Newton's Constant -- Not So Constant?

Newswise ^ | 5/8/2002 | Mike Martin

[Nebullis]

For your bump list.

[steve-b]

My colleagues and I have successfully experimentally demonstrated that the force of gravitation between two test bodies varies with their orientation in space, relative to a system of distant stars

If so, there should be detectable anomalies in the orbits of asteroids that orbit at an inclination to the ecliptic.

[KayEyeDoubleDee]

Mach's Principle

[KayEyeDoubleDee]

pong

[rederic]

Not a very skilled leg-pull. Rederic

[NetValue]

The "gravity" of the situation lies in the fact that it shakes the very foundations of every formula in modern physics.

[tictoc]

Swing a bucket of water at the end of rope and centrifugal forces pull it up and away. These forces result from the combined gravitational pull of all the distant stars and planets, Austrian physicist Ernst Mach wrote.

?

I am searching my peanut-sized brain for memories of high-school physics...spitballs ...the clingy sweater on the pigtailed girl ... sorry ... ah yes!

It went something like this: There is no "centrifugal force", inertia makes a body continue in a straight line once it has been set in motion, but the rope and the earth's gravity prevent that (disregarding friction). There was nothing about "pull of all the distant stars and planets". In fact, we were told that astrology was laughable precisely any gravity effect from the planets or stars was so immeasurably small as to be entirely negligible.

Was I told wrong, or this journalist full of it?

[jbstrick]

I thought all forces were 'relative' to the observer. Damn. I'll have to break out Hawking's book again...

[Paradox]

Newton's gravitational constant G "changes with the orientation of test masses by at least 0.054 percent,"

That is quite a large amount actually. When I started reading, I thought it would be something like .0000005474% or something like that. Seems to me this should be confirmable by others..

But it really doesn't matter... there is no "gravity". Truth be told, matter sucks.

[Linda Liberty]

Is this a hoax? .05% is way too huge to be plausible. G has been measured to some ridiculous accuracy. I have to believe something like this would have been noticed before. In fact, I have to believe that a discrepancy of .05% would show up in planetary orbits, or in calculations of missile trajectories. N f-ing way.

[Dead Dog]

The Two-body assumption would never have worked.

He must be looking for a grant in order to stay in the US.

[epluribus_2]

Yes but it's a smiling Der Elter whose always observing...

[Nebullis]

Is this a hoax?

Not exactly a hoax. It ties in to the recent Notes from a parallel universe thread. This fellow is dead serious.

[quietolong]

Your not wrong. This guy is full of it!

[Frumious Bandersnatch]

Heck, I can lose more than that just by switching scales...

[KayEyeDoubleDee]

See the link at post#5.

[SauronOfMordor]

If so, there should be detectable anomalies in the orbits of asteroids that orbit at an inclination to the ecliptic.

I can't believe the variation is as big as this article claims. SOMEBODY would have noticed the effects on orbiting bodies.

[steve-b]

According to the Theory of Special Relativity, the laws of physics should work the same regardless of your "frame of reference" (i.e. your velocity of movement relative to some other observer).

The Theory of General Relativity extends this principle to accelerated frames of reference (i.e. your velocity and acceleration relative to some other observer should be irrelevant). For instance, if you're in a rocket accelerating at 50 m/s^2 (relative to the earth), you should get the same results if you make your measurements on the assumption that the rocket is standing still and the entire universe is accelerating at 50 m/s^2 in the opposite direction.

However, the first observation you'd make in such a situation is that you're getting squashed under 5 Gs. This must be explained in a manner consistent with either frame of reference. If we use a frame of reference in which the rocket is accelerating, then the G effects come from the fact that the couch you're sitting in is exerting a force upon you to make you accelerate along with it. If we use a frame of reference in which the rocket is standing still and the rest of the universe is accelerating, then the G effects come from gravitational effects produced by accelerating the entire universe at 50 m/s^2.

I've paged Physicist in case I garbled the explanation.