GRAVITY DOES NOT PULL YOU FORWARD!!!!!!!!!!

tank wrote:

How does gravity act upon objects millions of light years away instantly?

It doesn't. This is a difference between Newtonian gravitation and relativistic (Einsteinian) gravitation.

I think you need to study your physics before pursuing this thread any further.

JimFiore wrote:

What's specious is redefining the problem. Everyone here agrees that given potential energy (PE), one can increase velocity in a direction normal to the force of gravity through translation of PE into KE (kinetic energy). This is not the argument. The argument is whether one can increase the net efficiency of running on a level surface through some application of this principle. The answer is no. NET efficiency includes the "buy" of the initial PE. You cannot ignore this in a closed system. The only way you will get a boost is by running downhill and not having to run back up the hill.

Under this interpretation, I agree. Unless it's a very short distance and you were to somehow lower you center of gravity gradually (crotching while running), which isn't practical. Unless under Fiore's circumstances an intial "standing up" is taken into account.

Stick to the 7th grade.

I was stating a hypothetical. Obviously an object in orbit is not going to come to a complete stop in the absence of gravity. But IF gravity is what caused the object's forward motion (and not momentum) then in the absence of that gravity the object would come to a complete stop. In reality there is momentum involved.

Using your example of a ball being released off of a cliff there is both a momentum to the ball and gravity acting on the ball causing the ball to accelerate downward. Now IF gravity is what caused the ball to move downward then in the absence of gravity the ball would stop in midair. In reality there is a momentum component and the ball would continue falling at a constant speed.

asdef wrote:

We're all saying the same thing, it's just our interpretation of the statement. When we say gravity, do we mean purely gravity? If we do, then it cannot be redirected into forward motion as in the previous examples (half-pipe, rollercoaster, etc). Also, does the word "pull" imply energy being added to the system, or simply an increase in speed.

Under my interpretation, it means an increase in speed in a normal environment. This is very possible. In other people's interpretations, however, it means something very different and something very impossible.

This is gobbledy gook. It is not clear thinking. We are not all sying the same thing. You can't just wave your hands and make the problem go away by saying it's one person's interpretation over another's. To be blunt, the appropriate application of gravity (suggested by some as "falling forward") will not create "an increase in speed in a normal environment". It is not "very possible". It is not a matter of interpretation. This is not art or some other subjective endeavor. This is the analysis of a physical system. One's personal feelings of the situation do not matter. You will only produce a net gain in energy due to gravity if you somehow lower your center of mass continually from start to finish. That is not practical while running over a level surface.

Jim, when you speak about "forward momentum" and then go on to mention "velocity and mass", I think of the term "inertia", which, for the people watching at home, is a body's resistance to change in speed or direction.

Your description of the components of movement during a runner's stride help to convey the part gravity plays in this, but I would challenge those who think gravity helps them run faster on the flat to simply think about what energy sources are used to take that very first step of a run, and the part gravity plays in overcoming the inertia of standing still.

This is a funny thread BTW, destined to be one of LetsRun's all time best no doubt.

In the part of my statement you chose not to quote I said practically this exact statement. Also, if we're both solving different problems due to how we read the problem, our interpretation is important. The english language is an art, open for interpretation. Once you finally made your problem statement clear I agreed that this is not possible/practical. What I was arguing earlier was that gravity can cause an increase in velocity perpendicular to the direction the gravity is working.

JimFiore wrote:

You will only produce a net gain in energy due to gravity if you somehow lower your center of mass continually from start to finish. That is not practical while running over a level surface.

newton wrote:

Stick to the 7th grade.

I was stating a hypothetical. Obviously an object in orbit is not going to come to a complete stop in the absence of gravity. But IF gravity is what caused the object's forward motion (and not momentum) then in the absence of that gravity the object would come to a complete stop. In reality there is momentum involved.

Using your example of a ball being released off of a cliff there is both a momentum to the ball and gravity acting on the ball causing the ball to accelerate downward. Now IF gravity is what caused the ball to move downward then in the absence of gravity the ball would stop in midair. In reality there is a momentum component and the ball would continue falling at a constant speed.

This nearly made my head explode. PLEASE stop using the name "newton". Sir Isaac is undoubtedly spinning in his grave so rapidly as to significantly counter the Earth's rotation.

From your comments I don't think you understand the simple relation between velocity and momentum or any of Newton's laws of motion. Meanwhile, I have useful things to do. Later, folks.

tank wrote:

Question for Einsteins - What actually is momentum? What is that invisible force still acting upon an object which causes it to stay in motion?

momentum is not a force. there is no force that is required to keep an object in constant motion. there is only a force required to accelerate an object.

however the momentum of an object is a potential energy that can impose a force on another object if it collides with another object.

How is space actually warped by gravity? Does it become increasing warped the closer you get to create the sense of falling?

space is not warped by gravity. space is warped by mass. warped space causes the effect of gravity.

newton wrote:

...the momentum of an object is a potential energy...

BOOOM!!!

(Mr. Fiore's head has exploded. He will no longer be posting today.)

JimFiore wrote:

This nearly made my head explode. PLEASE stop using the name "newton". Sir Isaac is undoubtedly spinning in his grave so rapidly as to significantly counter the Earth's rotation.

From your comments I don't think you understand the simple relation between velocity and momentum or any of Newton's laws of motion. Meanwhile, I have useful things to do. Later, folks.

you're a supercilious idiot who has taken my quote out of context.

someone previously asked how gravity could not be said to cause objects to fall forward, givng objects moving in orbit as an example. it was that posters understanding that an object that is in orbit moves around the earth because of gravity. in reality, gravity only causes the acceleration towards the center of the earth of an object in orbit, with the objects momentum causing the forward shift. but thinking in a mindset approximating that of this poor ignorant poster who i was attempting to enlighten, if gravity not only caused the object to accelerate towards the center but also is what caused the object to move forward (that is, if gravity was the SOLE factor of the objects motion) then in the absence of gravity the object would come to a complete stop. that is so counter-intuitive that it should have made the poster suddenly realize he was wrong and that it is not in fact gravity that moves an object forward in its orbit.

using the same logic for a ball falling off of a cliff, if gravity was the ONLY thing causing the ball to move (notice i didnt say accelerate) then in the absence of gravity the object would come to a stop in midair.

newton wrote:

...the momentum of an object is a potential energy...

JimFiore wrote:

BOOOM!!!

(Mr. Fiore's head has exploded. He will no longer be posting today.)

perhaps if you didn't have such an inflated ego and think of yourself as such a genius above all of us intellectual peons you would have recognized my error as a simple typo and corrected my statement to read "kinetic" energy.

ass

Jim,

Thanks for putting up the good fight in the name of science today. The confustion on this thread shows how poorly educated many Americans now are in the basics of science.

CE

Jim & Newton,

I certainly agree that on a level plane when running gravity will not add to forward momentum. You're right that it is a closed system and you can't run in a certain way to use gravity to help you run.

Certainly the force of gravity can be used to increase forward momentum in some situations.

Obviously mass warps space which causes gravity. The force of gravity if infinite and related to the inverse square of the distance between objects times mass.

No one posting here understands gravity and the how and why the warping of space occurs.

Momentum may seem simple but it is really complex. Think about it a minute and many paradoxes may occur to you.

I recently talked to Isaac Newton with my time machine. Here's what he said.

Here are my three laws of motion. They apply because we're dealing with a problem in which the more advanced, modern theories of gravity tend to correspond extremely closely with my own initial approximation to the truth. All other considerations tend to be negligible, so we can assume that my theory applies. Einstein ended up being more correct than I was, with his warped-space, speed-of-light-is-the-limit approach, but he isn't all that necessary under these conditions.

"I. Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it."

So if an object orbits the earth (meaning it always possesses tangential velocity), and gravity is removed, it flies off due to the lack of continual acceleration back towards the earth, formerly provided by gravity.

"II. The relationship between an object's mass m, its acceleration a, and the applied force F is F = ma. Acceleration and force are vectors (as indicated by their symbols being displayed in slant bold font); in this law the direction of the force vector is the same as the direction of the acceleration vector."

Combined with the first law, this tells us that a runner's velocity in any direction cannot be changed except by the application of a force that has a component in that direction.

To simplify things, we can draw a free-body diagram to show the forces that act on our runner. Do it yourself. You'll end up seeing that three forces act on our runner. One of these is gravity. Due to my Law of Universal Gravitation (not shown here, but look it up, you ignoramus--even if you think you know it), that force is directed toward the Earth's center of mass. Straight down. This means it has no horizontal component. If the runner is moving horizontally (as said runner would, if running on a flat surface), this means that gravity does not affect this runner's motion. Wrong direction. See the previous paragraph.

"III. For every action there is an equal and opposite reaction."

What does affect our runner's motion? Remember the other two forces? Air resistance is one. When you move, you're pushing against air. According to my Law III, this means air also pushes against you, slowing you down.

But if you're going to run forward, you have to maintain a forward velocity. You do this through a third force. The ground applies a force to you.

Wait, what? Why would it do that? Because you push against it with your leg. My Law III says that this means it pushes against you. And since you're less massive than the object you're pushing against (the Earth tends to outmass any human being, so we'll assume this is true), you end up being the one that accelerates more. The forces are equal, but the actual acceleration is inversely proportional to the mass of the object that accelerates. So you accelerate the Earth by some small quantity, and it accelerates you by an amount that's rather larger.

And to forestall any complaints that the ground can't push against us in a horizontal direction, I'd call upon you to remember friction. Our leg pushes down, yes, which causes us to move upward. But that's only one component of the force our leg produces. The leg pushes at an angle, and so would tend to slide across the ground, but for friction, which keeps it stationary on the ground. Gravity ends up countering the vertical motion--we don't tend to become significantly airborne when we run--but not the horizontal motion.

The upshot of it all is that gravity doesn't pull you forward. My laws of motion, which apply in this case, prevent this. What lets you go forward is a push from your leg on the ground.

newton wrote:

perhaps if you didn't have such an inflated ego and think of yourself as such a genius above all of us intellectual peons you would have recognized my error as a simple typo and corrected my statement to read "kinetic" energy.

Mr. Fiore is not a genius and has never stated such. He does, however, know that momentum is equal to mass times velocity while kinetic energy is equal to one half of mass times velocity squared. Thus, momentum is not energy, be it phrased as potential (mgh) or kinetic.

JimFiore's Doctor wrote:

He does, however, know that momentum is equal to mass times velocity while kinetic energy is equal to one half of mass times velocity squared. Thus, momentum is not energy, be it phrased as potential (mgh) or kinetic.

Or at least he did know that. Sir Isaac Newton and I would be very impressed if he had developed a method by which he could retain his superior knowledge base despite his recent episode of cephalic combustion.

This discussion is very nice, but it misses one of the points of the Pose method. Dr. Romanov does not say that gravity and gravity alone moves you forward. Gravity is one of the forces acting on the body. Pose method is a method to run efficiently in harmony with the forces of nature (not engaging in unnecessary and often counter-productive movements). The article below is just one example, but you really need to understand all of what Dr. Romanov is saying, rather than pick a phrase out of context.

http://www.posetech.com/training/archives/000286.html

I have it on good authority that Bill Frist will be looking in on Mr. Fiore's condition via video conference and will make a determination at that time.

JimFiore's Doctor wrote:

Mr. Fiore is not a genius and has never stated such. He does, however, know that momentum is equal to mass times velocity while kinetic energy is equal to one half of mass times velocity squared. Thus, momentum is not energy, be it phrased as potential (mgh) or kinetic.

you're being a hypercritical ass again. momentum is directly related to energy, which are both directly related to force. that was the key point. an object with momentum has energy and is capable of imparting a force.