Does Inertia effect time?

[Alan McDougall]

WHAT CAUSES INERTIA?

 

Does inertia effect time and if so how does it??

[Greg H.]

Inertia is a property of matter. Specifically it is the property of matter that resists changes in the state of that matter's motion. (The old objects in motion tend to remain in motion, etc etc).

 

However, a cursory google search of the terms "time inertia" gives a few results that look like theories relating the two via relativity (I didn't take the time to read more than the abstracts of a couple of them). Maybe one of our learned physics colleagues can expand on the topic.

 

 

 

[swansont]

Depending on the context, inertia can refer mass or (occasionally) momentum; it's the tendency to resist changes in motion.

 

 

Inertia doesn't effect time. It might affect it, but a more precise answer requires a more precise question.

[alpha2cen]

WHAT CAUSES INERTIA?

 

Does inertia effect time and if so how does it??

 

Is an inertia, which is circulating with time, the inertia?

[elfmotat]

Inertia is a property of matter.

 

BILL! BILL! BILL! BILL! BILL! Bill Nye the Science Guy!

 

 

Anyway, it depends on what you mean really. The "inertial coefficient" called "mass" can cause clocks to tick at different rates while they are placed near massive objects.

[Alan McDougall]

BILL! BILL! BILL! BILL! BILL! Bill Nye the Science Guy!

 

 

Anyway, it depends on what you mean really. The "inertial coefficient" called "mass" can cause clocks to tick at different rates while they are placed near massive objects.

 

Moving object influence the expansion of space. First the objects resist change in their state of motion. This resistance is due to interaction of space with mass and not due to action at distance of masses out there in the universe. The energy used up to overcome this resistance is used up in t="increasing the mass of the object. This causes what we call inertia.

 

Mass increases gravity, higher gravity slows time. Maybe one answer?

Edited July 19, 2012 by Alan McDougall

[alpha2cen]

Inertia is a property of matter.

 

 

kinetic energy in the space.

 

v=C , E_k = infinite, usually not exist. Other example, photon m=0

...

..

v=v_{i ,} E_k=E_ki

...

..

v=C - C, E_k=0

 

F=rma, m=F/r(dv/dt)

kinetic meaning of mass

 

r; scale dependent factor

r=1/(1-(v/C)²)^0.5

 

Inertia is a conservation phenomena of kinetic energy.

Edited July 19, 2012 by alpha2cen

[swansont]

Mass increases gravity, higher gravity slows time. Maybe one answer?

 

It's more subtle than that. It's not the value of g that gives you the amount of time dilation, it's the gravitational potential. They aren't the same thing.

[Alan McDougall]

It's more subtle than that. It's not the value of g that gives you the amount of time dilation, it's the gravitational potential. They aren't the same thing.

 

Gravity is the attraction between bodies of matter. Or the bending of space-time by matter, says Einstein and others.

Potential energy is what matter possesses because the gravity field is pulling on it. This energy can be changed to kinetic energy if support is removed.

[swansont]

Gravity is the attraction between bodies of matter. Or the bending of space-time by matter, says Einstein and others.

Potential energy is what matter possesses because the gravity field is pulling on it. This energy can be changed to kinetic energy if support is removed.

 

And yet "high gravity slows time" is still not an accurate portrayal of the effect.

[alpha2cen]

Gravity is the attraction between bodies of matter. Or the bending of space-time by matter, says Einstein and others.

Potential energy is what matter possesses because the gravity field is pulling on it. This energy can be changed to kinetic energy if support is removed.

 

High speed or positive acceleration gives us time dilation. Gravity is one of accelerations.

[Greg H.]

And yet "high gravity slows time" is still not an accurate portrayal of the effect.

 

Here's a question that I'm really not sure of the answer of

 

Let us suppose that I am in a rocket capable of travelling at .9c, and I am falling through a gravity well in that rocket at .9c (i.e. the gravitational attraction of the massive body is capable of propelling my rocket at the same speed as the engines.)

 

Obviously, I will feel some relativistic effects as I fall through the gravity well, due to my velocity.

 

My question is, if I turn on the rocket engines with an acceleration vector that exactly counters the force of the gravity:

 

A) Would my motion through the gravity well stop, assuming no other outside influences, and

B) Would that cancel the relativistic effects of my former motion?

[Alan McDougall]

Hi Greg,

 

A) Would my motion through the gravity well stop, assuming no other outside

influences, and

B) Would that cancel the relativistic effects of my former

motion?

 

The answer A) is yes you would be weightless

 

 

The answer B) is yes.

[burhan hafiz]

It doesn't effect time.....

[Alan McDougall]

It doesn't effect time.....

 

 

Explain why?

Moving objects influence the expansion of space. First the objects resist change intheir state of motion. This resistance is due to interaction of space with massand not due to action at distance of masses out there in the universe. The energy used up to overcome this inertia is used up in increasing the mass of the object. Once an object is set in motion, the expansion of space in front of the object slows producing slowing of time. While behind the moving object the expansion of space increases producing a faster time

 

.

 

Edited July 26, 2012 by Alan McDougall

[ACG52]

Moving objects influence the expansion of space.

 

No, they don't.

 

Once an object is set in motion, the expansion of space in front of the object slows producing slowing of time. While behind the moving object the expansion of space increases producing a faster time

 

 

No, it doesn't.

[Alan McDougall]

No, they don't.

 

 

 

No, it doesn't.

 

 

Explain such short statements are meaningless?

[D H]

Here's a question that I'm really not sure of the answer of

 

Let us suppose that I am in a rocket capable of travelling at .9c, and I am falling through a gravity well in that rocket at .9c (i.e. the gravitational attraction of the massive body is capable of propelling my rocket at the same speed as the engines.)

 

Obviously, I will feel some relativistic effects as I fall through the gravity well, due to my velocity.

 

My question is, if I turn on the rocket engines with an acceleration vector that exactly counters the force of the gravity:

 

A) Would my motion through the gravity well stop, assuming no other outside influences, and

B) Would that cancel the relativistic effects of my former motion?

Hi Greg,

The answer A) is yes you would be weightless

The answer B) is yes.

Greg, ignore Alan. His answer to you was completely wrong.

 

 

There's a basic problem with your question: Let us suppose that I am in a rocket capable of travelling at .9c, ... What do you mean by this? There's a problem with that 0.9c itself. With respect to what? The way you stated that "let us suppose" makes it appear that you think there is some universal reference against which one can measure velocity. There isn't. Everything is relative. One way to interpret your "let us suppose" is that you have a spaceship that is somehow capable of accelerating to 0.9c relative to the initial state of the spaceship. This acceleration of course takes time.

 

You can't just instantaneously change velocity without violating several laws of physics. Unfortunately, I think you are doing just that (violating known physics) with your parenthetical remark (i.e. the gravitational attraction of the massive body is capable of propelling my rocket at the same speed as the engines). If that is the case, the answer to your question is "who knows?" This is a question along the lines of Suppose I have a device that violates all known laws of physics. What do the laws of physics say will happen when I use this device? The answer is "who knows?" I'm not saying that the known laws of physics are not sacrosanct. They are but an approximation of reality. But when you posit something that goes outside those laws, well, you've gone outside those laws. The known laws of physics no longer apply. The question just said so!

 

I'll try to add some (known physics) realism to your question. One interpretation is that your spaceship was already going at 0.9c relative to this object well before it came into the gravitational influence of the object. (The gravitational influence does extend to infinity, but it's small, really, really small, at great distances.) In this case you'll zip through the object's sphere of influence so quickly that nothing much of interest will happen.

 

Another interpretation is that your spaceship is falling straight into a black hole. Suppose you used your engines to keep the ship at rest with respect to the black hole at some constant distance from the black hole. Suddenly your engines fail and you don't get them back online until your velocity with respect to the black hole is 0.9c. You are screwed. Unless you have engines that violate the known laws of physics, that is. You might be okay if you happen to have engines that violate the known laws of physics (e.g., engines that can instantaneously transfer momentum to somewhere else), but now asking what the known laws of physics say will happen is a bit of a silly question.

[ACG52]

Explain such short statements are meaningless?

 

 

What was meaningless was your original statements.

 

Moving objects influence the expansion of space.

 

Once an object is set in motion, the expansion of space in front of the object slows producing slowing of time. While behind the moving object the expansion of space increases producing a faster time

 

 

 

 

Those are meaningless.

[Greg H.]

Greg, ignore Alan. His answer to you was completely wrong.

 

 

There's a basic problem with your question: Let us suppose that I am in a rocket capable of travelling at .9c, ... What do you mean by this? There's a problem with that 0.9c itself. With respect to what? The way you stated that "let us suppose" makes it appear that you think there is some universal reference against which one can measure velocity. There isn't. Everything is relative. One way to interpret your "let us suppose" is that you have a spaceship that is somehow capable of accelerating to 0.9c relative to the initial state of the spaceship. This acceleration of course takes time.

 

You can't just instantaneously change velocity without violating several laws of physics. Unfortunately, I think you are doing just that (violating known physics) with your parenthetical remark (i.e. the gravitational attraction of the massive body is capable of propelling my rocket at the same speed as the engines). If that is the case, the answer to your question is "who knows?" This is a question along the lines of Suppose I have a device that violates all known laws of physics. What do the laws of physics say will happen when I use this device? The answer is "who knows?" I'm not saying that the known laws of physics are not sacrosanct. They are but an approximation of reality. But when you posit something that goes outside those laws, well, you've gone outside those laws. The known laws of physics no longer apply. The question just said so!

 

I'll try to add some (known physics) realism to your question. One interpretation is that your spaceship was already going at 0.9c relative to this object well before it came into the gravitational influence of the object. (The gravitational influence does extend to infinity, but it's small, really, really small, at great distances.) In this case you'll zip through the object's sphere of influence so quickly that nothing much of interest will happen.

 

Another interpretation is that your spaceship is falling straight into a black hole. Suppose you used your engines to keep the ship at rest with respect to the black hole at some constant distance from the black hole. Suddenly your engines fail and you don't get them back online until your velocity with respect to the black hole is 0.9c. You are screwed. Unless you have engines that violate the known laws of physics, that is. You might be okay if you happen to have engines that violate the known laws of physics (e.g., engines that can instantaneously transfer momentum to somewhere else), but now asking what the known laws of physics say will happen is a bit of a silly question.

 

DH,

 

Thanks for this - I admit, it was a bit of a simplistic case, and I see the issues with it now that you've pointed them out. Your answer makes sense, and I appreciate the clarification.

 

Cheers!

[MigL]

Didn't Ernest Mach propose that inertia is simply the additive gravitational potential of everything else in the universe ( observable ?? ) on any one particular object ? This then accounts for GR's equivalence of gravitational and inertial mass.