Taking a Fresh Look at the Physics of Radiometers.
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From: NoEinstein on 11 Jun 2010 01:41 On Jun 10, 10:09 pm, spudnik <Space...(a)hotmail.com> wrote: > Dear Spudnik: Your reply is long; I only have time to read the first of it. Thanks for the "Wow!" What part of your question didn't I answer? Very simply, my X, Y, and Z interferometer has a HeNe laser mounted on the Z axis, pointing down. The frame is 40 x 80 mm extruded aluminum with the vertical leg about 48" long; and the horizontal leg 24" long. Those legs rest on a Lazy Susan so that the axis of the laser is centered on it. It is 36" from the back mirror of the laser to a one x one centimeter first surface prism that bends the beam 90 degrees to a 12 mm diameter, precision first surface mirror, set perpendicular and 12 away. Such turns the light back toward the laser. There is a 1 mm precision pin hole, in a mount, that is bonded to the front of the laser. Over the pin hole is a 7/8" diameter paper target with a bigger hole. The light comes through the center of the target, and the bulls eye fringe is a nominal 3/8" diameter with six or seven alternating bands. The CONTROL part of the above is the down and straight back light course reflecting off of a 1" diameter 60T, 40R beamsplitter, set perpendicular to the laser beam, just an inch or so above the prism mirror. The fringes can be made concentric by carefully aiming both light courses. The fringes can be observed while standing, by holding a hand mirror and gently rotating the top part of the 40 x 80 frame. There are an estimated 250 "pulses" of the fringes in 360 degrees of rotation. I've recently figured out that the pulses of the fringes are caused by the fact the control course of light is shorter than the "test" course. When the two different size "fringe components" are in the optimum alignment, there is a pulse. That means that the number of fringe shifts could be six or eight times the 250. Once I construct an interferometer with better geometry, the actual number of fringe shifts can be counted. Those represent the absolute total speed of the Earth in the Cosmos. Half-way around, the fringes will change from an advance to a retard fringe pattern. The exact point of the change will allow determining Earth's absolute direction of motion. So, I can get Earths speed and direction without reference to any stars! NoEinstein P.S.: I'll send a simple drawing of the above interferometer to anyone who sends me their email address. > > wow, you almost answered my question! > > so, what is an XYZ interferometer, and > have you actually built & used it, and > why do you need rocks o'light in your theory, > taht says that the target moves toward the light? > > thus&so: > there's a guy, a mister Griffith, an academic in theology, > who publishes books about the "9/11 controlled demo.' > > I went to a talk he gave, got there late, and only caught > his last, two, bogus statements, which I challenged (hint: > one involves "box-cutters"). > > his next book removed these two items! > > thus&so: > see if you can find the U.S. Reference Climate Network, > without googoling yourself. well, recently, > when I tried to find it with a search, > it was stated that it had somehow been abandoned, > even though it was nothing but a dataset of 28 continental stations. > > thus&so: > wow, what a quibble. of course, if > you think in terms of blackbody absorption & radiation, > the distinction is rather slighter, and > NASA's qualifying terms are correcter. > > thus&so: > cap&trade is as old as Waxman's '91 bill under HDubya, and > the editors of the WSUrinal just love it; however, > they refer to Waxman's current bill as "cap&tax," > without ever explaining, why. (see my letter to Rep. Hamilton, > belowsville .-) > > thus&so: > really; my city promotes all green stuff, in cooperation, > I suppose, with the WAND Corp., and also "global" warming. > they just had two authors of a book, _Smoke and Mirrors_, > at the library, who use the tobacco science baddies > to demonize the "global" warming deniers. they just had > an editorial in the LAtribcoTIMES, and they dyssed S. Fred Singer, > as per usual with mainstream GCMers -- which is mostly > what they are, not really AGWers. > look at Singer's retrospective metastudy on glaciers, > please; thank *you*. > > thus&so: > Schroedinger's cat is dead; > long-live Schroedinger's cat! > > thus&so: > I tried the 3D glasses, the other day, and it was really weird, > *without* closing one eye in the mirror; makes one's eye's look flat & > glassy. > (I assumed, UA wasn't using the red & blue kind.) > > thus&so: > how does the "gravity swing" differ essentially > from the radiometer, if both are just pendula? > how does merely asserting the error of Lorent's contraction, > which seems quite reasonable to those of us, > who believe that atoms have angular momentum, > mean that you have disproven special relativity? > > > I don't see how e = hf applies where there may be no atomic absorption. > > >http://en.wikipedia.org/wiki/Radiation_pressure > > Dear Rep. Lee (http://centeroncongress.org): > Californians are at fault, probably being User #1 of Gulf oil & gas > via pipelines ... all because of spill off of Santa Barbara in '68. > Now, A.G. Brown is determined not to drill, at all. (Also, the > offloading facilities in the Delta must have contributed greatly to > the problems with Katrina.) > > Look; oil comes out of the ground, by itself, under pressure. Perhaps > it was a Natl.Geo. article on offshore driiling, showed that approx. > one XXValdez/year seeps (organically) from the bottom of the Gulf -- > while "we" are pumping like crazy. > > British P. is the #1 operator in the Gulf and Alaska; maybe, their USA > ops should be nationalized. The WSUrinal often likens Waxman's bill > to "cap&tax," but as far as I know (and as Rep. Waxman seemed to > admit, in our brief conversation) it is just "let the arbitrageurs and > daytrippers make as much money on our energy, as they can." > > An expert on emmissions at a UCLA forum agreed that a small carbon tax > would achieve the same ends, but that "that is politically > impossible." The Urinal also noted-in-passing that a tax would work, > but that was in a guest editorial, promoting cap&trade ... the same as > the Kyoto Protocol, which Dubya'd have signed, if he knew that it was > just "free trade, free beer & freedom in the free market." And, it is > the same as Waxman's '91 cap&trade bill on NOX and SO2, viz acid rain. > > So, how did it go, then, and who made the money? > > --Sincerely, Brian
From: Tim BandTech.com on 11 Jun 2010 07:07 On Jun 9, 5:55 pm, "Sue..." <suzysewns...(a)yahoo.com.au> wrote: > On Jun 9, 2:20 pm, "Tim BandTech.com" <tttppp...(a)yahoo.com> wrote: > > > On Jun 7, 8:58 pm, "Sue..." <suzysewns...(a)yahoo.com.au> wrote: > > > > On Jun 7, 6:42 pm, "Tim BandTech.com" <tttppp...(a)yahoo.com> wrote: > > > > > On Jun 7, 5:55 pm, "Sue..." <suzysewns...(a)yahoo.com.au> wrote: > > > > > > On Jun 7, 7:41 am, "Tim BandTech.com" <tttppp...(a)yahoo.com> wrote: > > > > > > Beyond this thermodynamics remains open in my book. > > > > > > This is a bit disturbing at this point in the thread. > > > > > Reynolds explained Crooks radiometer with > > > > > ~thermodynamics~ . > > > > > > Your discussion with Timo seems to be about > > > > > Nichols radiometer. The distinction was > > > > > made earlier in the thread but you will be > > > > > talking past one another if you are not > > > > > about the same device and effect. > > > > > Thanks for the attempt at resolution, but we are on to other aspects > > > > now. > > > > He seems to think that when you attribute all of a photons energy to > > > > momentum that somehow the energy is independent of that momentum. I'm > > > > not going to buy that, but if you can falsify either of us then I > > > > think that input is very welcome. > > > > I'll take your side because radiation~suction > > > fits an induction gravity mechanism better. > > > > (Timo can conscript a few students if he > > > thinks we are ganging up on him.) > > > > > We're really not beyond anything > > > > more than > > > > e = h f , e = m c c , > > > > > and such simple product relationships. > > > > I don't see how e = hf applies where there > > > may be no atomic absorption. > > > > <<The requirements of energy and momentum > > > conservation generally forbid the absorption > > > of photons by free carriers, and the process can > > > only take place by interband transitions or with > > > the assistance of phonon absorption or emission. >>http://www.colin-baxter.com/academic/research/downloads/prl063802.pdf > > > >http://en.wikipedia.org/wiki/Nichols_radiometerhttp://en.wikipedia.or... > > > > > > Apologies if I am covering old ground but > > > > > it is a long thread and I got here late. > > > > > Hey Sue, no problem. I guess one of the key points is that the > > > > radiometer itself is not quite what most of the discussion is about. > > > > Isolation of radiation pressure from the radiation is more like it. > > > > What I now understand and had overlooked for much of the thread is > > > > that the radiation pressure is merely the photon momentum, as is > > > > overlooked at > > > > http://en.wikipedia.org/wiki/Radiation_pressure > > > > and likely elsewhere. Nichols work is here: > > > > http://books.google.com/books?id=8n8OAAAAIAAJ&pg=RA5-PA329#v=onepage&... > > > > <<Theory > > > It may be shown by electromagnetic theory, by quantum > > > theory, or by thermodynamics, making no assumptions as > > > to the nature of the radiation, that the pressure against > > > a surface exposed in a space traversed by radiation > > > uniformly in all directions is equal to one third of the > > > total radiant energy per unit volume within that space.>> > > http://en.wikipedia.org/wiki/Radiation_pressure > > > > > > > > Hmmm... 1/3 is a pretty nice number and the statement > > > is very inverse square-ish. Is it too late to > > > switch to Timo's team? I am a sore looser. > > > > I see the traversed volume here:http://hyperphysics.phy-astr.gsu.edu/hbase/forces/isq.html > > > But all of it, half of it or 1/3 of it is not > > > doing anything for me unless we put some gas in > > > it and give it a temperature. > > > > Yeah... That's the steam. > > > Eggs explode in my microwave oven because > > > of radiation pressure. > > > > > which is actually linked to in that wiki you just gave. > > > > Some if his argumentation is quite poor imo. There is a 1933 paper by > > > > a woman Bell that I do not have access to which claims to resolve the > > > > study down to 10E-6 torr. I posted that link a few days ago here. > > > > In fairness, I should read about Timo's light-bullets > > > a bit closer before we declare victory. > > > > Photons (Phonons?) can be a pretty good model translating > > > angular momentum in a dielectric. I am becoming > > > sceptical however because acoustic radiation pressure > > > is lumped in, apparently as the same effect. > > > > If it is just molecules in the traversed volume > > > jiggling more, induction gravity should be unscathed > > > and it really shouldn't matter how you describe the > > > heating process. light bullets, flaming arrows, or > > > Ella Fitzgerald on Memorex. > > > Well, if the photon momentum is taken to be coming from the entire > > photon energy, then there is no room for the rotational quality to > > contain more energy. This is the logical trouble with the existing > > theory. > > The light is *all* angular momentum until charges in > the gas convert it through interaction. Antenna are > necessary for any directed energy. > > (With a minor exception) <<for a highly relativistic > charge the radiation is emitted in a narrow cone > whose axis is aligned along the direction of motion.>>http://farside.ph.utexas.edu/teaching/jk1/lectures/node33.html > > > As you say, we should take freedoms in describing these > > things. Ella Fitzgerald may be going a bit far, > > The wiki references indicate the principle is the same > for sound so Ella is not "too far" but specifically > included. Anything that heats the media is what > I understand for the Nichols device. Hmmm... I thought by going to 10E-6 torrs that the temperature effects were being diminished. Likewise sound does not travel in a vacuum- although this very word 'vacuum' is pretty dubious. As soon as you put anything in a vacuum it cannot be a vacuum anymore. So as soon as we plop down a Nichols device within the vacuum we ought perhaps to state that the Nichols device has been isolated, rather than use the vacuum terminology. Still, to what degree is the isolation perfect? Just tap the lab table and you've got your sound transmission again. > > >but as you take > > interest in gravitation there is room for a photon relationship with > > gravitation to provide gravitational shadowing, which could then > > provide the dark matter resolution. > > The term shadowing has a negative connotation > from some dubious shielding experiments but yes there > is mechanism for enhancement or attenuation > along a gravitational path so the "shadowing" > label seems to stick. > > It is not and bad as a big red "A" on your > blouse and it might even be a source > of pride when Mercury and Hulse-Taylor are > considered. Well, I looked at some Hulse-Taylor links. I suppose if it is true that gravitational shadowing is an effect then the planetary orbits will take on more dynamics and might help explain all of the strange angles of rotational axes, magnetic axes, maybe even how they can be in such a clean plane. That would be quite some fine tuning and would put the inner planets as the leaders. Anyway Sue it's nice to see you consider this idea, though cryptically. Here is a simple question for you: Is radiation pressure a unique effect from photon momentum? My answer is no, but I am still not getting much clear feedback on this, and as I read there is little direct connection made, though the math appears to work out directly. This is based on a wiki link number of the sun's radiation pressure, so I'm not feeling so solid. As I recall it is 4.6E-6 Pascals of solar radiation pressure here on the earth's surface from 1375 watts of solar radiation energy per square meter. It's rather alot of heat for a little kick. I'm trying to give this theory a kick in the pants. Speaking of panting, I'd better see what Timo has been up to on this thread. - Tim
From: Tim BandTech.com on 11 Jun 2010 07:38 On Jun 10, 10:31 pm, Timo Nieminen <t...(a)physics.uq.edu.au> wrote: > On Thu, 10 Jun 2010, Tim BandTech.com wrote: > > On Jun 10, 3:19 pm, Timo Nieminen <t...(a)physics.uq.edu.au> wrote: > > > On Jun 10, 9:43 pm, "Tim BandTech.com" <tttppp...(a)yahoo.com> wrote: > > > > On Jun 9, 3:40 pm, Timo Nieminen <t...(a)physics.uq.edu.au> wrote: > > > > > On Jun 10, 4:10 am, "Tim BandTech.com" <tttppp...(a)yahoo.com> wrote: > > > > > > > If we had, say, a large lead ball hanging on a > > > > > > string in stasis, and sent a tiny steel ball into the lead ball at > > > > > > high velocity then we would observe some heating, but too achieve the > > > > > > level of heating that light achieves will be quite some trick to mimic > > > > > > in the terms of massive collisions. > > > > > > Not at all. Wikipedia tells me that the energy of a typical 5.56mm > > > > > NATO bullet when fired is 1.7kJ. Shoot them into a massive target at a > > > > > little under 1 round per second, and you achieve approximately the > > > > > same heating. (Not the same force as with light! Just the same > > > > > heating.) > > > > > Here again I see your obfuscatory tactic. Firstly you falsify and in > > > > your conclusion you agree. > > > > You were quite specific: "level of heating that light achieves will be > > > quite some trick to mimic". This level of heating is easy to mimic. > > > > > The amount of heating that light is capable > > > > of when absorbed versus the work that can be done mechanically due to > > > > that absorption are remarkable in comparison to your NATO bullet. > > > > So, you want to change "level of heating" to "amount of heating versus > > > work"? If you meant this in the first place, you weren't clear enough. > > > To criticise my reply to your actual original words on the basis of > > > your _changed_ version lies somewhere on the scale from weaseling to > > > complete bullshit. > > > I'll have to own here that I should have used the word 'relative' > > within the context, but I see it is fairly easy to interperet since > > the context of the whole argument is still present. Hell, I can match > > the heat of sunlight rubbing some steel on a rock. The lead of the > > bullet will melt on impact. Your interpretation of my writing is > > clearly not coherent at many levels. > > Your original argument wasn't coherent, then. As far as I could tell, you > thought it improper that almost all of the energy should go into heating, > not work. Jeeze. I pity any onlooker who attempts to decode your own position. Now, via double crossing, I must admit that I do agree with your statement above and that this is exactly what I've been discussing all along. > > We see the same thing in Newtonian mechanics for a light object in > inelastic collision with a heavy object. Qualitatively, the same type of > thing, most of the energy going into heating. It is a peculiar thing to discuss an inelastic collision this way. There are more dynamics here and the options as to what happens with the energy are numerous. For instance, if we could design a spring with a ratchet to capture the projectile then we would only heat by the inefficiency of the spring device, rather than by the objects entire kinetic energy. Likewise as I stated before, this capture mechanism could as well generate electricity, and of course this is the quest of many right now; to capture electricity from the sun, and to do it at a better margin than 20%. We cannot grant the heat clause unconditionally, and instead want the mechanism of that heating. It is not so difficult to see electron disturbance; literally microcurrents flowing in short circuit fashion which provide the heating effect. That these charge concerns are so nearby to the Nichols device is a caveat on the operation of that device. That your light traps are so behaved is likewise a caveat. Some would like to free these electrons to take a larger path. Others would like to ignore them for their inconvenient truth. > > > The context of the discussion for me revolves around the photon energy > > and how we can come to attribute the photon momentum to the photon > > energy without concern for such things as angular momentum. > > We're not attributing the photon momentum to the photon energy. > > For a moving bullet, does the kinetic energy cause the momentum? Does the > momentum cause the kinetic energy? Do we attribute one to the other? > > For the photon, consider a spin +1 photon. How much of its energy is "in" > the angular momentum? > > Be specific: consider a 500nm photon, with hbar angular momentum. We can > write down 3 numbers: its energy, its momentum, and its angular momentum. > How are these 3 related to each other, showing appropriate concern for > angular momentum? > > How about for a 5Hz photon? Do the same. Does this mean that a 5Hz photon > shouldn't have any momentum? > > The ratios or values of energy, momentum, and angular momentum, as > commonly stated for photons, come straight out of classical > electromagnetic theory. Are these ratios or values wrong? Yes or no, no > handwaving, no waffle, just a straight answer. From what I've read of the quantum stuff the angular momentum is not so easy to observe. They even go so far as to grant a photon an orbital angular momentum, though the orbital context is not present in freely propagating light. And yet the light as an oscillation is still a coherent concept, and so the rotation momentum that I am considering is more like your NATO bullet spinning. As I recall the 5Hz photon will have the same quantum angular momentum than will the 500nm photon, but will have less total energy via e=hf. As you seek a straight answer I must ask you how crooked is the path of modern theory? Yes, we'd all like a straight answer, yet we do not actually have one yet. This is not to say that we should give up. We seek a straight answer, but I must admit that I do not yet have one. Simply eating particle/wave duality will deny a straight answer, but beyond this it seems that in the accumulation the overlap of radiation pressure with photon momentum has gotten lost in the shuffle. This is a great topic, and so difficult to discuss that I believe you and I both deserve credit, even while this discussion erodes. - Tim
From: NoEinstein on 11 Jun 2010 13:53 On Jun 11, 7:38 am, "Tim BandTech.com" <tttppp...(a)yahoo.com> wrote: > Dear Tim: The 'spin' of a NATO (or other) bullet isn't some huge additional momentum. If the KICK of the gun is 30 pounds, and the inertia of the gun is 10 pounds (the static weight), then the total KE is just 40 pounds, including the angular "KE" of the spinning bullet. That spin is produced by sacrificing some of the forward momentum. The effect is to rotate the gun in the direction opposite to the spin of the bullet. It isn't the KE nor the momentum of the bullet causing the penetration as much as the REDUCTION in the strengths of the materials that are hitwhich don't "like" rapidly applied loads, nor loads of more than one stress type at the same time. NoEinstein > > On Jun 10, 10:31 pm, Timo Nieminen <t...(a)physics.uq.edu.au> wrote: > > > On Thu, 10 Jun 2010, Tim BandTech.com wrote: > > > On Jun 10, 3:19 pm, Timo Nieminen <t...(a)physics.uq.edu.au> wrote: > > > > On Jun 10, 9:43 pm, "Tim BandTech.com" <tttppp...(a)yahoo.com> wrote: > > > > > On Jun 9, 3:40 pm, Timo Nieminen <t...(a)physics.uq.edu.au> wrote: > > > > > > On Jun 10, 4:10 am, "Tim BandTech.com" <tttppp...(a)yahoo.com> wrote: > > > > > > > > If we had, say, a large lead ball hanging on a > > > > > > > string in stasis, and sent a tiny steel ball into the lead ball at > > > > > > > high velocity then we would observe some heating, but too achieve the > > > > > > > level of heating that light achieves will be quite some trick to mimic > > > > > > > in the terms of massive collisions. > > > > > > > Not at all. Wikipedia tells me that the energy of a typical 5.56mm > > > > > > NATO bullet when fired is 1.7kJ. Shoot them into a massive target at a > > > > > > little under 1 round per second, and you achieve approximately the > > > > > > same heating. (Not the same force as with light! Just the same > > > > > > heating.) > > > > > > Here again I see your obfuscatory tactic. Firstly you falsify and in > > > > > your conclusion you agree. > > > > > You were quite specific: "level of heating that light achieves will be > > > > quite some trick to mimic". This level of heating is easy to mimic. > > > > > > The amount of heating that light is capable > > > > > of when absorbed versus the work that can be done mechanically due to > > > > > that absorption are remarkable in comparison to your NATO bullet. > > > > > So, you want to change "level of heating" to "amount of heating versus > > > > work"? If you meant this in the first place, you weren't clear enough. > > > > To criticise my reply to your actual original words on the basis of > > > > your _changed_ version lies somewhere on the scale from weaseling to > > > > complete bullshit. > > > > I'll have to own here that I should have used the word 'relative' > > > within the context, but I see it is fairly easy to interperet since > > > the context of the whole argument is still present. Hell, I can match > > > the heat of sunlight rubbing some steel on a rock. The lead of the > > > bullet will melt on impact. Your interpretation of my writing is > > > clearly not coherent at many levels. > > > Your original argument wasn't coherent, then. As far as I could tell, you > > thought it improper that almost all of the energy should go into heating, > > not work. > > Jeeze. I pity any onlooker who attempts to decode your own position. > Now, via double crossing, I must admit that I do agree with your > statement above and that this is exactly what I've been discussing all > along. > > > > > We see the same thing in Newtonian mechanics for a light object in > > inelastic collision with a heavy object. Qualitatively, the same type of > > thing, most of the energy going into heating. > > It is a peculiar thing to discuss an inelastic collision this way. > There are more dynamics here and the options as to what happens with > the energy are numerous. For instance, if we could design a spring > with a ratchet to capture the projectile then we would only heat by > the inefficiency of the spring device, rather than by the objects > entire kinetic energy. Likewise as I stated before, this capture > mechanism could as well generate electricity, and of course this is > the quest of many right now; to capture electricity from the sun, and > to do it at a better margin than 20%. We cannot grant the heat clause > unconditionally, and instead want the mechanism of that heating. It is > not so difficult to see electron disturbance; literally microcurrents > flowing in short circuit fashion which provide the heating effect. > That these charge concerns are so nearby to the Nichols device is a > caveat on the operation of that device. That your light traps are so > behaved is likewise a caveat. Some would like to free these electrons > to take a larger path. Others would like to ignore them for their > inconvenient truth. > > > > > > > > > > The context of the discussion for me revolves around the photon energy > > > and how we can come to attribute the photon momentum to the photon > > > energy without concern for such things as angular momentum. > > > We're not attributing the photon momentum to the photon energy. > > > For a moving bullet, does the kinetic energy cause the momentum? Does the > > momentum cause the kinetic energy? Do we attribute one to the other? > > > For the photon, consider a spin +1 photon. How much of its energy is "in" > > the angular momentum? > > > Be specific: consider a 500nm photon, with hbar angular momentum. We can > > write down 3 numbers: its energy, its momentum, and its angular momentum. > > How are these 3 related to each other, showing appropriate concern for > > angular momentum? > > > How about for a 5Hz photon? Do the same. Does this mean that a 5Hz photon > > shouldn't have any momentum? > > > The ratios or values of energy, momentum, and angular momentum, as > > commonly stated for photons, come straight out of classical > > electromagnetic theory. Are these ratios or values wrong? Yes or no, no > > handwaving, no waffle, just a straight answer. > > From what I've read of the quantum stuff the angular momentum is not > so easy to observe. They even go so far as to grant a photon an > orbital angular momentum, though the orbital context is not present in > freely propagating light. And yet the light as an oscillation is still > a coherent concept, and so the rotation momentum that I am considering > is more like your NATO bullet spinning. > > As I recall the 5Hz photon will have the same quantum angular momentum > than will the 500nm photon, but will have less total energy via e=hf. > > As you seek a straight answer I must ask you how crooked is the path > of modern theory? Yes, we'd all like a straight answer, yet we do not > actually have one yet. This is not to say that we should give up. We > seek a straight answer, but I must admit that I do not yet have one. > Simply eating particle/wave duality will deny a straight answer, but > beyond this it seems that in the accumulation the overlap of radiation > pressure with photon momentum has gotten lost in the shuffle. This is > a great topic, and so difficult to discuss that I believe you and I > both deserve credit, even while this discussion erodes. > > - Tim- Hide quoted text - > > - Show quoted text -- Hide quoted text - > > - Show quoted text -
From: NoEinstein on 11 Jun 2010 14:02
On Jun 10, 10:31 pm, Timo Nieminen <t...(a)physics.uq.edu.au> wrote: > Dear Timo: There are various kinds of energy which make up the TOTAL energy implied as being 'conserved' in the Law of the Conservation of Energy. The following reply of mine was to explain, as clearly as possible, how the KE of falling objects accrues. Most of the readers, not just you, should find the explanations clear. NE Dear PD: Most structural engineering problems involve the use of statics, rather than dynamics, to solve the equations. In statics, a one pound force, matched head-on by a one pound resisting force, wont allow the point of reaction to go accelerating away. On more than one occasion, when Ive said that the force must be equal to the resistancefor falling objects, that involves dynamics, not statics. Ill explain the difference. Suppose that there is a one pound object that is the payload of a rocket with a one pound net thrust; i.e., the rocket thrust is one pound MORE than the weight of the rocket minus the payload. Under those conditions, Newtons Second Law says that the rocket will be accelerating at 32.174 feet per second, each secondbetter known as the acceleration of gravity, g. As is the case for one pound objects on the surface of the Earth, the uniform force of gravity will cause any such object to press against the ground with a force of one pound. The ground, in turn, must offer an upward resistance of one pound to order to maintain static equilibrium (zero motion). Einstein himself noted that a person in a windowless box thats accelerating at g cant tell whether the box is resting, stationary, on the Earth, or flying through space. The box will be experiencing the weight of the person, and the person will experience the support (force) offered by the box. As required by Newtons Third Law, the action (the persons weight) is exactly matched by the reaction the supporting force provided by the box. Those two are equal and opposite, exactly as in the solving of problems in statics. The design equations for the box would be identical to the ones used on Earth for static loading. The INERTIA of falling objects isnt a constant force thats equal to the static weight, but can have any value *from zero up to the static weight. If a one pound block is resting on frictionless ice, that block can be caused to slide at, say, one ounce of force. In order to experience the maximum inertia of one pound, it will require applying a force, via some point of reaction, that is capable of moving 32.174 feet per second in the first second. So, the inertial resistance of any mass is VELOCITY dependent, within the limits, *above. Consider that payload being accelerated by a one pound net thrust rocket. If the payload weight is one pound, the acceleration will be g. If the payload weight were somehow reduced to .5 pounds, while the net rocket thrust remains one pound, the acceleration would jump to 2g. If the payload weight, somehow, could be increased to two pounds, the acceleration would be cut to .5g. It is very well known that all compact, near-Earth falling objects are accelerating at g'. Since the uniform force of gravity, acting on the one pound object, always causes such to accelerate at g, then, the force must be matched by the inertia of the objectas required by Newtons Third Law of Motion. PD, you have repeatedly claimed that there can be a downward one- pound force of gravity, WITHOUT there being a resistance. But heres why that cant be: Gravity requires an object to act upon. An object that has no resistance, also has no inertia, and will, therefore, have zero mass. You, erroneously, claim that a force can remain at one pound without there being a resistance. Heres why that is never the case: A big black house fly is circling your den, and aggravating you. So, you roll a newspaper into a one pound bat and swing away at the fly. After several misses, you finally hit the pest. Your hand and the newspaper were traveling exactly 32.174 feet per second. You figure you just smashed the fly with a one pound force on its tiny body. But much to your surprise, the fly hits the floor, readjusts its wings, and flies away, apparently unharmed. The physics of the above is simple: The impact of the fly and the newspaper will never cause a force thats greater than the inertia of the FLYquite small indeed! Since the flys body is always functioning under its full weight, accelerating it to 'g isnt a killing force. The fly could be stunned, allowing you to smash it flat, but you can never do that with a bat of ANY weight that isnt traveling faster than 32.174 feet per second. If the fly had ZERO resistance or zero inertia, the newspaper wouldnt experience any force at allexactly as if you had missed hitting it at all. Learn this, PD: The available force of gravity on a one pound dropped object, is 100% expended in causing the linear increase in the kinetic energy, as is given by my equation, KE = a/g (m) + v / 32.174 (m). Each second of fall, there is a COASTING carryover velocity from the end of each of the previous seconds. Coasting is what causes the free- drop curve to be parabolic in shape, rather than linear. Since 100% of the force of gravity produces only a linear increase in KE, then, there is no net force available to act through the remaining distance of fall, to cause the work that you imagine is being done. You err, PD, by assuming that a one pound force is available for both the coasting portion of the curve, and the straight line portion. As for a hockey puck already sliding on frictionless ice, there is no force needed to keep the puck moving, or coasting. If you still suppose that there is then you are ignoring the Law of the Conservation of Energy. Ive taken this long amount of time to walk-you-through the physics, not because I expect you to ever get it, but because I want 97.5% of the readers to know, that I know, that I know! NoEinstein > > On Thu, 10 Jun 2010, Tim BandTech.com wrote: > > On Jun 10, 3:19 pm, Timo Nieminen <t...(a)physics.uq.edu.au> wrote: > > > On Jun 10, 9:43 pm, "Tim BandTech.com" <tttppp...(a)yahoo.com> wrote: > > > > On Jun 9, 3:40 pm, Timo Nieminen <t...(a)physics.uq.edu.au> wrote: > > > > > On Jun 10, 4:10 am, "Tim BandTech.com" <tttppp...(a)yahoo.com> wrote: > > > > > > > If we had, say, a large lead ball hanging on a > > > > > > string in stasis, and sent a tiny steel ball into the lead ball at > > > > > > high velocity then we would observe some heating, but too achieve the > > > > > > level of heating that light achieves will be quite some trick to mimic > > > > > > in the terms of massive collisions. > > > > > > Not at all. Wikipedia tells me that the energy of a typical 5.56mm > > > > > NATO bullet when fired is 1.7kJ. Shoot them into a massive target at a > > > > > little under 1 round per second, and you achieve approximately the > > > > > same heating. (Not the same force as with light! Just the same > > > > > heating.) > > > > > Here again I see your obfuscatory tactic. Firstly you falsify and in > > > > your conclusion you agree. > > > > You were quite specific: "level of heating that light achieves will be > > > quite some trick to mimic". This level of heating is easy to mimic. > > > > > The amount of heating that light is capable > > > > of when absorbed versus the work that can be done mechanically due to > > > > that absorption are remarkable in comparison to your NATO bullet. > > > > So, you want to change "level of heating" to "amount of heating versus > > > work"? If you meant this in the first place, you weren't clear enough.. > > > To criticise my reply to your actual original words on the basis of > > > your _changed_ version lies somewhere on the scale from weaseling to > > > complete bullshit. > > > I'll have to own here that I should have used the word 'relative' > > within the context, but I see it is fairly easy to interperet since > > the context of the whole argument is still present. Hell, I can match > > the heat of sunlight rubbing some steel on a rock. The lead of the > > bullet will melt on impact. Your interpretation of my writing is > > clearly not coherent at many levels. > > Your original argument wasn't coherent, then. As far as I could tell, you > thought it improper that almost all of the energy should go into heating, > not work. > > We see the same thing in Newtonian mechanics for a light object in > inelastic collision with a heavy object. Qualitatively, the same type of > thing, most of the energy going into heating. > > > The context of the discussion for me revolves around the photon energy > > and how we can come to attribute the photon momentum to the photon > > energy without concern for such things as angular momentum. > > We're not attributing the photon momentum to the photon energy. > > For a moving bullet, does the kinetic energy cause the momentum? Does the > momentum cause the kinetic energy? Do we attribute one to the other? > > For the photon, consider a spin +1 photon. How much of its energy is "in" > the angular momentum? > > Be specific: consider a 500nm photon, with hbar angular momentum. We can > write down 3 numbers: its energy, its momentum, and its angular momentum. > How are these 3 related to each other, showing appropriate concern for > angular momentum? > > How about for a 5Hz photon? Do the same. Does this mean that a 5Hz photon > shouldn't have any momentum? > > The ratios or values of energy, momentum, and angular momentum, as > commonly stated for photons, come straight out of classical > electromagnetic theory. Are these ratios or values wrong? Yes or no, no > handwaving, no waffle, just a straight answer.- Hide quoted text - > > - Show quoted text - |