Known physics defeated by simple puzzle?
in [Relativity]
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From: Ste on 9 Apr 2010 19:26 On 9 Apr, 22:24, PD <thedraperfam...(a)gmail.com> wrote: > On Apr 9, 3:31 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > But that is not what happens. > > > For example, if I see a car traveling west at 10 kmh, and a car > > > traveling east at 35 kmh, then you have the expectation that, to a > > > passenger riding in the car traveling east, the other car is traveling > > > 45 kmh west. > > > But in fact, it is not traveling at 45 kmh west to a passenger in that > > > car. > > > It is traveling at something close to that, but only approximately. > > > > The bottom line is, the basic sum rule you've been taught for relative > > > velocities is a LIE. > > > i would expect the combined speed to be a real 45kmh, yes, although > > it's quite possible that none of them will any longer agree on the > > definition of "hour" or "kilometer". > > Oh, no, they agree on the definition of hour and kilometer, alright. > Something that is measured locally to be a km will still be measured > locally to be a km. And a standard process that locally takes an hr > will still locally take an hour. Indeed, the question is whether their respective measures of "an hour" are truly identical. After all, if I slow the clock down by half, but also work half as fast, then something that previously took "an hour" still takes "an hour" by the new, slower, definition of "an hour".
From: Inertial on 9 Apr 2010 19:46 "Ste" <ste_rose0(a)hotmail.com> wrote in message news:b55913f6-a3d0-401c-878b-4d0ec3677fa3(a)11g2000yqr.googlegroups.com... > On 9 Apr, 22:24, PD <thedraperfam...(a)gmail.com> wrote: >> On Apr 9, 3:31 pm, Ste <ste_ro...(a)hotmail.com> wrote: >> >> > > But that is not what happens. >> > > For example, if I see a car traveling west at 10 kmh, and a car >> > > traveling east at 35 kmh, then you have the expectation that, to a >> > > passenger riding in the car traveling east, the other car is >> > > traveling >> > > 45 kmh west. >> > > But in fact, it is not traveling at 45 kmh west to a passenger in >> > > that >> > > car. >> > > It is traveling at something close to that, but only approximately. >> >> > > The bottom line is, the basic sum rule you've been taught for >> > > relative >> > > velocities is a LIE. >> >> > i would expect the combined speed to be a real 45kmh, yes, although >> > it's quite possible that none of them will any longer agree on the >> > definition of "hour" or "kilometer". >> >> Oh, no, they agree on the definition of hour and kilometer, alright. >> Something that is measured locally to be a km will still be measured >> locally to be a km. And a standard process that locally takes an hr >> will still locally take an hour. > > Indeed, the question is whether their respective measures of "an hour" > are truly identical. What do you mean by 'truly identical' > After all, if I slow the clock down by half, but > also work half as fast, then something that previously took "an hour" > still takes "an hour" by the new, slower, definition of "an hour".
From: Ste on 9 Apr 2010 19:52 On 9 Apr, 22:37, PD <thedraperfam...(a)gmail.com> wrote: > On Apr 9, 3:37 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > > On 9 Apr, 16:01, PD <thedraperfam...(a)gmail.com> wrote: > > > > On Apr 8, 9:12 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > It ought to be of scientific interest that there are lots of things > > > > > that cannot be verified by experiment but inferred from other > > > > > measurements? No, I don't think so. > > > > > But I do think so. It's a bit like how I infer the moon exists even > > > > when I'm not observing it, even though by definition I can't be sure > > > > what is happening when I'm not observing. > > > > But there ARE ways of confirming the moon's presence, even when you're > > > not observing the moon. For example, you could predict what would > > > happen to the orbits of other celestial bodies if the moon disappeared > > > when you were not looking at it. > > > But then you are drawing inferences without direct observation. Which > > is precisely what I said we should do, and *must* do. > > No, I'm making a direct test on a direct and distinguishing > implication of a hypothesis. That is, the trajectories of other bodies > would be measurably *different* under the hypothesis that the moon > disappeared between direct observations, compared to what they would > be under the hypothesis that the moon did not disappear. This > measurable *difference* is what constitutes the test between the > hypotheses. But it isn't a difference. I just said that, if the rest of your existing theory about the heavens is also wrong, then the moon could disappear despite there being no effect on the trajectories of other planets. Of course, this is an entirely contrived scenario, but the point I'm making is that almost any meaningful "measurement" involves presupposing some theoretical framework. The test you devised above rests on presupposing a correct model of the heavens (and gravity) in general. And of course, if we continue to ask what evidence each theory rests upon, then eventually you either come back round in a circle (because the theories are interlocked on the assumption of each other's truth), or you get down to more basic assumptions that lack any test of their truth. Often the final justification is simply that the body of theory "works" - which of course can once have been said even for since-discredited theories. Which is not to say all this is a bad thing, but it is a death blow for anyone who claims that they rely entirely on measurement, and not loose inferences or fundamental axioms. > > > Then when you did look again and saw > > > that the moon had at least reappeared, you could test the hypothesis > > > that it had disappeared in between. > > > There is always the option of saying that the heavens don't work in > > the way we thought they did, and so the moon *did* in fact disappear, > > but we weren't measuring any of the variables that would have been > > affected by its absence. > > Which is similar to the notion that the Earth is really 6600 years old > as indicated in the Bible, but God has arranged things to *fool* us > into thinking that it is really 4.3 billion years old. Indeed, it is a very similar argument. And one that cannot be logically refuted, except by disqualifying it as an explanation that invokes the supernatural. > There is always > this loose, hand-waving out: "Maybe we only *think* there are laws of > physics, but there aren't laws at all and we're just given the > appearance that there are," or "I choose to believe that the laws that > you've deduced are all wrong, and that there are some other laws that > are at work instead. I haven't got the foggiest idea what they are, > but they surely will be easier for me to accept than the ones you've > found so far." Indeed. If the odds of history are anything to go by, it is always best to bet against the truth of any current scientific theory. > > > > > That would apply to angels and demons. No, thank you. > > > > > As I've said before, I think science would do better to simply assert > > > > it's naturalistic ideology, rather than pretending that the > > > > demarcation between science and religion lies in the method. > > > > There are those that believe that angels are real and therefore > > > natural creatures, under the presumption that anything that is real in > > > the universe is also natural. So you'd have to be a little clearer > > > about that which belongs to "naturalistic ideology" and that which > > > does not. > > > As I've said, there is ultimately no way to exclude religious concepts > > with science, except by excluding them a priori. > > In which case, there is no distinction WHATSOEVER in your mind between > science and religion, or for that matter any belief system including > morals, customs, common opinions, fads and fancies. That is because > there is no such thing as "naturalistic ideology" other than a > completely subjective and capricious assignment on an item by item > basis: "This is natural. This, too, is natural. This, however, is not, > and neither is that over there." And in fact, you can make no > distinction whatsoever between the study of the natural universe and > head-scratching over whether a round belly on a woman is to be > considered beautiful. Since you can make no defensible distinction > between these two, or in fact, any two contentions of any variety > whatsoever, I'm curious why you have an interest in science, other > than as another example of mental diddling. I'm interested in science because I'm interested in the natural world, and how things work, and I'm reasonably certain that there is an understandable explanation. However, as I've said, I think it is pointless to try and demarcate science from religion.
From: Ste on 9 Apr 2010 20:04 On 10 Apr, 00:46, "Inertial" <relativ...(a)rest.com> wrote: > "Ste" <ste_ro...(a)hotmail.com> wrote in message > > news:b55913f6-a3d0-401c-878b-4d0ec3677fa3(a)11g2000yqr.googlegroups.com... > > > > > > > On 9 Apr, 22:24, PD <thedraperfam...(a)gmail.com> wrote: > >> On Apr 9, 3:31 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > >> > > But that is not what happens. > >> > > For example, if I see a car traveling west at 10 kmh, and a car > >> > > traveling east at 35 kmh, then you have the expectation that, to a > >> > > passenger riding in the car traveling east, the other car is > >> > > traveling > >> > > 45 kmh west. > >> > > But in fact, it is not traveling at 45 kmh west to a passenger in > >> > > that > >> > > car. > >> > > It is traveling at something close to that, but only approximately. > > >> > > The bottom line is, the basic sum rule you've been taught for > >> > > relative > >> > > velocities is a LIE. > > >> > i would expect the combined speed to be a real 45kmh, yes, although > >> > it's quite possible that none of them will any longer agree on the > >> > definition of "hour" or "kilometer". > > >> Oh, no, they agree on the definition of hour and kilometer, alright. > >> Something that is measured locally to be a km will still be measured > >> locally to be a km. And a standard process that locally takes an hr > >> will still locally take an hour. > > > Indeed, the question is whether their respective measures of "an hour" > > are truly identical. > > What do you mean by 'truly identical' In other words, whether they are measuring the same periods of time - whether the interval of each tick of each clock would be the same as each other.
From: Inertial on 9 Apr 2010 20:24
"Ste" <ste_rose0(a)hotmail.com> wrote in message news:a3f09b2c-2003-4d33-bf42-25606b0e4118(a)u31g2000yqb.googlegroups.com... > On 10 Apr, 00:46, "Inertial" <relativ...(a)rest.com> wrote: >> "Ste" <ste_ro...(a)hotmail.com> wrote in message >> >> news:b55913f6-a3d0-401c-878b-4d0ec3677fa3(a)11g2000yqr.googlegroups.com... >> >> >> >> >> >> > On 9 Apr, 22:24, PD <thedraperfam...(a)gmail.com> wrote: >> >> On Apr 9, 3:31 pm, Ste <ste_ro...(a)hotmail.com> wrote: >> >> >> > > But that is not what happens. >> >> > > For example, if I see a car traveling west at 10 kmh, and a car >> >> > > traveling east at 35 kmh, then you have the expectation that, to a >> >> > > passenger riding in the car traveling east, the other car is >> >> > > traveling >> >> > > 45 kmh west. >> >> > > But in fact, it is not traveling at 45 kmh west to a passenger in >> >> > > that >> >> > > car. >> >> > > It is traveling at something close to that, but only >> >> > > approximately. >> >> >> > > The bottom line is, the basic sum rule you've been taught for >> >> > > relative >> >> > > velocities is a LIE. >> >> >> > i would expect the combined speed to be a real 45kmh, yes, although >> >> > it's quite possible that none of them will any longer agree on the >> >> > definition of "hour" or "kilometer". >> >> >> Oh, no, they agree on the definition of hour and kilometer, alright. >> >> Something that is measured locally to be a km will still be measured >> >> locally to be a km. And a standard process that locally takes an hr >> >> will still locally take an hour. >> >> > Indeed, the question is whether their respective measures of "an hour" >> > are truly identical. >> >> What do you mean by 'truly identical' > > In other words, whether they are measuring the same periods of time - > whether the interval of each tick of each clock would be the same as > each other. If we are talking about SR .. then (assuming the clocks are accurate), yes they do measure the same amount of time. But they only measure time for things at rest wrt them. |