**Ask a monkey a physics question thread**

[OngBonga]

If there is a difference it's going to be small and I can't imagine that small effect is going to cause that big of a difference.

It might be just enough for some people that there's a noticeable trend over time in favour of one particular lace becoming undone. Perhaps the imbalace in his arm strength is more profund than most, perhaps due to a poor tying tequnique.

I think he needs to practise tying up his right boot. Four hours a day for a month should do it.

[OngBonga]

If you happen to have a few hundred silica gel sachets lying around, that should help keep humidity under control.

[Poopadoop]

Ong is basically right about the shoe-tying in principle. One or both hands learned how to tie a shoe better while in a particular postural configuration.* More of a question about motor control than physics though since there's nothing inherently in a left or right shoe that makes it harder to tie.

Either that or banana had a stroke.

* Or more aptly, the neural regions controlling the hand, since the hand itself is just the mechanical part of the system.

[CoccoBill]

Ong is basically right about the shoe-tying in principle. One or both hands learned how to tie a shoe better while in a particular postural configuration.* More of a question about motor control than physics though since there's nothing inherently in a left or right shoe that makes it harder to tie.

Either that or banana had a stroke.

* Or more aptly, the neural regions controlling the hand, since the hand itself is just the mechanical part of the system.

Obv has nothing to do with hand strength. This phenomenom is caused by coriolis force. Banana ties an identical knot on both shoes, which means on one shoe the direction of the knot is aligned with the direction of the force exerted by walking, and on the other it's not. QED.

[MadMojoMonkey]

Obv has nothing to do with hand strength. This phenomenom is caused by coriolis force. Banana ties an identical knot on both shoes, which means on one shoe the direction of the knot is aligned with the direction of the force exerted by walking, and on the other it's not. QED.

Also, this is cocco's nobel prize. I'm not taking this away from him.

Coco said QED - Quod Erat Demonstrandum - as it has been demonstrated - but he didn't actually demonstrate anything.

This is bound to piss off the Nobel committee.

Better fix that prior to official publication.

[OngBonga]

Coco said QED - Quod Erat Demonstrandum - as it has been demonstrated - but he didn't actually demonstrate anything.

This is bound to piss off the Nobel committee.

Better fix that prior to official publication.

Those stiffs probably don't even know what QED means and just think it's a qualification, like "hey I'm a professor" so they go "ok he knows his stuff, we'll believe him".

[OngBonga]

Another solution is to replace the ice with potassium.

[OngBonga]

Another solution is to replace the ice with potassium.

This, actually, is the best solution. Instead of cooling the drink, you're heating it, so condensation won't happen. It's also fun to watch.

The coaster might still get wet if the glass breaks though, which is quite possible, especially if the potassium is the same size as the ice. Eye protection would be advised.

[OngBonga]

Seal the room and have a huge motherfucker of a fan controlling an "air in" vent, while making sure as little air as possible can leave the room. When pressure is so great that you're feeling dizzy, put the ice in the glass and see if condensation forms.

[OngBonga]

Ok I have a cheap solution... when you're putting the ice in the glass, make sure you're got a fan blowing directly at it. This will ensure that any evaporation that takes place will not saturate the air around the glass, as the air is moving. It might be possible to have the condensation evaporate almost as quickly as it formed, which would at least mean it isn't running down the glass and getting the coaster wet. If the air isn't moving around the glass, then the water droplets will evaporate slower, because the RH of the surrounding air is increasing as evaporation takes place.

So yeah, blowing the glass might be enough, but a fan would be much better.

[Savy]

Whilst that may work (I've no idea) it still isn't a good practical solution. Every time I want a drink with ice in it fuck about finding a fan, letting it blow cold air. Nah.

Also thick enough kitchen towel instead of or on top of a coaster also solves the problem much easier than that.

[OngBonga]

Also thick enough kitchen towel instead of or on top of a coaster also solves the problem much easier than that.

Yeah but this is messy and more annoying than simply having a wet coaster stick to the bottom of the glass when I pick it up.

Ok, well keep your windows open. That's a free solution that will keep humidity low, perhaps low enough to eliminate condensation when you put ice in the drink. I assume it's warm enough to have the windows open if it's warm enough to have ice in your drink. If you're one of these morons who has ice in drinks in winter, then I don't care about your humidity problems to be quite honest. I hope you have a mouldy bathroom.

[BananaStand]

Did Tom Brady do it?

Scientifically speaking, how likely is it that the 'ideal gas law' resulted in deflating footballs before 2014 AFC Championship game.

[Savy]

Scientifically speaking, how likely is it that the 'ideal gas law' resulted in deflating footballs before 2014 AFC Championship game.

Not ideal.

#bestsciencejoke2k17

Yeah but this is messy and more annoying than simply having a wet coaster stick to the bottom of the glass when I pick it up.

Ok, well keep your windows open. That's a free solution that will keep humidity low, perhaps low enough to eliminate condensation when you put ice in the drink. I assume it's warm enough to have the windows open if it's warm enough to have ice in your drink. If you're one of these morons who has ice in drinks in winter, then I don't care about your humidity problems to be quite honest. I hope you have a mouldy bathroom.

Here is the clever bit, enough kitchen roll so that the bottom piece doens't become wet then you just pick up that bottom bit and magic easy to clean up. Still both my solutions aren't even close to solving the problem just much easier lazy ways to deal with it.

I usually have my window open, I like my room being quite cold.

[MadMojoMonkey]

Scientifically speaking, how likely is it that the 'ideal gas law' resulted in deflating footballs before 2014 AFC Championship game.

Quite likely.

Historically, the story goes back to Archimedes of Syracuse ca 250 BCE. He studied buoyancy and density for the first time in recorded western history.

Jump forward 1850 years to Gallileo (ca 1600), who demonstrated that changes in temperature of a fluid cause it to change its density, too.

Then another 50 years or so to Pascal and Boyle (ca 1650) demonstrating that force equals pressure times area and that the pressure times the volume of a closed system is constant.

Then about 1800 it all takes off. Charles Law (1787) that volume over temperature is a constant. About the same time Avogadro did his seminal work in chemistry and told us his namesake number, 6.022(10)^23. In 1809 Gay-Lussac showed that pressure over temperature of a closed system is also constant.

Then a 35 year old in 1834 named Emil Clapeyron was all, "lolz, PV = nRT, ya noobs. Get gud."

This is all pretty well documented, too. In famous old books that people been talking about for centuries in other books.

[BananaStand]

Quite likely.

Fuck off. Tom Brady did that shit.

If it's so likely, how come balls being under-inflated wasn't a problem for the previous 90 something years in the NFL? There were other games played on cold days

[OngBonga]

pfft geometry. I'd have got to that solution perhaps after another four or five spliffs.

[OngBonga]

Please replace the ice with potassium.

[Savy]

Please replace the ice with potassium.

I'm not going to drink enough tonight to do this but I was going to put a banana in a glass and post a picture. Imagine how funny that would have been.

[MadMojoMonkey]

FYP.

with a 10 sec google search.

noob. get gud.

[Savy]

FYP.

with a 10 sec google search.

noob. get gud.

You're american, I think that is the only way I can describe why you think that'd be adequate.

[OngBonga]

I'm not going to drink enough tonight to do this but I was going to put a banana in a glass and post a picture. Imagine how funny that would have been.

It would've made me smile, but not nearly as much as I would if you uploaded a video of you putting ice-cube sized chunks of potassium in a glass of water.

You're american, I think that is the only way I can describe why you think that'd be adequate.

I find it amusing that in the states, they have ten gallons of soda and a wheelbarrow of popcorn to watch a film, but for healthy eating they have diddy little bananas that fit inside pint glasses.

[OngBonga]

I get the feeling that the water is making the banana look bigger than it actually is. And it still looks tiny compared to what I have for bedtime, I mean healthy snacks.

[OngBonga]

cocco might have nailed it.

[Poopadoop]

cocco might have nailed it.

Doesn't each foot have to be moving in the opposite direction for that to work? I dunno about anyone else, but last I checked that's not what happens when you walk.

But hey, don't let reason dissuade you from the chance to turn down a Nobel Prize

[OngBonga]

Doesn't each foot have to be moving in the opposite direction for that to work? I dunno about anyone else, but last I checked that's not what happens when you walk.

But hey, don't let reason dissuade you from the chance to turn down a Nobel Prize

No, you just need one foot to be more "north" than the other, meaning different rates of rotation around the earth's axis.

[MadMojoMonkey]

Doesn't each foot have to be moving in the opposite direction for that to work? I dunno about anyone else, but last I checked that's not what happens when you walk.

Walking is when you swing your legs in an opposing pendular fashion and oscillate your hips so that you transfer weight to the "backward" moving leg on each legs swing cycle, so that your CG moves forward.

Your legs are always moving in opposite directions relative to each other, or stationary w.r.t each other when you're walking.

I mean. Your point still works because when your right leg is moving forward you have angular momentum one way, but when your left leg is moving forward, you have angular momentum the other way, so on average, the net angular momentum is 0 kgm^2/s... unless you always twirl in circles when you walk, which would be entertaining, but socially awkward, I imagine.

***
In inertial reference frames, so long as 2 objects are changing their position relative to each other, then there is (are) some reference frame(s) in which those objects are moving in opposite directions (at least along the line which connects their CG's).

If we allow for relativistic and accelerating reference frames, then whether or not any 2 objects are moving w.r.t. each other is a matter of perspective. So the matter that objects which are not moving w.r.t. each other are never moving in opposite directions doesn't even hold.

[OngBonga]

Also, this is cocco's nobel prize. I'm not taking this away from him.

[OngBonga]

This is a great suggestion because while it's obviously not the reason why banana is having lace problems, coriolis will indeed have a fractional impact on our results. If we're walking in a westerly direction, our right foot is more "north" than our left. The ground underneath the left foot is rotating faster than the ground underneath the right, but both our feet are attached to one body and are rotating at the same rate. This means the right foot (the more northerly one) has more rotational energy than the ground underneath it, and might, over the course of a lifetime, mean you have to tie up your right lace one or two times more than your left.

The problem with this is that over the course of a lifetime, and on average, one imagines that neither of our feet will be more northerly than the other. Of course, perhaps banana walks west to work, then gets the bus back because he can't wait to get back home to inject some heroin. This would mean, on average, the right foot is more northerly than the left. So coriolis could have the most fracional of influences, in theory.

[OngBonga]

Tides probably play a fractional role, too.

[BananaStand]

then gets the bus back because he can't wait to get back home to inject some heroin.

I shoot heroin ON the bus. Duh!

[OngBonga]

I shoot heroin ON the bus. Duh!

Are you from my town?

[CoccoBill]

My proof's being audited by the feds, they'll just have to take my word for it.

In all seriousness, I bet banana ties a proper knot in one shoe and a granny knot in the other.

[MadMojoMonkey]

My proof's being audited by the feds, they'll just have to take my word for it.

In all seriousness, I bet banana ties a proper knot in one shoe and a granny knot in the other.

Actually plausible, but goes against my expectation for human learning and conscious involvement in mundane tasks.
(I'm basically the opposite of an expert on this subject, though, so grain of salt.)

I'd think that the physical, tactile process of tying the laces is practically identical for both shoes. Muscle memory has nothing to do with your muscles storing memories, but it's still a cheat that the brain uses to avoid thinking about stuff. Why bother putting conscious thought into tying your shoes when your subconscious can repeat rote tasks w/o much effort at all? Why try to re-invent the knot when knowing that yesterday's knot was good enough and so long as your fingers feel the same feedback in the process of recreating that knot, no conscious effort required.

It's fully possible that bananananana was taught to tie his shoelaces in a non-congruent fashion, though.

***
The point about tying pro knots and not noob knots is a worthy question, though.

Are you trying doubly-slipped square knots? or doubly-slipped granny knots?

The granny knot has less hold and is prone to coming loose due to vibrations.

[Poopadoop]

On what planet does a parent teach their child to tie two different knots in their two shoes? Gtfo with that theory.

We need some video of bananaman tying his laces so we can subject it to kinematic analysis.

[OngBonga]

On what planet does a parent teach their child to tie two different knots in their two shoes? Gtfo with that theory.

We need some video of bananaman tying his laces so we can subject it to kinematic analysis.

It could be a matter of poor tequinique when teaching. Granny knots and square knots are similar, it's easy to accidentally tie a granny knot when trying to make a square knot. That said, it's possible that one shoe has a granny knot, and the other square, due to improper tying tequnique which was taught from a young age by accident. It's certainly plausible.

[Poopadoop]

It could be a matter of poor tequinique when teaching. Granny knots and square knots are similar, it's easy to accidentally tie a granny knot when trying to make a square knot. That said, it's possible that one shoe has a granny knot, and the other square, due to improper tying tequnique which was taught from a young age by accident. It's certainly plausible.

Doesn't almost everyone use the knot in this video? In my childhood, Granny knots or square knots were only used by kids too uncoordinated to do it the easy way. The same kids who were the last to get picked for your team in gym class.




Waiting for video of bananaman tying a sheep shank in his left shoe and a square hitch in his right.

[OngBonga]

That's how I do mine, but mojo started going on about granny knots and square knots, so I figured I was making one of those knots, and wasn't sure which.

[Poopadoop]

He was probably one of those uncoordinated kids and just assumes everyone else does it that way too lol.

[Poopadoop]

There was a real nice guy who worked IT in our department who was thinking about buying a motorcycle. I heard about it and told him 'You're barely coordinated enough to walk, if you try to ride a motorcycle you will probably die on the first ride.' He never got one. I like to think I saved his life.

True story.

[MadMojoMonkey]

Doesn't almost everyone use the knot in this video?

I use that knot, but I tie it in a more tedious way. That technique is familiar to me, but not worth the mental effort to re-train myself.

The trouble is that this is a doubly slipped square knot, but if you switch which loose end is forward and backward when you set up for the final pull to create and cinch the knot, then you have a doubly slipped granny knot. They look basically the same when you're done, but the granny knot is more prone to loosening.

In my childhood, Granny knots or square knots were only used by kids too uncoordinated to do it the easy way.

I'm not sure you and I are talking about the same thing. The level of coordination is exactly the same for both knots. The only difference is the symmetry of the 2 steps in making the knot.
The first step is the 1/2 hitch under the bow-knot. If that is NOT a mirror image of the bow-knot, then you have a granny knot. If it is a mirror image, then a square.

The same kids who were the last to get picked for your team in gym class.

Hey! That was me, you jerk.

That's how I do mine, but mojo started going on about granny knots and square knots, so I figured I was making one of those knots, and wasn't sure which.

He tied a doubly slipped square knot. So I figure you are making "one of those knots."

He was probably one of those uncoordinated kids and just assumes everyone else does it that way too lol.

Your face is uncoordinated!

[Poopadoop]

...

You know way too much about knots. I'm not surprised you were chosen last in gym class.

The bow is the hardest part of the knot to do. If one were a clumsy kid they first tied the basic bow knot (poorly), then took the two loops of the bow and tied another knot using them. Then when they got home they got their mom to untie it for them 'cause it was pretty much impossible to do it yourself.

I remember one kid showing it to me like it was the greatest thing in the world. So I tried it and went wtf this kid's an idiot.

[Poopadoop]

The trouble is that this is a doubly slipped square knot, but if you switch which loose end is forward and backward when you set up for the final pull to create and cinch the knot, then you have a doubly slipped granny knot. They look basically the same when you're done, but the granny knot is more prone to loosening.

So ok if I tie my shoes the normal way i first pass the right lace over the left to make the hitch part, then I make the bow in the left lace, draw the right lace OVER the loop and my thumb, then pull the second bow out through the hole where my thumb is, pull my thumb out with the bow and pull the knot tight.

You're saying a retard would do that with one shoe but replace the OVER movement with an UNDER movement on the other shoe? And then spend the next thirty-odd years wondering why one lace never stays tied up?

I would pay to see that.

[BananaStand]

Clueless, all of you.

I just figured it out

It's because i drive with my right foot.

[Poopadoop]

Clueless, all of you.

I just figured it out

It's because i drive with my right foot.

How many years you been driving?

[OngBonga]

You guys drive backwards to us. So you'll have accelerator, brake, clutch. Your right foot should be next to the clutch, while your left foot does the accelerating and braking. Your left foot should be doing more work, so if your right lace is coming undone more, you probably have a fucked clutch and need to get that fixed.

I don't drive, but I can figure out what's wrong with your car based on shoelaces. How am I not famous?

[Poopadoop]

You guys drive backwards to us. So you'll have accelerator, brake, clutch. Your right foot should be next to the clutch, while your left foot does the accelerating and braking. Your left foot should be doing more work, so if your right lace is coming undone more, you probably have a fucked clutch and need to get that fixed.

I don't drive, but I can figure out what's wrong with your car based on shoelaces. How am I not famous?

The pedals are still in the same position - right foot is gas or velocirator or whatever people call it here.

Most people in N. A. drive an automatic - no clutch. Though I can see bananaman driving a hummer or tank or something that he uses to run over homeless people and liberals.

Also, if pushing a pedal loosens your laces, you haven't tied them properly, otherwise everyone would have the same problem. Ergo we're back to him being a bad tier-upper.

[MadMojoMonkey]

right foot is gas or velocirator or whatever people call it here.

It's definitely controlling the angular acceleration of the engine, which is equivalent to controlling the linear acceleration of the car, given the drive train is not switching gears. It increases the fuel-air flow into the cylinders (and some other things to facilitate this), which increases the force delivered per engine cycle, which increases the acceleration, 'cause F = ma.

It can seem like you're controlling the velocity of the car with that pedal, because it's easy to forget that the wind resistance accelerating your car in the opposite direction increases with the square of velocity. When you increase your forward acceleration, the backward acceleration increases, too, so you reach a "terminal velocity" rather than keep increasing in velocity.

What it's called may not be relevant to the physics, though.

[Poopadoop]

That's cool.

Back to the laces though. What actually happens, physically, that would cause a knot to come undone? I can imagine there being two things: First, physical pushing and pulling which might happen if (e.g.) the arch of the foot were pushing against the laces. Second, vibration which might happen when (e.g.) the foot hits the ground on each step.

Similarly, what are the qualities, physically, that makes a knot resistant to these forces and stay done up? Is it the friction between the laces of a tight knot that does it?

[BananaStand]

physical pushing and pulling which might happen if (e.g.) the arch of the foot were pushing against the laces.

You mean like the flexing of a foot operating a gas pedal?

vibration which might happen when (e.g.) the foot hits the ground on each step.

or maybe vibrations caused by being in contact with something attached to a running engine?

Similarly, what are the qualities, physically, that makes a knot resistant to these forces and stay done up?

Even I know that one!

Is it the friction between the laces of a tight knot that does it?

Yeah

[BananaStand]

http://www.hampshiredome.com/club/sc...?NS=FAQ&DN=FAQ

^So this thing collapsed this week. 20 inches a snow and pffffffft.

What brilliant branch of physics came up with the idea that giant balloons make good buildings?

[MadMojoMonkey]

What brilliant branch of physics came up with the idea that giant balloons make good buildings?

That would be civil engineering.

David H. Geiger invented the air-supported structure.

[OngBonga]

So they drive on the left, but the accelerator is still on the right? Fucking weird.

[Poopadoop]

So they drive on the left, but the accelerator is still on the right? Fucking weird.

It's all pretty arbitary and thus irrelevant which side the gas pedal is on. If pushing the right pedal made your car go left I could see this being a problem.

[OngBonga]

What actually happens, physically, that would cause a knot to come undone?

I would have thought there are two main culrpits... vibration, and tension... and both will be overcome by not tying a slack knot. Where the knot is slack, the vibrations/tension allows motion of the lace.

When you tie a knot, after letting go of the lace, you might note the knot will slacken a touch if it's loose enough. For example, I just tied up my dressing gown belt, and immediately after letting go, it undoes slightly and is a touch more comfortable than when I first pulled it. That's not my breathing, or air movement. That's tension and would happen if there were no other factors at play. Once the tension of the belt reaches equilibrium, it will no longer slacken. The eqilibrium in question is affected by the geometry of the knot... the tighter it is, the less space there is for movement. Ideally, the loop is exactly the same size as the thread going through it. And yes, I think friction is the reason that under such circumstance, there is no motion.

This is all a guess though.

[Poopadoop]

I would have thought there are two main culrpits... vibration, and tension... and both will be overcome by not tying a slack knot. Where the knot is slack, the vibrations/tension allows motion of the lace.

Good point about the tension. I'm guessing that has something to do with the elasticity of the laces. So when you pull it tight you stretch the lace, then it springs back.

I just tied up my dressing gown belt.

I like the idea that it's past noon and you're still in your getting out of bed clothes.

[Poopadoop]

For some knots it must also be the case that outside push/pull forces work to loosen one part of the knot but tighten the other, making the knot thus more resistant to loosening.

[Poopadoop]

We need an experiment where Banana puts each foot on a vibrating plate and times how long it takes for the laces to come undone. If those times are statistically indistinguishable then it's not the tying that's the issue. If the time is less for the right vs. left foot, then tying is the problem.

Get to work banana. You'll need to do a lot of trials for each foot so we get some reliable data.

[MadMojoMonkey]

I strongly suspect that the driving / gas pedal is a red herring.

My foremost hypothesis has not been directly refuted yet, so I'm not sure if I should drop it or not.
I.e. are you 100% certain that you're tying square knots and not granny knots?

***
There are many knots and they serve different purposes.
Some have moving or slippery parts and stationary or fixed parts, yes. A slipknot has a loose part that forms the actual loop, and a fixed part which holds the loop closed.

[Poopadoop]

My foremost hypothesis has not been directly refuted yet, so I'm not sure if I should drop it or not.
I.e. are you 100% certain that you're tying square knots and not granny knots?

I thought you just finished telling me this wasn't your hypothesis?

Also, the hypothesis assumes he's tying two different knots in the left and right shoe, so you're asking the wrong question Mr. Science.

Banana, do you tie the knots with the exact same steps in each shoe?

[MadMojoMonkey]

I thought you just finished telling me this wasn't your hypothesis?

Also, the hypothesis assumes he's tying two different knots in the left and right shoe, so you're asking the wrong question Mr. Science.

Banana, do you tie the knots with the exact same steps in each shoe?

Well... I am still not directly hypothesizing that he's tying 2 different knots, but you have made an excellent point.

I was opining that he was tying granny knots on both shoes, and that they are more likely to slip. That completely ignores the issue that only one is consistently coming untied, which implies that my question is still moot unless I'm suggesting he's tying 2 different knots, which I'm not.

Fair play. Good observation. My bad.
Thanks for catching it.

[BananaStand]

I.e. are you 100% certain that you're tying square knots and not granny knots?

I make an x, loop one end through the bottom of the x and pull.

Then I make two bunny ears. I make an X with bunny ears, loop one through the bottom and pull

[MadMojoMonkey]

I make an x, loop one end through the bottom of the x and pull.

Then I make two bunny ears. I make an X with bunny ears, loop one through the bottom and pull

If you go right-over-left on the x, then go left-over-right on the X, that's a square knot.
Also if you do those in reverse order.

If you repeat the same thing twice, it is a granny knot.
I.e. if you go right-over-left on the x and the X, or left-over-right on the x and the X, then granny.

(lol, an alternate name for a granny knot is a lubber knot. I'm guessing as in land lubber. This knot is only known by insulting names. lol.)

[BananaStand]

Holy shit you guys got a lot of mileage out of this

[OngBonga]

Holy shit you guys got a lot of mileage out of this

I can get milage out of a conversation about how much milage we can get from inane conversations.

[OngBonga]

At extreme temperatures, such as those in the first few billionths of a second of the universe according to big bang, electromagnetism and the weak nuclear force are unified into the electrowaek force.

The question begs... as the universe expands and cools further, would we not expect more forces to emerge as the forces we currently observe as one break down? If not, how can we be sure? And if so, would it be an abrupt change?

Is superconductivity, ie zero electrical resistance, an example of different forces at super-cool temperatures?

[MadMojoMonkey]

The question begs... as the universe expands and cools further, would we not expect more forces to emerge as the forces we currently observe as one break down? If not, how can we be sure? And if so, would it be an abrupt change?

I don't think so.
We can be sure by looking at the current theory and seeing what it predicts about that temperature regime. We can do experiments where we cool things down to ludicrously low temperatures (many orders of magnitude colder than anything expected to be naturally occurring in the universe), and see what's up with them.

Depending on your criteria, the lowest temp achieved by a lab is open to interpretation.
Collections of sodium atoms have been cooled to 500 picoKelvin (1/2 a billionth of a degree C). These are miniscule in volume, but do exhibit an exotic form of matter called the Bose-Einstein condensate. This is predicted by the Standard Model of Particle Physics. This phase of matter may qualify under your hypothesis, but it's not likely to be a widespread state of matter in the universe on any timescale that I know of.

Some solids have been cooled to a few milliKelvin. A 1m by 1m by 1m block of copper has been cooled such by an Italian group of researchers. I don't believe they discovered any new forces or any physics that isn't predicted by the Standard Model.


If so, it would be an abrupt change. Anything which goes from a steady state of 0 to a non-0 is abrupt.

Is superconductivity, ie zero electrical resistance, an example of different forces at super-cool temperatures?

Kind of... they're different from the macroscopic world you and I find intuitive, but they're fully described by the Standard Model.

Superconductivity is described in multiple ways, and I'm not sure if those ways are equivalent or if they're complimentary.
I've gotten different information from different sources and it's not clear to me if either explanation is simplifying things so that I am less confused.

One way is the formation of Cooper Pairs of electrons at cold temperatures. A spin-up and a spin-down electron can become entangled if their thermal energy is low enough to not break this bond as soon as it would have formed. This is essentially a new force which exists as the body cools. It was really there all along, but unable to express itself, due to the ambient energy density being so great that the pair would immediately dissociate if it formed in the first place, due to the bombardment of thermal particles all around.

This is directly analogous to the early universe. The energy density was so high that at first no particles could form. Then only the lightest particles could form and interact via other light particles. As the universe expanded and cooled, gradually more and more particles were able to coalesce out of the maelstrom of energy and interact with other stuffs.

The formation of the Cooper pair is remarkable, in that it takes 2 spin 1/2 particles (fermions - which obey the exclusion principle) and binds them into a spin 1 particle system (a boson, which does not follow the exclusion principle). So the individual electrons cannot be in the same state as other electrons, but the cooper pair certainly can. Weird.

Another way that superconductivity happens is due to the uniform vibrations which happen in the crystal lattice against which the Cooper pairs are moving. Standing waves can set up in the body of the crystal, which change the nature of applied forces on the particles moving nearby.

When superconductivity happens, I suspect there is a resonance between the phonons (quanta of lattice vibrational states) and the Cooper pairs. This resonance is such that these 2 systems don't express any forces on each other, hence the 0 resistance of a superconductor.


EDIT: The bit in red is mostly wrong, and where it's not wrong, it's probably misleading.
A better description is hinted at below, but when the energy density is high, particles can spontaneously come into existence, so there would be massive particles. My understanding is that with the energy density higher than the electroweak epoch, anything larger than a quark or gluon would be so instantly annihilated, so that only quarks and gluons existed in any notable %-age. I'm not sure what this means for photons.

I understand this poorly at best, to be perfectly honest. I'll see what I can learn in the next few days.

[OngBonga]

Thanks for that detailed answer. I have another question...

How did light behave in the electoweak world? What about before when the strong force (assumingly) unified with EW?

[MadMojoMonkey]

Thanks for that detailed answer.

I have another question...

Keep 'em comin'.

How did light behave in the electoweak world?

Light is light. Photons are photons. They behaved the same then as now. They mediate the electromagnetic interactions. By mediate, I mean they are the exchange particles which express transfers of momentum. Changes in momentum over time are forces, recall. F = dp/dt, where F is force, dp is a small change in momentum, dt is a small change in time, and dp/dt is the incremental change in momentum over an incremental change in time.

What changed is the W and Z bosons. They mediate the weak nuclear interactions. I'm not an expert on symmetry breaking, and that's what all the information on this topic cites. What I understand about symmetry breaking is that as things get colder, the randomness of the particles lessens, and patterns can emerge.
E.g. Iron above the Curie temperature is non-magnetic, because the thermal motions of the particles make all the internal magnets align randomly. As the metal cools, the magnets' forces of interaction with each other are no longer dominated by the thermal forces of collisions, and the magnets begin to align. The rise of a permanent magnetic field as the Iron cools is a spontaneous symmetry breaking.

I can speak to the reference in our discussion of thermal energy in the early universe. The rest mass of the W and Z bosons is 80 GeV/c^2 and 90 GeV/c^2. So when the average thermal energy of the universe was greater than ~100 GeV, these particles could spontaneously manifest themselves in the universe, so the population was insanely much higher than after this period (the electroweak epoch) ended. Of course, they were likely to get blasted apart by anything they interacted with, so they were popping in and out of the universe in a constant wash. Symmetry.

I presume that weak interactions were commonplace during this epoch, that quarks were freely changing their "flavor" constantly, due to interactions with the proliferation of W and Z bosons about. This means that protons and neutrons weren't so stable, and probably that loads of exotic particles were more abundant.

Once the average thermal energy of the universe cooled below ~80 MeV, W and Z bosons could no longer be spontaneously created from the background wash of energy in the universe, so they would have decayed in their normal time and the universe was basically the one we observe today, with 4 forces. Broken symmetry.

What about before when the strong force (assumingly) unified with EW?

This is entirely hypothetical. Grand Unified Theories happen prior to electroweak epoch, by necessity. It is not clear if any hypotheses accurately describe the universe prior to the electroweak epoch.

Even the electroweak theory has some questionable parts, but mostly is solid theory. The existence of the W and Z bosons, as well as the Higgs, were predicted by electroweak theory prior to their observation. Once again, this is a hallmark of good science, and supplies great credibility to the theory.

One part that is up for debate is when, exactly, the electroweak epoch happened. Some hypotheses place is as early as 10^-36 s after the big bang, while others place it at 10^-12 s after the big bang.

As far as I understand it, the establishment of the credibility of the electroweak theory is why we believe the Standard Model is an accurate description (excellent approximation) of the universe from after the end of inflation up to now, and why we believe the laws of physics have been constant for at least that long.

[MadMojoMonkey]

I edited the prior post in red to indicate where I did a poor job 'splaining things.

[OngBonga]

What I understand about symmetry breaking is that as things get colder, the randomness of the particles lessens, and patterns can emerge.

This has a name, doesn't it? Entropy?

One part that is up for debate is when, exactly, the electroweak epoch happened. Some hypotheses place is as early as 10^-36 s after the big bang, while others place it at 10^-12 s after the big bang.

This is why I was curious about the behaviour of light in the EW epoch. I mean honestly, it seems ludicrous to use the word "epoch" to refer to a period of time so infintesimal that we can't even begin to comprehend how quick that is to us. How far does light travel in that time? It's like the entire era that was the electroweak epoch had started and was over before light could travel a nanometer. I really can't get my head around how so much can happen in such a short amount of time. How many high energy collisions can a particle experience in a nanosecond in the most insanely dense environment one cannot even begin to imagine?

My head is melting.

[OngBonga]

How many high energy collisions can a particle experience in a nanosecond in the most insanely dense environment one cannot even begin to imagine?

oh snap

This is directly analogous to the early universe. The energy density was so high that at first no particles could form. Then only the lightest particles could form and interact via other light particles. As the universe expanded and cooled, gradually more and more particles were able to coalesce out of the maelstrom of energy and interact with other stuffs.

[OngBonga]

Light is light. Photons are photons. They behaved the same then as now. They mediate the electromagnetic interactions. By mediate, I mean they are the exchange particles which express transfers of momentum. Changes in momentum over time are forces, recall. F = dp/dt, where F is force, dp is a small change in momentum, dt is a small change in time, and dp/dt is the incremental change in momentum over an incremental change in time.

Ok, but what I wanted to know is if light still travels at c in the EW universe. I don't think it will, but not because EM is different, rather because gravity will be truly immense.

[MadMojoMonkey]

Ok, but what I wanted to know is if light still travels at c in the EW universe. I don't think it will, but not because EM is different, rather because gravity will be truly immense.

Light always travels at c. It even does so when the Index of Refraction is not exactly 1, but the QM is trickier to understand than the classical approximation of just assuming it moves slower by a factor of the IoR.

Gravity doesn't change the speed of light, only the wavelength of the light.... and the stuff you know about directions and geodesics. Block holes don't trap light by slowing it down. They trap light by red-shifting it to the limit of infinite red shift, which has infinite wavelength, and therefore 0 energy. If it has 0 energy, it's not really a photon, it's been wholly absorbed by the black hole and its energy is converted to ... IDK... heat? It's a black hole... anything else it would be heat. With black holes, I'm not sure what heat means.

[MadMojoMonkey]

oh snap

I ninja edited that bit. I'm sure I don't understand it all, but I hypothesize it's like this:

Symmetry
The energy density is off the charts, so anything can pop into existence. BUT the energy density is so high that as soon as it exists, it's annihilated by other stuffs. It's a quantum mess of random sameyness all over everywhere.

I wonder if the quark-gluon plasma idea doesn't all arise from quark confinement. Quarks are funny because the strong force holds them to each other and the strong force doesn't diminish with increasing distance like the other forces. Rather the opposite happens. The further apart 2 quarks are, the more strongly they attract each other. The gluons are the mediators of the strong force.

If you try to pull a pair of quarks apart, eventually, the energy density in the gap pulling them back together creates new quarks, and you'll end up with (at least) 2 pairs of quarks when you started by pulling apart 1 pair of quarks. This isn't hypothetical, this is everyday stuff in a particle accelerator lab.

So, in the early universe, quarks start popping into existence, but then the energy density bombards them, destroying some and forcing others apart, which creates more quarks, which are immediately bombarded, etc.


***
Your comments on how far can a photon travel in such a short time span are cool.

IDK. This is all quite removed from what I've studied.