Think of it this way barbarian: Imagine a 12 foot high test tube filled with 10 feet of water. Imagine this test tube moving at 10 mph and as it passes under a certain spot in the sky, the test tube contains 11 feet of water until it passes that spot where it goes back to 10 feet of water. The volume of water is being stretched as it passes over the spot.
toldailytopic: How old is the earth?
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The rotational angular momentum of the Earth decreases and consequently the length of the day increases. The net tide raised on Earth by the Moon is dragged ahead of the Moon by Earth's much faster rotation. Tidal friction is required to drag and maintain the bulge ahead of the Moon, and it dissipates the excess energy of the exchange of rotational and orbital energy between the Earth and Moon as heat. If the friction and heat dissipation were not present, the Moon's gravitational force on the tidal bulge would rapidly (within two days) bring the tide back into synchronization with the Moon, and the Moon would no longer recede.
http://en.wikipedia.org/wiki/Tidal_acceleration
Tides stretch the oceans, and to a small extent, the solid mass of a planet or satellite. In one complete rotation, the planet material keeps deforming and relaxing. This takes energy away from the rotation, transforming it into heat.
In effect, this is a frictional loss, like a giant brake on the planet. Over the centuries, the moon's rotation on its own axis has slowed until it presents essentially the same face to the earth.
Since the earth and its oceans are continuously deformed by the tides of the moon and sun, the earth's rotation is also being slowed. Each century, the day increases by about 3 milliseconds. This seems small, but over 100 million years (not long in geological time), the day will increase by about an hour.http://www.physics.mcgill.ca/~crawford/PSG/PSG11/204_97_L11.9_tidfric.html
http://www.britannica.com/EBchecked/topic/595127/tidal-friction
The secular change in the planet's rotation is a classical topic in geophysics. It goes back some 300 years to when Sir Edmond Halley first hypothesized that the moon was accelerating in its orbit. Most of Halley's lunar acceleration was only apparent. It was actually the earth's rotation slowing down, making the moon appear to accelerate. The moon does accelerate (strictly, it decelerates), but the larger effect is the earth's rotational braking. This braking is caused by tidal friction. Throughout the earth's history tidal braking has played, and it will continue to play, a dominant role in the rotation. Currently the secular change in the rotation rate increases the length of day by some 2.3 milliseconds per day per century. http://bowie.gsfc.nasa.gov/ggfc/tides/intro.html
Can't happen. Water is essentially incompressible. And the bulge is not the same water, it's constantly changing. You've confused the wave with the water, again.
Wind, actually.
But you're right and Barbie doesn't understand how he is standing on his own yacht blowing into the sails and expecting to move.
That energy is simply transferred from one part of the earth into another part. The energy is not transferred off the earth and to the moon which is what is required to describe a response in both. What is it that causes both the earth to slow and the moon to recede? It most certainly is not friction.
Yip. It is your problem, not mine.
How is friction on the earth transferred to the moon?
Originally Posted by The Barbarian View Post
I understand you want us to believe that. You might even believe it yourself. But there is that problem of physics. The forces generated by the movement of the Earth under the tidal bulge, draw energy from the Earth's rotation, slowing it.
Has to be. The recession of the moon requires additional energy which comes from the friction of the tides on the earth. It can't magically get that energy from nothing. From where do you think that energy comes, Stipe?
See the links above. That's what happens.
Barbarian encourages:
C'mon Stipe, you've come a long way from your original belief here; just go a bit further, and you're home. Remember your example of the person standing on the deck of a sailboat, blowing on the sail?
It won't work because of the friction of that person's feet on the deck. You can't get a torque like that without friction. And that what the torque on the Earth is. The Earth moves under the tidal bulge, and the friction from that movement is the energy lost by the Earth and gained by the Moon.
No, Stipe. Read some of the links, look at the physics involved. The physicists are right. You've got it wrong.
The total energy of the Earth/Moon system must remain constant, unless acted upon by an outside force. So the frictional force slowing the earth adds energy to the Moon.
The Tidal bulge produces friction with the Earth, and the gravity of the tidal bulge pulls the Moon eastward, accelerating it.
I understand you want us to believe that. You might even believe it yourself. But there is that problem of physics. The forces generated by the movement of the Earth under the tidal bulge, draw energy from the Earth's rotation, slowing it.
Has to be. The recession of the moon requires additional energy which comes from the friction of the tides on the earth. It can't magically get that energy from nothing. From where do you think that energy comes, Stipe?
See the links above. That's what happens.
Barbarian encourages:
C'mon Stipe, you've come a long way from your original belief here; just go a bit further, and you're home. Remember your example of the person standing on the deck of a sailboat, blowing on the sail?
It won't work because of the friction of that person's feet on the deck. You can't get a torque like that without friction. And that what the torque on the Earth is. The Earth moves under the tidal bulge, and the friction from that movement is the energy lost by the Earth and gained by the Moon.
No, Stipe. Read some of the links, look at the physics involved. The physicists are right. You've got it wrong.
The total energy of the Earth/Moon system must remain constant, unless acted upon by an outside force. So the frictional force slowing the earth adds energy to the Moon.
The Tidal bulge produces friction with the Earth, and the gravity of the tidal bulge pulls the Moon eastward, accelerating it.
Gravity. How do you imagine energy is transferred from the earth to the moon by friction?
Friction doesn't slow the earth's rotation. You can scrape your feet on a rock against the spin of the earth as much as you like. You're never going to slow the rotation of the earth because you are part of the earth system. Water can flow against the spin of the earth all it likes. The friction generated is never going to have an effect because the water is part of the earth system.
You're trying to stand in your own sailboat and make it move by blowing into the sails.
Your physics is completely wrong.
Something other than friction must transfer energy from the earth to the moon in order to create their relationship. That energy is not transferred by friction. Can't be.
Note all the explanations from real astrophysicists, showing you that it does.
You're confusing your self with the Moon.
It is, if the Moon's gravity is pulling on it, just as a wind will move a sailboat, even if a fan bolted to the deck won't.
You're trying to stand in your own sailboat and make it move by blowing into the sails.
If so, Newton and all those astrophysicists are wrong.
Tides stretch the oceans, and to a small extent, the solid mass of a planet or satellite. In one complete rotation, the planet material keeps deforming and relaxing. This takes energy away from the rotation, transforming it into heat.
In effect, this is a frictional loss, like a giant brake on the planet. Over the centuries, the moon's rotation on its own axis has slowed until it presents essentially the same face to the earth.
Since the earth and its oceans are continuously deformed by the tides of the moon and sun, the earth's rotation is also being slowed. Each century, the day increases by about 3 milliseconds. This seems small, but over 100 million years (not long in geological time), the day will increase by about an hour.
http://www.physics.mcgill.ca/~crawford/PSG/PSG11/204_97_L11.9_tidfric.html
That's about as simple as anyone can make it, Stipe.
Actually, there is. It's just very small, relative to that of the oceans. As you learned, there is also a very small tidal bulge on the Earth's solid part, but it is so small that it contributes very little to the recession of the Moon.
Because the effect is due to the displacement of the bulge and the mass of the bulge. Not hard to figure out.
This situation is the result of tidal forces. The gravitational force of the Moon "pulls" on Earth's oceans and crust, creating the twice-daily tides. Likewise, Earth's gravity pulls on the Moon, distorting our companion so that it is slightly egg-shaped. These tidal effects produce bulges on the Moon's surface, and Earth pulls on these bulges a little more than on the surrounding regions because of the concentration of mass there. Earth's constant pull on the Moon's tidal bulge caused its rotation to slow down from its much faster initial spin rate to its current rate of 27.3 days.
http://www.astronomy.com/asy/default.aspx?c=a&id=2195
Atheists love to point to the popularity of an idea as if it has some impact upon the truth of the idea.
No, the ocean. The ocean is on the earth, remember?
So now it is gravity that is yanking on the earth? Please make up your mind!
No, I'm pretty sure it's just you and a few other evolutionists.
And it's talk about friction is also completely redundant, just like yours. The deformation it speaks of creates a bulge that gravity can work on. Friction plays no part in the energy transferred between to separated bodies.
Let me repeat that. Friction plays no part in the relationship between the earth and the moon.
Why do you insist that it is so important?
The moon always shows the same face to the earth because all the maria is on that side creating a mass imbalance.
The production of maria had nothing to do with earth's gravity.
Barbarian observes:
Note all the explanations from real astrophysicists, showing you that it does.
That would be odd. There are relatively few of them. Or are you admitting what people have suggested, that you're an atheist, trying to make theists look stupid?
It remains true that people who actually know about a subject are probably a good source of information.
Barbarian observes:
It is, if the Moon's gravity is pulling on it, just as a wind will move a sailboat, even if a fan bolted to the deck won't.
It doesn't "yank." But it is the cause of tidal friction, as all those physicists told you.
Barbarian observes:
If so, Newton and all those astrophysicists are wrong.
All those links to all those calculations were from physicists and astronomers. You don't like what the physicists have found about it, so you made up a little fairy tale of your own.
[OLOR="Red"]Tides stretch the oceans, and to a small extent, the solid mass of a planet or satellite. In one complete rotation, the planet material keeps deforming and relaxing. This takes energy away from the rotation, transforming it into heat. In effect, this is a frictional loss, like a giant brake on the planet. Over the centuries, the moon's rotation on its own axis has slowed until it presents essentially the same face to the earth. Since the earth and its oceans are continuously deformed by the tides of the moon and sun, the earth's rotation is also being slowed. Each century, the day increases by about 3 milliseconds. This seems small, but over 100 million years (not long in geological time), the day will increase by about an hour.[/color][/i] url]http://www.physics.mc gill.ca/~crawford/PS G/PSG 11/204_97_L11.9_tidfric.html[/url]
That's about as simple as anyone can make it, Stipe.
I can believe you, or the people who actually understand it. Not much of a choice, um?
Given the evidence, I don't think mindlessly repeating your belief is going to help you.
You think if you say it often enough, reality will change to accomodate you? :chuckle:
It's true. The truth matters. It should matter to you.
Note all the explanations from real astrophysicists, showing you that it does.
That would be odd. There are relatively few of them. Or are you admitting what people have suggested, that you're an atheist, trying to make theists look stupid?
It remains true that people who actually know about a subject are probably a good source of information.
Barbarian observes:
It is, if the Moon's gravity is pulling on it, just as a wind will move a sailboat, even if a fan bolted to the deck won't.
It doesn't "yank." But it is the cause of tidal friction, as all those physicists told you.
Barbarian observes:
If so, Newton and all those astrophysicists are wrong.
All those links to all those calculations were from physicists and astronomers. You don't like what the physicists have found about it, so you made up a little fairy tale of your own.
[OLOR="Red"]Tides stretch the oceans, and to a small extent, the solid mass of a planet or satellite. In one complete rotation, the planet material keeps deforming and relaxing. This takes energy away from the rotation, transforming it into heat. In effect, this is a frictional loss, like a giant brake on the planet. Over the centuries, the moon's rotation on its own axis has slowed until it presents essentially the same face to the earth. Since the earth and its oceans are continuously deformed by the tides of the moon and sun, the earth's rotation is also being slowed. Each century, the day increases by about 3 milliseconds. This seems small, but over 100 million years (not long in geological time), the day will increase by about an hour.[/color][/i] url]http://www.physics.mc gill.ca/~crawford/PS G/PSG 11/204_97_L11.9_tidfric.html[/url]
That's about as simple as anyone can make it, Stipe.
I can believe you, or the people who actually understand it. Not much of a choice, um?
Given the evidence, I don't think mindlessly repeating your belief is going to help you.
You think if you say it often enough, reality will change to accomodate you? :chuckle:
It's true. The truth matters. It should matter to you.
Gravity does not need to cause friction in order to produce an effect. The tidal bulge is attracted to the moon regardless of any friction on earth. Friction has nothing to do with the energy transferred between the earth and the moon.
Not true at all. I have provided a link several times and you still have not shown any signs that you even clicked on it.
The evidence I provided requires no discussion of friction in order to account for the relationship between the earth and the moon. That should be profoundly obvious to even the most uninitiated. But if you're only interested in your understanding and not interested in actually discussing what I have presented there's not much point, is there?
The evidence is that the moon is retreating from the earth according to a model that leaves the maximum age of the earth-moon system at 1.2 billion years.
I believe that evidence to be valid. You've shown nothing that discounts it. You've not even looked at the evidence.
Barbarian. You have admitted that the earths pull on the tidal bulge of the moon slowed down its rotation. There is no friction there. You failed to acknowledge that. If the moon can slow down without friction so can the earth. All it takes is the pull and resistance to slow it down. You insist that ocean friction against against tidal bulges is THE reason for the slowdown. What evidence do you have that the energy lost due to friction is greater than the pull of the moon on the bulge and the resistance and the energy converted to loss of angular momentum?
Barbarian. Would you agree with the following equation for lunar rate of recession? dr/dt = k/R^6 where R is the semi major lunar axis of its orbit around the earth and t is time and K is a proportionality constant? K can even be adjusted to account for reduced heat loss to friction during times of less continental resistance.
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