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Awesome HD Slinky Slow-Mo…Does Gravity Really Work Like We Think It Does?
Veritasium ^ | Sept 29, 2012 | Jim Caldwell

Posted on 10/04/2012 4:04:07 PM PDT by jwsea55

Watching this video, I have to ask, do we really understand gravity? When we release an object from our hands, it falls. Right? Not always? Or at least, not right away?

Veritasium has put some pretty cool videos to explain how science and physics work. They have been working with slinkies on a number of videos (and you thought your kid didn’t have any potential at 3 years old), this video seems to capture the essences of their work.

So listening to a couple of science guys explain this, does this give one a solid enough understanding why that darn bottom of the slinky doesn’t move? OK, I get the propagating communication of information thing, and that gravity has a constant force on the center of gravity but when I step back from all that, why doesn’t that slinky’s bottom move? Jim Caldwell


TOPICS: Arts/Photography; Miscellaneous; Science
KEYWORDS: gravity; physics; slinky
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Looked at this a few times. Still find it puzzling.
1 posted on 10/04/2012 4:04:14 PM PDT by jwsea55
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To: jwsea55

Fascinating. Thanks for posting that.


2 posted on 10/04/2012 4:12:34 PM PDT by .45 Long Colt
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To: .45 Long Colt
Thanks.
I just watched a couple of times. Even with an explanation, why doesn't the bottom move?
3 posted on 10/04/2012 4:15:35 PM PDT by jwsea55
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To: jwsea55

My computer has no sound and I do no read lips. I do not know the explanation the guy on the video provided.

The bottom doesn’t move because it is still attached to the rest of the slinky.


4 posted on 10/04/2012 4:24:31 PM PDT by SatinDoll (NATURAL BORN CITZEN: BORN IN THE USA OF CITIZEN PARENTS.)
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To: SatinDoll
My computer has no sound and I do no read lips. I do not know the explanation the guy on the video provided.

The bottom doesn’t move because it is still attached to the rest of the slinky.

Essentially, two science geeks yakking in physic's speak. The bottom doesn't move because of the slinky's tensioned coil. The tension has not allowed the "communication" of release from the top of slinky to transfer down to the bottom. Does that work?

5 posted on 10/04/2012 4:35:02 PM PDT by jwsea55
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To: jwsea55
Awesome is right! I was and still am, a mediocre math student; but I love physics. Wish I would have paid more attention in school.

The closest explanation that I could comprehend in the simplest way, was “external force” on the “center of mass”

6 posted on 10/04/2012 4:52:46 PM PDT by KittenClaws (You may have to fight a battle more than once in order to win it." - Margaret Thatcher)
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To: jwsea55

I’ll try my hypothesis...

The downward pull of the stored tension in the slinky plus gravity is exactly the same as the tension of the slinky thus counteracting the pull of gravity. Once the tension+gravity equalizes to the weight of the slinky alone, the slinky falls at the normal rate of 32 ft.per sec./per sec.

I hope that makes this clearer for you.

If not, well you can say I’m full of $hit.


7 posted on 10/04/2012 4:58:28 PM PDT by Randy Larsen (Damned if I do, Damned if I don't. Damn it, I will!)
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To: KittenClaws
It is very puzzling. Gravity's force is supposed to be acting on everything with equal force. So why doesn't the bottom move?
8 posted on 10/04/2012 5:01:09 PM PDT by jwsea55
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To: Randy Larsen

I agree. The lower part is being lifted by the collapsing force of the upper part. That is what causes the rotation at the bottom. It is being pulled into the compacted coil.

I had high school physics and I believe it was the most useful course I took in school that helped me in my adult life.


9 posted on 10/04/2012 5:03:41 PM PDT by rw4site (Little men want Big Government!)
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To: jwsea55

My take? A released spring contracts towards the center from both ends. The movement of the spring from the bottom up is being counteracted by the force of gravity down, and so stays stationary. Just a guess.


10 posted on 10/04/2012 5:07:51 PM PDT by Sergio (An object at rest cannot be stopped! - The Evil Midnight Bomber What Bombs at Midnight)
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To: rw4site; Randy Larsen
The lower part is being lifted by the collapsing force...

That's the funny thing. The bottom is going against gravity. All the energy is getting transferred to the compression and rotation.

11 posted on 10/04/2012 5:08:59 PM PDT by jwsea55
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To: jwsea55

Slo-Mo is right, I waited 5 minutes for the video to start......and it never did.


12 posted on 10/04/2012 5:11:08 PM PDT by Hot Tabasco (')
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To: jwsea55

All the energy [one would think is being exerted on the bottom] is getting transferred to the compression and rotation.


13 posted on 10/04/2012 5:11:43 PM PDT by jwsea55
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To: jwsea55
It is very puzzling. Gravity's force is supposed to be acting on everything with equal force. So why doesn't the bottom move?

It IS acting on everything with equal force. But the bottom of the slinky is actually the end of a spring that is compressing while it is being dropped. So the bottom is coming up at the same rate it is dropping, which makes it seem that it isn't moving at all because the forces are being cancelled out - until the top of the spring "catches up" with it, finishes the compression, and the whole thing drops.

The MORONS who made this video spouting off about "gravity messages not reaching the bottom of the spring" are either too stupid to live, or are educational disinformation agents.

Consider - the speed of gravity is FASTER than the speed of light. And this is easily proven. It takes light over eight minutes to reach the earth from the sun, yet the earth follows an exactly curving eliptic gravitational path of constant adjustments every micro-second to follow that ellipse, rather than simply go flying off into space.

So the sun "communicates" it's gravity to earth that fast, but gravity can't manage to "communicate" to the bottom of a slinky?

Like I said, too stupid to live.

14 posted on 10/04/2012 5:13:50 PM PDT by Talisker (One who commands, must obey.)
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To: jwsea55
It is very puzzling. Gravity's force is supposed to be acting on everything with equal force. So why doesn't the bottom move?

I can't remember the time it took in (split) seconds for the top of the slinky to make its way to the bottom without watching the video again, but that seems to be the key.

Slo-mo plays with our minds a bit. The bottom does move, but not until the top reaches a "critical mass" point. The bottom is connected to the top, after all.

The slinky is a whole object, but its mass is "spread out" by design, the physicists discuss this - the same thing happens with a "solid" object (say, a lead bar), just quicker.

Like I said, my math skills are mediocre.

15 posted on 10/04/2012 5:15:38 PM PDT by KittenClaws (You may have to fight a battle more than once in order to win it." - Margaret Thatcher)
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To: Hot Tabasco
Slo-Mo is right, I waited 5 minutes for the video to start......and it never did.

Not sure, I just loaded the page again and played it. No problem. Maybe cached on my machine.

16 posted on 10/04/2012 5:16:57 PM PDT by jwsea55
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To: Randy Larsen

I’ll try my hypothesis...

The downward pull of the stored tension in the slinky plus gravity is exactly the same as the tension of the slinky thus counteracting the pull of gravity. Once the tension+gravity equalizes to the weight of the slinky alone, the slinky falls at the normal rate of 32 ft.per sec./per sec.

I hope that makes this clearer for you.

If not, well you can say I’m full of $hit.

_______________________________________

Thanks, that helped me out a bit.


17 posted on 10/04/2012 5:17:33 PM PDT by KittenClaws (You may have to fight a battle more than once in order to win it." - Margaret Thatcher)
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To: jwsea55
Think of it this way. The bottom has already fallen.
The constant force of gravity can only tension the slinky so much. Since it has already “fallen” as far as it can with gravity there is the opposite tension already loaded in the slinky. Let go of the top and the gravity and tension (being equal) have to catch up to eachother before the bottom will fall.

If you were to stretch the slinky longer than plain gravitational forces the bottom would actually rise before falling because the tension is more than gravity. If you compress the slinky all the way and drop it the whole thing will fall at once.

18 posted on 10/04/2012 5:22:20 PM PDT by Organic Panic
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To: KittenClaws

The red dot on the moving chart is supposed to represent where the center of mass is moving. The blue on the spring represents the compressed part.


19 posted on 10/04/2012 5:24:08 PM PDT by jwsea55
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To: jwsea55

Pretty cool. Definitely gets you to think about the various forces, stored energy, etc. in play, and how they interact with one another as the center of mass of the object falls.


20 posted on 10/04/2012 5:27:56 PM PDT by MCH
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To: jwsea55

Looks like the folks at Looney Toons understood gravity, with some help from Wylie Coyote.


21 posted on 10/04/2012 5:28:19 PM PDT by rabidralph
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To: Talisker

It would seem that the easiest way to envision this is to realize that the entire Slinky has not been released all at once. That is, the top has been released but the tension in the Slinky continues to hold the bottom up as though the bottom was never released at all. This occurs UNTIL the Slinky contracts enough that there is inadequate tension to hold the bottom up any longer. Then the whole thing falls.


22 posted on 10/04/2012 5:29:13 PM PDT by johniegrad
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To: KittenClaws

Just dang!

I wanted to brag about spelling HYPOTHESIS correctly.

Glad I could help though.


23 posted on 10/04/2012 5:29:24 PM PDT by Randy Larsen (Damned if I do, Damned if I don't. Damn it, I will!)
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To: Talisker

I like your answer; LOL


24 posted on 10/04/2012 5:31:44 PM PDT by Dust in the Wind (U S Troops Rock)
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To: jwsea55
The red dot on the moving chart is supposed to represent where the center of mass is moving. The blue on the spring represents the compressed part.
______________________________________________

I watched it again and you're right. But, the blue and the red dot meet the end at (seemingly) the same moment.

25 posted on 10/04/2012 5:32:12 PM PDT by KittenClaws (You may have to fight a battle more than once in order to win it." - Margaret Thatcher)
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To: Organic Panic
Interesting!!! Thanks.

It is amazing how the energy stored in a tensioned coil changes things. But that "damn bottom" still doesn't move. Ha Ha.

26 posted on 10/04/2012 5:32:42 PM PDT by jwsea55
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To: Randy Larsen

Just dang!

I wanted to brag about spelling HYPOTHESIS correctly.

Glad I could help though.

__________________________________

LOL! You’re beyond me - I had to spell check “slinky”.


27 posted on 10/04/2012 5:34:10 PM PDT by KittenClaws (You may have to fight a battle more than once in order to win it." - Margaret Thatcher)
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To: Talisker

Pretty much agree. These guys may have too much education.


28 posted on 10/04/2012 5:37:38 PM PDT by jwsea55
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To: Talisker

Thanks for your post.... Very interesting

Of course now I will be up the night... Thinking about it....

I never considered that gravity moved faster than light....


29 posted on 10/04/2012 5:37:44 PM PDT by Popman (In a place you only dream of Where your soul is always free)
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To: Popman
See post 18, too.
You have to love Freerepublic. I figured we would get some people who could put this in plain English.
30 posted on 10/04/2012 5:42:57 PM PDT by jwsea55
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To: Popman

I never considered that gravity moved faster than light....

So human eyes and the lens of a camera see light but gravity is faster.....that can only mean that every fumble, TD and infraction in the NFL is wrong upon review! /s


31 posted on 10/04/2012 6:00:53 PM PDT by JouleZ (You are the company you keep.)
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To: JouleZ

LOL....

I should have been more technically correct...the force of gravity is faster than light....

I’m still trying to wrap my head around that idea....


32 posted on 10/04/2012 6:05:18 PM PDT by Popman (In a place you only dream of Where your soul is always free)
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To: jwsea55

Like I read on this website one time...”Liberals are like slinkies, they don’t do much, but it’s fun to watch them get pushed a flight of stairs.”


33 posted on 10/04/2012 6:10:51 PM PDT by drinktheobamakoolaid (How do you replace an empty suit? Vote on November 6, 2012)
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To: jwsea55

Yeah, but that seems to be what I said.

If the slinky, instead of being a plastic coil was a solid-walled plastic cylinder, the bottom would move at the same time as the top.


34 posted on 10/04/2012 6:20:41 PM PDT by SatinDoll (NATURAL BORN CITZEN: BORN IN THE USA OF CITIZEN PARENTS.)
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To: Organic Panic; Randy Larsen; jwsea55
Tension / gravity / center of mass / clear solutions versus some ersatz geek with a video camera.

That's all pretty clear.

What it leaves me wondering at is the simple genius behind the Slinky itself.

(Which, by the way, worked way better in the original steel version..I just couldn't avoid buying one of the current plastic [!] imitations.)

35 posted on 10/04/2012 6:29:54 PM PDT by norton
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To: jwsea55; Slings and Arrows

Neat stuff!


36 posted on 10/04/2012 6:37:05 PM PDT by Jet Jaguar (The pundits have forgotten the 2010 elections.)
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To: jwsea55
It's fairly simple, though quite interesting.

The slinky starts out under tension, like an extended spring. The top is being pulled down toward the center and the bottom is being pulled up toward the center.
To give the slinky its other interesting properties, the spring-rate has been matched to gravitational forces.
As a result, the bottom is pulled up by the tension in the 'spring' with about the same force as the gravitational effect, so it barely moves, and that is true elsewhere in the slinky, until the coil above it has collapsed.
At the start, the second coil is pulled up by the pull from the top coil, but the top coil is pulled down by both the tension and gravitation, and falls. As it falls, the next coil down loses the pull from the top coil and starts to fall under gravity no longer balanced by the upward pull from the top coil, and so on down the slinky.
If the spring constant of the slinky were higher (or the weight of the coils lower), the bottom coil would start to rise instead of staying put -- but it wouldn't be a slinky, able to do those weird tricks, then.

37 posted on 10/04/2012 6:41:06 PM PDT by expat2
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To: norton
What it leaves me wondering at is the simple genius behind the Slinky itself.

Perfect add!

If I can I will find the story on that and post. For some reason I am thinking it was sort of interesting...but it has been decades since I heard it.

38 posted on 10/04/2012 8:30:07 PM PDT by jwsea55
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To: expat2
expat2 said: "The slinky starts out under tension, like an extended spring. "

Well, sort of ...

First, an anecdote from my college days while taking elementary physics.

I was fortunate enough to have "tutors" in the form of mechanical engineers while I was working and attending college. Almost every day included a science lesson of some sort.

As an interesting project, I was encouraged to create a device which consisted of a single spring, similar to the slinky and a cylindrical mass attached to the bottom of the spring with the top of the spring attached to a rigid support.

The spring constants, the weight of the cylindrical mass and the moment of inertia about its axis were chosen to accomplish a system of two linked oscillators.

One oscillator stored energy alternately in the extension or compression of the spring and in the vertical motion of the mass. In an idealized spring-mass system, the spring constant and the weight allow one to calculate the frequency of oscillation.

The "twist" in this project was to select the mass such that the torsional spring constant and the moment of inertia of the mass about its vertical axis would form a torsional spring-mass system. In this system, the energy would alternately be stored in the twisting of the spring and in the angular momentum of the mass as it rotated about its vertical axis.

By a suitable choice of diameter for the cylindrical mass, it was possible to create a system of two linked oscillators, the natural frequencies of which differed by a small amount.

The result could be observed by pulling the mass downward and releasing it to impart the initial energy to the system. After several vertical oscillations, the magnitude of the vertical motion would decrease, eventually reaching zero. During the decrease in magnitude of the vertical oscillations, the spring was delivering energy into the torsional spring-mass system. The mass would begin rotating first one way about the vertical axis and then reverse to the opposite direction.

The secret to the effect was the fact that a helical spring must "unwind" a little bit as it is stretched. Each coil, being further from its neighbors when the spring is stretched, must cover a greater distance. The stretching of the spring creates a twisting force. This force is reversed when the spring is unstretched. Each stretching of the spring in the spring-mass system I described transfers a bit of the energy which was in the vertically translating mass into rotation of the mass about the vertical axis.

The above description explains why we see the twisting of the slinky in the video as the compression of the slinky changes.

The other key observation I would make concerns the fact that the slinky has no "mass" attached to the bottom of it. In a classical spring-mass system, the spring is typically mass-less. The spring-constant describes the extension or compression of the mass-less spring when acted upon by an external force, typically a mass acting under the effects of gravity.

In the slinky video, the spring is not mass-less. The extension of the slinky is entirely due to ITS OWN mass. The result is that the upper coils of the slinky are far apart due to the fact that these coils are supporting the entire slinky. To a first-approximation, the coils at the center of the slinky should be half as far apart, since those coils are supporting only the half of the slinky that hangs below them. The coils at the bottom are supporting hardly any mass at all.

Suspending the slinky as it is in the video results in a non-uniform extension of the spring, with the extension starting at zero at the bottom of the slinky and rising linearly to a value at the top which can be predicted by knowing the spring constant of the slinky.

Now imagine for a moment that we could somehow take this slinky, in its non-uniformly extended state, and place it in a space without a gravitational field. Recall that the extension of the spring at the top was exactly that which was needed to counteract the affect of gravity on the bottom of the spring. Without the gravitational field, that spring force would be that which would accelerate the bottom of the spring at 32 feet per second per second toward the center of mass of the spring.

The top of the spring would accelerate toward the center of mass of the spring at a greater rate, that which would result in the center of mass remaining still, since the spring is not being acted upon externally.

When the slinky is released as in the video, the bottom of the spring is accelerating toward the center of mass of the spring at 32 feet per second per second. At the same time, the center of mass of the spring is accelerating toward the center of the earth at 32 feet per second per second. The two accelerations cancel exactly at the bottom of the spring, causing the bottom to be motionless in the non-accelerating frame of reference which is the earth. The bottom of the spring IS accelerating in the frame of reference of the moving center of mass of the slinky.

39 posted on 10/04/2012 8:30:48 PM PDT by William Tell
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To: SatinDoll
If the slinky, instead of being a plastic coil was a solid-walled plastic cylinder, the bottom would move at the same time as the top.

This has to be God's sense of humor.

40 posted on 10/04/2012 8:33:59 PM PDT by jwsea55
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To: Jet Jaguar

Thanks


41 posted on 10/04/2012 8:35:05 PM PDT by jwsea55
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To: expat2
At the start, the second coil is pulled up by the pull from the top coil, but the top coil is pulled down by both the tension and gravitation, and falls. As it falls, the next coil down loses the pull from the top coil and starts to fall under gravity no longer balanced by the upward pull from the top coil, and so on down the slinky. If the spring constant of the slinky were higher (or the weight of the coils lower), the bottom coil would start to rise instead of staying put -- but it wouldn't be a slinky, able to do those weird tricks, then.

If you had different tensions/thickness of steel at the oppsite ends of the slinky, I wonder if that would produce humorous results upon release?

42 posted on 10/04/2012 8:42:12 PM PDT by jwsea55
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To: William Tell
Cool! Thanks for the adding to this! A lot going on in this 'simple' little experiment.

I do have a question on the The extension of the slinky is entirely due to ITS OWN mass.

Is this still a correct statement when you lay the slinky on its side (Xing out old slinkies will want to flop on their ends)?

Thanks again for the great post.

43 posted on 10/04/2012 8:59:27 PM PDT by jwsea55
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To: Hot Tabasco

44 posted on 10/04/2012 9:15:03 PM PDT by Daffynition (Self-respect: the secure feeling that no one, as yet, is suspicious. ~ HLM)
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To: SatinDoll; Jet Jaguar; expat2; William Tell; norton; Organic Panic; Randy Larsen; Popman; ...
Thanks for all the contributions to the slinky.

I thought there was an interesting story behind the slinky...It is. The story is fitting of the slinky itself.

In 1943, Richard James was a naval engineer trying to develop a meter designed to monitor horsepower on naval battleships. Richard was working with tension springs when one of the springs fell to the ground. He saw how the spring kept moving after it hit the ground and an idea for a toy was born.

Traespiral
Richard James told his wife Betty, "I think I can make a toy out of this" and then spent the next two years figuring out the best steel gauge and coil to use for the toy. Betty James found a name for the new toy after discovering in the dictionary that the word "Slinky" is a Swedish word meaning traespiral - sleek or sinuous.

Slinky debuted at Gimbel's Department Store in Philadelphia, Pennsylvania during the 1945 Christmas season and then at the 1946 American Toy Fair. Richard nervous at the first demonstration of his toy convinced a friend to attend and buy the first Slinky. However, this turned out to be unnecessary as 400 were sold during the 90 minute Gimbel demonstration.

James Spring & Wire Company
Richard James and Betty James founded James Spring & Wire Company (renamed James Industries) with $500 dollars and began production. Today, all Slinkys are made in Hollidaysburg, Pennsylvania using the original equipment designed and engineered by Richard James. Each one is made from 80 feet of wire and over a quarter billion Slinkys have been sold worldwide.

Richard James - Cult Involvement
Around 1960, Richard James suffered from a mid-life crisis and left his wife, six children, and the Slinky Empire to join a Bolivian religious order/cult. Betty James took over as CEO of James Industries and rescued the company from the debts left by her husband's generosity to his religion. She moved the company to its current Hollidaysburg location from Philadelphia and began an active advertising campaign complete with the famous Slinky jingle. Richard James died in 1974.

Betty James Continues
Betty James also replaced the original material of blue-black Swedish steel with silver colored American metal. She added other toys to the line: Slinky Jr., Plastic Slinky, Slinky Dog, Slinky Pets, Crazy Eyes (glasses with Slinky-extended fake eyeballs) and Neon Slinky. The line was sold in 1998 to Poof Toys. Betty James was inducted into the Toy Industry Hall of Fame in 2001.

http://inventors.about.com/od/sstartinventions/a/slinky.htm

45 posted on 10/04/2012 9:39:00 PM PDT by jwsea55
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To: .45 Long Colt

I forgot to add you to post 45. History of the slinky...fitting of the slinky. Checkout some of the post above that. Descriptions on how that thing works.


46 posted on 10/04/2012 9:52:57 PM PDT by jwsea55
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To: expat2; William Tell; jwsea55
The math of it is a thing a beauty. :)

W. G. Unruh's succinct paper on the matter here.

When a Slinky is dropped, the bottom of the Slinky remains motionless as the top collapses towards it, making it appear to the observer as though the Slinky is levitating. By considering the Slinky as a tightly wound, pretensioned spring, the static equilibrium of a hanging Slinky was solved for using Hooke's law (Equation 1). This result was used to measure the spring constant of an actual metal Slinky. The motion of the Slinky after it is released at time t=0 was then solved for to derive an expression for the time over which the bottom of the Slinky remains motionless and the Slinky appears to levitate (Equation 7). This expression gave a value of t = 0.29 ± 0.05 seconds for the Slinky used in the experiments, which matches up very well with the experimentally measured value of t = 0.4 ± 0.1 seconds

47 posted on 10/04/2012 9:56:53 PM PDT by Daffynition (Self-respect: the secure feeling that no one, as yet, is suspicious. ~ HLM)
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To: jwsea55
jwsea55 said: "Is this still a correct statement when you lay the slinky on its side (Xing out old slinkies will want to flop on their ends)? "

All of the examples I talked about pretty much presume that the axis of the slinky, which is vertical when the slinky is suspended in the video, remains vertical and straight at all times. A real slinky gets its extension/compression spring constant and its torsional spring constant from the nature of the material making up the coils.

Bending the slinky so that its axis is not a straight line, which is what I think you are suggesting, would be a demonstration of a degree of freedom which is not taken into account whatever in my description. Such bending introduces additional ways in which the slinky can interact with a gravitational field or store energy by changing shape.

If you lay the slinky on its side on a horizontal surface such that the axis is straight, and ignoring friction with the surface, the slinky should seek out its neutral position of minimal energy. For a real slinky, this may in fact be where the sides of adjacent coils are touching. There would be no freedom to compress the slinky any further, barring deformation of the coils.

Without friction with the surface, the slinky would exhibit a spring constant describing the amount of force required to separate the coils a particular distance, the distance being proportional to the force.

Sitting on its side, the slinky, though nominally of circular shaped coils, would undergo a very slight deviation from that circular shape due to gravity, similar to the non-uniform extension that I previously described.

Each circular coil of the slinky is supported at a point on the bottom of the coil. This section of each coil supports the entire coil. The parts of the coil halfway from the point of contact to the upper edge of the coil will be supporting only the upper half of the coil. Each coil will then VERY SLIGHTLY (due to the stiffness of the coil) change shape to reflect the load on it. To a first approximation, the circular coil will become slightly oval due to this loading. I think the curvature at the bottom of the coil will be less than the curvature at the top but of this I'm not certain.

Did I understand your question?

48 posted on 10/04/2012 10:19:15 PM PDT by William Tell
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To: Daffynition
Thanks! Amazing what people will get away with for research. "I need $20,000 to investigate the traespiral relationship between coiled steel and the potential energy under unique tensional relationships influenced under exogenous events."

It has been a few years away from this type of stuff (in a totally different area using math). The most important thing one can remember when going through grad school, "You CAN'T divide by ZERO!"

49 posted on 10/04/2012 10:22:34 PM PDT by jwsea55
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To: William Tell
Thanks for the clarification. I was thinking that was what you meant but there just wasn't the reference to the necessity 'verticality'.

Sounds like you could teach half a year's physics class on thing. It really is one amazing device for storing and releasing energy.

I am sure I am not the only one who appreciates your time and thoughts! This has been a very entertaining and informative thread.

50 posted on 10/04/2012 10:35:37 PM PDT by jwsea55
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