ASSumptions of science
in [Physics]
|
From: PD on 13 Apr 2010 10:38 On Apr 13, 8:46 am, Huang <huangxienc...(a)yahoo.com> wrote: > On Apr 13, 8:31 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Apr 12, 10:05 pm, Huang <huangxienc...(a)yahoo.com> wrote: > > > > On Apr 12, 1:45 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Apr 11, 3:54 pm, Huang <huangxienc...(a)yahoo.com> wrote: > > > > > > On Apr 11, 12:32 pm, Sam Wormley <sworml...(a)gmail.com> wrote: > > > > > > > On 4/11/10 11:46 AM, Huang wrote: > > > > > > > > Science draws conclusions based on calculations using on primary tool > > > > > > > which is mathematics. > > > > > > > Even your first sentence is flawed -- Look up "science". > > > > > > I was not trying to redefine science, Sam. Just making a simple > > > > > observation. > > > > > > Science and mathematics proceed this way. > > > > > Assume [a] exists, then you can say that [b] [c] [d] exist, and so > > > > > on....and that there are logical relationships among these things.. But > > > > > you must start by ASSuming existence. You start with "that which is", > > > > > and you and with "that which is". Everything is proveable. > > > > > > There is no reason why that should be the only way to do science. > > > > > > If I start instead by saying "what might be", and building up a system > > > > > of things which also "might be", and all of these things are > > > > > consistent with respect to each other, then you have achieved the same > > > > > thing that mathematics did with some fundamentally different > > > > > ASSumptions. > > > > > The difficulty with this scheme is that not everything conceivable > > > > will produce the outcome we desire. For example, it is possible to > > > > imagine things such that the laws of physics are much different than > > > > what we've discovered so far. And we can come up with a wholly > > > > different physics that is based on this alternate set of assumptions. > > > > But if you actually tried to build a device or something useful that > > > > would be based on that alternate physics, it's our experience that > > > > such devices do not work -- that is, they will not actually produce an > > > > desired outcome in the set of circumstances created by them. > > > > > PD- Hide quoted text - > > > > > - Show quoted text - > > > > Actually, it is quite usefull to refer back to the allegory of the > > > cave. > > > > Physics based on mathematics seems to ignore Plato completely. We see > > > things and we take them as existent, we model them for what "they > > > are", based on the fact that they "appear to exist", and so we model > > > them as if indeed they do. > > > > But we have no proof that anything exists at all. > > > > If I see a truck, or a rock, or a planet, I might suppose instead that > > > "maybe it exists" because it appears to do so but I really have no > > > proof. I dont really know that it exists because it is very likely > > > just a projection on the wall of a cave. So, I am much safer saying > > > that indeed "maybe it exists" and then proceed along those lines. > > > Please reread what I said. The point of science is not to determine > > whether what's behind the shadows really exists or not. All that > > matters is that if you do so-and-so in such-and-such circumstances, > > then the shadows will reliably and predictably produce a certain > > desired result. And we can build devices that produce those desired > > shadows. > > > It really DOES NOT MATTER whether there is something beyond the > > shadows, since it is only the shadows revealed by our senses that we > > want to control and manipulate. > > > And because it does not matter, then it doesn't do any good to say, > > maybe it doesn't exist after all. > > I actually agree with this with one caveat. Using mathematics to model > thing implies existence of those things you are modelling. By using > mathematics you are peeking behind the shadows and implying "what is". > This is because mathematics is based exclusively on the existent, and > so there is a subtle implication which is inherited by every > application of mathematics - even in physics. I disagree with the statement that mathematics implies existence. I'll give you an example from group theory. There are physical instances of many examples of mathematical groups, such as SO(3). But there are also other groups, for example the so-called "monster group", for which it is not assumed there is any physical instance at all. > > What John said about Dark Matter is interesting because it seems that > this matter does not exist, or cannot be observed. And John is wrong about that. Something that cannot be observed is, in physics, taken to be a useless concept and for all practical purposes does not exist. Dark matter is not presumed to be in that category. However, it is also not presumed that dark matter exists, either. What is said is that IF this model of gravity accurately describes nature, than this would *predict* the existence of dark matter in order to be consistent with observations. This prediction would then be put to independent experimental verification, whereby the existence of dark matter would be tested by some means other than the gravitational model. If it turns out this existence is so established, then the model of gravity finds support; if not, then this model of gravity starts to get into trouble. Note there is no *presumption* of existence of dark matter; it is a matter to be tested. > I would -never- > make models based on nonexistent things. But saying "maybe it exists" > is a different approach. A different approach to probabilistic > reasoning. > > Regardless, if I use mathematics, and if I insist on using mathematics > for some physical model, then my model will inherit all of the subtle > implications regarding existence upon which mathematics is based. > > I feel it is better to embrace Plato and to say that : > We can model things as if they exist, and we can model things as if > existentially indeterminate, both modelling approaches are equivalent > because they produce identical numbers, and we still dont know what it > actually causing those shadows nor can we really, and this is more > evidence that Plato was even right, even today, he could have never > envisioned how right he was. > > Insisting on mathematics is like peeking behind the shadows, it > implies that we know something about nature which we really dont and > cannot know.
From: john on 13 Apr 2010 12:07 On Apr 13, 8:38 am, PD <thedraperfam...(a)gmail.com> wrote: > On Apr 13, 8:46 am, Huang <huangxienc...(a)yahoo.com> wrote: > > > > > > > On Apr 13, 8:31 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > On Apr 12, 10:05 pm, Huang <huangxienc...(a)yahoo.com> wrote: > > > > > On Apr 12, 1:45 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > On Apr 11, 3:54 pm, Huang <huangxienc...(a)yahoo.com> wrote: > > > > > > > On Apr 11, 12:32 pm, Sam Wormley <sworml...(a)gmail.com> wrote: > > > > > > > > On 4/11/10 11:46 AM, Huang wrote: > > > > > > > > > Science draws conclusions based on calculations using on primary tool > > > > > > > > which is mathematics. > > > > > > > > Even your first sentence is flawed -- Look up "science". > > > > > > > I was not trying to redefine science, Sam. Just making a simple > > > > > > observation. > > > > > > > Science and mathematics proceed this way. > > > > > > Assume [a] exists, then you can say that [b] [c] [d] exist, and so > > > > > > on....and that there are logical relationships among these things. But > > > > > > you must start by ASSuming existence. You start with "that which is", > > > > > > and you and with "that which is". Everything is proveable. > > > > > > > There is no reason why that should be the only way to do science. > > > > > > > If I start instead by saying "what might be", and building up a system > > > > > > of things which also "might be", and all of these things are > > > > > > consistent with respect to each other, then you have achieved the same > > > > > > thing that mathematics did with some fundamentally different > > > > > > ASSumptions. > > > > > > The difficulty with this scheme is that not everything conceivable > > > > > will produce the outcome we desire. For example, it is possible to > > > > > imagine things such that the laws of physics are much different than > > > > > what we've discovered so far. And we can come up with a wholly > > > > > different physics that is based on this alternate set of assumptions. > > > > > But if you actually tried to build a device or something useful that > > > > > would be based on that alternate physics, it's our experience that > > > > > such devices do not work -- that is, they will not actually produce an > > > > > desired outcome in the set of circumstances created by them. > > > > > > PD- Hide quoted text - > > > > > > - Show quoted text - > > > > > Actually, it is quite usefull to refer back to the allegory of the > > > > cave. > > > > > Physics based on mathematics seems to ignore Plato completely. We see > > > > things and we take them as existent, we model them for what "they > > > > are", based on the fact that they "appear to exist", and so we model > > > > them as if indeed they do. > > > > > But we have no proof that anything exists at all. > > > > > If I see a truck, or a rock, or a planet, I might suppose instead that > > > > "maybe it exists" because it appears to do so but I really have no > > > > proof. I dont really know that it exists because it is very likely > > > > just a projection on the wall of a cave. So, I am much safer saying > > > > that indeed "maybe it exists" and then proceed along those lines. > > > > Please reread what I said. The point of science is not to determine > > > whether what's behind the shadows really exists or not. All that > > > matters is that if you do so-and-so in such-and-such circumstances, > > > then the shadows will reliably and predictably produce a certain > > > desired result. And we can build devices that produce those desired > > > shadows. > > > > It really DOES NOT MATTER whether there is something beyond the > > > shadows, since it is only the shadows revealed by our senses that we > > > want to control and manipulate. > > > > And because it does not matter, then it doesn't do any good to say, > > > maybe it doesn't exist after all. > > > I actually agree with this with one caveat. Using mathematics to model > > thing implies existence of those things you are modelling. By using > > mathematics you are peeking behind the shadows and implying "what is". > > This is because mathematics is based exclusively on the existent, and > > so there is a subtle implication which is inherited by every > > application of mathematics - even in physics. > > I disagree with the statement that mathematics implies existence. I'll > give you an example from group theory. There are physical instances of > many examples of mathematical groups, such as SO(3). But there are > also other groups, for example the so-called "monster group", for > which it is not assumed there is any physical instance at all. > > > > > What John said about Dark Matter is interesting because it seems that > > this matter does not exist, or cannot be observed. > > And John is wrong about that. Something that cannot be observed is, in > physics, taken to be a useless concept and for all practical purposes > does not exist. Dark matter is not presumed to be in that category. > However, it is also not presumed that dark matter exists, either. What > is said is that IF this model of gravity accurately describes nature, > than this would *predict* the existence of dark matter in order to be > consistent with observations. This prediction would then be put to > independent experimental verification, whereby the existence of dark > matter would be tested by some means other than the gravitational > model. If it turns out this existence is so established, then the > model of gravity finds support; if not, then this model of gravity > starts to get into trouble. Note there is no *presumption* of > existence of dark matter; it is a matter to be tested. > > > > > I would -never- > > make models based on nonexistent things. But saying "maybe it exists" > > is a different approach. A different approach to probabilistic > > reasoning. > Ha ha. Read what PD wrote above: "IF this model of gravity accurately describes nature, than this would *predict* the existence of dark matter ... If it turns out this existence is so established, then the model of gravity finds support" Maybe it exists, Huang, and if it exists (in just the right places) our model of gravity is correct. Otherwise, and observationally at the present time, it is wrong. john
From: PD on 13 Apr 2010 21:59 On Apr 13, 11:07 am, john <vega...(a)accesscomm.ca> wrote: > On Apr 13, 8:38 am, PD <thedraperfam...(a)gmail.com> wrote: > > > On Apr 13, 8:46 am, Huang <huangxienc...(a)yahoo.com> wrote: > > > > On Apr 13, 8:31 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Apr 12, 10:05 pm, Huang <huangxienc...(a)yahoo.com> wrote: > > > > > > On Apr 12, 1:45 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > On Apr 11, 3:54 pm, Huang <huangxienc...(a)yahoo.com> wrote: > > > > > > > > On Apr 11, 12:32 pm, Sam Wormley <sworml...(a)gmail.com> wrote: > > > > > > > > > On 4/11/10 11:46 AM, Huang wrote: > > > > > > > > > > Science draws conclusions based on calculations using on primary tool > > > > > > > > > which is mathematics. > > > > > > > > > Even your first sentence is flawed -- Look up "science". > > > > > > > > I was not trying to redefine science, Sam. Just making a simple > > > > > > > observation. > > > > > > > > Science and mathematics proceed this way. > > > > > > > Assume [a] exists, then you can say that [b] [c] [d] exist, and so > > > > > > > on....and that there are logical relationships among these things. But > > > > > > > you must start by ASSuming existence. You start with "that which is", > > > > > > > and you and with "that which is". Everything is proveable. > > > > > > > > There is no reason why that should be the only way to do science. > > > > > > > > If I start instead by saying "what might be", and building up a system > > > > > > > of things which also "might be", and all of these things are > > > > > > > consistent with respect to each other, then you have achieved the same > > > > > > > thing that mathematics did with some fundamentally different > > > > > > > ASSumptions. > > > > > > > The difficulty with this scheme is that not everything conceivable > > > > > > will produce the outcome we desire. For example, it is possible to > > > > > > imagine things such that the laws of physics are much different than > > > > > > what we've discovered so far. And we can come up with a wholly > > > > > > different physics that is based on this alternate set of assumptions. > > > > > > But if you actually tried to build a device or something useful that > > > > > > would be based on that alternate physics, it's our experience that > > > > > > such devices do not work -- that is, they will not actually produce an > > > > > > desired outcome in the set of circumstances created by them. > > > > > > > PD- Hide quoted text - > > > > > > > - Show quoted text - > > > > > > Actually, it is quite usefull to refer back to the allegory of the > > > > > cave. > > > > > > Physics based on mathematics seems to ignore Plato completely. We see > > > > > things and we take them as existent, we model them for what "they > > > > > are", based on the fact that they "appear to exist", and so we model > > > > > them as if indeed they do. > > > > > > But we have no proof that anything exists at all. > > > > > > If I see a truck, or a rock, or a planet, I might suppose instead that > > > > > "maybe it exists" because it appears to do so but I really have no > > > > > proof. I dont really know that it exists because it is very likely > > > > > just a projection on the wall of a cave. So, I am much safer saying > > > > > that indeed "maybe it exists" and then proceed along those lines. > > > > > Please reread what I said. The point of science is not to determine > > > > whether what's behind the shadows really exists or not. All that > > > > matters is that if you do so-and-so in such-and-such circumstances, > > > > then the shadows will reliably and predictably produce a certain > > > > desired result. And we can build devices that produce those desired > > > > shadows. > > > > > It really DOES NOT MATTER whether there is something beyond the > > > > shadows, since it is only the shadows revealed by our senses that we > > > > want to control and manipulate. > > > > > And because it does not matter, then it doesn't do any good to say, > > > > maybe it doesn't exist after all. > > > > I actually agree with this with one caveat. Using mathematics to model > > > thing implies existence of those things you are modelling. By using > > > mathematics you are peeking behind the shadows and implying "what is".. > > > This is because mathematics is based exclusively on the existent, and > > > so there is a subtle implication which is inherited by every > > > application of mathematics - even in physics. > > > I disagree with the statement that mathematics implies existence. I'll > > give you an example from group theory. There are physical instances of > > many examples of mathematical groups, such as SO(3). But there are > > also other groups, for example the so-called "monster group", for > > which it is not assumed there is any physical instance at all. > > > > What John said about Dark Matter is interesting because it seems that > > > this matter does not exist, or cannot be observed. > > > And John is wrong about that. Something that cannot be observed is, in > > physics, taken to be a useless concept and for all practical purposes > > does not exist. Dark matter is not presumed to be in that category. > > However, it is also not presumed that dark matter exists, either. What > > is said is that IF this model of gravity accurately describes nature, > > than this would *predict* the existence of dark matter in order to be > > consistent with observations. This prediction would then be put to > > independent experimental verification, whereby the existence of dark > > matter would be tested by some means other than the gravitational > > model. If it turns out this existence is so established, then the > > model of gravity finds support; if not, then this model of gravity > > starts to get into trouble. Note there is no *presumption* of > > existence of dark matter; it is a matter to be tested. > > > > I would -never- > > > make models based on nonexistent things. But saying "maybe it exists" > > > is a different approach. A different approach to probabilistic > > > reasoning. > > Ha ha. > Read what PD wrote above: > "IF this model of gravity accurately describes nature, > than this would *predict* the existence of dark matter ... > If it turns out this existence is so established, then the > model of gravity finds support" > > Maybe it exists, Huang, and if it exists (in just the right places) > our model of gravity is correct. > Otherwise, and observationally at the present time, > it is wrong. > > john That's not quite right, John. A theory is not presumed wrong if there is an assertion that has not yet been tested. For example, Mendeleev posted a periodic table of the elements that had several holes in it where he thought elements should be. In between the time the table was proposed and those elements were in fact wrong, the periodic table was not considered wrong. It just made a prediction that had not yet been tested. A theory is wrong if the theory makes a definitive prediction that something should happen, and the test is performed, and what should happen in fact does not happen. That is, it is only AFTER the test that the determination of right or wrong is made. Likewise here, there are predictions about how dark matter should interact with ordinary matter. Once those tests are done (and they are underway) and it is discovered that dark matter does not interact with ordinary matter in this way, then that model is indeed wrong. PD
From: Huang on 13 Apr 2010 23:43 > > I actually agree with this with one caveat. Using mathematics to model > > thing implies existence of those things you are modelling. By using > > mathematics you are peeking behind the shadows and implying "what is". > > This is because mathematics is based exclusively on the existent, and > > so there is a subtle implication which is inherited by every > > application of mathematics - even in physics. > > I disagree with the statement that mathematics implies existence. I'll > give you an example from group theory. There are physical instances of > many examples of mathematical groups, such as SO(3). But there are > also other groups, for example the so-called "monster group", for > which it is not assumed there is any physical instance at all. > > > > > What John said about Dark Matter is interesting because it seems that > > this matter does not exist, or cannot be observed. > > And John is wrong about that. Something that cannot be observed is, in > physics, taken to be a useless concept and for all practical purposes > does not exist. Dark matter is not presumed to be in that category. > However, it is also not presumed that dark matter exists, either. What > is said is that IF this model of gravity accurately describes nature, > than this would *predict* the existence of dark matter in order to be > consistent with observations. This prediction would then be put to > independent experimental verification, whereby the existence of dark > matter would be tested by some means other than the gravitational > model. If it turns out this existence is so established, then the > model of gravity finds support; if not, then this model of gravity > starts to get into trouble. Note there is no *presumption* of > existence of dark matter; it is a matter to be tested. Kinematic equations are regarded as being correct, and all the dark matter data implies the presence of something which remains unobserved. I would argue that contemporary theory implies the existence of something unobserved, hence the mystery. Dark matter could be regarded as already being observed indirectly. If one considers indirect observation valid, it has already been observed in the data. Im not so sure that this would be an incorrect conclusion to draw at this point. But I agree with everything you said above, it's a frontier of science and so being absurd about it is not really very mature so I wont try to quibble about the dark matter in this regard. What I'm getting at is pretty subtle and it's better to look at simple examples. Lets try something more academic. You have a billiard table. The 8-ball is at rest, and then suddenly accelerated in some direction on the table. You can derive all kinds of things about the energy involved in this situation, but the overall model assumes that the 8 ball exists, and at least one other ball exists which collided with it. The existence of the balls and the existence of the forces involved is widely regarded as common sense, that these things exist is never questioned. The math and the logic involved seems to support the notion of existence and so existence becomes a forgone conclusion. It is clearly the case that the billiard balls do not satisfy having the property of nonexistence, and so anything other than "billiard balls exist" is regarded as being absurd. There are many such examples. Math is constantly being used to make forecasts and to predict the (physical) existence of things in the real world such as the KT Crater, when it will rain or snow i.e. when rain will exist or when snow will exist, etc. Existence in the abstract model implies existence of things in the real world, and although the distinction between the abstract and the physical is sacrosanct you still have an implication in the minds of most people IMO.
From: PD on 14 Apr 2010 01:14
On Apr 13, 10:43 pm, Huang <huangxienc...(a)yahoo.com> wrote: > > > I actually agree with this with one caveat. Using mathematics to model > > > thing implies existence of those things you are modelling. By using > > > mathematics you are peeking behind the shadows and implying "what is".. > > > This is because mathematics is based exclusively on the existent, and > > > so there is a subtle implication which is inherited by every > > > application of mathematics - even in physics. > > > I disagree with the statement that mathematics implies existence. I'll > > give you an example from group theory. There are physical instances of > > many examples of mathematical groups, such as SO(3). But there are > > also other groups, for example the so-called "monster group", for > > which it is not assumed there is any physical instance at all. > > > > What John said about Dark Matter is interesting because it seems that > > > this matter does not exist, or cannot be observed. > > > And John is wrong about that. Something that cannot be observed is, in > > physics, taken to be a useless concept and for all practical purposes > > does not exist. Dark matter is not presumed to be in that category. > > However, it is also not presumed that dark matter exists, either. What > > is said is that IF this model of gravity accurately describes nature, > > than this would *predict* the existence of dark matter in order to be > > consistent with observations. This prediction would then be put to > > independent experimental verification, whereby the existence of dark > > matter would be tested by some means other than the gravitational > > model. If it turns out this existence is so established, then the > > model of gravity finds support; if not, then this model of gravity > > starts to get into trouble. Note there is no *presumption* of > > existence of dark matter; it is a matter to be tested. > > Kinematic equations are regarded as being correct, and all the dark > matter data implies the presence of something which remains > unobserved. I would argue that contemporary theory implies the > existence of something unobserved, hence the mystery. Dark matter > could be regarded as already being observed indirectly. If one > considers indirect observation valid, it has already been observed in > the data. Im not so sure that this would be an incorrect conclusion to > draw at this point. > > But I agree with everything you said above, it's a frontier of science > and so being absurd about it is not really very mature so I wont try > to quibble about the dark matter in this regard. What I'm getting at > is pretty subtle and it's better to look at simple examples. > > Lets try something more academic. > > You have a billiard table. The 8-ball is at rest, and then suddenly > accelerated in some direction on the table. You can derive all kinds > of things about the energy involved in this situation, but the overall > model assumes that the 8 ball exists, and at least one other ball > exists which collided with it. The existence of the balls and the > existence of the forces involved is widely regarded as common sense, > that these things exist is never questioned. The math and the logic > involved seems to support the notion of existence and so existence > becomes a forgone conclusion. > > It is clearly the case that the billiard balls do not satisfy having > the property of nonexistence, and so anything other than "billiard > balls exist" is regarded as being absurd. I disagree. It is entirely possible that the what we *perceive* as a billiard ball has no basis in reality. But what is true is that if we take a series of pictures, where those pictures are something we can observe later, then there will be an image in those pictures that appears to change location at a regular rate. Note again I'm not making any claims about *reality*. I'm just making note of what it is we *observe*. Then we can make some additional claims about regularities noted in those observations. It makes no difference whatsoever whether that billiard ball *exists*, nor is it absurd to think that it doesn't exist. The fact remains is that we have observations with regularities in them. [And in fact, what the billiard ball "is" is likely much different than what we perceive it to be. For example, we consider a billiard ball to be a solid, which means that it occupies a definite volume and shape. However, volume is not a property of fundamental entities. It is a *collective* property of composite things, where the volume derives not from the constituents so much as from the interactions between the constituents. For another example, we common associate the billiard ball with a definition location and path, but we know believe that if there is any reality to the billiard ball, it is as a quantum object, which means that it does not have a single, definite trajectory through space.] > > There are many such examples. Math is constantly being used to make > forecasts and to predict the (physical) existence of things in the > real world such as the KT Crater, when it will rain or snow i.e. when > rain will exist or when snow will exist, etc. No, math doesn't produce that. What produces it is observed circumstances, and behavioral rules we induce from observed circumstances. This is what a *model* does, is it says: if you see such-and-such circumstances, then by the rules we have learned apply in systems of observations like this, we should be able to reliably count on seeing so-and-so results. It so happens that the rules have a quantitative, calculational basis that makes those predictions definite, but it still stems from *observations*. > Existence in the > abstract model implies existence of things in the real world, and > although the distinction between the abstract and the physical is > sacrosanct you still have an implication in the minds of most people > IMO. I disagree. It is the implication you have discovered in yourself, perhaps, and one that you are trying to liberate yourself from. I, however, do not share that, nor do I have strong evidence that more people share your view than mine. PD |