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Fucking electromagnetism: How does it work?
October 26, 2010 6:13 AM   Subscribe

Physicist responds to Troll Physics.
posted by emilyd22222 (59 comments total) 10 users marked this as a favorite

 
Feedin' trolls: why doesn't it work?
posted by chavenet at 6:16 AM on October 26, 2010 [2 favorites]


But the "expanding gold in the vacuum dome" will work, right? RIGHT?
posted by Harvey Jerkwater at 6:19 AM on October 26, 2010


Man not in on joke rebuts joke.
posted by Nomiconic at 6:19 AM on October 26, 2010


You don't really need a guy with a PhD to explain to you that bacon isn't a plant, right?

But you do need a guy with a PhD to explain to you that troll physics isn't really physics, right?
posted by three blind mice at 6:21 AM on October 26, 2010 [3 favorites]


It would appear that David Morgan is an idiot.
posted by ninebelow at 6:21 AM on October 26, 2010


You don't really need a guy with a PhD to explain to you that bacon isn't a plant, right?

My wife recently dealt with an acquaintance who was going off dairy to alleviate some medical condition. She was despairing that this meant she couldn't have muffins because they contain eggs. Multiple people explained the eggs come from chickens, which do not give milk, indeed are not even mammals. Eventually she (the acquaintance) gave up the entire project because it was "too complicated".
posted by DU at 6:25 AM on October 26, 2010 [17 favorites]


My son has this meme going with his friends that consists of a troll, then a response that appears to fall for the troll but in fact is another troll, etc., so that the whole day's conversation is a series of trolls. You people might be being trolled, but there is no way to tell. In quantum terms, you are being trolled and not being trolled at the same time.
posted by weapons-grade pandemonium at 6:30 AM on October 26, 2010 [14 favorites]


DU,

I think because they're always co-located in supermarkets people develop a strong association between them.
posted by atrazine at 6:31 AM on October 26, 2010 [2 favorites]


Eggs are in the dairy section of the store: QED.
posted by empath at 6:36 AM on October 26, 2010 [6 favorites]


My son has this meme going with his friends that consists of a troll, then a response that appears to fall for the troll but in fact is another troll, etc., so that the whole day's conversation is a series of trolls.

Teenage sarcasm isn't really a new thing. I'm not sure I said a single thing that I actually meant in the entire 10th grade.
posted by empath at 6:37 AM on October 26, 2010 [1 favorite]


empath,

Anti-eponysterical?
posted by lukemeister at 6:39 AM on October 26, 2010 [1 favorite]


They chose some really poor examples to debunk. Some of the troll physics strips (like this one) actually require some amount of thought. In that example, you'd have to know that the buoyancy force that pulls a hollow ball upward is created by water settling into the empty spot the ball used to occupy, and that the force required to displace the water to push a new ball up into the bottom through the seal would cancel out any net buoyancy. Or this classic which requires knowing that no object is perfectly rigid and that any movement travels through the stick at the speed of sound in that material, not instantly.
posted by Rhomboid at 6:39 AM on October 26, 2010 [6 favorites]


Is this supposed to be like the snarky explanations of Marmaduke thing? Because that was funnier.
posted by nowonmai at 6:41 AM on October 26, 2010


In that example, you'd have to know that the buoyancy force that pulls a hollow ball upward is created by water settling into the empty spot the ball used to occupy

And the ball used to occupy the empty spot because it has been moved upwards by the buoyancy force, amirite?
Your argument is exactly like the picture.
posted by weapons-grade pandemonium at 6:48 AM on October 26, 2010


So this FPP is a troll? Well I'm just not going to respond.
posted by Obscure Reference at 6:51 AM on October 26, 2010


Teenage sarcasm isn't really a new thing

Of course it is. That is why I said it was a new thing in my comment. Teenagers never used to do this.
posted by weapons-grade pandemonium at 6:53 AM on October 26, 2010 [5 favorites]


Also, what is this "sex" thing the kids these days just invented? I gather it's something to do with their loud music and big pants.
posted by ROU_Xenophobe at 7:20 AM on October 26, 2010 [1 favorite]


I'm not sure that he's not so much "not in on the joke" as just not really caring about it. I like this line:

To give a sense of how hard of a push that is, let's assume that the stupid troll thing in the wagon weighs 50 kg.

I thought his approach was actually pretty funny.
posted by ORthey at 7:22 AM on October 26, 2010 [3 favorites]


In quantum terms, you are being trolled and not being trolled at the same time.

Ah, yes. Schrodinger's troll; the famous gedankenexperiment in which the troll function is undefined until a response is made, at which time it collapses to become either troll or not troll. In essence, the responder is an integral part of the forum being trolled.
posted by TedW at 7:25 AM on October 26, 2010 [6 favorites]


I've wondered for years what the deal is with water conservation... When water runs down the drain, it should be absorbed back into the ground, naturally filtered by evaporation, and rain back down again, constantly replenishing the supply. That's how I was taught the water cycle works, anyway. The law of conservation of mass says tells me the water might change forms but it will never go away. Bill Nye said (I remember it vividly) that the glass of water I drink today may once have been dinosaur spit. Seems like nature's got this whole water thing figured out, and there must not be anything to worry about.

But that theory doesn't seem to have much in common with reality. Everybody stresses the importance of saving water. So I do it, because it's supposedly the right thing to do, but I don't understand how this resource can be in danger of "running out." Guess I'm trolling myself.
posted by The Winsome Parker Lewis at 7:26 AM on October 26, 2010


Repeated here because some people would rather snark than read to the bottom of the page:

We'd like to thank Dr. David Morgan for playing along with us, and we assure readers that he very much "gets" the joke. He is probably still shaking his head at this stuff, though.
posted by straight at 7:37 AM on October 26, 2010 [2 favorites]


I don't understand how this resource can be in danger of "running out."

Because the vast majority (I think 99% but I can't be bothered to track the actual number down right now) is undrinkable and it is easy to decrease that even further through pollution and contamination; unclean water then needs to be processed which can be an expensive, energy intensive process. So keep up the good work of not wasting that resource.
posted by TedW at 7:37 AM on October 26, 2010 [4 favorites]


But that theory doesn't seem to have much in common with reality. Everybody stresses the importance of saving water. So I do it, because it's supposedly the right thing to do, but I don't understand how this resource can be in danger of "running out." Guess I'm trolling myself.

Fresh water is a limited resource. Water is not.
posted by empath at 7:38 AM on October 26, 2010 [1 favorite]


From TFA:
We'd like to thank Dr. David Morgan for playing along with us, and we assure readers that he very much "gets" the joke. He is probably still shaking his head at this stuff, though.


From nomiconic:
Man not in on joke rebuts joke.

Man not in on man being in on joke, not in on joke.
posted by kcds at 7:41 AM on October 26, 2010 [4 favorites]


Your argument is exactly like the picture.

Not at all. The balls initially move up for a short distance (once), until it comes time to push a new ball through the bottom, at which point the buoyancy force pulling up isn't enough to counteract the displacement force it would take to move enough water out of the way.

I don't understand how this resource can be in danger of "running out."

It's not that a physical substance is in danger of running out, but rather the fact that for any given area there is only so much rainfall that can be captured and purified and delivered, with much of it already spoken for by agriculture. If everyone in LA for example started using twice the amount of water that they use now, the LA water municipality would have no choice but to start buying it from places farther and farther away, most likely thousands of miles away. And that's assuming those people want to sell, which they don't because they're probably farmers and they need it themselves and don't have any to sell.
posted by Rhomboid at 7:44 AM on October 26, 2010 [1 favorite]


RR voice: where's your sense of humor?
This is the most dowdy person I think I've seen in a long time. Must be a super-fun-guy at parties.
posted by Old'n'Busted at 7:45 AM on October 26, 2010


I suspect MetaFilter is just a very, very long con troll. I await the denouement with interest.
posted by everichon at 7:49 AM on October 26, 2010


Don't let the Vulcans see that logic humping gif or the future will never come.
posted by empatterson at 7:49 AM on October 26, 2010 [3 favorites]


OK, really guys? Responding in a serious way to something silly is a classic gag. Whether you think it works or not in this instance is a different matter, but that's clearly what's going on.
posted by kmz at 7:54 AM on October 26, 2010


Surely you can't be serious
posted by TedW at 8:02 AM on October 26, 2010


empath: "Eggs are in the dairy section of the store: QED."

BTW, dairy/non-dairy is a great game you can play with your friends. You simply take turns naming items and everyone tries to decide if the item in question is dairy or non-dairy. Eggs are a good one, but cake is a stumper, and cows usually leads to an interesting discussion.

Also, in Kansas/not in Kansas, awesome/not awesome, emergency/not an emergency, and Jewish/Goyish are fun variations.
posted by that's candlepin at 8:02 AM on October 26, 2010


Also, what is this "sex" thing the kids these days just invented? I gather it's something to do with their loud music and big pants.

It's actually an abstinence movement started in the early 90s by the venerable M.C. Hammer.
posted by mannequito at 8:04 AM on October 26, 2010


I know I never got any while wearing MC Hammer pants.
posted by oddman at 8:10 AM on October 26, 2010


...emergency/not an emergency...

That one's great! We play it with the surgeons at work all the time!
posted by TedW at 8:10 AM on October 26, 2010 [1 favorite]


Man not in on man being in on joke, not in on joke

Does this mean irony is or is not magnetic?
posted by MuffinMan at 8:11 AM on October 26, 2010 [2 favorites]


> We play it with the surgeons at work all the time!

I usually do it by asking on AskMe.
posted by bjrn at 8:13 AM on October 26, 2010 [1 favorite]


I feel I am being metatrolled by those of you who disingenously express the view that the respondents who write that the physicist does not think he is being trolled are insincere.
posted by dickasso at 8:17 AM on October 26, 2010


While it was clear the physicist understood that the bits were gags, his responses died on the screen. If the dryness of the answers was supposed to contribute to hilarity, mission failed. Explaining why something intentionally stupid is stupid without coming across as a dismissive pedant is tricky.

Also to consider: http://stuffgeekslove.wordpress.com/2009/03/13/destroying-humor/
posted by Harvey Jerkwater at 8:31 AM on October 26, 2010


Dammit, forgot to make that reference into a link.
posted by Harvey Jerkwater at 8:32 AM on October 26, 2010


Very well, I've been trolled. Trolls trolling trolls trolling trolls indeed.
posted by Nomiconic at 8:56 AM on October 26, 2010 [1 favorite]


I feel I am being metatrolled by those of you who disingenously express the view that the respondents who write that the physicist does not think he is being trolled are insincere.

Are you serious? I can't tell if you're being serious. Have I just been trolled?
posted by kcds at 8:58 AM on October 26, 2010


It's just...trolls all the way down.
posted by Ouisch at 9:12 AM on October 26, 2010 [4 favorites]


A physicist is unqualified to determine whether bacon is a plant. They should have asked a biologist about that one.
posted by DevilsAdvocate at 9:21 AM on October 26, 2010 [2 favorites]


Does this come from 4chan culture? is that why they're saying "fag" all the time? I wish they wouldn't do that.
posted by Galaxor Nebulon at 9:32 AM on October 26, 2010 [1 favorite]


I've wondered for years what the deal is with water conservation... When water runs down the drain, it should be absorbed back into the ground, naturally filtered by evaporation, and rain back down again, constantly replenishing the supply.

It's about entropy. If you have 30 grams of salt and 1 litre of fresh water you have two valuable things. Mix them, and you have nothing you can't pull out of the ocean with a bucket. If we had infinite energy then it wouldn't matter because we could desalinate as much as we needed. Also conserving fresh water is very important in New Mexico because the marginal cost in energy and money of each additional gallon is very high. In Maine, not so much.
posted by atrazine at 9:35 AM on October 26, 2010 [3 favorites]


This actually makes an interesting point, sort of. Why don't you recoil when you shine a beam of light? The answer is -You actually do! But not at the same SPEED as the light - with the same MOMENTUM as the light. The momentum (p) of a single photon of light is equal its energy divided by the speed of light (E = c p). So how much momentum does a beam of light carry? Well, suppose we shine a 100 Watt spotlight - we are producing 100 Joules of light energy per second (a Watt is a Joule of energy per second). So every second we are giving that light a momentum of (100J) / (300,000,000m/s) = .00000033 kg m/s.

To give a sense of how hard of a push that is, let's assume that the stupid troll thing in the wagon weighs 50 kg. To accelerate the wagon up to a speed of 1 m/s (around 3 feet per second... which is still pretty slow) would take (33 million * 50) seconds, which is 52 years. And that's assuming no friction!
Totally worth it for this.
posted by nebulawindphone at 10:14 AM on October 26, 2010


at which point the buoyancy force pulling up isn't enough to counteract the displacement force it would take to move enough water out of the way.

Isn't the problem more about the magical frictionless seal at the bottom of the tank?
posted by ook at 10:19 AM on October 26, 2010


My wife recently dealt with an acquaintance who was going off dairy to alleviate some medical condition. She was despairing that this meant she couldn't have muffins because they contain eggs.

Everybody knows muffins are made with cow eggs, Poindexter.
posted by rusty at 12:49 PM on October 26, 2010


Eggs are in the dairy section of the store: QED.

Our local grocery store recently remodeled and moved the eggs from the dairy department to the meat department. Now they're right next to the bacon, which makes so much sense and is quite beautiful in its simplicity.

I still keep forgetting they're there, though.
posted by amyms at 1:09 PM on October 26, 2010


Does this come from 4chan culture?

Yes. Have fun (NSFW).
posted by clorox at 1:46 PM on October 26, 2010


And since you have much more mass than the chair, the force you and the chair exert on one another will speed up the chair's descent much more than it slows your own.

I read this to mean that it would work with a very large chair.

If I am 170lbs, how heavy would the chair need to be?
posted by mrgrimm at 3:06 PM on October 26, 2010


Does this come from 4chan culture? is that why they're saying "fag" all the time? I wish they wouldn't do that.

Oh, I'm sure they will get right on that for you. Terribly sorry the internet's offended you.
posted by xmutex at 4:04 PM on October 26, 2010


And since you have much more mass than the chair, the force you and the chair exert on one another will speed up the chair's descent much more than it slows your own.
I read this to mean that it would work with a very large chair.
Yes, but also only if you have a very short building.
posted by ErWenn at 6:01 PM on October 26, 2010


All this nonsense about whether someone who is trolling a troll is actually being trolled and whatnot can be resolved with a simple observation.

There is no such thing as a troll.

"Troll" is a semantic trick, a word that doesn't actually describe a real thing, like the "least interesting person in the world" or the "set that contains all sets that don't contain themselves."

A person that thinks they have the power to fool people into thinking that they're a dumbass is just a dumbass. They're not "fooling" anyone because they actually are a dumbass.

And with that realization, the paradoxes just disappear.


If only that worked on the dumbasses too.
posted by ErWenn at 6:20 PM on October 26, 2010


Isn't the problem more about the magical frictionless seal at the bottom of the tank?

Well, that's a practical issue, yes. But even if you assume for a moment that it is possible to make such a perfect frictionless seal, the thing still wouldn't work.

Look at it from the point of view of potential energy -- let a ball at the surface be zero potential, and thus ball at the bottom of the tank has maximum potential. Since gravity is a conservative force (meaning it doesn't matter the path taken between two endpoints when calculating that change in potential) we can see that taking a ball out of the top and hauling it around the outside of the water container and then pushing it up through a magic frictionless seal to the bottom of the tank is exactly equivalent* in terms of energy expended as simply taking a ball at the surface and pushing it down through the water to the bottom. Thus the contraption is equivalent to one where both sides of the conveyor belt -- the rising and falling -- are in the water. Hopefully now it's clear that any force that wants to make the balls rise is exactly equal to and cancels out the force required to dunk them again to return them to the bottom.

You can also reformulate it in terms of another potential energy problem, such as logs rolling down a hill. A log at the top of the hill is like a hollow ball at the bottom of the water. When released, it will roll down/float up until coming to rest at its zero potential at the bottom of the hill/surface of the water. Returning the log to the top of the hill is like putting the ball back on the bottom surface of the tank. The troll device for logs would therefore be a bunch of logs rolling down a hill, which pull on harnesses that turn a pulley at the top of the hill that raises logs from the bottom of the hill back up to the top. Or a ski lift with equal masses in all the chairs, up and down. Again it's apparent that whatever energy there is available from the masses descending is exactly counterbalanced by the energy required to ascend an equal number of those masses.

* Technically it's not the same as there is friction in the form of fluid damping when you push the ball through the water, but assume you push it slow enough that this is not an issue. Besides, the other route has friction as well, so let's say they are equal.
posted by Rhomboid at 8:02 PM on October 26, 2010


Back around 2003ish when I was living in Seattle, Sparks was all the rage within my circle of friends. Stuff gets you drunk, but you don't notice for a long time because you're too busy bouncing off the walls.
posted by zardoz at 9:09 PM on October 26, 2010


...occasionally bouncing into the wrong room, where everyone else notices that you are drunk.
posted by weapons-grade pandemonium at 9:24 PM on October 26, 2010


nebulawindphone: "And that's assuming no friction!"

Obligatory XKCD.

(Sardoz: Wrong thread?)
posted by brokkr at 1:56 AM on October 27, 2010 [1 favorite]


Yes, folks, sorry, wrong thread. Mods, can you delete me here?
posted by zardoz at 12:00 AM on October 28, 2010


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