Science a GoGo's Home Page Forums General Discussion Physics Forum Is the physical world real?

Then you really can lift yourself up into the air there is nothing to stop you doing it :-)

Superman eat your heart out!

I have not suggested that gravity is straight line motion, or anything to that effect (Of course, I think there is relation between speed and gravity). I just don't get what relevance your example has. Here, there is no need of an alternate explanation. Your body tries to pull your feet up and at the same time tries to keep your feet down. It is perfectly balanced.

No tie a rope to your feet and put a strain gauge on it.

When you are standing there according to you I have no force I just am. read the strain gauge it will be at zero I am not pulling.

Now I am going to pull on the string I can clearly see I am putting a force on the string THIS IS VERY DIFFERENT TO JUST STANDING.

What is opposing the new force I am applying you can see and measure it but it doesnt do anything there is nothing pushing my feet down I am allowed to have a one side force the strain gauge clearly shows I am applying a one sided force.

The only option I can see in your world you can have forces that don't do anything?????

Orac, have you ever thought at what speed you are moving in space? The earth moves at a speed of 30Km/s. The sun moves at a speed of nearly 250Km/s and carries the earth along with it. The galaxy containing the sun is moving at a still higher speed. The galaxy-cluster to which our galaxy belongs will be moving at a still higher speed (I think it will be close to one-third the speed of light). That is, we along with the earth is moving at a terrific speed. No superman has claimed to attain that speed!

Just put another gauge under your feet to measure the pressure you exert. It will also show the same reading.

Okay so lets move to your world a force can exert on itself put you hands around behind yourself and push youself a little faster now you are moving a little faster push again.

I am sure you can push yourself up to the speed of light in your world Finiter ... that is how stupid this idea is.

See in audio ampflifier we call it feedback an amplifier with a gain over 1 can exhibit positive feedback what newtons 3rd law tells you is our real world is an amplifier with a gain guarateed to be less than 1 ... that is no positive feedback is possible.

In our world we can't push ourselves up to the speed of light that law apparently doesn't hold in your world :-)

See the problem yet!

Wrong it will be unchanged you don't weight anymore ... you are exerting a force on yourself.

And if it was under the string under your feet it will clearly show there is a force upwards under your feet SO WHY DON'T THEY MOVE whats resisting it :-)

Is your world relativistic? If it is, how can you know that the Earth is not stationary? What do moving, and being stationary really mean?

Bill S. - Relativistic or non-relativistic, if the Earth is stationary then the whole universe is spinning around us like a top, and the parts that are millions of light years away are going around at speeds many times the speed of light.

I have serious doubts that the earth is stationary.

Bill Gill

That's a question very easy to dismiss according to common sense, but not according Ernst Mach and what Einstein referred to as Mach's Principle.

I certainly share your doubts, Bill; I was simply making the point that, according to SR, we cannot know if we are moving, unless we are accelerating; and I was wondering what, if any, influence that might have on the point Finiter was making.

Actually you are much better reading the life and times of Robert Hooke (http://en.wikipedia.org/wiki/Robert_Hooke) for this argument.

See in essence Newtons 3rd law is really the bit Hookes added in.

Hookes is an interesting man but to me he should be known as the man of balance and it's no surprise the law of elasticity bears his name.

Essentially Hookes idea is there is only two ways to balance a "system" that is to

1.) Have a system opposed by a system going the other way
2.) Have a system the result of which is measured and the measured result used to adjust the system

His idea was basic any system was inherently unstable and subject to runaway. He applied the idea mecahnics, biology, philospophy, human biology and behaviour.

Hookes argued strongly about seperating the powers of government and law enforcement based around the balancing problem that a government system would run into unbalance.

It was only later with Nobel and dynamite and later nuclear critical runaway was the idea of how bad a single sided force runaway can be.

In electric circuits it was realized that the forward force (voltage) was always opposed by resistance in the circuit and in fluid and air dynamics pressure was opposed by drag. Friction was thus added in by Guillaume Amontons (although Leonardo Da Vinci had actually noted the effect much earlier) as the counter balance to motion.

In essence science had realized what Hookes had always said a system can only remain balanced by monitoring or by counter balancing two opposing systems. Thus finally we added the counterbalancing of forces into the laws of motion.

I actually once saw an interesting presentation that basically said if you accept big bang is about gravity and you accept gravity as a force then you can argue it must be a one sided force because big bang is in someways gravity in runaway in the same way we see thermodynamic explosions or nuclear runaway explosions. The suggestion was as things move faster they get heavier via relativity (ergo gravity drives it's own demise).
So the universe expands faster and faster until essentially everything is very close to the speed of light at which point the universe runs out of gravity and you get "the big pop". Weird idea but worth throwing in the context we are talking here.

BTW: The translation of the book "System of the World" by Hookes is a recommended read if you ever get a chance.

No. If you have gauges to measure both the pull exerted by your hand and the push exerted by your feet, then either both will be zero or both will show the same reading.

The present view is that we cannot distinguish whether we are moving or not. So the fact may be either 'we are moving' or 'we are not moving'. Both the answers are equally logical, and so we can chose one. I opt for the former, ie, we are moving. (as stated earlier, I propose that energy is the quality of matter and so no body can remain at rest).

Going further in that direction, I would say that it is possible to know whether we are moving (without any reference point that remains at rest). What I propose is a G that depends upon speed, ie, G is directly proportional to square of the speed. When a mass like Earth is at rest the measured value of G would be zero.

The balancing act is very interesting. In my opinion: In a one-dimensional frame, a force and a counter force can balance if they are equal, and the body will remain stationary. But in a two dimensional frame, three forces will be required to keep it stationary. With only two forces, the body will be having a circular motion, and forces will remain balanced. And, in a three dimensional frame, a body will require four forces to remain stationary, and three forces to remain moving around on a spherical surface.

On what do you base this choice, personal preference, or science?



Are you throwing out SR? If so, I suspect you will have to come up with some convincing material if you are to impress the scientific community.



You are talking about speed, rather than acceleration?

Finiter, before looking further at your balancing act with forces in various dimensions, I would like to be sure of one thing: are you saying that motion is intrinsic to any body, so it can be at rest only if appropriate forces are acting on it?

Other way around Bill S from what I understand finiter says things inherently don't move you apply a force to make them move. So when they are stationary there are no forces exerted on them they are in balance with there enviroment.

Thats why he finds it weird in 3D we would need 3 paired forces he is assuming (X,Y,Z).

Of coarse Bill G and I will tell him there there aren't 3 paired forces there are literally billions. Newtons gravity law is explicit gravity has no space limit and each and everybody exerts a force on use and we exert one back on them.

When we do normal physics calculations almost all of the forces as so small we ignore them as trivial.

Of coarse when we move to GR theory we say gravity is a fiction force like centripetal acceleration and all that is happening is the time scale becomes stretched due to spacetime distortion around the planetary object. Thus there is only 1 force the once between the two surfaces against each other. There are no lateral forces for a stationary body in GR.

When both are equally logical, we can choose one and try whether it agrees with our model. SR is one theory that I think is unnecessary and metaphysical(the concept of space-time). I am talking about speed.

The problem is there is a specific test for SR anybody can do and it has been done countless ways

http://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment

Explain away how does the twin paradox effect come about.

These days we measure time shift of lifting something as little as a foot(http://www.wired.com/wiredscience/2010/09/ordinary-relativity/) and expect that to be up by probably ten fold by the end of next year.