The Moon is shrinking........

[Agonaces of Susa]

So you and Kant claim.

However, what about Mars?

Mars has no surface water friction to slow it's rotation.

Both moons have approximately the same so-called "mass".

Therefore, according to the now falsified 17th century hypothesis of gravitation (F = G x(m1m2)/r^2), Deimos should fall to Mars as fast as Phobos.

But that's not happening.

While Phobos is falling towards Mars, Deimos has secular acceleration away from Mars which violates both gravitation and the mythological Hill Sphere.

 

[sfs]

However, what about Mars?

Mars has no surface water friction to slow it's rotation.

Tides exist whether or not there is water. Tidal bulges still act on moons -- that's why I qualified the effect as being "mostly" about water. A liquid surface makes the effect bigger, but it occurs even in its absence.

Both moons have approximately the same so-called "mass".

Yes, "mass" is what we call it. You don't have to put quotes around it or add the "so-called".

Therefore, according to the now falsified 17th century hypothesis of gravitation (F = G x(m1m2)/r^2), Deimos should fall to Mars as fast as Phobos.

No, Deimos should not fall to Mars as fast as Phobos. As my original explanation should make clear, if a moon's orbital period is faster than the planet's rotation, then the attraction between the moon and the tidal bulge will be pulling against the moon's motion, speeding up the planet and moving the moon to a lower orbit. This will continue until the moon breaks up.

Mars has an rotational period (= day) of 25 hours. Phobos has an orbital period of 11 hours, while Deimos has an orbital period of 131 hours. Therefore, Phobos should spiral slowly in while Deimos should spiral out, which is what's happening. Quite simple, really.

You really should learn something about the real world -- it's a fascinating place.

 

[Agonaces of Susa]

Tides exist whether or not there is water.

Then why did you mention water?

Tidal bulges still act on moons -- that's why I qualified the effect as being "mostly" about water.

How come tidal bulges don't effect Phobos?

A liquid surface makes the effect bigger, but it occurs even in its absence.

So why did you mention water?

Yes, "mass" is what we call it. You don't have to put quotes around it or add the "so-called".

I don't know what people mean when they say "mass" so I put it in quotes.

"What we call mass would seem to be nothing but an appearance, and all inertia to be of electromagnetic origin." -- Henri Poincaré, physicist, 1908

No, Deimos should not fall to Mars as fast as Phobos.

Why?

Don't you believe in gravitation?

If gravitation is only an attractive force, then why are Deimos and Phobos falling in opposite directions?

As my original explanation should make clear, if a moon's orbital period is faster than the planet's rotation, then the attraction between the moon and the tidal bulge will be pulling against the moon's motion, speeding up the planet and moving the moon to a lower orbit. This will continue until the moon breaks up.

Mars has an rotational period (= day) of 25 hours. Phobos has an orbital period of 11 hours, while Deimos has an orbital period of 131 hours. Therefore, Phobos should spiral slowly in while Deimos should spiral out, which is what's happening. Quite simple, really.

That makes absolutely no sense whatsoever.

You really should learn something about the real world -- it's a fascinating place.

If you're the one doing the "teaching" I think I'll pass.

 

[sfs]

Then why did you mention water?

Because the water has the largest effect on Earth, which is what we were talking about.

How come tidal bulges don't effect Phobos?

They do. Did you not read the post you're responding to?

So why did you mention water?

Because the water has the largest effect on Earth, which is what we were talking about. It's also easier to visualize.

I don't know what people mean when they say "mass" so I put it in quotes.

The correct procedure when you don't understand something is to learn. Quotation marks really don't help.

"What we call mass would seem to be nothing but an appearance, and all inertia to be of electromagnetic origin." -- Henri Poincaré, physicist, 1908

"Poincaré was wrong about mass." -- S. Schaffner, physicist, 2010

Why?

For the reason that I explained in the next sentence. Did you not read it, or did you simply not understand it?

Don't you believe in gravitation?

If gravitation is only an attractive force, then why are Deimos and Phobos falling in opposite directions?

For the reason that I explained in the next sentence. Did you not read it, or did you simply not understand it?

That makes absolutely no sense whatsoever.

Ah, you simply didn't understand it. Tough noogies. Try harder.

 

[Agonaces of Susa]

Ah, you simply didn't understand it.

Exactly.

No one understands it.

"… in the course of our experiments, we were led away from the primary object of the Committee, namely, the measurement of the Lunar Disturbance of Gravity…." — George H. Darwin, physicist, 1882

"But what do you know about gravitation? Nothing, except that it is a very recent development, not too well established, and that the math is so hard that only twelve men in Lagash are supposed to understand it." -- Isaac Asimov, writer, 1941

"Newton’s gravitational theory is regarded as proved by the action of the tides. But studying the tides, Newton came to the conclusion that the moon has a mass equal to one fortieth of the earth. Modern calculations, based on the theory of gravitation (but not on the action of the tides), ascribe to the moon a mass equal to 1/81 of the earth’s mass." -- Immanuel Velikovsky, polymath, 1946

Tough noogies.

That is not a logical or scientific explanation.

"Since Newton announced his universal law of gravitation, scientists have accepted and educators taught it, and rarely has it been questioned. Occasionally one has the temerity to say that gravitation is a myth, an invented word to cover scientific ignorance." -- C.H. Kilmer, historian, October 1915

Try harder.

Why?

Try harder to understand Cinderella's invisible pink unicorns aboard Noah's Ark.

"...to establish it [gravitation] as original or primitive in certain parts of matter is to resort either to miracle or an imaginary occult quality." -- Gottfreid W. Leibniz, polymath, July 1710

 

[keith99]

I've asked this question before, but honestly, I just don't really understand it too well, so please forgive me for asking again.

By why don't a planet's moons crash into it, or why don't we crash into the sun? Since all of them have gravity, wouldn't it make sense that Jupiter's moons should've crashed into it, or that Mercury should've burned up in the sun by now?

Get yourself a ball and put in on a string. Now hold onto the string and run. See the ball follow yuo? That is because of the force exerted on the ball through the string. Now stop and hold onto the string and swing the ball around you in a circle. When you do so you can feel that you are pulling the ball, yet it does not 'fall' into you.

Planets do not fall into the sun because of their motion perpendicular to the sun. If there were no gravatational force the planets would just keep going straight (and be long gone). The force exerted by hte Sun is just enough to keep the planets in a (pretty much) circular orbit.

There is a lot more, but to show that yuo need the math, and if you had the math yuo would not be asking the question. (And I am very very rusty and it would be real work to get the math right).

 

[Agonaces of Susa]

Get yourself a ball and put in on a string. Now hold onto the string and run. See the ball follow yuo? That is because of the force exerted on the ball through the string. Now stop and hold onto the string and swing the ball around you in a circle. When you do so you can feel that you are pulling the ball, yet it does not 'fall' into you.

Planets do not fall into the sun because of their motion perpendicular to the sun. If there were no gravatational force the planets would just keep going straight (and be long gone). The force exerted by hte Sun is just enough to keep the planets in a (pretty much) circular orbit.

There is a lot more, but to show that yuo need the math, and if you had the math yuo would not be asking the question. (And I am very very rusty and it would be real work to get the math right).

Do you claim to know the math better than Sir Isaac Newton and Gottfried Leibniz?

"...lest the systems of the fixed stars should, by their gravity, fall on each other, he [God] hath placed those systems at immense distances from one another." -- Isaac Newton, mathematician, 1687

"...to establish it [gravitation] as original or primitive in certain parts of matter is to resort either to miracle or an imaginary occult quality." -- Gottfreid W. Leibniz, polymath, July 1710

 

[shinbits]

The vacuum of space has nothing to do with it. The friction is (mostly) between the Earth and the water in the tidal bulge raised by the Moon. Because the Earth rotates faster than the Moon orbits, and because there is friction between the Earth and the water, the Earth pulls the bulge ahead of the Earth-Moon line. The off-axis gravitational force between the bulge and the Moon transfers angular momentum from the Earth to the Moon, slowing the Earth and boosting the Moon into a higher orbit. This tidal acceleration is why bodies orbiting one another eventually end up tidally locked, with matching orbital and rotational periods.

Would this phenomena between the earth and moon happen if there were no ocean on earth? Or what if earth had just as much water, but it was much further away from the sun, making it an ice planet?

 

[Nabobalis]

Do you claim to know the math better than Sir Isaac Newton and Gottfried Leibniz?

"...lest the systems of the fixed stars should, by their gravity, fall on each other, he [God] hath placed those systems at immense distances from one another." -- Isaac Newton, mathematician, 1687

"...to establish it [gravitation] as original or primitive in certain parts of matter is to resort either to miracle or an imaginary occult quality." -- Gottfreid W. Leibniz, polymath, July 1710

I would think that alot of physics/math students do know math better than newton. Math has been extended shed loads since newtons time. We did his math in the first year of our physics degree.

 

[Agonaces of Susa]

I would think that alot of physics/math students do know math better than newton. Math has been extended shed loads since newtons time. We did his math in the first year of our physics degree.

Do you claim to know geometry and gravitational calculus better than Newton and Leibniz?

 

[chilehed]

Do you claim to know geometry and gravitational calculus better than Newton and Leibniz?

Heck, yes, and you would as well if you had bothered to major in Physics or Mathematics in college...in which case you wouldn't be making the comments you currently are making.

 

[Nabobalis]

Heck, yes, and you would as well if you had bothered to major in Physics or Mathematics in college...in which case you wouldn't be making the comments you currently are making.

Agreed. Admittedly I'm going to learn most of the math this year. But by the end, I should (if I learn it ) know math better than Newton ever did.

 

[Agonaces of Susa]

Heck, yes, and you would as well if you had bothered to major in Physics or Mathematics in college...in which case you wouldn't be making the comments you currently are making.

LOL.

You say that on account of ignorance and a lack of education.

One of my majors was the History of Science and Mathematics which is why I trust Newton and Leibniz's word on geometry and gravitational calculus over yours.

 

[chilehed]

LOL.

You say that on account of ignorance and a lack of education.

One of my majors was the History of Science and Mathematics which is why I trust Newton and Leibniz's word on geometry and gravitational calculus over yours.

ROTFLOL! "I don't know anything about math or physics, but in school I read a lot about guys who did."

 

[Nabobalis]

LOL.

You say that on account of ignorance and a lack of education.

One of my majors was the History of Science and Mathematics which is why I trust Newton and Leibniz's word on geometry and gravitational calculus over yours.

No we say that because we have gone through the math. We have done it and been shown its limitation.

I don't claim that I'm smarter then them, I can claim that I know math better because math has moved one since they were alive.

 

[halloween]

"The Moon is shrinking......."
Thanks for the info

 

[AV1611VET]

Scientists used to think the moon had seas on it.

The lunar maria are large, dark, basaltic plains on Earth's Moon, formed by ancient volcanic eruptions. They were dubbed maria, Latin for "seas", by early astronomers who mistook them for actual seas.

That's one bit of cosmology they can't nero (blame on Christians).

 

[sandwiches]

Scientists used to think the moon had seas on it.

That's one bit of cosmology they can't nero (blame on Christians).

And I like cream on my enchiladas.

So, what does my post and yours have in common? They are completely irrelevant to this thread.