Fishteacher73 Posted May 19, 2005 Report Share Posted May 19, 2005 This though arose on the news section with the generating bouy. It was expressed that this would deplete the gravitaionally enduced momentum in out spin and eventually slow the Earth. I disagree with this scenerio (Although it is true the Earth is slowing. Between 1 -2.2 seconds per 100,000 years). As opposed to have a discussion on the comment section of the news post I decided to make a thread about it. Quote Link to comment Share on other sites More sharing options...
UncleAl Posted May 19, 2005 Report Share Posted May 19, 2005 gravitaionally enduced momentum in out spinUgh. Gravity has nothing to do with it. The Earth's rotational energy is 2.137x10^29 joules. If you pull some out the Earth's spin slows. 2002 worldwide primary energy production was 4.3x10^20 J. Most of the Earth's mass is in its Mars-sized iron core. That is exactly the wrong mass distribution for an efficient flywheel. Even minor mass perturbations alter the Earth' spin rate. The recent Richter 9.3 Indonesian temblor knocked a microsecond off the day via mass redistribution. China's Three Gorges dam will pile up 1.39 trillion cubic feet of water (39.4 billion tonnes), adding microseconds to the day. Generating power from tide, wind, and wave is incredibly stupid. It is the Enviro-whiner trinity of trading nugatory fears for real world disasters: expensive, shoddy, deadly. Quote Link to comment Share on other sites More sharing options...
bumab Posted May 19, 2005 Report Share Posted May 19, 2005 UA is right about the mass distribution being the issue. It's really just a conservation of angular momentum problem, you redistribute the water, you affect the mass distribution on the earth and spin has to change to accomodate. Same with affecting the tides and the moon- affect the tides (i.e. utilize them for energy production- hence slowing them) you affect the moon. However, the assertation that it will be the end of the world is a little dubious. The overall effect of this slight perturbation is so small, it is really negligable compared to other methods of power production. I say go for it. Quote Link to comment Share on other sites More sharing options...
C1ay Posted May 19, 2005 Report Share Posted May 19, 2005 However, the assertation that it will be the end of the world is a little dubious. The overall effect of this slight perturbation is so small, it is really negligable compared to other methods of power production. I say go for it.Yeah, I'm not completely sold on that either. I think a lot of the energy in the oceans is indirect solar energy that is a result of the sun heating the oceans. Converting that energy to other forms is energy that the sun will continue to contribute to the Earth's energy total. These buoys will extract energy from the Earth but will it be more than the energy the sun imparts on the Earth's oceans? Quote Link to comment Share on other sites More sharing options...
bumab Posted May 19, 2005 Report Share Posted May 19, 2005 It's not that you are somehow extracting energy from the moon's gravity in a subjective, ephemeral way. The tides pull on the moon just as much as the moon pulls on the ocean (causing the tides). Slowing those tides to create power will affect the moon in the same way. I think Uncle Al explained it pretty well in the actual news thread. It's not about how much energy you extract, but what you are affecting by extracting it. Everything effects everything. You gain energy from falling water, but you also slow the water down. Same thing with the moon. You gain energy from the moon pulling on water, but you also reduce the amount of pulling the water can do on the moon (by redistribution of the water's mass), and thus increase the moon's orbit. Clear as mud? Quote Link to comment Share on other sites More sharing options...
Smokinjoe9 Posted May 19, 2005 Report Share Posted May 19, 2005 I know this is of base but, Is it thought the Earth's spin assists gravity, or is generated by gravity? Or better yet has nothing to do with it. Quote Link to comment Share on other sites More sharing options...
Fishteacher73 Posted May 19, 2005 Author Report Share Posted May 19, 2005 Gravity is a property of mass not motion. Through inertia forces can be exerted that seem like gravity, but are not resultant from. Quote Link to comment Share on other sites More sharing options...
Smokinjoe9 Posted May 19, 2005 Report Share Posted May 19, 2005 Gravity is a property of mass not motion.Relative to mass? Quote Link to comment Share on other sites More sharing options...
Fishteacher73 Posted May 19, 2005 Author Report Share Posted May 19, 2005 Gravitation is the tendency of masses to move toward each other. Weight is a force caused by gravity equal to the product of the acceleration of gravity and the mass of the object. Exactly why two masses separated in space have a gravitational attraction to one another remains largely unknown, despite much research and various theories.As per Wiki. The force of attraction = the product of the two masses devided by the distance multipled by a gravitational constant.F=(m1xm2/r)G Quote Link to comment Share on other sites More sharing options...
C1ay Posted May 19, 2005 Report Share Posted May 19, 2005 It's not that you are somehow extracting energy from the moon's gravity in a subjective, ephemeral way. The tides pull on the moon just as much as the moon pulls on the ocean (causing the tides). Slowing those tides to create power will affect the moon in the same way. I think Uncle Al explained it pretty well in the actual news thread. It's not about how much energy you extract, but what you are affecting by extracting it. Everything effects everything. You gain energy from falling water, but you also slow the water down. Same thing with the moon. You gain energy from the moon pulling on water, but you also reduce the amount of pulling the water can do on the moon (by redistribution of the water's mass), and thus increase the moon's orbit. Clear as mud?Yes, if you do something to damp the tides it extracts energy from the Earth-Moon system and you do have an effect on the orbital radius of the moon. The oceans are not limited to tidal energy though. In addition to the approximate 12 hour cycle of the tides there are other waves moving up and down in ocean that derive their energy from the weather. Winds moving across the surface of the water impart energy into the oceans as does the heat of the sun. This is all of the smaller, choppy wave activity on the surface indepent of the long wavelength activity of the tides. This lower amplitude wave energy riding on top of the tidal wave energy should be available for extraction. Quote Link to comment Share on other sites More sharing options...
Smokinjoe9 Posted May 19, 2005 Report Share Posted May 19, 2005 As per Wiki. The force of attraction = the product of the two masses devided by the distance multipled by a gravitational constant.F=(m1xm2/r)G First, I need to understand this better, and yes I am like a rock you need to keep hitting me in the head til I get it...Second should I start a new thread to throughly understand the principle of gravity? I would like that... let me see..Force = 2 masses / distance and then * what gravitaional constant?I realize this is very simplistic to you, as I am not a scientist, but I want to understand this, as I have trouble believing it. edit: the 2 masses I speak of are m1*m2I'll rephrase..Product mass / distance * what gravitational constant? Quote Link to comment Share on other sites More sharing options...
Smokinjoe9 Posted May 19, 2005 Report Share Posted May 19, 2005 "Gravity is the attractive force of one mass on another mass. The weakest of the four forces of nature, gravity requires a very large amount of mass to be apparent. A 1 kilogram mass experiences a gravitational force of approximately 9.8 Newtons, pulled toward the 5,987,419,284,000,000,000,000,000 kilogram Earth. The pull of gravity decreases rapidly as the distance between the bodies increases." This is a quote from an encyclopedia...... Ok, so an object with mass has gravity?Does a magnetic force get weaker with distance?Does gravity get weaker with distance?The mass has to be very large for gravity to be apparent? Quote Link to comment Share on other sites More sharing options...
UncleAl Posted May 20, 2005 Report Share Posted May 20, 2005 Smokinjoe9 needs to crack a physics textbook. This is not a Liberal arts mercy hump wherein everything and its opposite are true by majority vote, generating dialog and critique. The math has objective answers validated or falsified by empirical observation. That your computer's CPU operates without error is not an article of faith, it is engineering. A Pentium 4 Extreme Edition has 178 million transistors that can be on or off, 2^(178 million) = one chance in 1.7x10^(53,583,339) of getting it right, nanoscond by nanosecond. Can see the difference between science and the squirrely crap? They don't mix if you want the science to work. Quote Link to comment Share on other sites More sharing options...
Smokinjoe9 Posted May 20, 2005 Report Share Posted May 20, 2005 That your computer's CPU operates without error is not an article of faith, it is engineering. A Pentium 4 Extreme Edition has 178 million transistors that can be on or off, 2^(178 million) = one chance in 1.7x10^(53,583,339) of getting it right, nanoscond by nanosecond. Can see the difference between science and the squirrely crap? They don't mix if you want the science to work. I understand the difference, but you did not say the P4 doesn't error, did you? I don't care what the odds of error are the fact there is error means.1. There is room for improvement.2. Error leads to erroneous data, period!There is no difference between 1 error and 10 especially in hardware and software.. Quote Link to comment Share on other sites More sharing options...
Smokinjoe9 Posted May 20, 2005 Report Share Posted May 20, 2005 I do not think math and observation do not work. I just do not want to be accidently deceived... Quote Link to comment Share on other sites More sharing options...
Fishteacher73 Posted May 23, 2005 Author Report Share Posted May 23, 2005 "Gravity is the attractive force of one mass on another mass. The weakest of the four forces of nature, gravity requires a very large amount of mass to be apparent. A 1 kilogram mass experiences a gravitational force of approximately 9.8 Newtons, pulled toward the 5,987,419,284,000,000,000,000,000 kilogram Earth. The pull of gravity decreases rapidly as the distance between the bodies increases." This is a quote from an encyclopedia...... Ok, so an object with mass has gravity?{/QUOTE]YesDoes a magnetic force get weaker with distance?yes..magnetic fore is not the same thing as gravity though. Does gravity get weaker with distance?yes.. with F=g(m1m2/r) as r increases the other porperties stay the same. The force will decreace. The mass has to be very large for gravity to be apparent?Yes and no..(that was clear huh?). On a human scale masses must be decent sized to exert any real force upon you. (Jupiter has a greater force of gravity upon you than, say a dog sitting next to you). Yet if you examine the equation, if r gets very small...the force gets much larger. Quote Link to comment Share on other sites More sharing options...
Smokinjoe9 Posted May 26, 2005 Report Share Posted May 26, 2005 Ok, so an object with mass has gravity?{/QUOTE]Yes ok? yes..magnetic fore is not the same thing as gravity though. I understand the magnetic force... yes.. with F=g(m1m2/r) as r increases the other porperties stay the same. The force will decreace. Ok, I sort of get it, however, if all the properties stay the same with the exception of r, then gravity does not decrease it remains constant. As the masses get farther apart gravity appears to get weaker, IMO, the force does not get weaker. If gravity is based on the mass, for the gravity to get weaker the mass would have to get smaller... Yes and no..(that was clear huh?). On a human scale masses must be decent sized to exert any real force upon you. (Jupiter has a greater force of gravity upon you than, say a dog sitting next to you). Yet if you examine the equation, if r gets very small...the force gets much larger. "You or me" should also apply a huge force on a really small object, say in space.I don't see that when the astronaut is in space, a small piece of food(say) when let go in 0 gravity does not fly at the astronauts face, it just sits there?I am still working on this. keep it coming if you like.. Quote Link to comment Share on other sites More sharing options...
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