What is the root cause of Inertia?

Re: What is the root cause of Inertia?


I'm not so sure we know this.. We DO know that a body in motion will remain in motion but only so long as there is no outside force acting upon it. Those outside forces though, are what causes resistance to both motion and acceleration. If there is no outside force then there is no resistance.

(Unless you are using the word resistance here to not mean resistance as in friction but as in "change"... but I think "change" would take you back to statement #1.. i.e. resisted by mass.. Or I'm just reading the whole statement wrong! lol)

Some not so simple answers to your question

If these folks can't settle on an answer, I doubt that this forum's going to resolve anything...

rosborne,

I was just viewing one of the links

http://casa.colorado.edu/~ajsh/schwp.html

you provided me with and something occurred to me. I am not sure how relative (no pun intended) it is but I wanted to get it down on paper so it could be picked at or discarded.

Looking at the Schwarzschild geometry demonstrated in the illustrated embedding diagram I noticed that one could interpret the lines depicting space warpage of a black hole caused by its mass in another light.

I'll try to verbally describe want I mean but viewing the picture is helpful. If one draws a vertical line down the center of the diagram thereby bisecting the singularity (call it line A) and then draws a line tangent to inside of the curve describing space warpage (line B) the magnitude of the angle formed at the intersection of A and B (with respect to the vertical) is inversely proportional to the gravity/space warpage of the mass at the center of the diagram. Given that a more massive body warps space more and a more massive body has more inertia, could these two observations be brought together to explain inertia? Am I back to Mach's principle maybe?

Looking at the diagram this relationship seems to break down at the black hole's horizon and looks like it actually reverses itself. I wonder if this is just due to the drawing or, perhaps, some fundamental property of the singularity itself, but then a lot of things go out the window once the horizon is breached!

JM

P.S. I tried to cut and paste the diagram into this body of text but was unsuccessful. Any body have any suggestions on how to do this if possible?

Hi Fishin',

By resistance, I meant resistance to change (inertia)

Hi Patio,

Thanks for the links. I have done a fair amout of research into this already, and I knew is probably couldn't be "answered" here, but it's a fun question to explore anyway. Inertia is a very well known thing, which can be experienced directly in every day life, but it's one of those basic things which science doesn't really understand yet also.

Hi James,

Thanks for trying. I think your observation just confirms that the more massive a body is, the greater it warps space. But I don't think this links into the relation of Inertia to the warp.

My idea was to infer that the symetry of the warp (or rather the asymetry) was the cause of Inertia due to the tendency of space to warp symetrically. The same way a bubble wants to be a sphere and not a pyramid (conservation of energy).

I think there is some type of conservation law which compels gravitational fields to by symetric rather than distorted. And I think it's this *unidentified* conservation law which is at the heart of Inertia.

In previous abuzz discussions, Satt mentioned "conservation of time", which I thought was an interesting thought. In our world, we think of conservation of energy, but maybe in the larger world of quantum and GR physics, there is a Conservation of something else... maybe time, or spacial dimensions or something... ???

Just thinking. :-)

Zero Point Force
The following is from the link provided by Patidog (Thanks). It talks about ZPF (Zero Point Force) and tries to relate it to Inertia by an asymtric distortion of the ZPF. It is essentially, the same argument I'm using for Inertia, except that they are talking about distortion of ZPF while I'm talking about distortion of a gravitational field. Interesting.

"We have found that when an object is forced to accelerate, it will see the ZPF to be asymmetric, or in other words, distorted. Due to this distortion the accelerating object will see a zero-point flux of energy and momentum coming at it, whereas ordinarily, when the object is not being accelerated, the ZPF is perfectly uniform and symmetric. A key result of our analysis is that these fluxes prove to be proportional to the acceleration of the object, i.e. the more rapid the acceleration, the more the ZPF is distorted. Material objects consist of charged quarks and electrons, which will tend to scatter any oncoming electromagnetic flux. When all the quarks and electrons in an object scatter the distorted ZPF passing through, the object will experience a kind of drag force. We are proposing that this might be what the inertia reaction force really is... the drag force due to being accelerated through the vacuum fields. In this view, objects would not intrinsically resist being accelerated; objects would not possess mass. Mass would really be just a way of characterizing the resistance due to the ZPF molasses (or in the future more general case, the quantum vacuum molasses) that kicks in upon acceleration. Of course the limitation that we are only, so far, considering the electromagnetic ZPF means that what we have found may be only a part of the story. The electromagnetic ZPF may contribute to inertia but still not account for all the mass."

http://www.calphysics.org/questions.html

Well, it's mostly cause you get settled into that couch and once you have a beer and some nuts or chips you don't feel like mowing the damn lawn anymore. Hell, the kids have been playing with your goggles and earmuffs, there's probably not enough gas in the mower and is the grass really that high? And like, it looks like rain too. Get us another coldie could ya huns? Do we have any of that dip left over?.....

"Whaddya mean? I can get off my fat ass and get it myself??"

I don't think that this is a logical conclusion.

Inertia is a resistance to force, not a resistance to gravity.

Under Newton gravity is treated as a force. Under Relativity gravity is not a "force" and technically the inertia of an object does not come into play. Of course in most situations Newton and Relativistic solutions come up with the exact same answer.

Of course, under relativity forces (that are not gravity) can cause an acceleration . The mass of the object still provides "inertia" that resists this acceleartion, which does not have to do with any curvature of space.

The curvature of space is a property of mass. Under relativity this curvature is used to explain gravity. I don't know what you mean by "asymetric" curvature.

Inertia is a property of mass. The curvature of space is a property of mass. There is no reason that I know to say that one is the curvature of space is a cause of inertia.

Maybe I don't understand what you are getting at. Can you give a physical example?

Let's say I am in space (outside of any signifcant gravity) and put a force on a small rock. The rock will accelerate, but not as much as a smaller rock would. How do you see the curvature of space is related to the inertia of the rock that resists my push in this case?

Ambivalence . . .

Hi EBrown, thanks for stopping by... first, a quick note. Even though Inertia is a common attribute of matter, there is currently no exact definition in physics for what causes Inertia (lots of links in Google which describe this).



Yes, let me try to give you a visual on what I'm getting at here.

Picture an object floating in space, and image the shape of the gravitational dimple surrounding it. Use theoretically "perfect" objects and conditions for the sake of this argument.

I see the gravitational dimple as analogous to a soap bubble which forms the most energy efficient shape it can. In the case of the soap bubble it's a sphere because that's the most efficient shape in three dimensions. It doesn't have any bumps or corners, and most importantly, it's symetrical in spacial geometry.

Now, back to the object with the gravitational dimple. Do you agree that this gravitational dimple is "symetrical" in an analogous way to the soap bubble (no corners or bulges)?

But what happens to the dimple if you push (accelerate) the object in space, does it still maintain its shape, or will it distort (analogous to the bubble if you blow on it)?

My conjecture is that the gravitational dimple is distorted (and I can back this up with General Relativity). My conclusion, and this is the radical part, is that it is this distortion of the dimple itself which is the cause of inertia. More specifically, it is the resistance to the distortion, from space which results in inertia.

It's hard for me to explain in writing like this, but does that give you some idea of what I'm getting at?

Thanks,

I thought that a thread in limbo tends to stay in limbo...


For what it's worth, I've got a picture in my head, but it likely means nothing. Listening ignorantly...

Here's a bit of background on the Origin of Inertia: http://www.commonsensescience.org/pdf/inertial_mass.pdf

As you can see, it's not as straight forward as it seems.

Rosborne, thanks for inviting me.

I have a picture of what you are envisioning now. The "cause" of inertia is one of the big questions in physics now (as you know).

My initial intuition tells me that this model has an internal contradiction, but I need time to figure out what it is. (My intuition is sometimes wrong on account of maleness).

To prove your model, you need to explore the implications for energy, and a model for how a "distortion" in a gravity field would cause resistance.

I will ponder and respond later...

Ha Normally it does, unless acted upon by an external force... me

Thanks for showing up.



You may be right about a contradition, but I haven't found one yet. My intuition tells me that I may be making a circular argument, which doesn't provide any information, but I haven't been able to confirm that yet either



Yes, exactly. I think we're on the same track of thought here now.

And I already think I know the answer to this, and it's surprisingly simple: It's a function of Conservation of Energy. Same as it is with the spherical shape of a bubble.

I'm guessing that it is somehow energy inefficient for a gravitational dimple to be distorted out of its most energy efficient shape, and just like the elasticity of the bubble, the conservation of energy tries to resist the distortion (resulting in Inertia).

The other advantage of this idea is that unlike Mach's Principle, it doesn't rely on instantaneous reaction at a distance (Mach thought that inertia was caused by the gravitational fields of all the other mass in the universe interacting on every object, but this resulted in a conflict with causality and instantaneous information transfer).



Excellent Thank you.

Hey rosbourne!

You know I'm not really qualified to answer but since you invited me, I shall try

Intuitive rubbish only of course....
...and the more I looked at your theory, the more I got to thinking this way.....

Could inertia be the result of your attempt to change the actual physical dimensions of the mass itself?

If you imagine an ACTUAL soap bubble at rest relative to you. If you push on it, just nudge it, the shape should change (flatten) and bounce back to spherical, if you continue to accelerate against it, I assume the shape remains the same (flattened) for the duration of the acceleration until the acceleration ceases, and then it becomes spherical once again due to the same forces that make it spherical in the first place. While it was out of shape, the forces that normally force it INTO shape, well that energy was being expended directly against you. When you stop accelerating, it becomes a sphere once more.

All matter has dimensions and would resist your attempt to change it's shape .....and your attempt to change it's shape is resisted in more or less the same way.

If I pushed an atom of hydrogen, I imagine I would throw the sphere of the electron path out of shape and out of "center" with the proton and the weak EM force would be acting against me to resist my attempt to do that.

It requires no relationship with other matter or with gravity as far as I can see.

My theory would hold if the soap bubble and I were the only matter in the universe.

Well there's my thoughts, such as they are

From others, I would appreciate an explanation about why I'm obviously wrong apart from the fact that I don't have a PhD. PM me if you don't want to bore the whole room

Addendum: Perhaps if this much is obvious, the next question is: why does the bubble flatten? Why does the opposite side of the bubble resist thereby causing the change of shape? Well that has to be a function of time and the elasticity of the mass in question. If you imagined a line of dominoes across the middle of the bubble, you can see it takes time for the acceleration on one side the bubble to be experienced by the other. The more elastic the mass, the longer it takes for inertia to be experienced by the accelerating body (luckily for pole vaulters) and the longer it takes for the body to change it's vector accordingly.

Perhaps play with Higgs fields and Higgs bosons or ponder if it isn't a quantum mechanics side effect tripping into our classical reality

Hi Eorl, you are essentially re-stating my theory, except that you are saying "distort the mass" and I'm saying "distory the gravitational field". But "mass" *is* the inertial field. There is no other way to quantify mass. So I think we're saying the same thing.



Good question. And this is the part of my theory which is testable and makes a prediction. I predict that the distortion is caused by the speed of light limit and propogation delay in gravity waves. The distortion occurs because the gravitational field can not be instantly affected across its entire shape due to light speed limits.

Over all, it sounds like you agree with my theory.