Captainzen Posted February 12, 2015 Share Posted February 12, 2015 Hello everyone I would like to see what is known about this subject by this community. This is something that has made me loose a lot of sleep. We all know what causes gravity. From what I understand, mass is the underlying component here. The higher, or more concentrated the mass is, the stronger the gravity. So, we definitely know what magnetism is, and as a result we have been able to reproduce it, essentially benefiting us directly. But we do not know yet what gravity is, because we have not been able to reproduce it like we have with magnetism. Correct? Please leave out artificial gravity like that of the space station by rotating something. As far as I understand, we yet do no know what the force is, physically. I welcome any insight into this subject. Zen Link to comment Share on other sites More sharing options...
Strange Posted February 12, 2015 Share Posted February 12, 2015 We understand what gavity is to exactly the same degree to which we understand what magnetism is. https://www.youtube.com/watch?v=qjmtJpzoW0o Link to comment Share on other sites More sharing options...
imatfaal Posted February 12, 2015 Share Posted February 12, 2015 Hello everyone I would like to see what is known about this subject by this community. This is something that has made me loose a lot of sleep. We all know what causes gravity. Nope. We have models that allow us to predict gravitational influence - the simple every day model uses mass, the more complex and sometimes more accurate and revealing uses the quantities you can cram into the stress-energy tensor. But as above these are just models rather than explanations. So, we definitely know what magnetism is, and as a result we have been able to reproduce it, essentially benefiting us directly. But we do not know yet what gravity is, because we have not been able to reproduce it like we have with magnetism. See Feynman above on magnetism. For your guidance Dirac predicted the magnetic monopole in 1931 - and we still haven't found it; many hypotheses rely on it and as many rely on it being impossible. I don't think your assertion is true. Please leave out artificial gravity like that of the space station by rotating something. As far as I understand, we yet do no know what the force is, physically. But our greatest insights into gravity have come from the recognition of the equivalence of the force we feel standing here on earth and the force we feel when accelerating at 9.8m/s^2 1 Link to comment Share on other sites More sharing options...
swansont Posted February 12, 2015 Share Posted February 12, 2015 As far as I understand, we yet do no know what the force is, physically. Mass attracts other mass (in Newtonian gravity). Similarly, charge repels or attracts other charge. I'm not sure to what extent you can say we know why mass acts that way to a lesser extent than we can say why charge acts that way. We say it's the electrostatic force. We model it as the exchange of photons, but we can also model gravity as the curvature of space. So why is gravity being singled out here? Link to comment Share on other sites More sharing options...
StringJunky Posted February 12, 2015 Share Posted February 12, 2015 I don't think we know what any of the forces or fundamental components are ontologically. Scientists attempt to model things in a way that has a classical analogue i.e. that makes sense via our limted senses. 2 Link to comment Share on other sites More sharing options...
Captainzen Posted February 14, 2015 Author Share Posted February 14, 2015 We understand what gavity is to exactly the same degree to which we understand what magnetism is. https://www.youtube.com/watch?v=qjmtJpzoW0o This interview just tells me he knows nothing of the question he was asked and is simply beating around the bush. Ok so let me reapeat this once again. We know how to reproduce magnetism, ie: electric motors. So we know what magnesim is and how to reproduce it. We know what causes Gravity but we do not know how to reproduce it the same way. Do you understand the question? That being, we do not know what kind of wave it is. -2 Link to comment Share on other sites More sharing options...
StringJunky Posted February 14, 2015 Share Posted February 14, 2015 This interview just tells me he knows nothing of the question he was asked and is simply beating around the bush. He is trying to deliver verbally that which can only really be understood mathematically. AFAIK Richard Feynman has few peers in explaining very difficult ideas in layman's terms and if you can't understand him you are in a difficult place. Link to comment Share on other sites More sharing options...
Strange Posted February 14, 2015 Share Posted February 14, 2015 This interview just tells me he knows nothing of the question he was asked and is simply beating around the bush. That is very droll. I assume you don't know who Feynman is? Ok so let me reapeat this once again. We know how to reproduce magnetism, ie: electric motors. So we know what magnesim is and how to reproduce it. We know what causes Gravity but we do not know how to reproduce it the same way. We know exactly how to produce it (with mass, energy, momentum, pressure or acceleration). That being, we do not know what kind of wave it is. It is not a wave. (Although there are gravitational waves.) Link to comment Share on other sites More sharing options...
Captainzen Posted February 15, 2015 Author Share Posted February 15, 2015 (edited) So what you are saying is that we know how to reproduce gravity without relying on spinning (artificial gravity), or using rocket or air. ???? He is trying to deliver verbally that which can only really be understood mathematically. AFAIK Richard Feynman has few peers in explaining very difficult ideas in layman's terms and if you can't understand him you are in a difficult place. What he was asked is basically what I am asking. To me he misunderstood the question. I believe he is trying to explain physically what it is, where he was asked what it is. Am I making any sense? Let me put it to you this way. Is there any technology that can hide anything from gravity? Or oppose it? (here on Earth)!! Edited February 15, 2015 by Captainzen Link to comment Share on other sites More sharing options...
Strange Posted February 15, 2015 Share Posted February 15, 2015 (edited) So what you are saying is that we know how to reproduce gravity without relying on spinning (artificial gravity), or using rocket or air. ???? Of course. But I am not sure why you randomly exclude acceleration, as it is the same thing: it is indistinguishable from gravity. What he was asked is basically what I am asking. To me he misunderstood the question. I believe he is trying to explain physically what it is, where he was asked what it is. Am I making any sense? He was asked what it "really" is. That is not a question that science can answer. Is there any technology that can hide anything from gravity? No. (Usual caveats of "according to our current best theories" etc.) Although, being in free fall does a pretty good job of hiding it. Look at those guys in the space station; it looks like they are in zero gravity. Or oppose it? (here on Earth)!! My chair does a pretty good job of that. Edited February 15, 2015 by Strange Link to comment Share on other sites More sharing options...
whiskers Posted February 15, 2015 Share Posted February 15, 2015 A machine could be built which would *increase* Earth's gravity - it would simply suck matter from space and cram it into the Earth. Doesn't science get any points for that? Link to comment Share on other sites More sharing options...
Captainzen Posted February 16, 2015 Author Share Posted February 16, 2015 (edited) A machine could be built which would *increase* Earth's gravity - it would simply suck matter from space and cram it into the Earth. Doesn't science get any points for that? Where does that come from? Is this a fact? How would you manage that ? Lets say we built a teeter totter where one end contained a 2 ton weight. On the other end a 1 ton weight with ratchet system that would actuate a 4 kw generator. Now tell me know we can hide That 2 ton weight from earth's gravity just until the other end goes down. Are you getting my drift? Perhaps now we can start to talk about manipulating gravity is this form (knowing that we do not really understand it fully yet). Edited February 16, 2015 by Captainzen Link to comment Share on other sites More sharing options...
Endy0816 Posted February 16, 2015 Share Posted February 16, 2015 That is a result of the equation: If the Earth's mass increases, then the force of gravity for the planet will increase(assuming a constant radius). Attaching rockets and nudging something to collide with the planet, would work(though current residents might object). We don't have any technology at present that can hide mass. Considering the space-time connection we may never have the means to do so. Possibly gravitons(if they exist) can be manipulated. That is the only vaguely possible way I can see. There are event horizons, though I'm not sure if the mass can be said to be truly hidden in those cases. Link to comment Share on other sites More sharing options...
Robittybob1 Posted February 16, 2015 Share Posted February 16, 2015 (edited) That is a result of the equation: If the Earth's mass increases, then the force of gravity for the planet will increase(assuming a constant radius). ... There doesn't have to be a constant radius. If the mass goes up Earth's gravity as a whole will increase (the "r" in the equation is not the radius of the Earth but the distance between the two masses M1 and M2. Edited February 16, 2015 by Robittybob1 Link to comment Share on other sites More sharing options...
Strange Posted February 16, 2015 Share Posted February 16, 2015 Where does that come from? Is this a fact? How would you manage that ? Lets say we built a teeter totter where one end contained a 2 ton weight. On the other end a 1 ton weight with ratchet system that would actuate a 4 kw generator. Now tell me know we can hide That 2 ton weight from earth's gravity just until the other end goes down. Are you getting my drift? Perhaps now we can start to talk about manipulating gravity is this form (knowing that we do not really understand it fully yet). The fact that we DO understand gravity, tells us that we cannot hide gravity. Link to comment Share on other sites More sharing options...
Endy0816 Posted February 16, 2015 Share Posted February 16, 2015 There doesn't have to be a constant radius. If the mass goes up Earth's gravity as a whole will increase (the "r" in the equation is not the radius of the Earth but the distance between the two masses M1 and M2. If the radius isn't assumed constant, the force produced could go up, down or even remain constant. ie. (2/4)F = 2m1m2G / (2r)2 Just easier if you minimize what you have to factor in. We can certainly imagine that the existing mass becomes denser. r is the distance between centers of mass. For anything human sized on the surface of the Earth, you may as well use the Earth's radius for simplicity. Link to comment Share on other sites More sharing options...
Captainzen Posted February 16, 2015 Author Share Posted February 16, 2015 Strange, on 16 Feb 2015 - 07:18 AM, said: The fact that we DO understand gravity, tells us that we cannot hide gravity. I do not doubt that we understand gravity, that is what I meant by "we know what causes gravity", but we still do not know what it is. We still have to discover those termed "gravitons" so that we can learn how to manipulate them. Why are we not dedicationg more research into it? We spent billions going after the God partical recearching the beginning of our universe. Have we transfered that knowledge to our every day lives? What benefits have we received from it? If we discovered how to manupulate gravity, we would have reaped a lot more benefits from it, no? Link to comment Share on other sites More sharing options...
Strange Posted February 16, 2015 Share Posted February 16, 2015 I do not doubt that we understand gravity, that is what I meant by "we know what causes gravity", but we still do not know what it is. At that level, we do not know what energy, matter, mass, magnetism, electrons, photons, etc. are. This is philosophy, not science. Link to comment Share on other sites More sharing options...
Captainzen Posted February 17, 2015 Author Share Posted February 17, 2015 At that level, we do not know what energy, matter, mass, magnetism, electrons, photons, etc. are. This is philosophy, not science. The fact that we do not know, does not mean it is not science. Science is the search of knowledge and how things work. Everything is matter. Everything is something. The search to understand it is not philosophy. Link to comment Share on other sites More sharing options...
StringJunky Posted February 17, 2015 Share Posted February 17, 2015 ...Science is the search of knowledge and how things work. Everything is matter. Everything is something. The search to understand it is not philosophy. Science can't tell you what something is, only how it behaves. Getting down to the nitty-gritty, outside of our sensory perception, what something is has no meaning. We can't know what it looks like, what it tastes like, what it smells like or what it feels like, so, what something is has no real meaning at the fundamental level because they are not amenable to our senses. When we talk about what something 'is' we relate it to our senses ...we can't in these cases but we can describe them in terms of their behaviour which is measurable. Link to comment Share on other sites More sharing options...
Captainzen Posted February 18, 2015 Author Share Posted February 18, 2015 Science can't tell you what something is, only how it behaves. Getting down to the nitty-gritty, outside of our sensory perception, what something is has no meaning. We can't know what it looks like, what it tastes like, what it smells like or what it feels like, so, what something is has no real meaning at the fundamental level because they are not amenable to our senses. When we talk about what something 'is' we relate it to our senses ...we can't in these cases but we can describe them in terms of their behaviour which is measurable. Senses? what senses? Who is talking about touching smelling or feeling? I am talking about discovering what it is so we can manipulate it. What kind of forum is this where I only see amature responses? Is this a student based forum? -4 Link to comment Share on other sites More sharing options...
ajb Posted February 18, 2015 Share Posted February 18, 2015 I do not doubt that we understand gravity, that is what I meant by "we know what causes gravity", but we still do not know what it is. Gravity is not really distinct in this sense. I could easily change the question from gravity to electromagnetism. We know how to describe mathematically what we mean by gravity (and electromagnetism) but you will not get a very clear answer to what the fields 'are' in the sense I think you are looking for. What kind of forum is this where I only see amature responses? Is this a student based forum? There are plenty of students that use this forum. Anyway, some the response here have been very good. Link to comment Share on other sites More sharing options...
Strange Posted February 18, 2015 Share Posted February 18, 2015 I am talking about discovering what it is so we can manipulate it. The fact we can generate and control magentic fields, electric currents, electromagnetic radiation etc. may not be because we "know what it is". It may just be a fundamental difference between the nature of electromagnetism and gravity. When we have a quantum theory of gravity (for example) we may still know that the only way to manipulate gravity is to add more mass (or energy, etc) or use acceleration. Link to comment Share on other sites More sharing options...
Phi for All Posted February 18, 2015 Share Posted February 18, 2015 The fact that we do not know, does not mean it is not science. Science is the search of knowledge and how things work. Everything is matter. Everything is something. The search to understand it is not philosophy. The search to understand why something is the way it is IS philosophy. Science is about observing and measuring a phenomenon in order to predict what might happen in different situations. We search for how it works, the way it applies to the natural world, not why. We can measure how in a very objective, substantive, trustworthy manner. Why is open to too much interpretation and subjective opinion. What kind of forum is this where I only see amature responses? Is this a student based forum? I love the irony of describing people as amateurs by misspelling amateurs. 1 Link to comment Share on other sites More sharing options...
StringJunky Posted February 18, 2015 Share Posted February 18, 2015 (edited) Senses? what senses? Who is talking about touching smelling or feeling? I am talking about discovering what it is so we can manipulate it. What kind of forum is this where I only see amature responses? Is this a student based forum? I originally wrote: I don't think we know what any of the forces or fundamental components are ontologically. Scientists attempt to model things in a way that has a classical analogue i.e. that makes sense via our limted senses. It clearly passed over your head so I simplified it for you. I totally resemble your remark, calling me an 'amateur'. I'll let your "amature" spelling mistake pass. Edited February 18, 2015 by StringJunky Link to comment Share on other sites More sharing options...
Recommended Posts