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Posted

OK, here's a quote from that site."force F by which the two material bodies Α and Β attract one another always depends on their material composition, and this force F is never independent of the bodies’ material composition, as Newton states in his first law of universal gravitation."

It's demonstrably false- rocks of different compositions and artificial satelites orbit in the same way (ie at same speed for any given distance).

 

Incidentally, it's difficult to say how right or wrong Newton is since he's dead- like this theory.

Posted

I_A: Newton's laws, the "Three laws" at least, (not including gravity) are always right. As far as I know, Einstein doesn't mess with the 3 laws.

Posted
I_A: Newton's laws, the "Three laws" at least, (not including gravity) are always right. As far as I know, Einstein doesn't mess with the 3 laws.

 

yeah it does. the ass changes in the second law depending on how fast your going. though in the local frame you can probably take it as uncahnged.

Posted
yeah it does. the ass changes in the second law depending on how fast your going. though in the local frame you can probably take it as uncahnged.

 

That doesn't really mess with the laws, more with the constants assumed.

Though you could interpret it as messing with the laws by replacing m with m0*(Lorentz factor)*a.

=Uncool-

Posted

1. The idea of "relativistic mass" has not been used by most physicists for several decades now.

 

2. Newton's second law says [math]F=\frac{d}{dt}p[/math] (force and momentum are vectors, of course. I don't know how to draw the arrows.)

This is just the definition of force.

Einstein just modifies momentum slightly so that [math]p=mv\gamma[/math] instead of just [math]p=mv[/math]

Again, do not let gamma be attached to the mass so that you have m(v)

Posted

2. Newton's second law says [math]F=\frac{d}{dt}p[/math] (force and momentum are vectors, of course. I don't know how to draw the arrows.)

This is just the definition of force.

Einstein just modifies momentum slightly so that [math]p=mv\gamma[/math] instead of just [math]p=mv[/math]

 

[math]\vec{F}=\frac{d}{dt}\vec{\rho}[/math] renders as [math]\vec{F}=\frac{d}{dt}\vec{\rho}[/math](and shouldn't that be a partial derivative?)

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