

It's hard to have a beneficial conversation until you at least ask explain your background and pose a real question that's understandable.

We've already answered the above, it's simply no. Why go any further?
DrZoidberg
#13
Jan8-14, 09:58 PM
P: 389
I'm guessing if you have two charged spheres, one with charge a and the other with charge b, you can treat them as a superposition of two situations.
1. Two spheres each with a charge of (a+b)/2
and 2. Two spheres, one with (a-b)/2 and the other with (b-a)/2
Paperweight
#14
Jan8-14, 11:38 PM
P: 5
Thank you, Student100, for preventing me from wasting more time on this homework-help-only forum. By the way, you seem to completely misunderstand the idea I was trying to get across.
Take two very cold pieces of ice. If you put them near each other, won't each pair of water molecules opposite from each other across the interface try to rotate and shift so that they align so that they attract each other instead of repulse? If the gap is small enough the attraction will become strong enough to "stick"?

Ah, whatever, you'll probably just call me an idiot again.
Integral
#15
Jan9-14, 08:42 AM
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Paperweight, glad you figured out that we do not allow speculation! It is in our forum rules that you read upon registration, so it should not be a big surprise. I am not sure why you think that makes this a homework help only forum. There is much to talk about in physics that does not require speculation.


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