What is the experimentally measurable difference between rest mass and the 'relativistic mass' of the photon ??!!
in [Relativity]
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From: BURT on 18 May 2010 16:13 On May 18, 1:09 pm, PD <thedraperfam...(a)gmail.com> wrote: > On May 18, 2:19 pm, "Androcles" <Headmas...(a)Hogwarts.physics_z> wrote: > > > > > Present the evidence; all you need do is argue your case logically, > > based on acceptable axioms, and I'll accept what you say. > > When one teaches, two learn. > > I'm quite willing to listen, but I'll jump down your throat and rip your > > lungs out (metaphorically, of course) if you try to bullshit me. > > > Able to follow? > > Sorry, but you're talking mathematics and philosophy, not physics. > Cases in physics are not made by arguing logically from mutually > acceptable axioms. > If this is how you'd like to proceed with physics, then you're barking > up the wrong tree. > > Physics does things a little differently. The proposer puts together a > model that includes some axioms, whether the axioms or the model are > considered acceptable or not. Quite often, the axioms are considered > outlandish and contrary to conventional wisdom. So what? From that > model and those *assumed* axioms, certain conclusions are deduced from > them, including a number of conclusions that are distinct from other > models and which can be directly or indirectly tested in experimental > measurement. When a significant number of those distinguishing > conclusions are found in accord with measurement, then this > provisionally *forces* the acceptance of the model and the axioms, in > that the model has demonstrated itself to be superior to competing > models on the grounds of experimental confirmation. > > If you think that's a sucky way to do business, and you're not about > to go along with that game plan, then that's fine, but you're no > longer doing physics. > > PD The kinetic energy of light would be universal due to the constant of C. But it is clear that all of light does not have the same energy. Light has no energy of motion only an energy of oscillation. Mitch Raemsch
From: Y.Porat on 19 May 2010 00:57 On May 18, 10:09 pm, PD <thedraperfam...(a)gmail.com> wrote: > On May 18, 2:19 pm, "Androcles" <Headmas...(a)Hogwarts.physics_z> wrote: > > > > > Present the evidence; all you need do is argue your case logically, > > based on acceptable axioms, and I'll accept what you say. > > When one teaches, two learn. > > I'm quite willing to listen, but I'll jump down your throat and rip your > > lungs out (metaphorically, of course) if you try to bullshit me. > > > Able to follow? > > Sorry, but you're talking mathematics and philosophy, not physics. > Cases in physics are not made by arguing logically from mutually > acceptable axioms. > If this is how you'd like to proceed with physics, then you're barking > up the wrong tree. > > Physics does things a little differently. The proposer puts together a > model that includes some axioms, whether the axioms or the model are > considered acceptable or not. Quite often, the axioms are considered > outlandish and contrary to conventional wisdom. So what? From that > model and those *assumed* axioms, certain conclusions are deduced from > them, including a number of conclusions that are distinct from other > models and which can be directly or indirectly tested in experimental > measurement. When a significant number of those distinguishing > conclusions are found in accord with measurement, then this > provisionally *forces* the acceptance of the model and the axioms, in > that the model has demonstrated itself to be superior to competing > models on the grounds of experimental confirmation. > > If you think that's a sucky way to do business, and you're not about > to go along with that game plan, then that's fine, but you're no > longer doing physics. > > PD -------------------------- crook PD one sign that you are talking a lot about how physics should be tells us the less physicist you are not a physicist you are a crook politician!! a parrot politician!! there is just one kind of mass !! no matter how do you call it it is shown easily by the momentum of the photon: P (photon momentum) =m c !!! see the Plank momentum Pl momentum = Plank mass times c !!! now in that m c THERE IS NOTHING 'RELATIVISTIC' (or anything else ) EVEN IF YOU WILL STAND ON YOUR BLOCKED crooked HEAD no gamma factor non of the slightest sign that that mass is something else than just **mass!!* the only mass that exists in that M K S system !! (it is the K there !!) FULL STOP !! NO NEED FOR LONGER MUMBLINGS !!!! keep well Y.Porat ---------------------------
From: PD on 19 May 2010 08:55 On May 18, 11:57 pm, "Y.Porat" <y.y.po...(a)gmail.com> wrote: > On May 18, 10:09 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On May 18, 2:19 pm, "Androcles" <Headmas...(a)Hogwarts.physics_z> wrote: > > > > Present the evidence; all you need do is argue your case logically, > > > based on acceptable axioms, and I'll accept what you say. > > > When one teaches, two learn. > > > I'm quite willing to listen, but I'll jump down your throat and rip your > > > lungs out (metaphorically, of course) if you try to bullshit me. > > > > Able to follow? > > > Sorry, but you're talking mathematics and philosophy, not physics. > > Cases in physics are not made by arguing logically from mutually > > acceptable axioms. > > If this is how you'd like to proceed with physics, then you're barking > > up the wrong tree. > > > Physics does things a little differently. The proposer puts together a > > model that includes some axioms, whether the axioms or the model are > > considered acceptable or not. Quite often, the axioms are considered > > outlandish and contrary to conventional wisdom. So what? From that > > model and those *assumed* axioms, certain conclusions are deduced from > > them, including a number of conclusions that are distinct from other > > models and which can be directly or indirectly tested in experimental > > measurement. When a significant number of those distinguishing > > conclusions are found in accord with measurement, then this > > provisionally *forces* the acceptance of the model and the axioms, in > > that the model has demonstrated itself to be superior to competing > > models on the grounds of experimental confirmation. > > > If you think that's a sucky way to do business, and you're not about > > to go along with that game plan, then that's fine, but you're no > > longer doing physics. > > > PD > > -------------------------- > crook PD > one sign that you are talking a lot about how physics should be > tells us the less physicist you are > not a physicist you are a crook politician!! > a parrot politician!! > > there is just one kind of mass !! > no matter how do you call it > > it is shown easily by the momentum > of the photon: > > P (photon momentum) =m c !!! That's not the momentum of the photon. It is not the momentum of any object known, in fact. We've already discussed this. Case closed. > > see the Plank momentum > Pl momentum = Plank mass times c !!! > > now > in that m c > > THERE IS NOTHING 'RELATIVISTIC' > (or anything else ) > EVEN IF YOU WILL STAND ON YOUR BLOCKED > crooked HEAD > no gamma factor non of the slightest sign that > that mass is something else than just **mass!!* > the only mass that exists in that M K S system !! > (it is the K there !!) > > FULL STOP !! > NO NEED FOR LONGER MUMBLINGS !!!! > keep well > Y.Porat > ---------------------------
From: Paul B. Andersen on 19 May 2010 09:31 On 18.05.2010 17:16, Inertial wrote: > "Paul B. Andersen" <paul.b.andersen(a)somewhere.no> wrote in message > news:hsu4au$2ald$2(a)news01.tp.hist.no... >> On 12.05.2010 15:55, Tony M wrote: >>> On May 12, 8:49 am, "Paul B. Andersen"<paul.b.ander...(a)somewhere.no> >>> wrote: >>>> On 12.05.2010 07:02, Koobee Wublee wrote: >>>> >>>> >>>> >>>> >>>> >>>>> Let's bring back the two >>>>> equations describing energy, mass, and momentum below. >>>> >>>>> *1* E^2 = m^2 c^4 + p^2 c^2 >>>>> *2* E^2 = m'^2 c^4 >>>> >>>>> Where >>>> >>>>> ** m = Rest mass >>>>> ** m' = Observed mass >>>>> ** p = Observed momentum >>>> >>>>> These equations are actually identical, but there are always bevies of >>>>> Einstein Dingleberries who would aloofly swear to their god Einstein >>>>> the nitwit, the plagiarist, and the liar that equation *1* is the only >>>>> one that is any valid. >>>> >>>> They are identical for massive objects only. >>>> What does *2* say the energy of a photon is? >>>> Is it correct? >>>> >>>> -- >>>> Paul >>>> >>>> http://home.c2i.net/pb_andersen/- Hide quoted text - >>>> >>>> - Show quoted text - >>> >>> >>> It says the energy of a photon is equal to its observed (or >>> relativistic) mass (not the rest mass) multiplied by c^2. >>> And yes, it is very correct. >> >> A massless particle has no 'relativistic mass'. >> The 'mass equivalent' of its energy, h*nu/c^2 >> is not the same as 'relativistic mass'. > > Sorrry. .but that appears not to be correct. Please specify your source > for those statements, It depend on how you define 'relativistic mass', it's not a very well defined entity. One definition is m' = E/c^2, which is applicable for all kind of particles, even massless ones. With this definition, you are right, then the 'relativistic mass' of a photon is indeed h*nu/c^2 But I find this definition rather pointless. Remember that it originally stems from Einstein (even if he didn't use that term in 1905); since momentum is mv, the mass has to increase at high velocities. This increased mass was later called the 'relativistic mass', as opposed to rest mass. The definition E/c^2 came much later. The trend now is, as I am sure you know, not to use the term 'relativistic mass' at all. It is confusing and utterly unnecessary. It's only one kind of mass, the invariant mass. The photon mass is zero. p = m*gamma*v for massive objects, p = h/lambda for photons E^2 = (mc^2)^2 + (pc)^2 works for both (without any 'relativistic mass') And I am sure you know how this equation relates to the energy-momentum four-vector. -- Paul http://home.c2i.net/pb_andersen/
From: Paul B. Andersen on 19 May 2010 09:56
On 18.05.2010 17:35, Inertial wrote: > "Paul B. Andersen" <paul.b.andersen(a)somewhere.no> wrote in message > news:hsu4aq$2ald$1(a)news01.tp.hist.no... >> On 13.05.2010 01:13, Inertial wrote: >>> "Paul B. Andersen" <paul.b.andersen(a)somewhere.no> wrote in message >>> news:hse85f$tnb$1(a)news01.tp.hist.no... >>>> On 12.05.2010 07:02, Koobee Wublee wrote: >>>>> Let's bring back the two >>>>> equations describing energy, mass, and momentum below. >>>>> >>>>> *1* E^2 = m^2 c^4 + p^2 c^2 >>>>> *2* E^2 = m'^2 c^4 >>>>> >>>>> Where >>>>> >>>>> ** m = Rest mass >>>>> ** m' = Observed mass >>>>> ** p = Observed momentum >>>>> >>>>> These equations are actually identical, but there are always bevies of >>>>> Einstein Dingleberries who would aloofly swear to their god Einstein >>>>> the nitwit, the plagiarist, and the liar that equation *1* is the only >>>>> one that is any valid. >>>> >>>> They are identical for massive objects only. >>>> What does *2* say the energy of a photon is? >>>> Is it correct? >>> >>> If you only define m' by using >>> >>> m' = gamma.m >>> >>> then you are correct, as that formula is indeterminate for the value of >>> m' when v=c and m=0 (it ends up 0/0 .. which can be any value) >>> >>> However, that is not the only way to calculate an m' value (in >>> particular for photons). >>> >> >> A massless particle has no 'relativistic mass'. > > So you disagree with > http://www.xs4all.nl/~johanw/PhysFAQ/Relativity/SR/mass.html > which says > > "Lastly, the energy E of an object, whether moving or at rest, is given > by Einstein's famous relation E = mc2, where m is its relativistic mass. > Because, for example, the photon has no rest mass but does have > relativistic mass, the use of relativistic mass makes it much easier to > describe the mass changes that happen when light interacts with matter." > > And disagree with > http://en.wikipedia.org/wiki/Mass_in_special_relativity#Later_relativistic_concepts > > which says > "In 1934, Tolman also defined relativistic mass as m = E / c^2 which > holds for all particles, including those moving at the speed of light." > > And with > http://www.relativisticmass.com/ > which says > "Relativistic mass may also be determined by energy / c^2" > See my other posting. Yet another demonstration of how confusing the obsolete 'relativistic mass' is. :-) -- Paul http://home.c2i.net/pb_andersen/ |