The behavior of a tethered helium balloon in a forward-moving van
April 22, 2014 1:29 PM Subscribe
The van goes forward, the balloon goes--wait a second. But truly, the cool balloon physics is the least terrific thing about this video. From Smarter Every Day. [slyt | via] Previously and previouslier
Fake. The same guy posted a video of a plane taking off on a conveyor belt.
posted by Tell Me No Lies at 1:32 PM on April 22, 2014 [7 favorites]
posted by Tell Me No Lies at 1:32 PM on April 22, 2014 [7 favorites]
I understood that!
posted by ThatCanadianGirl at 1:36 PM on April 22, 2014 [2 favorites]
posted by ThatCanadianGirl at 1:36 PM on April 22, 2014 [2 favorites]
Back in high school, we borrowed Jeff's Mom's van which happened to be hiding a couple birthday balloons. We stopped and started at least a hundred times observing this phenomenon, because we were high.
posted by I'm Doing the Dishes at 1:54 PM on April 22, 2014 [34 favorites]
posted by I'm Doing the Dishes at 1:54 PM on April 22, 2014 [34 favorites]
The best use of this sort of things was done by my high school physics teacher. He had floats attached to cords inside jars on the ends of a stick. After proving to us that the floats moved in the direction of acceleration, he spun the stick. The floats moved inward. Centripetal, not centrifugal force is real. Ta-da.
posted by Hactar at 1:55 PM on April 22, 2014 [5 favorites]
posted by Hactar at 1:55 PM on April 22, 2014 [5 favorites]
I've heard that Pythagoras liked eating hasheesh. "It's good to be curious about many things." F.R.
posted by jwhite1979 at 1:59 PM on April 22, 2014
posted by jwhite1979 at 1:59 PM on April 22, 2014
I'm Doing the Dishes: "We stopped and started at least a hundred times observing this phenomenon, because we were high"
So, in which direction do stoned high schoolers drift when their van accelerates?
posted by chavenet at 2:00 PM on April 22, 2014 [4 favorites]
So, in which direction do stoned high schoolers drift when their van accelerates?
posted by chavenet at 2:00 PM on April 22, 2014 [4 favorites]
These kids should work on their false enthusiasm; they are in for a lifetime of pretending to be interested in what their geeky dad does for fun.
posted by Think_Long at 2:02 PM on April 22, 2014 [13 favorites]
posted by Think_Long at 2:02 PM on April 22, 2014 [13 favorites]
Wow, he's the antimatter universe version of Calvin's dad.
posted by George_Spiggott at 2:03 PM on April 22, 2014 [6 favorites]
posted by George_Spiggott at 2:03 PM on April 22, 2014 [6 favorites]
Dear TruTV,
Please cancel Lizard Lick Towing, Operation Repo, Container Wars, Storage Hunters, South Beach Tow, All Worked Up, and Southern Fried Stings.
I would really like to see Smarter Every Day air on the Discovery Channel.
I am aware you aren't responsible for the programming on the Discovery Channel, but I just wanted to let you know that I really like Smarter Every Day, and the prior shows I mentioned really suck, like.. really bad.
Sincerely,
Lord Wigginsbottom
posted by Debaser626 at 2:06 PM on April 22, 2014 [22 favorites]
Please cancel Lizard Lick Towing, Operation Repo, Container Wars, Storage Hunters, South Beach Tow, All Worked Up, and Southern Fried Stings.
I would really like to see Smarter Every Day air on the Discovery Channel.
I am aware you aren't responsible for the programming on the Discovery Channel, but I just wanted to let you know that I really like Smarter Every Day, and the prior shows I mentioned really suck, like.. really bad.
Sincerely,
Lord Wigginsbottom
posted by Debaser626 at 2:06 PM on April 22, 2014 [22 favorites]
"Watch as I accelerate and decelerate this minivan repeatedly. See how the polar ice caps melt and the oceans acidify? Science, kids!"
posted by George_Spiggott at 2:19 PM on April 22, 2014 [10 favorites]
posted by George_Spiggott at 2:19 PM on April 22, 2014 [10 favorites]
Jeez, what dicks.
posted by jwhite1979 at 2:30 PM on April 22, 2014 [1 favorite]
posted by jwhite1979 at 2:30 PM on April 22, 2014 [1 favorite]
they are in for a lifetime of pretending to be interested in what their geeky dad does for funPretending? You underestimate the extent to which geekiness is hereditary. My one year old already begs for me and his older sister to do more chemistry experiments for him to watch. "Ment! Perryment! See!"
posted by roystgnr at 2:45 PM on April 22, 2014 [8 favorites]
I also noticed how well-mannered Destin's kids were. Turns out, so did a lot of other people -- some of whom apparently then accused him of being some goofball authoritarian jackass.
He replied, very well, on his Tumblr.
Lots of folks still teach that, in the South at least. It's not terribly correlated to socioeconomic class or ethnicity, either.
I'll add that, as a UA graduate and onetime resident of Alabama, I'm glad that SED gets the attention it does. Alabama isn't ALL idiot rednecks, football, and racism. (My guess is that certain BHM-area Mefites will back me up on this.)
posted by uberchet at 2:48 PM on April 22, 2014 [6 favorites]
He replied, very well, on his Tumblr.
Lots of folks still teach that, in the South at least. It's not terribly correlated to socioeconomic class or ethnicity, either.
I'll add that, as a UA graduate and onetime resident of Alabama, I'm glad that SED gets the attention it does. Alabama isn't ALL idiot rednecks, football, and racism. (My guess is that certain BHM-area Mefites will back me up on this.)
posted by uberchet at 2:48 PM on April 22, 2014 [6 favorites]
Pretending? You underestimate the extent to which geekiness is hereditary. My one year old already begs for me and his older sister to do more chemistry experiments for him to watch. "Ment! Perryment! See!"
They learned to suck up early I see.
posted by Tell Me No Lies at 2:55 PM on April 22, 2014
They learned to suck up early I see.
posted by Tell Me No Lies at 2:55 PM on April 22, 2014
It's called conditioning.
posted by benzenedream at 2:58 PM on April 22, 2014
posted by benzenedream at 2:58 PM on April 22, 2014
Now how about that backward underwater lawn sprinkler?
posted by crazy_yeti at 3:08 PM on April 22, 2014
posted by crazy_yeti at 3:08 PM on April 22, 2014
What a weird thread. I think the dad is cool, the kids are cute, and the "experiment" is amazing, and would appreciate a spoiler about why the balloon does what it does.
I do not care one fig about whether or not the dad is authoritarian or not (any moron can see that the family is well-connected) any other snark.
posted by KokuRyu at 3:14 PM on April 22, 2014 [6 favorites]
I do not care one fig about whether or not the dad is authoritarian or not (any moron can see that the family is well-connected) any other snark.
posted by KokuRyu at 3:14 PM on April 22, 2014 [6 favorites]
oh man that's awesome. I work with aerodynamics every day and I never end up thinking about buoyancy, his jar of water analogy is great. I wonder how I managed to get all the way through school without ever seeing this particular example.
posted by indubitable at 3:19 PM on April 22, 2014
posted by indubitable at 3:19 PM on April 22, 2014
Someone in the cafe where I was studying earlier today was watching this video on their phone with no headphones. I couldn't see the screen, and only overheard a tiny bit, but I could tell it was Smarter Every Day.
I never thought I wouldn't be annoyed at someone who was broadcasting audio from their phone for all to hear, but apparently when it's about physics I'm just happy that people are learning about science.
posted by ocherdraco at 3:26 PM on April 22, 2014 [6 favorites]
I never thought I wouldn't be annoyed at someone who was broadcasting audio from their phone for all to hear, but apparently when it's about physics I'm just happy that people are learning about science.
posted by ocherdraco at 3:26 PM on April 22, 2014 [6 favorites]
This is great, but I think his explanation is wrong.
There may be some effect due to 'sloshing,' but suppose he and the kids were in spacesuits in a nearly evacuated car, what would happen then?
The balloon would still go forward because the force due to (steady) acceleration and the force due to gravity added together wouldn't point straight down, it would point toward the back of the car a little bit, and the string would align itself with that direction-- and you can even see that when he has both the balloon and the pendulum in the car: the strings are almost parallel.
If the car had no windows, you couldn't tell the difference between the net force due to gravity and acceleration, and force due to gravity alone pointing in that direction, and of course the strings would align with gravity.
posted by jamjam at 3:27 PM on April 22, 2014 [1 favorite]
There may be some effect due to 'sloshing,' but suppose he and the kids were in spacesuits in a nearly evacuated car, what would happen then?
The balloon would still go forward because the force due to (steady) acceleration and the force due to gravity added together wouldn't point straight down, it would point toward the back of the car a little bit, and the string would align itself with that direction-- and you can even see that when he has both the balloon and the pendulum in the car: the strings are almost parallel.
If the car had no windows, you couldn't tell the difference between the net force due to gravity and acceleration, and force due to gravity alone pointing in that direction, and of course the strings would align with gravity.
posted by jamjam at 3:27 PM on April 22, 2014 [1 favorite]
Ok now do it with a blue balloon!
posted by Big_B at 3:29 PM on April 22, 2014 [7 favorites]
posted by Big_B at 3:29 PM on April 22, 2014 [7 favorites]
Assuming the balloon was still filled with lighter than the nearly evacuated air helium.
posted by jamjam at 3:30 PM on April 22, 2014 [3 favorites]
posted by jamjam at 3:30 PM on April 22, 2014 [3 favorites]
If they were in an evacuated car, the balloon (if we pretend it magically doens't just pop) would just sit on the floor - because there is nothing providing buoyancy.
As it is, it moves forward because the pressure gradient changes from vertical to slightly rearward -and slight is all you need.
posted by TravellingDen at 3:30 PM on April 22, 2014 [1 favorite]
As it is, it moves forward because the pressure gradient changes from vertical to slightly rearward -and slight is all you need.
posted by TravellingDen at 3:30 PM on April 22, 2014 [1 favorite]
... would appreciate a spoiler about why the balloon does what it does.
Here is a half-explanation.
According to general relativity theory, an accelerating frame of reference is indistinguishable from a non-accelerating frame of reference in a gravitational field oriented in the opposite direction of the acceleration. That is, if you were in a closed box, like an elevator car, you couldn't tell whether you were (1) accelerating up or (2) in a suitably strong gravitational field that points down. So, when the van accelerates forward, it is just like it is creating a gravitational field pointed toward its back. Since helium balloons tend to rise (against a gravitational field) in ordinary air, the helium balloon in the van tends to move toward the front of the van. Same story for why the balloon moves in the direction the van turns -- the van is accelerating in that direction, which is just like having a gravitational field pointing in the opposite direction.
As to why a helium balloon tends to rise against a gravitational field in ordinary air, you're on your own!
posted by Jonathan Livengood at 3:31 PM on April 22, 2014 [8 favorites]
Here is a half-explanation.
According to general relativity theory, an accelerating frame of reference is indistinguishable from a non-accelerating frame of reference in a gravitational field oriented in the opposite direction of the acceleration. That is, if you were in a closed box, like an elevator car, you couldn't tell whether you were (1) accelerating up or (2) in a suitably strong gravitational field that points down. So, when the van accelerates forward, it is just like it is creating a gravitational field pointed toward its back. Since helium balloons tend to rise (against a gravitational field) in ordinary air, the helium balloon in the van tends to move toward the front of the van. Same story for why the balloon moves in the direction the van turns -- the van is accelerating in that direction, which is just like having a gravitational field pointing in the opposite direction.
As to why a helium balloon tends to rise against a gravitational field in ordinary air, you're on your own!
posted by Jonathan Livengood at 3:31 PM on April 22, 2014 [8 favorites]
He can't prove God didn't do it.
posted by George_Spiggott at 3:31 PM on April 22, 2014 [1 favorite]
posted by George_Spiggott at 3:31 PM on April 22, 2014 [1 favorite]
The explanation about gravity is kind of misleading though... the real issue here is the air pressure gradient - which is, of course, caused by gravity. The balloon, being less dense than everything else in the car, is pushed by the higher pressure areas to the lower pressure areas.
Normally, that direction is straight up - but as the car accelerates, the air inside compresses in the direction opposite the acceleration - so the gradient pushes things forwards more than it normally would - so the balloon is pushed forwards.
It's important to realize this isn't unique to the helium balloon - only the motion is, because the buoyant forces at work are significantly stronger than the inertial forces and whatnot. A pendulum experiences the same forces, but as it's not buoyant, the pressure differences can be ignored, and the pendulum tends to stay at rest.
My point is that the balloon also tends to stay at rest - but the buoyant forces are strong enough, relatively speaking, to make it move.
posted by TravellingDen at 3:37 PM on April 22, 2014 [5 favorites]
Normally, that direction is straight up - but as the car accelerates, the air inside compresses in the direction opposite the acceleration - so the gradient pushes things forwards more than it normally would - so the balloon is pushed forwards.
It's important to realize this isn't unique to the helium balloon - only the motion is, because the buoyant forces at work are significantly stronger than the inertial forces and whatnot. A pendulum experiences the same forces, but as it's not buoyant, the pressure differences can be ignored, and the pendulum tends to stay at rest.
My point is that the balloon also tends to stay at rest - but the buoyant forces are strong enough, relatively speaking, to make it move.
posted by TravellingDen at 3:37 PM on April 22, 2014 [5 favorites]
appreciate a spoiler about why the balloon does what it does.
So you're probably familiar with the fact that air pressure drops as you go up. (Popping ears and all that).
Balloons rise because of that. They naturally move from places with more air pressure to places with less air pressure.
When you accelerate the van a bunch of air moves to the back, making the air pressure in the back of the van higher than the pressure in the front. The ballon does what it naturally does in that situation.
posted by Tell Me No Lies at 3:40 PM on April 22, 2014 [10 favorites]
So you're probably familiar with the fact that air pressure drops as you go up. (Popping ears and all that).
Balloons rise because of that. They naturally move from places with more air pressure to places with less air pressure.
When you accelerate the van a bunch of air moves to the back, making the air pressure in the back of the van higher than the pressure in the front. The ballon does what it naturally does in that situation.
posted by Tell Me No Lies at 3:40 PM on April 22, 2014 [10 favorites]
Thank you. I try not to think to much about what is happening as I motor around in a car, because, let's face it, cars are pretty scary.
posted by KokuRyu at 3:49 PM on April 22, 2014 [3 favorites]
posted by KokuRyu at 3:49 PM on April 22, 2014 [3 favorites]
The plane takes off.
posted by Ironmouth at 4:10 PM on April 22, 2014 [2 favorites]
posted by Ironmouth at 4:10 PM on April 22, 2014 [2 favorites]
I saw this on io9 the other day too, and I was far more disconcerted by how he and his kids interact than interested in the "science" he's demonstrating.
We don’t try to modify their behavior, we try to shepherd their hearts
Riiiight...
The sir business was creepy. Not because they said "sir," but because they said it like they would be in deep shit if they didn't.
Also, wtf is with him capitalizing "father" when referring to himself? Something is off here.
posted by nzero at 4:36 PM on April 22, 2014
We don’t try to modify their behavior, we try to shepherd their hearts
Riiiight...
The sir business was creepy. Not because they said "sir," but because they said it like they would be in deep shit if they didn't.
Also, wtf is with him capitalizing "father" when referring to himself? Something is off here.
posted by nzero at 4:36 PM on April 22, 2014
Surely you all mean air density, not air pressure?
posted by indubitable at 4:37 PM on April 22, 2014
posted by indubitable at 4:37 PM on April 22, 2014
nzero, I think you are reading waaaay too much into the whole sir thing. For most people in North Alabama (not just kids), it's just automatic nice speech, like please and thank you.
posted by ocherdraco at 4:44 PM on April 22, 2014 [13 favorites]
posted by ocherdraco at 4:44 PM on April 22, 2014 [13 favorites]
I mean, as someone who grew up there and very regularly visits, these kids sound completely normal.
posted by ocherdraco at 4:48 PM on April 22, 2014 [4 favorites]
posted by ocherdraco at 4:48 PM on April 22, 2014 [4 favorites]
Yeah, I've never been a 'sir' person, but really there are some places in the country and in the world where this is pretty darn normal and not indicative of anything sinister or note worthy. Just because it falls outside of someone's experience does not make it wrong.
posted by edgeways at 4:50 PM on April 22, 2014 [5 favorites]
posted by edgeways at 4:50 PM on April 22, 2014 [5 favorites]
Yeah, the "sir" thing's not a huge authoritarian deal; it's more of a southern-cultural deal. Sure, some people get a bit heavy-handed about it, but mostly it's about general courtesy and politeness. Hell, I'm 53 and I still say "sir" and "ma'am" sometimes in polite company, even to people younger than me. Not out of deference, per se, just bein' nice.
posted by Greg_Ace at 4:50 PM on April 22, 2014 [6 favorites]
posted by Greg_Ace at 4:50 PM on April 22, 2014 [6 favorites]
The sir business was creepy.
In my part of the country you even hear kids say "please" occasionally. I know it sounds like they must be regularly deprived of food, or maybe they get whipped a lot, but trust me when I say it's just sort of normal.
posted by swift at 4:53 PM on April 22, 2014 [8 favorites]
In my part of the country you even hear kids say "please" occasionally. I know it sounds like they must be regularly deprived of food, or maybe they get whipped a lot, but trust me when I say it's just sort of normal.
posted by swift at 4:53 PM on April 22, 2014 [8 favorites]
nzero, I think you are reading waaaay too much into the whole sir thing. For most people in North Alabama (not just kids), it's just automatic nice speech, like please and thank you.
I'm from deep south Georgia man, everyone here says 'sir' too. Hell, I call everyone sir. And I'm telling you, this rubs me the wrong way.
posted by nzero at 4:54 PM on April 22, 2014
I'm from deep south Georgia man, everyone here says 'sir' too. Hell, I call everyone sir. And I'm telling you, this rubs me the wrong way.
posted by nzero at 4:54 PM on April 22, 2014
The big takeaway here (imo) is that gases and fluids act the same way. The balloon floats in the air just like the bubble floats in the water jar. When the van accelerates forward everything inside of it is pushed back (Newton's Third Law of Motion), including the air. The air pooling in the back pushes the balloon forward, in the direction of acceleration. Then everything reverses when the car decelerates. The plumb bob doesn't float in air, so it more accurately shows the forces acting within the interior of the van.
posted by Kevin Street at 4:58 PM on April 22, 2014 [3 favorites]
posted by Kevin Street at 4:58 PM on April 22, 2014 [3 favorites]
Leave it to metafiler to overthink a plate of 'kids saying sir'. Jesus.
posted by efalk at 4:58 PM on April 22, 2014 [7 favorites]
posted by efalk at 4:58 PM on April 22, 2014 [7 favorites]
The video was cool.
Okay, now back to the derail.... the "sir" thing hit me recently last week when I was interviewing a recent architectural graduate for a position in our firm. Throughout the interview, he responded to every question with "Well yes sir." or "No sir...". I still consider myself somewhat young, and it made me feel really old.
I still made him an offer though.
posted by Benway at 5:00 PM on April 22, 2014
Okay, now back to the derail.... the "sir" thing hit me recently last week when I was interviewing a recent architectural graduate for a position in our firm. Throughout the interview, he responded to every question with "Well yes sir." or "No sir...". I still consider myself somewhat young, and it made me feel really old.
I still made him an offer though.
posted by Benway at 5:00 PM on April 22, 2014
Leave it to metafiler to overthink a plate of 'kids saying sir'. Jesus.
That is a ridiculous statement. Enough people were bothered by it, and voiced that bother, that he felt he had to respond on his blog defending himself. His defense sounded, well, like bullshit.
posted by nzero at 5:04 PM on April 22, 2014
That is a ridiculous statement. Enough people were bothered by it, and voiced that bother, that he felt he had to respond on his blog defending himself. His defense sounded, well, like bullshit.
posted by nzero at 5:04 PM on April 22, 2014
So does the criticism.
posted by BurntHombre at 5:07 PM on April 22, 2014 [8 favorites]
posted by BurntHombre at 5:07 PM on April 22, 2014 [8 favorites]
"Surely you all mean air density, not air pressure?"
Force = Pressure times Area, so it's all related. The balloon floats upward until it encounters air pressure that's at the same density as the helium inside of it, which is where the forces acting upon it are in balance.
Or to put it another way, the balloon floats upward until it reaches a point where it's weight is equal to to the weight of a similar sized chunk of the surrounding air, just as ships will rise until they reach their "waterline."
posted by Kevin Street at 5:09 PM on April 22, 2014 [1 favorite]
Force = Pressure times Area, so it's all related. The balloon floats upward until it encounters air pressure that's at the same density as the helium inside of it, which is where the forces acting upon it are in balance.
Or to put it another way, the balloon floats upward until it reaches a point where it's weight is equal to to the weight of a similar sized chunk of the surrounding air, just as ships will rise until they reach their "waterline."
posted by Kevin Street at 5:09 PM on April 22, 2014 [1 favorite]
At least he's teaching science. All this "it just feels wrong to me, so trust me, it's wrong" business is a bit ironic in this context, isn't it?
posted by jwhite1979 at 5:11 PM on April 22, 2014 [5 favorites]
posted by jwhite1979 at 5:11 PM on April 22, 2014 [5 favorites]
His defense sounded, well, like bullshit He also didn't include trigger warnings about his white patriarchal status, nor that of his kids. Or maybe this was a post about demonstrating science principles.
posted by efalk at 5:12 PM on April 22, 2014 [6 favorites]
posted by efalk at 5:12 PM on April 22, 2014 [6 favorites]
Dudes this is an awesome video showing how fluid dynamics works, and it's great that he's teaching his kids!
Saying "Yes, sir" and "no, sir", isn't creepy. Its normal. Typically used more in a formal setting but certainly used in a family setting also. It's not even a southern thing, I'm from northern Illinois and I do it.
posted by MrBobaFett at 5:15 PM on April 22, 2014 [2 favorites]
Saying "Yes, sir" and "no, sir", isn't creepy. Its normal. Typically used more in a formal setting but certainly used in a family setting also. It's not even a southern thing, I'm from northern Illinois and I do it.
posted by MrBobaFett at 5:15 PM on April 22, 2014 [2 favorites]
His defense sounded, well, like bullshit.
No, no, if you're going to do this Tumblry outrage crap right you have to say "his defense was problematic".
posted by Lentrohamsanin at 5:23 PM on April 22, 2014 [3 favorites]
No, no, if you're going to do this Tumblry outrage crap right you have to say "his defense was problematic".
posted by Lentrohamsanin at 5:23 PM on April 22, 2014 [3 favorites]
Another nice demonstration of this is the candle on a turntable trick. Put a candle in a jar near the end of a turntable, and start it spinning. Within the jar's frame of reference, the air is accelerated toward the outside of the turntable (centrifugal force) and the flame, being less dense, is bouyed/displaced toward the centre of the turntable. It's a cool effect.
(Obviously, be careful of sloshing hot wax, glass jars cracking from heat, and/or accidentally flinging your lit candle off the table)
posted by metaBugs at 5:25 PM on April 22, 2014 [1 favorite]
(Obviously, be careful of sloshing hot wax, glass jars cracking from heat, and/or accidentally flinging your lit candle off the table)
posted by metaBugs at 5:25 PM on April 22, 2014 [1 favorite]
Can you explain how his defense was problematic according to some reasonably objective standard?
posted by jwhite1979 at 5:32 PM on April 22, 2014 [1 favorite]
posted by jwhite1979 at 5:32 PM on April 22, 2014 [1 favorite]
(Obviously, be careful of sloshing hot wax, glass jars cracking from heat, and/or accidentally flinging your lit candle off the table)
Now I want to try this.
posted by Kevin Street at 5:34 PM on April 22, 2014
Now I want to try this.
posted by Kevin Street at 5:34 PM on April 22, 2014
Sandlin makes all these videos about interesting phenomena, and they're right up my alley, and on paper I would certainly enjoy them. But something about him personally has always repelled me. I wish I could say what it was. I guess deep down I'm sure he's about to tell me that Jesus wants me to join the military.
Anyway I'm not the least bit surprised that his kids say yessir and nosir, or that he explains this is a sign of his excellence and passion in parenting. Somehow that fits. Maybe he strikes me as a cargo-cultist.
My father was required to address his parents as sir and madam and while I don't think it did any good, really, I don't think it did him or his relationship with his parents any harm, either.
Hasn't every American seen the balloon thing by the time they're 10 or so? He's done better videos.
posted by Western Infidels at 5:39 PM on April 22, 2014 [1 favorite]
Anyway I'm not the least bit surprised that his kids say yessir and nosir, or that he explains this is a sign of his excellence and passion in parenting. Somehow that fits. Maybe he strikes me as a cargo-cultist.
My father was required to address his parents as sir and madam and while I don't think it did any good, really, I don't think it did him or his relationship with his parents any harm, either.
Hasn't every American seen the balloon thing by the time they're 10 or so? He's done better videos.
posted by Western Infidels at 5:39 PM on April 22, 2014 [1 favorite]
I thought the yes sir thing was fine on its face, but the tumblr defense kind of gave me the willies. "My kids call me sir because I take parenting really seriously" Ok buddy, if you say so.
Having to make the defense at all is a consequence of putting your children in the public eye, and also how everyone everywhere likes to tell all parents how they are doing it wrong. Both of which are dumb and lame.
posted by Kwine at 5:45 PM on April 22, 2014 [1 favorite]
Having to make the defense at all is a consequence of putting your children in the public eye, and also how everyone everywhere likes to tell all parents how they are doing it wrong. Both of which are dumb and lame.
posted by Kwine at 5:45 PM on April 22, 2014 [1 favorite]
"Surely you all mean air density, not air pressure?"
I didn't, but I was writing to be understood. Blurring over a small detail is far preferable to blurring over the eyes of the person listening to you.
posted by Tell Me No Lies at 5:46 PM on April 22, 2014 [2 favorites]
I didn't, but I was writing to be understood. Blurring over a small detail is far preferable to blurring over the eyes of the person listening to you.
posted by Tell Me No Lies at 5:46 PM on April 22, 2014 [2 favorites]
Can you explain how his defense was problematic according to some reasonably objective standard?
Well, I was trying to retreat gracefully-ish with levity.
But since you asked, he mentions brainwashing and spends ten minutes talking about how intense his parenting is, but then he says:
"We don’t try to modify their behavior, we try to shepherd their hearts."
The reaction of both the kids is so scripted, it has clearly (clear to me, anyhow) been drilled into them. Those two things, drilling "respect" into kids (yes, my assumption) and then calling it "shepherding their hearts," combined with his odd use of capitalization for the word "father" when referring to himself bothers me, because it is precisely the sort of talk and behavior I have witnessed firsthand in an abusive household.
That's why I said it rubbed me the wrong way. It disconcerted me when I first watched the video (but not enough to post about, just enough to make me sure I would never watch another video from this guy), but after I came here to read the comments, saw the issue had been brought up by others, and then read his creepily (I know, feelings, run away) worded "defense", I felt the need to at least call him out on that "shepherding their hearts" gibberish.
posted by nzero at 5:46 PM on April 22, 2014 [2 favorites]
Well, I was trying to retreat gracefully-ish with levity.
But since you asked, he mentions brainwashing and spends ten minutes talking about how intense his parenting is, but then he says:
"We don’t try to modify their behavior, we try to shepherd their hearts."
The reaction of both the kids is so scripted, it has clearly (clear to me, anyhow) been drilled into them. Those two things, drilling "respect" into kids (yes, my assumption) and then calling it "shepherding their hearts," combined with his odd use of capitalization for the word "father" when referring to himself bothers me, because it is precisely the sort of talk and behavior I have witnessed firsthand in an abusive household.
That's why I said it rubbed me the wrong way. It disconcerted me when I first watched the video (but not enough to post about, just enough to make me sure I would never watch another video from this guy), but after I came here to read the comments, saw the issue had been brought up by others, and then read his creepily (I know, feelings, run away) worded "defense", I felt the need to at least call him out on that "shepherding their hearts" gibberish.
posted by nzero at 5:46 PM on April 22, 2014 [2 favorites]
"We take parenting much more serious than most people you’ve come in contact with."
For me, this was the most problematic bit of his tumblr comment. I can appreciate a wide range of parenting styles, but that combo of smug and presumptuous is seriously gross.
posted by a box and a stick and a string and a bear at 6:06 PM on April 22, 2014 [6 favorites]
For me, this was the most problematic bit of his tumblr comment. I can appreciate a wide range of parenting styles, but that combo of smug and presumptuous is seriously gross.
posted by a box and a stick and a string and a bear at 6:06 PM on April 22, 2014 [6 favorites]
I get what you're saying, nzero. I actually despise religion and unwarranted authority, as well as the military industrial complex, so this guy does kind of seem creepy to me too. But I was also raised in household with a workaholic father and a mother who spent as much time in mental institutions as not, so on another level I still crave this kind of impassioned parental governance. I spent 4 years in a private Christian college, hoping at first to find that sort of surrogate authority over my life, but soon I just felt people were condescending and full of shit. Of my classmates, most came from conservative southern households and were probably taught to call their fathers "sir", and many were home-schooled. Of them, some small percentage have become atheists and are now hyper-aware of anything that's suggestive of a controlling parent, and I imagine this video could be something of a trigger for them. However, the vast majority are well-adjusted church-going adults with families of their own, and they're raising their families just as they themselves were raised. They are not traumatized. They're fine. And so are their kids.
posted by jwhite1979 at 6:12 PM on April 22, 2014
posted by jwhite1979 at 6:12 PM on April 22, 2014
Kevin Street's explanation is the correct one. This is simple fluid dynamics.
A helium balloon in the atmosphere near sea-level is pushed upward by the air below it.
Atmospheric pressure at a given elevation is the total weight of the column of air above that location. (That is, it's the weight of the column of air above a defined surface area, such as a square inch. The atmospheric pressure is the weight of that square-inch diameter column of air from that elevation to the top of the atmosphere.) For any given surface area, the maximum weight of anything that can be pushed upward by atmospheric pressure is that weight of that column of air above that surface area.
For example, when we measure atmospheric pressure with a simple mercury barometer, we use an evacuated tube suspended in a pool of mercury. Vacuums don't "suck" and the mercury isn't sucked upward into the evacuated tube. Instead, the mercury in the pool is pushed upward into the evacuated tube until the weight of the column of mercury in the evacuated tube from the top of the mercury pool to the top of the column is equal to the weight of the air (the column that's the same diameter as the mercury column and measured from the top of the mercury pool to the top of the atmosphere). The top portion of the tube remains evacuated because the weight of the air can't push the mercury any higher. When that column of air becomes heavier (because it's become more dense for some reason), then it will push the mercury a bit higher.
The same thing is what happens with a helium balloon or a hot-air balloon, though it's harder to describe in simple language.
When the van in this video accelerates, the air inside the van is also accelerated. While the air is accelerating, it behaves exactly the same way as air does in the atmosphere under gravity (this was the general relativity point made above) and "down" is the direction opposite the acceleration. The air in the van, being heavier than the balloon, displaces the balloon "upward", which is the direction of acceleration.
posted by Ivan Fyodorovich at 6:26 PM on April 22, 2014 [4 favorites]
A helium balloon in the atmosphere near sea-level is pushed upward by the air below it.
Atmospheric pressure at a given elevation is the total weight of the column of air above that location. (That is, it's the weight of the column of air above a defined surface area, such as a square inch. The atmospheric pressure is the weight of that square-inch diameter column of air from that elevation to the top of the atmosphere.) For any given surface area, the maximum weight of anything that can be pushed upward by atmospheric pressure is that weight of that column of air above that surface area.
For example, when we measure atmospheric pressure with a simple mercury barometer, we use an evacuated tube suspended in a pool of mercury. Vacuums don't "suck" and the mercury isn't sucked upward into the evacuated tube. Instead, the mercury in the pool is pushed upward into the evacuated tube until the weight of the column of mercury in the evacuated tube from the top of the mercury pool to the top of the column is equal to the weight of the air (the column that's the same diameter as the mercury column and measured from the top of the mercury pool to the top of the atmosphere). The top portion of the tube remains evacuated because the weight of the air can't push the mercury any higher. When that column of air becomes heavier (because it's become more dense for some reason), then it will push the mercury a bit higher.
The same thing is what happens with a helium balloon or a hot-air balloon, though it's harder to describe in simple language.
When the van in this video accelerates, the air inside the van is also accelerated. While the air is accelerating, it behaves exactly the same way as air does in the atmosphere under gravity (this was the general relativity point made above) and "down" is the direction opposite the acceleration. The air in the van, being heavier than the balloon, displaces the balloon "upward", which is the direction of acceleration.
posted by Ivan Fyodorovich at 6:26 PM on April 22, 2014 [4 favorites]
Now do it in a vacuum with a perfectly spherical balloon at the speed of light!
Where's your science now?!?!?
posted by blue_beetle at 6:34 PM on April 22, 2014 [3 favorites]
Where's your science now?!?!?
posted by blue_beetle at 6:34 PM on April 22, 2014 [3 favorites]
Wow this thread took a weird turn in my time away.
posted by Think_Long at 6:46 PM on April 22, 2014 [2 favorites]
posted by Think_Long at 6:46 PM on April 22, 2014 [2 favorites]
You see how the water in the jar sloshes to the back when the car accelerates? It sloshes to the back; and because the water is heavier than the air bubble it pushes the air bubble out of its way so the air bubble moves forward as the water moves backward. Well, air is a fluid, just like water is, and the balloon is filled with a gas that is lighter than air. The air inside the car sloshes to the back when the car accelerates, and the air pushes the balloon out of its way. If the car was a rocket or something it could accelerate so fast that all the air would slosh to the back, and the driver wouldn't be able to breathe!
posted by Joe in Australia at 6:52 PM on April 22, 2014
posted by Joe in Australia at 6:52 PM on April 22, 2014
That's why jet pilots can black out during high G maneuvers. The blood in their brains sloshes away from the direction of acceleration, which leads to temporary unconsciousness.
posted by Kevin Street at 6:57 PM on April 22, 2014
posted by Kevin Street at 6:57 PM on April 22, 2014
The explanation about gravity is kind of misleading though... the real issue here is the air pressure gradient.
No, the same thing would happen if it were a bubble of not so dense, incompressible liquid embedded in a dense, incompressible liquid--no gradient at all.
posted by jjwiseman at 7:34 PM on April 22, 2014
No, the same thing would happen if it were a bubble of not so dense, incompressible liquid embedded in a dense, incompressible liquid--no gradient at all.
posted by jjwiseman at 7:34 PM on April 22, 2014
There is a really simple explanation for this and it's that acceleration = gravity, and everything in a car that's accelerating forward will behave as if gravity shifted towards the back of the car..
posted by empath at 7:34 PM on April 22, 2014 [1 favorite]
posted by empath at 7:34 PM on April 22, 2014 [1 favorite]
We took a minivan, a helium balloon, a geeky dad and two adorable kids. What happens next will restore your faith in humanity...
posted by L.P. Hatecraft at 7:39 PM on April 22, 2014 [3 favorites]
posted by L.P. Hatecraft at 7:39 PM on April 22, 2014 [3 favorites]
Anyone who liked that candle-on-turntable experiment is likely to love the fire tornado.
posted by roystgnr at 7:44 PM on April 22, 2014
posted by roystgnr at 7:44 PM on April 22, 2014
We don’t try to modify their behavior, we try to shepherd their hearts.
By beating them as the first and only method of correction. "Shepherding their hearts" is a shibboleth for a particular form of violent, fear-based child rearing espoused by some christians. Cool videos though, for sure.
posted by Sternmeyer at 7:50 PM on April 22, 2014 [4 favorites]
By beating them as the first and only method of correction. "Shepherding their hearts" is a shibboleth for a particular form of violent, fear-based child rearing espoused by some christians. Cool videos though, for sure.
posted by Sternmeyer at 7:50 PM on April 22, 2014 [4 favorites]
As for the derail, and in particular one of the replies to my first comment:
I vaguely recall a (reddit?) comment by an author who claimed that he grew up without understanding that it was abnormal for him to be lacking in human empathy. So why would he seek help? He had learned young that you needed to fake empathy to get along in society, you see, and so he naturally assumed that everyone else was just putting on a mask too.
If your primary reaction to an expression of joy or curiosity or respect is really to try and figure out why it was being faked... well, you're still not in as bad a shape as the guy I'm remembering was, but you might also find it beneficial to correct an analogous misapprehension and see if there is an underlying cause that could be helped. I promise we're not all just wearing masks.
posted by roystgnr at 7:59 PM on April 22, 2014
I vaguely recall a (reddit?) comment by an author who claimed that he grew up without understanding that it was abnormal for him to be lacking in human empathy. So why would he seek help? He had learned young that you needed to fake empathy to get along in society, you see, and so he naturally assumed that everyone else was just putting on a mask too.
If your primary reaction to an expression of joy or curiosity or respect is really to try and figure out why it was being faked... well, you're still not in as bad a shape as the guy I'm remembering was, but you might also find it beneficial to correct an analogous misapprehension and see if there is an underlying cause that could be helped. I promise we're not all just wearing masks.
posted by roystgnr at 7:59 PM on April 22, 2014
No, the same thing would happen if it were a bubble of not so dense, incompressible liquid embedded in a dense, incompressible liquid--no gradient at all.
Density and pressure are different. Incompressible fluids can still have pressure gradients. Pressure is how a fluid exerts force locally, and that pressure gradient (= force gradient) is needed to explain the upward motion of a balloon or low-density bubble of other incompressible fluid (because otherwise, where locally is the upward force coming from?).
posted by Pyry at 8:02 PM on April 22, 2014 [1 favorite]
Density and pressure are different. Incompressible fluids can still have pressure gradients. Pressure is how a fluid exerts force locally, and that pressure gradient (= force gradient) is needed to explain the upward motion of a balloon or low-density bubble of other incompressible fluid (because otherwise, where locally is the upward force coming from?).
posted by Pyry at 8:02 PM on April 22, 2014 [1 favorite]
On the other hand, I'd never seen that book or heard the context for that phrase before. "Their kids say 'sir'" may not be damning, but "they seem to be quoting a book devoted to corporal punishment" is worrisome.
posted by roystgnr at 8:06 PM on April 22, 2014 [1 favorite]
posted by roystgnr at 8:06 PM on April 22, 2014 [1 favorite]
Incompressible fluids can still have pressure gradients.
Right, of course! Sorry, I'm not sure what I was thinking.
posted by jjwiseman at 8:12 PM on April 22, 2014
Right, of course! Sorry, I'm not sure what I was thinking.
posted by jjwiseman at 8:12 PM on April 22, 2014
It's air djinns what moved that ballooney, and none of your science jabber can account for it.
posted by Divine_Wino at 8:26 PM on April 22, 2014 [3 favorites]
posted by Divine_Wino at 8:26 PM on April 22, 2014 [3 favorites]
nzero: I'm from deep south Georgia man, everyone here says 'sir' too. Hell, I call everyone sir. And I'm telling you, this rubs me the wrong way.
ITYM "this rubs me the wrong way, sir."
posted by Greg_Ace at 8:49 PM on April 22, 2014 [1 favorite]
ITYM "this rubs me the wrong way, sir."
posted by Greg_Ace at 8:49 PM on April 22, 2014 [1 favorite]
I've heard that Pythagoras liked eating hasheesh.
But not beans. He wouldn't have liked it here; MeFites hanker after beans.
posted by homunculus at 8:54 PM on April 22, 2014 [1 favorite]
But not beans. He wouldn't have liked it here; MeFites hanker after beans.
posted by homunculus at 8:54 PM on April 22, 2014 [1 favorite]
You can also measure the rate of acceleration by the angle of the balloon or bob from the vertical. Acceleration is the tangent of the angle multiplied by g's -- 32 feet or 9.8 meters per second squared. If the angle were 45 degrees, the acceleration is exactly one g.
Just eyeballing, the angle is about 20 degrees, so about a third of a g, say 10 feet per second squared, which is about 7 mph after one second. Seems reasonable.
posted by JackFlash at 9:16 PM on April 22, 2014 [2 favorites]
Just eyeballing, the angle is about 20 degrees, so about a third of a g, say 10 feet per second squared, which is about 7 mph after one second. Seems reasonable.
posted by JackFlash at 9:16 PM on April 22, 2014 [2 favorites]
I have very conservative parents and got a sour little twitch in my stomach when the kids called him "sir," too. It's weird, because I generally appreciate polite children, so I tried to pick it apart in my head a little bit.
"Sir" is a sign of respect, sure. For a polite kid, it seems that grandfathers and teachers and most older guys should probably get a "sir," unless they say otherwise. And if your dad is telling you something Very Important about your Behavior, that warrants a "sir," too. But it seems a little intense when that's just the default response to your dad telling you something awesome about science.
Anyway, that balloon! Cool!
posted by redsparkler at 9:20 PM on April 22, 2014 [2 favorites]
"Sir" is a sign of respect, sure. For a polite kid, it seems that grandfathers and teachers and most older guys should probably get a "sir," unless they say otherwise. And if your dad is telling you something Very Important about your Behavior, that warrants a "sir," too. But it seems a little intense when that's just the default response to your dad telling you something awesome about science.
Anyway, that balloon! Cool!
posted by redsparkler at 9:20 PM on April 22, 2014 [2 favorites]
Its normal.
Maybe, but I'm not so sure about the robocams bolted to their temples and their lack of enthusiasm.
posted by rhizome at 9:26 PM on April 22, 2014 [1 favorite]
Maybe, but I'm not so sure about the robocams bolted to their temples and their lack of enthusiasm.
posted by rhizome at 9:26 PM on April 22, 2014 [1 favorite]
Did you stick around for the end, with the kids giggling at their dad's voice on helium? They didn't seem all that unenthusiastic to me.
posted by Greg_Ace at 9:53 PM on April 22, 2014
posted by Greg_Ace at 9:53 PM on April 22, 2014
My mother was a family psychologist when I was growing up and my father was a physicist. For this reason this thread is feelingly oddly homey to me.
posted by Tell Me No Lies at 10:09 PM on April 22, 2014 [5 favorites]
posted by Tell Me No Lies at 10:09 PM on April 22, 2014 [5 favorites]
Yeah... that tumblr response is tripping all kinds of alarms.
Engineers can do that to you.
posted by KokuRyu at 10:46 PM on April 22, 2014 [1 favorite]
Engineers can do that to you.
posted by KokuRyu at 10:46 PM on April 22, 2014 [1 favorite]
hey so did anyone notice that he calls his dad sir near the end of the video?
posted by 5_13_23_42_69_666 at 11:02 PM on April 22, 2014 [6 favorites]
posted by 5_13_23_42_69_666 at 11:02 PM on April 22, 2014 [6 favorites]
Well, all the dictionaries I've looked at say that "sir" derives from the Middle English "sire", which he certainly is to his kids: he sired them. So they're really not so much polite as pedantic.
posted by George_Spiggott at 12:04 AM on April 23, 2014 [1 favorite]
posted by George_Spiggott at 12:04 AM on April 23, 2014 [1 favorite]
Sandlin makes all these videos
It just occurred to me that having the same last name and my dad/grandparents being from northern Alabama means that I'm probably related to this guy. Like a distant cousin or something.
Just kind of a "whoa" moment for me.
posted by Fleebnork at 6:35 AM on April 23, 2014
It just occurred to me that having the same last name and my dad/grandparents being from northern Alabama means that I'm probably related to this guy. Like a distant cousin or something.
Just kind of a "whoa" moment for me.
posted by Fleebnork at 6:35 AM on April 23, 2014
Out of curiosity, where in North Alabama did you grow up? (Seeing as I'm from Decatur, and definitely knew some Sandlins growing up.)
posted by ocherdraco at 6:42 AM on April 23, 2014
posted by ocherdraco at 6:42 AM on April 23, 2014
I was born in Nashville. My dad was born in Alabama, but they moved to Ohio for a while when he was a kid and then ended up in Nashville.
I'm sure I have a lot of cousins in that part of the country. If you also knew some Sheltons, that would have been my grandmother's family.
posted by Fleebnork at 6:51 AM on April 23, 2014
I'm sure I have a lot of cousins in that part of the country. If you also knew some Sheltons, that would have been my grandmother's family.
posted by Fleebnork at 6:51 AM on April 23, 2014
Sandlin makes all these videos about interesting phenomena, and they're right up my alley, and on paper I would certainly enjoy them. But something about him personally has always repelled me. I wish I could say what it was. I guess deep down I'm sure he's about to tell me that Jesus wants me to join the military.
when you don't like someone or judge them based on something that you can't (or won't) identify specifically this is known as bias and it is usually frowned upon on metafilter when it applies to anyone who is maybe from a different culture than you...
just something to thing about.
posted by bartonlong at 1:57 PM on April 23, 2014 [1 favorite]
when you don't like someone or judge them based on something that you can't (or won't) identify specifically this is known as bias and it is usually frowned upon on metafilter when it applies to anyone who is maybe from a different culture than you...
just something to thing about.
posted by bartonlong at 1:57 PM on April 23, 2014 [1 favorite]
I grew up in New Jersey, but I like using Sir now as an adult. Especially in casual correspondence.
I see it as a post-modern ironic embellishment, but also as rather Nice.
posted by solipse at 4:35 PM on April 23, 2014
I see it as a post-modern ironic embellishment, but also as rather Nice.
posted by solipse at 4:35 PM on April 23, 2014
My dad had this tic where, in a particular context, he'd respond with a "yes, sir?" that was one-part friendly, one-part respectful, and one-part just slightly ironic. The context was when someone addressed him asking for his attention.
I picked that up from him.
So, for example, if a male someone I'm not already conversing with says from across the room, "Hey, Keith?", I will reflexively, unthinkingly respond with a "Yes, sir?"
This deeply unnerved my mom's husband the first time I did this with him (she married him long after I'd grown up). I had to explain it wasn't some formal, distancing respect thing, just an idiosyncrasy. I'm as likely to do it with someone younger, even a child.
That my dad didn't do the equivalent with women is probably meaningful and the inconsistency in me is regrettable. But I picked this up because I always liked that he did it — it's extremely relevant that he did it with me, even when I was a child. I like its subtext, that it's indiscriminately respectful, in a friendly way, a way that's not all about status and seniority. Which makes it very different than what we're discussing ... probably.
Because my mom's husband only knew to interpret my "Yes, sir" as people here are interpretating these.
Which proves nothing either way, obviously. I, too, find a lot of authoritarian-related manners within a family to be more disturbing than "admirable" — but we don't know if that's what we're seeing here. Even if it is, lots of people are authoritarian oriented about family life and think that's good.
posted by Ivan Fyodorovich at 7:20 PM on April 23, 2014
I picked that up from him.
So, for example, if a male someone I'm not already conversing with says from across the room, "Hey, Keith?", I will reflexively, unthinkingly respond with a "Yes, sir?"
This deeply unnerved my mom's husband the first time I did this with him (she married him long after I'd grown up). I had to explain it wasn't some formal, distancing respect thing, just an idiosyncrasy. I'm as likely to do it with someone younger, even a child.
That my dad didn't do the equivalent with women is probably meaningful and the inconsistency in me is regrettable. But I picked this up because I always liked that he did it — it's extremely relevant that he did it with me, even when I was a child. I like its subtext, that it's indiscriminately respectful, in a friendly way, a way that's not all about status and seniority. Which makes it very different than what we're discussing ... probably.
Because my mom's husband only knew to interpret my "Yes, sir" as people here are interpretating these.
Which proves nothing either way, obviously. I, too, find a lot of authoritarian-related manners within a family to be more disturbing than "admirable" — but we don't know if that's what we're seeing here. Even if it is, lots of people are authoritarian oriented about family life and think that's good.
posted by Ivan Fyodorovich at 7:20 PM on April 23, 2014
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posted by jwhite1979 at 1:30 PM on April 22, 2014 [1 favorite]