Freethought & Rationalism Archive

Starspun · 07-09-2002, 05:31 AM

So, another bout of insomnia hit me last night. Hopping on the web, I ran across a remark from T Paine:

Quote:

"In the first place, admitting matter to have properties, as we see it has, the question still remains, how came matter by those properties? To this they will answer, that matter possessed those properties eternally. This is not solution, but assertion; and to deny it is as impossible of proof as to assert it.

"It is then necessary to go further; and therefore I say - if there exist a circumstance that is not a property of matter, and without which the universe, or to speak in a limited degree, the solar system composed of planets and a sun, could not exist a moment, all the arguments of atheism, drawn from properties of matter, and applied to account for the universe, will be overthrown, and the existence of a superior cause, or that which man calls God, becomes discoverable, as is before said, by natural philosophy.

"I go now to show that such a circumstance exists, and what it is.

"The universe is composed of matter, and, as a system, is sustained by motion. Motion is not a property of matter, and without this motion, the solar system could not exist. Were motion a property of matter, that undiscovered and undiscoverable thing called perpetual motion would establish itself.

"It is because motion is not a property of matter, that perpetual motion is an impossibility in the hand of every being but that of the Creator of motion. When the pretenders to atheism can produce perpetual motion, and not till then, they may expect to be credited.

"The natural state of matter, as to place, is a state of rest. Motion, or change of place, is the effect of an external cause acting upon matter. As to that faculty of matter that is called gravitation, it is the influence which two or more bodies have reciprocally on each other to unite and be at rest. Everything which has hitherto been discovered, with respect to the motion of the planets in the system, relates only to the laws by which motion acts, and not to the cause of motion.

"Gravitation, so far from being the cause of motion to the planets that compose the solar system, would be the destruction of the solar system, were revolutionary motion to cease; for as the action of spinning upholds a top, the revolutionary motion upholds the planets in their orbits, and prevents them from gravitating and forming one mass with the sun. In one sense of the word, philosophy knows, and atheism says, that matter is in perpetual motion.

"But the motion here meant refers to the state of matter, and that only on the surface of the Earth. It is either decomposition, which is continually destroying the form of bodies of matter, or recomposition, which renews that matter in the same or another form, as the decomposition of animal or vegetable substances enters into the composition of other bodies.

"But the motion that upholds the solar system, is of an entirely different kind, and is not a property of matter. It operates also to an entirely different effect. It operates to perpetual preservation, and to prevent any change in the state of the system.

"Giving then to matter all the properties which philosophy knows it has, or all that atheism ascribes to it, and can prove, and even supposing matter to be eternal, it will not account for the system of the universe, or of the solar system, because it will not account for motion, and it is motion that preserves it.

"When, therefore, we discover a circumstance of such immense importance, that without it the universe could not exist, and for which neither matter, nor any nor all the properties can account, we are by necessity forced into the rational conformable belief of the existence of a cause superior to matter, and that cause man calls GOD.

"As to that which is called nature, it is no other than the laws by which motion and action of every kind, with respect to unintelligible matter, are regulated. And when we speak of looking through nature up to nature's God, we speak philosophically the same rational language as when we speak of looking through human laws up to the power that ordained them.

"God is the power of first cause, nature is the law, and matter is the subject acted upon."

So, what causes planets to spin. If the spin stopped, would the gravity from the sun then be able to attract nearby planets? Does what this guy have to say make any sense?

[ July 09, 2002: Message edited by: Starspun ]

Godless Dave · 07-09-2002, 06:09 AM

Well Thomas Paine was a political philosopher, not an astrophysicist, and writing at the end of the eighteenth century he didn't have the benefit of current knowledge about gravity and astronomy.

Quote:

So, what causes planets to spin?

Momentum from the accretion disk they formed in. Planets weren't formed at the beginning of the universe. Our solar system formed from a spinning disk of cosmic dust. Said dust was formed when an older star or stars went nova. Matter has been flying around the universe for 15 billion years (give or take).

Quote:

If the spin stopped, would the gravity from the sun then be able to attract nearby planets?

No more than it already is. The sun's gravity is what keeps all the planets, asteroids, and comets in their orbits. An objects gravitational force depends on its mass, not whether it's spinning or not.

Quote:

Does what this guy have to say make any sense?

Not to me. This sentence is just plain false:

Quote:

Gravitation, so far from being the cause of motion to the planets that compose the solar system, would be the destruction of the solar system, were revolutionary motion to cease; for as the action of spinning upholds a top, the revolutionary motion upholds the planets in their orbits, and prevents them from gravitating and forming one mass with the sun.

The motion of objects in the universe is explainable by the laws of physics just as much as gravity is. According to modern physics such laws are properties of the universe, not something imposed from "outside". One can forgive Paine for not understanding that, living over a hundred years before Einsteing, Bohr, et al.

But this is bullshit:

Quote:

And when we speak of looking through nature up to nature's God, we speak philosophically the same rational language as when we speak of looking through human laws up to the power that ordained them.

Comparing laws of nature, which can be tested and quantified mathematically, with laws written by humans to govern human behavior is worse than apples and oranges.

Shadowy Man · 07-09-2002, 06:26 AM

I think he was referring to the orbital motion of the planets, not their spinning. If the planets weren't in orbit around the sun, they would fall in to the sun.

liquid · 07-09-2002, 06:27 AM

Quote:

"Gravitation, so far from being the cause of motion to the planets that compose the solar system, would be the destruction of the solar system, were revolutionary motion to cease; for as the action of spinning upholds a top, the revolutionary motion upholds the planets in their orbits, and prevents them from gravitating and forming one mass with the sun. In one sense of the word, philosophy knows, and atheism says, that matter is in perpetual motion.

This is actually true in an unwieldy manner - Paine was obviously not aware that we are subject to gravity whether we rotate or not, but he is correct that the rotation is what prevents us from getting closer to the sun.

The tangental 'spinning' component of the velocity effectively tranforms the 'falling inward' acceleration into a circular path. It's centripetal motion.

beausoleil · 07-09-2002, 06:43 AM

Momentum from the accretion disk they formed in. Planets weren't formed at the beginning of the universe. Our solar system formed from a spinning disk of cosmic dust...

"Angular momentum", not momentum.

Gravitation, so far from being the cause of motion to the planets that compose the solar system, would be the destruction of the solar system, were revolutionary motion to cease; for as the action of spinning upholds a top, the revolutionary motion upholds the planets in their orbits, and prevents them from gravitating and forming one mass with the sun.

Actually this seems like a not unreasonable account. Gravity is the centripetal force that accelerates the planets so that they orbit the sun. If the planets didn't have a tangential velocity, that force would cause them to form one mass with the sun.

Starspun · 07-09-2002, 07:05 AM

I think, on further reading, what he seems to be hinting at is that our 'laws of physics' are a 'creators' divine scheme for the universe. I'm not saying this is a reasonable presumption, just what he seems to be saying.
So, playing devil's advocate, and with a lack of astro-physics to back me in my endevour, I have a question:
Planets formed around Suns from matter left over from the big bang, correct? Now, I would assume that gravity was the catalyst for this formation, but, at what point does gravity cause objects to spin and why didn't the sun pull the forming matter to a certain doom before the transformation was complete?

[ July 09, 2002: Message edited by: Starspun ]

liquid · 07-09-2002, 08:04 AM

An object reaches a circular orbit (bearing in mind this is an approximation to the true orbits of the planets) when:

F = (mv^2)/r

Where F is the gravitational centripetal force
m is the mass of the object
v is the tangental velocity of the object
and r is the radius of the orbit.

As you can see, pretty much any object entering the solar system will have a given m and v (unless it is heading within a narrow angle directly toward the sun). As it crosses the solar system, F evidently changes with r. Sometimes the object will not come close enough to be 'trapped' by the centripetal force, and it will merely travel on a curved path. Sometimes it doesn't have enough tangental velocity, and heads for the sun. Sometimes, it will settle into a stable orbit. This also holds for matter already in the system at inception.

Because there is so little matter in space, the loss of kinetic energy is small and orbits can be held for a very very long time.

And of course, the various orbiting pieces will be on slightly different paths, and attracting each other, and they will accrete. As angular momentum is a conserved quantity, the accreted bodies continue to orbit.

Does that help?

liquid · 07-09-2002, 08:11 AM

Perhaps this visualisation will help:

You are aware that a ball follows a curved path down till it hits the ground when thrown horizontally? Think about how the curve is more gradual the faster you throw the ball.

Imagine there is negligible resistance to the ball of any kind - you are throwing it and it will not slow down, it's like you are in a vacuum.

Now imagine throwing it so hard that the curved path it follows is that of the earth's surface. I'm sure you can imagine it will travel around one quarter of the earth, at which point it is dropping straight down, in relation to where you are standing.

Now the trick is this: realise that at that point, it is exactly the same situation as when you threw it, except rotated 90 degrees. It might help if you draw it on a piece of paper. It is travelling tangental to the earth (as if you were standing there and throwing it horizontally), still with the same speed required to follow the curve of the earth. So it will continue round and round - an orbit!

Starspun · 07-09-2002, 08:40 AM

Quote:

F = (mv^2)/r

As I can see??

I truley admire people that can formulate these calculations. I wish I could learn this.

Liquid, thanks for explaining it in layman terms. While looking on my own here for answers:

<a href="http://www.damtp.cam.ac.uk/user/gr/public/bb_home.html" target="_blank">http://www.damtp.cam.ac.uk/user/gr/public/bb_home.html</a>

I just now, after 30 years, realize they are able to use the trajectory of the galaxies movement (in relation to the expansion of the universe) and conclusively state that these galaxies came from a single point in space. Bigeth bangeth.

Ok, on with the devils advocate:
What causes (if anything) the laws of physics? Gravity, inertia, etc.? Can the Thomas Paines of the world still claim that a divine intelligence 'made it so'?

EDIT: I just found these unanswered questions. Anyone care to take a hypothetical guess?

<a href="http://www.damtp.cam.ac.uk/user/gr/public/bb_problems.html" target="_blank">http://www.damtp.cam.ac.uk/user/gr/public/bb_problems.html</a>

EDITx2--I hope people don't think Im attempting a deconversion with my questions. I am a skeptic myself and, after spending time here at II, I respect the input of you all. Although I don't know if my mind could grasp more than the basics of cosmology or astro-physics, I find the science of the origin of the universe and the origin of life fascinating.

[ July 09, 2002: Message edited by: Starspun ]

[ July 09, 2002: Message edited by: Starspun ]

Shadowy Man · 07-09-2002, 10:37 AM

Quote:

Ok, on with the devils advocate:
What causes (if anything) the laws of physics? Gravity, inertia, etc.? Can the Thomas Paines of the world still claim that a divine intelligence 'made it so'?

As far as we know, things like gravity, etc. appear to be intrinsic to the universe. So, I guess one could say that a "divine intelligence" made the universe to work the way it does.

As for those unanswered questions:

I think the first two, flatness and horizon problem, are addressed by the Inflationary Theory. I also think the density fluctuation problem has been addressed, but I don't recall the answer. The universe timescale with Hubble's constant and stellar lifetimes has been reconciliated.

To me, the biggest problem on the list is that of Dark Matter. (The second biggest would be the Cosmological Constant).

But remember, just because we don't have complete answers yet doesn't mean the rest of our theories are wrong.

[ July 09, 2002: Message edited by: Shadowy Man ]

07-09-2002, 07:05 AM	#6
Starspun Regular Member Join Date: Apr 2002 Location: Texas Posts: 334	I think, on further reading, what he seems to be hinting at is that our 'laws of physics' are a 'creators' divine scheme for the universe. I'm not saying this is a reasonable presumption, just what he seems to be saying. So, playing devil's advocate, and with a lack of astro-physics to back me in my endevour, I have a question: Planets formed around Suns from matter left over from the big bang, correct? Now, I would assume that gravity was the catalyst for this formation, but, at what point does gravity cause objects to spin and why didn't the sun pull the forming matter to a certain doom before the transformation was complete? [ July 09, 2002: Message edited by: Starspun ]</p>

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07-09-2002, 06:26 AM	#3
Shadowy Man Veteran Member Join Date: Jun 2002 Location: A Shadowy Planet Posts: 7,585	I think he was referring to the orbital motion of the planets, not their spinning. If the planets weren't in orbit around the sun, they would fall in to the sun.

07-09-2002, 06:43 AM	#5
beausoleil Senior Member Join Date: May 2002 Location: US and UK Posts: 846	Momentum from the accretion disk they formed in. Planets weren't formed at the beginning of the universe. Our solar system formed from a spinning disk of cosmic dust... "Angular momentum", not momentum. Gravitation, so far from being the cause of motion to the planets that compose the solar system, would be the destruction of the solar system, were revolutionary motion to cease; for as the action of spinning upholds a top, the revolutionary motion upholds the planets in their orbits, and prevents them from gravitating and forming one mass with the sun. Actually this seems like a not unreasonable account. Gravity is the centripetal force that accelerates the planets so that they orbit the sun. If the planets didn't have a tangential velocity, that force would cause them to form one mass with the sun.

07-09-2002, 08:04 AM	#7
liquid Veteran Member Join Date: Jan 2001 Location: UK Posts: 1,440	An object reaches a circular orbit (bearing in mind this is an approximation to the true orbits of the planets) when: F = (mv^2)/r Where F is the gravitational centripetal force m is the mass of the object v is the tangental velocity of the object and r is the radius of the orbit. As you can see, pretty much any object entering the solar system will have a given m and v (unless it is heading within a narrow angle directly toward the sun). As it crosses the solar system, F evidently changes with r. Sometimes the object will not come close enough to be 'trapped' by the centripetal force, and it will merely travel on a curved path. Sometimes it doesn't have enough tangental velocity, and heads for the sun. Sometimes, it will settle into a stable orbit. This also holds for matter already in the system at inception. Because there is so little matter in space, the loss of kinetic energy is small and orbits can be held for a very very long time. And of course, the various orbiting pieces will be on slightly different paths, and attracting each other, and they will accrete. As angular momentum is a conserved quantity, the accreted bodies continue to orbit. Does that help?

07-09-2002, 08:11 AM	#8
liquid Veteran Member Join Date: Jan 2001 Location: UK Posts: 1,440	Perhaps this visualisation will help: You are aware that a ball follows a curved path down till it hits the ground when thrown horizontally? Think about how the curve is more gradual the faster you throw the ball. Imagine there is negligible resistance to the ball of any kind - you are throwing it and it will not slow down, it's like you are in a vacuum. Now imagine throwing it so hard that the curved path it follows is that of the earth's surface. I'm sure you can imagine it will travel around one quarter of the earth, at which point it is dropping straight down, in relation to where you are standing. Now the trick is this: realise that at that point, it is exactly the same situation as when you threw it, except rotated 90 degrees. It might help if you draw it on a piece of paper. It is travelling tangental to the earth (as if you were standing there and throwing it horizontally), still with the same speed required to follow the curve of the earth. So it will continue round and round - an orbit!

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