Amusing science misconceptions

[LoopQuantumGravity]

I'm not so sure. In physics, there are certainly some things that we are told, even at a highschool or college level, that are lies, simply because we're not quite equiped to understand and make use of the truth.

For instance, "An electron has a magnetic moment (called Spin) because it is a ball charge, and it itself is spinning, so it creates a magnetic field".

This is, if I am not misremembering, bull. I don't quite remember the calculations, but the 'surface' of the electron would have to be spinning faster than the speed of light for this to be true. Electron 'spin' is simply an intrinsic property of the electron.

But, it's convenient to think of it as a spinning ball of charge. Until you get to quantum mechanics or relativity, you don't really *need* to think of Spin as an intrinsic property. I think half of teaching physics is starting out with a bunch of convenient lies (half of which the physics students KNOW are lies: There are no frictionless pulleys or massless surfaces), and slowly peeling them away as the student gets more and more able to deal with the more complicated mathematics, etc. If you just shoved everything at them at once, I really think it would be information overload.

It's called spin because we used to think it was literally spin! And the quantum mechanical operators that describe spin look identical to the angular momentum ones. So it's not really that far off to think of it as spin. It's just crazy spin, and not literal spin. And it may very well correspond to some kind of actual spinning (string theory can do things like this).

[gmalivuk]

Hey, children sometimes should be told half-lies. If you are intelligent enough to reason about water distribution processes, natural water recycling circle and such, good for you. But try explaining this to 5 years old chap who pours it out of the window just to frighten a cat outside.

No they shouldn't. Kids aren't stupid.

You're right. They're not.

They can understand much more than adults!

I wouldn't go that far, though.

When I was little, my dad explained thunder to me in terms of electric discharge and the sudden heating and expansion of the air around lightening. I am very grateful for this explanation, as opposed to the stories some of my friends got about angels bowling or some shit.

However, there's still the matter of whether to tell the *whole* truth to a kid at that age. Learning, when I was 4 or 5, that electrons were orbiting (as in, going around) the nucleus of an atom did me no great disservice. I don't think I would have understood any discussion of electron "clouds" and the shapes of orbitals, anyway. More relevantly, my parents didn't understand those concepts well enough to answer every question I would have had about it at that age. They knew the "going around" story wasn't quite true, both being well-educated people. But they also knew that it was a "good enough" explanation for my overall level of understanding. Telling a high school chemistry student this story, I think, would be a problem. But a four-year-old kid? Not really.

[LoopQuantumGravity]

Hey, children sometimes should be told half-lies. If you are intelligent enough to reason about water distribution processes, natural water recycling circle and such, good for you. But try explaining this to 5 years old chap who pours it out of the window just to frighten a cat outside.

No they shouldn't. Kids aren't stupid.

You're right. They're not.

They can understand much more than adults!

I wouldn't go that far, though.

When I was little, my dad explained thunder to me in terms of electric discharge and the sudden heating and expansion of the air around lightening. I am very grateful for this explanation, as opposed to the stories some of my friends got about angels bowling or some shit.

However, there's still the matter of whether to tell the *whole* truth to a kid at that age. Learning, when I was 4 or 5, that electrons were orbiting (as in, going around) the nucleus of an atom did me no great disservice. I don't think I would have understood any discussion of electron "clouds" and the shapes of orbitals, anyway. More relevantly, my parents didn't understand those concepts well enough to answer every question I would have had about it at that age. They knew the "going around" story wasn't quite true, both being well-educated people. But they also knew that it was a "good enough" explanation for my overall level of understanding. Telling a high school chemistry student this story, I think, would be a problem. But a four-year-old kid? Not really.

I had no trouble explaining electron clouds to kids. Even more conceptually more complicated ideas like evolution aren't that hard to understand.... If you can't reasonably explain a concept to a kid, you really don't understand it very well. No one's saying you have to give the technical details. My explanation of electron clouds is obviously not going to include a discussion of operators, Hilbert spaces, and differential equations (although one could easily enough give a hand-wavy explanation of those, if they had the patience to listen).

[Iori_Yagami]

OK, let us put it that way: certain kids can understand much more that certain adults.
But general rule of thumb - knowledge is sequential, gradual. Don't you realize that functions do not make ANY sense to someone who has trouble flipping equations around? That is arrogance - ignoring the fact that most people learn, and learn slowly, even if you are ten times smarter than they are.
And yes, half-lies are not complete wacky 'angel or elf' explanations. They are simplifications of real things. And don't tell me that simplifications has no use in science - it has. All models are what appears after you omit some information, by definition. Why do pupils have to learn that v = S / t if velocity is almost never constant? Should we just at once throw derivatives and integrals and everything on them? That would turn down even those few who still have interest in science and not in pop culture, movies, drinkings and goofing.
At first, you learn that clean fresh water is a resource - it has value. Do not mindlessly spill it. It may be of little scientific value and is culture and technology dependant - but it is useful knowledge nonetheless.

[LoopQuantumGravity]

OK, let us put it that way: certain kids can understand much more that certain adults.
But general rule of thumb - knowledge is sequential, gradual. Don't you realize that functions do not make ANY sense to someone who has trouble flipping equations around? That is arrogance - ignoring the fact that most people learn, and learn slowly, even if you are ten times smarter than they are.

No, they have trouble with math because they have shitty teachers. I know, I taught basic math (arithmetic to pre-calc) at a community college to people between teenage and their 90s. Teachers apparently don't realize how people learn, books don't have good examples, and no one bothers to talk to students about what they understand.

Things like functions are very easy to understand. It's just a relation between two things. Names to people, temperatures to locations, speeds to positions, x to f(x). "Flipping equations around" doesn't have anything to do with understanding functions. That's just a mechanical aspect of finding a specific representation of something.

And yes, half-lies are not complete wacky 'angel or elf' explanations. They are simplifications of real things. And don't tell me that simplifications has no use in science - it has. All models are what appears after you omit some information, by definition. Why do pupils have to learn that v = S / t if velocity is almost never constant?

Because it's true! It's just not always true. And there's nothing wrong with approximations, as long as you know when they work. It's fine to not teach careful details as long as they understand when it works. Or else I have to spend 3 god damn hours trying to explain to a person why you can take the square root of negative numbers because they were always taught "that doesn't make any sense." And thinking that makes people very resistant to learning. I can speak from experience that it frustrates a lot of people to be told contradicting things like that. And then later on they forget which way is right, since they've been told both, and fuck things up. And then they get more frustrated and give up.

[tiny]

Gee Willikers LoopQuantumGravity? I just understood what these function miracle things are O.O Seriously.
Relations... Why did no one ever bother to explain it to me like this?

When I asked my dad some years ago what thunder is, he told me that it was the sound of charged clouds colliding. Seemed odd to me at this time, but daddy couldn't be bothered with further questions. Cloud crashes. Kaboom. Now stfu.

[Nomic]

Reminds me of a Calvin and Hobbes strip where Claving asks his dad where wind comes from. Dad says it's caused by trees sneezing and when Claving says that can't be right he says "no, but the truth is much more complicated". In the last frame Claving and Hobbes are walking outside and Claving says "The trees sure are sneezing hard today" or something along those lines.

[Hawknc]

...Claving?

[ThorFluff]

Sub-conciouss Cravings for the chinese dope.

[Akula]

Assuming time travel is even possible... it's still more difficult then movies let on.

If you travel a day into the past, you're going to emerge in outer space.

[Morphing Ball]

Assuming time travel is even possible... it's still more difficult then movies let on.

If you travel a day into the past, you're going to emerge in outer space.

I'm ashamed to admit that I've never actually considered the Earth's movement in relation to time travel. That is what we're talking about here, right?

[The Tick]

The terminal velocity of a penny is pretty low. I mean, a penny probably hits it's terminal velocity when chucked off the roof of a single story building.*

It'll sting, probably, but I doubt it'd even break skin.


*talking out my ass here.. probably a five-story building. Hell if I know, I just know it's going to hit it quick.

There's a Mythbusters episode where they tested this...basically you are correct.

[Akula]

Assuming time travel is even possible... it's still more difficult then movies let on.

If you travel a day into the past, you're going to emerge in outer space.

I'm ashamed to admit that I've never actually considered the Earth's movement in relation to time travel. That is what we're talking about here, right?

Indeed.

Nevermind it's Solar orbit... you've got the Galactic orbit to consider... and the expansion of the universe. It's probable you aren't even going to be in the solar system anymore. So even if you manage to travel through time... you're also going to have to make it transport you through space as well. And then your going to have to be able to calculate the movement of the Earth in relation to the entire universe.

Of course, we are also assuming time travel is instantaneous. We can't even instantly move from one point to another in 3 dimensions... what makes people think we can do so in the 4th?

[bigglesworth]

What about the time machines that send you through a multicoloured tube with clocks flying around you? There are few time machines that are not plot devices.

[TizzyFoe]

Assuming time travel is even possible... it's still more difficult then movies let on.

If you travel a day into the past, you're going to emerge in outer space.

I'm ashamed to admit that I've never actually considered the Earth's movement in relation to time travel. That is what we're talking about here, right?

Indeed.

Nevermind it's Solar orbit... you've got the Galactic orbit to consider... and the expansion of the universe. It's probable you aren't even going to be in the solar system anymore. So even if you manage to travel through time... you're also going to have to make it transport you through space as well. And then your going to have to be able to calculate the movement of the Earth in relation to the entire universe.

Of course, we are also assuming time travel is instantaneous. We can't even instantly move from one point to another in 3 dimensions... what makes people think we can do so in the 4th?

i'm not sure i agree with you. If you used a worm-hole type strategy, then both the exit and entrance would be built on earth so this wouldn't be a problem. worm holes and http://en.wikipedia.org/wiki/Tipler_cylinder are the only methods of time travel i've ever heard of.

[gmalivuk]

And then your going to have to be able to calculate the movement of the Earth in relation to the entire universe.

You lose at relativity. (If a time machine's entrance and exit points are in the same "place", what frame of reference is that sameness measured in? And if the wormhole or whatever is a real entity, it probably curves spacetime, and so would itself be orbiting around something.)

And yes, half-lies are not complete wacky 'angel or elf' explanations. They are simplifications of real things. And don't tell me that simplifications has no use in science - it has. All models are what appears after you omit some information, by definition. Why do pupils have to learn that v = S / t if velocity is almost never constant?

Because it's true! It's just not always true. And there's nothing wrong with approximations, as long as you know when they work. It's fine to not teach careful details as long as they understand when it works.

No, it's not true. It's just another approximation. (Again, with the relativity.)
What would you say is the difference between a half-lie and an approximation? The way I see it, the only difference is in degree. Is it a lie to teach a kid Newtonian mechanics at all? We know now that it's not true, right? And yet, you can send a space probe to Jupiter without needing to include any relativity equations.

[TV4Fun]

Airflow over a wing somehow "must" meet up at the trailing edge, so the faster flow over the longer top side causes lower pressure and thus lift. (Ugh. That's a common misconception even among first-year AE students.)

I heard this explanation on Bill Nye or Beakman or one of those shows when I was 10 and it made absolutely no sense to me then. I don't know how people can believe this.

[TV4Fun]

Assuming time travel is even possible... it's still more difficult then movies let on.

If you travel a day into the past, you're going to emerge in outer space.

I'm ashamed to admit that I've never actually considered the Earth's movement in relation to time travel. That is what we're talking about here, right?

Indeed.

Nevermind it's Solar orbit... you've got the Galactic orbit to consider... and the expansion of the universe. It's probable you aren't even going to be in the solar system anymore. So even if you manage to travel through time... you're also going to have to make it transport you through space as well. And then your going to have to be able to calculate the movement of the Earth in relation to the entire universe.

Of course, we are also assuming time travel is instantaneous. We can't even instantly move from one point to another in 3 dimensions... what makes people think we can do so in the 4th?

You're assuming the existence of a privileged reference frame that the earth is moving through. In point of fact, whether the earth is moving at all will depend on your choice of reference frame. So if you chose a reference frame where the earth was stationary, you would still end up at the same point. On the other hand, if you chose a reference frame that was an inertial reference frame, since the velocity of the earth is also changing, then the earth would only be stationary to begin with and then would move out of that frame. If you chose such a frame, then its origin would be moving tangentially from the earth's position and velocity at its starting point, and would eventually move very far away from the earth and not move back, which is probably not what you wanted. You would have to try and choose a reference frame where the earth was at the same point in space at two different times. Then again, you would also want to choose it so that the earth's velocity was the same, or close to the same, otherwise you might be smacked into the earth rather hard when you did this. Assuming the reference frame used was one with your time machine at the origin, then you would have to get your time machine to the appropriate velocity for your reference frame to work right. This does rather limit your potential choices.

[TV4Fun]

What would you say is the difference between a half-lie and an approximation? The way I see it, the only difference is in degree. Is it a lie to teach a kid Newtonian mechanics at all? We know now that it's not true, right? And yet, you can send a space probe to Jupiter without needing to include any relativity equations.

Most of the classical mechanics portion of my physics education was qualified with "relativity and/or quantum mechanics has shown that this is not always the case" or "this is a good approximation for low speeds" or something similar. A lot of the time when we tell these stories to our kids, we do not provide such a qualification. They are left thinking these things are always true and trying to build a model of the universe around these half-true concepts. This can be extraordinarily confusing. Why not explain to the kids in as much detail as they can understand, when they can't understand something, provide them with a simplifying approximation, but make it clear that it is an approximation, and tell them to spend the next several years of their life trying to figure out the way it actually is?

[Solt]

Here's one: That wing that's deforming so wildly and keeping you up has NO cracks in it and is TOTALLY solid.

You could really scare the shit out of people by only telling them a little bit about micro fractures.

[Birdman]

Microfractures?! Hah!

There's nothing micro about them. Try "quite a substantial portion of what should be metal in that wing is actually corrosion salts held together largely by paint", "You call that a fuel leak? Let me show you something..." and "Although a significant number of the bolts, screws and other fasteners aren't actually the right size, and are made of the wrong material, they do kind of look like the right ones. Also a bunch are missing."

The above shouldn't be taken as representative of any airline I may or may not work for. We also see customer airlines' aircraft. Ewwww. On the other hand, even the very worst very rarely crash. I mean really... Do you have any idea how many bolts and things are in those things? There are heaps of extras. Trust me. Look! I have a screwdriver and everything!

[Belial]

........never flying again.

[Mecks]

........never flying again.

Oh, man, just wait until they start talking about car tires and rails. You thought airline wings were bad?

[oxoiron]

Here's one: That wing that's deforming so wildly and keeping you up has NO cracks in it and is TOTALLY solid.

You could really scare the shit out of people by only telling them a little bit about micro fractures.

I remember coming back from Ireland on a Delta L1011 (in my seat slightly behind the wing, as usual) and seeing a gaping crack in the flap as it was extended for landing. I thought about telling someone, but I figured I'd end up in a secure room for hours while somebody interrogated me about my "unusual interest" in airplane wings. About two weeks later I saw a news report about a plane that lost a flap on takeoff.

Turns out it was an L1011.

[Master Gunner]

Ok, from now on, it's boat or zeppelin for me.

[scowdich]

As far as that goes, I plan on staying inside all the time now for 2 reasons:

Zeppelin: "Oh, the humanity!"
Boat: I really don't like drowning.

Buses are out, too. That whole "can't go below 50" thing.

Trains are reasonably okay. Everyone was okay at the end of Silver Streak, right?

[gmalivuk]

Ok, from now on, it's boat or zeppelin for me.

Yes, because water ships and airships never have *any* problems...

[Cheese]

Anything that gives a length of time a human would take to walk around the world, without stating their means of crossing oceans, or that they are close to the north or south pole - and of course latitude and longditude are perpendicular (at any point on the earth's surface), so the person could just walk round their town, or in a small circle, if they lived on the equator (unless you take 'walking round' to involve the largest possible circular path on the surface of a [near] sphere).

[Nath]

........never flying again.

Oh, man, just wait until they start talking about car tires and rails. You thought airline wings were bad?

You thought care tires, rails and airline wings were bad? Wait till they start talking about human beings. Fragile bits of meat, barely held together by a bunch of skin.

...never living again.

[Alisto]

........never flying again.

Oh, man, just wait until they start talking about car tires and rails. You thought airline wings were bad?

An old buddy of mine used to be a mechanic in the Air Force. He told me a lot of stories that can be summed up thusly: They went through a lot of duct tape.

[oxoiron]

Not so much a misconception as a simplification that can lead to misconceptions.

In first semester Gen Chem, one is taught that solids are either soluble or insoluble.

In second semester Gen Chem, one learns about solubility product constants and the common-ion effect.

In Anal Chem, one learns that K_sp is a rough approximation only, and to get more accurate measurements, one must take into account the "ionic atmosphere" present in the solution.

In Phys Chem, one learns that the "ionic atmosphere" is a quick and dirty approximation of the cumulative interactions between the molecules in solution, which can really only be assessed statistically because it is impossible to predict the behavior of an individual molecule.

In the end, one goes from the solid certainty that something is soluble or insoluble to knowing that the complete solvation or insolubility of anything is impossible to prove, because it is impossible to know that all molecules of the solute will fully dissociate or remain together.

[TV4Fun]

Not so much a misconception as a simplification that can lead to misconceptions.

In first semester Gen Chem, one is taught that solids are either soluble or insoluble.

In second semester Gen Chem, one learns about solubility product constants and the common-ion effect.

In Anal Chem, one learns that K_sp is a rough approximation only, and to get more accurate measurements, one must take into account the "ionic atmosphere" present in the solution.

In Phys Chem, one learns that the "ionic atmosphere" is a quick and dirty approximation of the cumulative interactions between the molecules in solution, which can really only be assessed statistically because it is impossible to predict the behavior of an individual molecule.

In the end, one goes from the solid certainty that something is soluble or insoluble to knowing that the complete solvation or insolubility of anything is impossible to prove, because it is impossible to know that all molecules of the solute will fully dissociate or remain together.

This is why real scientists study physics :p. And what exactly is anal chem?

[Alpha Omicron]

In the end, one goes from the solid certainty that something is soluble or insoluble to knowing that the complete solvation or insolubility of anything is impossible to prove, because it is impossible to know that all molecules of the solute will fully dissociate or remain together.

We invented this method called scientific empiricism. It works pretty well. Try it.

[stockpot]

In first semester Gen Chem, one is taught that solids are either soluble or insoluble.

In second semester Gen Chem, one learns about solubility product constants and the common-ion effect.

In Anal Chem, one learns that K_sp is a rough approximation only, and to get more accurate measurements, one must take into account the "ionic atmosphere" present in the solution.

In Phys Chem, one learns that the "ionic atmosphere" is a quick and dirty approximation of the cumulative interactions between the molecules in solution, which can really only be assessed statistically because it is impossible to predict the behavior of an individual molecule.

In the end, one goes from the solid certainty that something is soluble or insoluble to knowing that the complete solvation or insolubility of anything is impossible to prove, because it is impossible to know that all molecules of the solute will fully dissociate or remain together.

I learned all of this at once (rather shallowly) in one semester of a high school class. Quickly realized just why our course began with a lecture on significant figures. "No, we're not being completely accurate, but the reaction still works for the most part."

[oxoiron]

...what exactly is anal chem?

Analytical chemistry. It just sounds like more fun that way.

[Belial]

This is why real scientists study physics :p.

And real programmers only code in binary.....

[oxoiron]

We(?) invented this method called scientific empiricism. It works pretty well. Try it.

It doesn't work very well when trying to figure out the shape of a molecule in solution. Try it.

EDIT: For example, look at the molecule represented by my avatar. I have collected a mountain of spectroscopic and empirical evidence regarding this proposed shape. However, I cannot know for sure that the atoms are really in this configuration unless I am able to get a crystal structure, which is almost impossible (take a look at how many μ-1,2-peroxo crystal structures have been published) and even if I did get a crystal structure, I can't assume that it accurately reflects a solvated molecule because of crystal packing effects, solvent coordination, etc. Depending on the parameters used, DFT both "confirms" and "refutes" this proposed structure, so that isn't very helpful either. I'm hoping that, since you helped invent scientific empiricism, perhaps you would be kind enough to pop over to my lab and figure this out for me.

[Umlaut]

This is why real scientists study physics :p.

And real programmers study binary.....

It's a (mostly) valid comparison. If you are trying to discover the why to something, physics will provide a foundation. It's the same with programming; it isn't necessary to learn it, but it sure can help you understand (and optimize!) your code.

[Belial]

Of course, study is used in two different senses in those sentences, or at least I perceived them that way.

When you say "study" binary, you mean learn, understand, etcetera.

When you "study" in science, it could be that meaning, or it could mean "run experiments on, perform studies on, and generally do", essentially causing the first sentence to mean "real scientists are physicists".

Or at least that's how I understood it, and what I was commenting on.

[Umlaut]

Of course, study is used in two different senses in those sentences, or at least I perceived them that way.

When you say "study" binary, you mean learn, understand, etcetera.

When you "study" in science, it could be that meaning, or it could mean "run experiments on, perform studies on, and generally do", essentially causing the first sentence to mean "real scientists are physicists".

Or at least that's how I understood it, and what I was commenting on.

Yeah, with your meaning, it's just asinine.