G-Shock Bending Gravity? Or is it just an illusion?

# Thread: G-Shock Bending Gravity? Or is it just an illusion?

1. ## G-Shock Bending Gravity? Or is it just an illusion?

So I was finding a place on my desk to put my Rangeman when not using or when doing work (sometimes hurts my wrists when typing or writing). Well I found this position that seems impossible/scary yet it seems to be stable. Btw that was this ikea shelf that is bolted to the wall on top of my table.

*sorry but it appears hay my ipad can only uplaod images sideways, dunno why, guess you'll have to look at it sideways...
Does anybody have an explanation for this? Should I keep on doing this or are there other alternatives. If you don't think it looks dangerous, try it with your watch or g on some surface like this (coffee table?). It could make a good way to store and display wtches. Any physicists around? Do you guys know why?

2. ## Re: G-Shock Bending Gravity? Or is it just an illusion?

What exactly is the question? "Should you keep doing this?" or "How is a G-Shock able to hang off the shelf like that?"

Your watch is able to stay on the shelf like that because of simple physics: the "center of mass" of the watch and strap is located in empty space, in the middle of the letter "C" shaped by the watch and strap:

As Wikipedia puts it, "The center of mass may be located outside the physical body, as is sometimes the case for hollow or open-shaped objects, such as a horseshoe." https://en.wikipedia.org/wiki/Center...ter_of_gravity

Or, as this website puts it, "The center of mass of a solid body does not have to lie within the body. The center of mass of a hula-hoop is at its center where there is no hoop, just hula." http://faculty.wwu.edu/vawter/PhysicsNet/Topics/Momentum/TheCenterOfMass.html

While gravity is pulling down on the entire C-shaped watch, we only need to focus on the center of mass, and where it is in relation to the edge of the shelf:

As long as the center of mass is underneath the shelf, the watch will remain on the shelf.

If the center of mass is in front of the shelf, the watch will fall off.

That's the simplified version of what's happening, as if we were doing the same thing with an unbending C-shaped object, like a steel horseshoe. If we were rocket scientists at NASA, we might be able to calculate the other small forces at work with the G-Shock, including the flex of the resin watch strap and the friction of the strap against the shelf IF the center of mass was just barely in front of the edge of the shelf.

If you keep "storing" your watch like that, the resin strap may eventually bend SLIGHTLY, which shouldn't be a problem unless that changes the "center of mass" to a point just in front of the shelf, at which point your watch would fall off. But since it's a G-Shock, it should be able to survive falling a few feet from a shelf indoors.

3. ## Re: G-Shock Bending Gravity? Or is it just an illusion?

Is this thread just an illusion?

Am I awake...

4.

5. ## Re: G-Shock Bending Gravity? Or is it just an illusion?

Originally Posted by Mike K
What exactly is the question? "Should you keep doing this?" or "How is a G-Shock able to hang off the shelf like that?"

Your watch is able to stay on the shelf like that because of simple physics: the "center of mass" of the watch and strap is located in empty space, in the middle of the letter "C" shaped by the watch and strap:

As Wikipedia puts it, "The center of mass may be located outside the physical body, as is sometimes the case for hollow or open-shaped objects, such as a horseshoe." https://en.wikipedia.org/wiki/Center...ter_of_gravity

Or, as this website puts it, "The center of mass of a solid body does not have to lie within the body. The center of mass of a hula-hoop is at its center where there is no hoop, just hula." http://faculty.wwu.edu/vawter/PhysicsNet/Topics/Momentum/TheCenterOfMass.html

While gravity is pulling down on the entire C-shaped watch, we only need to focus on the center of mass, and where it is in relation to the edge of the shelf:

As long as the center of mass is underneath the shelf, the watch will remain on the shelf.

If the center of mass is in front of the shelf, the watch will fall off.

That's the simplified version of what's happening, as if we were doing the same thing with an unbending C-shaped object, like a steel horseshoe. If we were rocket scientists at NASA, we might be able to calculate the other small forces at work with the G-Shock, including the flex of the resin watch strap and the friction of the strap against the shelf IF the center of mass was just barely in front of the edge of the shelf.

If you keep "storing" your watch like that, the resin strap may eventually bend SLIGHTLY, which shouldn't be a problem unless that changes the "center of mass" to a point just in front of the shelf, at which point your watch would fall off. But since it's a G-Shock, it should be able to survive falling a few feet from a shelf indoors.

Just wondering though, is it possible you have too much time on your hands? (as many of us sometimes do?!)

6. ## Re: G-Shock Bending Gravity? Or is it just an illusion?

Originally Posted by idkfa
Is this thread just an illusion?

Am I awake...
How Can Mirrors Be Real If Our Eyes Aren't Real

7. ## Re: G-Shock Bending Gravity? Or is it just an illusion?

Originally Posted by Time4Playnow

Just wondering though, is it possible you have too much time on your hands? (as many of us sometimes do?!)
Thanks to "File => Save As" and "Undo" I could knock out all four of those drawings pretty quickly. (I didn't spend very much time thinking up file names, either. )

8. ## Re: G-Shock Bending Gravity? Or is it just an illusion?

How sticky is your shelf? :D

9. ## Re: G-Shock Bending Gravity? Or is it just an illusion?

Originally Posted by d2mac
How sticky is your shelf? :D
what are you implying?

are you suggesting that perhaps that shelf is where he sets his laptop at 'anxious' times?

10. ## Re: G-Shock Bending Gravity? Or is it just an illusion?

Originally Posted by Mike K
What exactly is the question? "Should you keep doing this?" or "How is a G-Shock able to hang off the shelf like that?"

Your watch is able to stay on the shelf like that because of simple physics: the "center of mass" of the watch and strap is located in empty space, in the middle of the letter "C" shaped by the watch and strap:

As Wikipedia puts it, "The center of mass may be located outside the physical body, as is sometimes the case for hollow or open-shaped objects, such as a horseshoe." https://en.wikipedia.org/wiki/Center...ter_of_gravity

Or, as this website puts it, "The center of mass of a solid body does not have to lie within the body. The center of mass of a hula-hoop is at its center where there is no hoop, just hula." http://faculty.wwu.edu/vawter/PhysicsNet/Topics/Momentum/TheCenterOfMass.html

While gravity is pulling down on the entire C-shaped watch, we only need to focus on the center of mass, and where it is in relation to the edge of the shelf:

As long as the center of mass is underneath the shelf, the watch will remain on the shelf.

If the center of mass is in front of the shelf, the watch will fall off.

That's the simplified version of what's happening, as if we were doing the same thing with an unbending C-shaped object, like a steel horseshoe. If we were rocket scientists at NASA, we might be able to calculate the other small forces at work with the G-Shock, including the flex of the resin watch strap and the friction of the strap against the shelf IF the center of mass was just barely in front of the edge of the shelf.

If you keep "storing" your watch like that, the resin strap may eventually bend SLIGHTLY, which shouldn't be a problem unless that changes the "center of mass" to a point just in front of the shelf, at which point your watch would fall off. But since it's a G-Shock, it should be able to survive falling a few feet from a shelf indoors.
Thanks! I guess one reason that it seemed weird was cause I didn't think the strap would be that heavy. One correction you could make: a top down diagram would be better cause the current one seems like the watch is placed flat on a table. The whole "effect" also has a lot to do with the centre of mass on a 3 dimensional world, basically meaning that the lower the centre of mass is, the more stable it would be (how those birdy toys work). Note that the whole bird is leaning downwards.

Another important factor is that the downward weight of the watch isn't enough to cause the watch to move horizontally across a level plane. This is why high jump athletes cannot convert 100% of their run energy into kinetic upwards energy. The lowered centre of gravity also causes those same athletes to potentially jump higher with the "Fosbury Flop", the centre of gravity is significantly lower than the high jump pole itself.

Let's get back to the birds, the lowered centre of gravity actually allows the bird to stay on the supporting point even when the centre of mass/gravity is not exactly on the support point.
(C is Centre of mass, P is the point of contact with the finger.)
This means that even if the centre of mass is outside of the whole support polygon, as long as it is below it, it should be stable and not fall. That's are what I think at least...

11. ## Re: G-Shock Bending Gravity? Or is it just an illusion?

I just tried this and I noticed that the groove in the band greatly helps to keep the watch from slipping as well.

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