Poll related to: "Big Troubles Brewing For The Theoretical Physics Smart-set"

[eccentrically1]

Ovyyus might be asleep down under, I'll try to respond for him dan.

Gravity assist is a misnomer. Gravity doesn't do the assisting. The assist is from the rotation of the planet. After the satellite exits the other side, the planet is rotating at a tiny fraction of a second slower. Gravity is what makes the 'slingshot effect' possible, it pulls the satellite toward itself, then the satellite begins to leave the planet's field at the right time (like a pendulum at 6; but it escapes the field or it crashes), however the gravity doesn't add or subtract energy to/from the satellite.

[murilo]

misconception:

I have spent the last three days, machining fabricating and testing one small but significant part for my design. I will continue to do so until the problem is solved to my satisfaction. It has to do with friction verses applied force. It is not radial and need not be a misconception of/or part of a wheel.

Reminds me of Edison and the praise he was given for inventing an improved light bulb. His response was that nobody gave praise for the 10,000 ways he tried that did not won't work.

Here are more inspirational quotes by Edison;

“Many of life's failures are people who did not realize how close they were to success when they gave up.�

“Genius is 1 percent inspiration and 99 percent perspiration.�

“This problem, once solved, will be simple.�

And this one, which I find most fitting for the occasion:

“The most necessary task of civilization is to teach people how to think. It should be the primary purpose of our public schools. The mind of a child is naturally active, it develops through exercise. Give a child plenty of exercise, for body and brain. The trouble with our way of educating is that it does not give elasticity to the mind. It casts the brain into a mold. It insists that the child must accept. It does not encourage original thought or reasoning, and it lays more stress on memory than observation.�

The bold is of my doing; it is my response to those who have been taught that there are impossibilities and continue their attempts to persuade others into their way of thinking.

I have not kept track of the numbers of failures I have endured, but inspiration and innovation continues and so does my endeavors.

Ralph

Worst of all are the stuffs that you don't know that you ignore... 8(
What means, quadratic troubles and quadratic errors. 8((((
TC!
M
PS edition: all this in the supposition that your emotions are not blinding you! ('you' and 'your' are a generalization speaking.)

[rlortie]

Dave,

Your above posts are not to be ignored and is sharp, and to the point.

I do not consider myself as being a true blood PM "oxymoron" but as for being incongruous I agree!

I will heed your advice and not let the influence of euphoria of an idea, an idea that most regard as contradictory to my past and present input. The idea is not contradictory, and only a "proof of concept" will suffice in proving that point.

I will accept your advice and STFU or as Jim_Mich might say" crawl into my hole (shop), turn on the heat and pull a rock over my head.

Thank you Dave, and all who have not only gave me inspiration but pointed out my misgivings in a futile debate between the perpetualist and the bashing naysayers. For which I stand my ground that to date neither side has objective proof for their reasoning.

With this in mind, I shall attempt to with-strain myself from making any more posts regarding this topic.

Ralph

[rasselasss]

"Be still my beating heart"....Amen to that...

[rlortie]

murilo,

Worst of all are the stuffs that you don't know that you ignore...

On a closing note to Murilo:

How does one ignore what they do not know? To ignore known knowledge of something is one thing, not knowing of its existence when it exists is not ignoring it, it is being ignorant of its existence.

Ralph

[ovyyus]

Would gravity not induce extra KE into the satilite , even at a angled aproach , I cannot understand if you say gravity is not the energy source.

Yes, as Ecc said I was asleep here down under.

Dan, you can find a thorough explanation here: http://en.wikipedia.org/wiki/Gravity_assist

In part:

A close terrestrial analogy is provided by a tennis ball bouncing off a moving train. In the cartoon at right, a boy throws a ball at 30 mph toward a train approaching at 50 mph. The engineer of the train sees the ball approaching at 80 mph and then departing at 80 mph after the ball bounces elastically off the front of the train. Because of the train's motion, however, that departure is at 130 mph relative to the station.

Translating this analogy into space, then, a "stationary" observer sees a planet moving left at speed U and a spaceship moving right at speed v. If the spaceship has the proper trajectory, it will pass close to the planet, moving at speed U + v relative to the planet's surface because the planet is moving in the opposite direction at speed U. When the spaceship leaves orbit, it is still moving at U + v relative to the planet's surface but in the opposite direction (to the left). Since the planet is moving left at speed U, the total velocity of the rocket relative to the observer will be the velocity of the moving planet plus the velocity of the rocket with respect to the planet. So the velocity will be U + ( U + v ), that is 2U + v.

[jim_mich]

Yes, as Ecc said I was asleep here down under.

Isn't it hard to sleep hanging upside down? :)

[ovyyus]

Lucky I have gravity supplying all this constant free energy which keeps me stuck to your ceiling :D

[eccentrically1]

:D

[murilo]

murilo,

Worst of all are the stuffs that you don't know that you ignore...

On a closing note to Murilo:

How does one ignore what they do not know? To ignore known knowledge of something is one thing, not knowing of its existence when it exists is not ignoring it, it is being ignorant of its existence.

Ralph

Ralph,
no discussion, but I'm sure you got the meaning of my msg.
TC!
M

[daanopperman]

Hi ovyyus and eccentrically1 , and wubbly
I have visited the link supplied , but I only see " gavity " . In the opening salvo it is stated
" The assist is provided by the motion of the gravitating body as it pulls on the spacecraft . " The assist will then depend on the velocity and trajectory of the gravitating body , which I agree with , it is like a skier behind a speedboat , the velocity increase of the skier will depend on the trajectory of the skier and the boat .
" A gravity assist or slingshot manuver around a planet changes a spacecraft's velocity relative to the Sun , though the spacecraft's speed relative to the planet on effectively entering and leaving it's gravitational field , will remain the same . " Now here is the question , from where did the assist come from , from the Sun or from the planet . If it came from the planet the relative velocity to the Sun is irellevant . It is like the 130 mph relavant to the station , but a perrigrine falcon flying 130 mph past the station see the ball standing still in the air , but it is irellevant to the speed of the ball which is 80 mph . Why the F would we want to bring in a party that does not participate or have a effect in the outcome of the fly-by .

[eccentrically1]

From the planet.
Further down:

"This explanation might seem to violate the conservation of energy and momentum, but the spacecraft's effects on the planet have not been considered. The linear momentum gained by the spaceship is equal in magnitude to that lost by the planet, though the planet's enormous mass compared to the spacecraft makes the resulting change in its speed negligibly small. These effects on the planet are so slight (because planets are so much more massive than spacecraft) that they can be ignored in the calculation."

Most of the mass of the solar system is contained in the sun, over 99%. So I can't imagine how many decimal places it would take to show the effect a satellite would have on the sun from reducing the planet's momentum. Trillions upon trillions of 0's, maybe.

[rlortie]

"Pretenders to the Perpetual Motion"

"Everything that is in process, then,must be acted upon by an agent, the agent being in turn acted upon by another or not being so acted upon. And a moved mover requires a first unmoved mover, whereas the latter does not require the former for there can be no infinite series of moved movers, since an infinite series has no first term. If, then everything that is in movement is acted upon by something else, then the first mover must be self-moved."

-From Aristotle's Physics, Book VIII, "Eternity of Movement"
Translated by Richard Hope:
Lincoln: University of Nebraska Press 1961p.156

Under score by me.

Ralph

[rlortie]

More Isaac Newton;

"I frame no hypotheses".
A famous statement in the "General Scholium" of the third edition, indicating his belief that the law of universal gravitation was a fundamental empirical law, and that he proposed no hypotheses on how gravity could propagate. Variant translation: I feign no hypotheses.
As translated by Alexandre Koyré (1956)

I have not as yet been able to discover the reason for these properties of gravity from phenomena, and I do not feign hypotheses. For whatever is not deduced from the phenomena must be called a hypothesis; and hypotheses, whether metaphysical or physical, or based on occult qualities, or mechanical, have no place in experimental philosophy. In this philosophy particular propositions are inferred from the phenomena, and afterwards rendered general by induction.

As translated by I. Bernard Cohen and Anne Whitman (1999).

[rasselasss]

Here we go again!!!