I agree with that. Either way you have changed the measured. On Sunday, August 19, 2012, Harry Veeder wrote:
> The measuring system can either transfer energy from itself to the > system being measured or do the reverse and transfer energy from the > system being measured to itself. > > harry > > On Sun, Aug 19, 2012 at 6:58 AM, ChemE Stewart <[email protected]> wrote: > > The act of measuring requires one to impart some energy (photons or > other) > > or matter upon the particle. Upon the object being measured, the object > may > > instantly increase in mass or change velocity. Over time this energy > will > > be transferred back to its environment as it evaporates... > > > > On Saturday, August 18, 2012, Harry Veeder wrote: > >> > >> BTW, I appear to contradict myself when I said "measuring cannot > >> increase the energy of the particle" > >> vs I agree with the claim that measuring can concentrate energy in a > >> system. In the former, I mean I don't accept the idea that measuring > >> can somehow increase the energy the particle without the transfer of > >> energy from somewhere else. > >> > >> Harry > >> > >> On Sat, Aug 18, 2012 at 7:31 PM, Harry Veeder <[email protected]> > >> wrote: > >> > Hi LP, > >> > > >> > I haven't read the paper, but I don't disagree with claim. In fact it > >> > should not be unexpected. > >> > > >> > Even in a macroscopic system a concentration energy can come about as > >> > a result of energy being transferred from the measuring system to the > >> > system being measured. Of course, such a measuring system would be > >> > considered defective because it provides a distorted picture of the > >> > energy content of system being measured. However, classical mechanics > >> > says a measuring system can be designed in theory to have an > >> > arbitrarily small distorting effect, whereas quantum mechanics says > >> > this is not possible in theory. > >> > > >> > Harry > >> > > >> > On Sat, Aug 18, 2012 at 2:44 PM, <[email protected]> wrote: > >> >> Hello Harry, > >> >> > >> >> To be really precise, though, an energy measurement of a particle in > a > >> >> superposition of energy eigenstates might find it in one of the > states > >> >> higher than the weighted average energy of its wavefunction. So, you > >> >> might say that the measurement increased its energy, but over many > such > >> >> measurements would just produce the mean energy of the wavefunction. > >> >> > >> >> While I am not convinced they are correct, the authors of the paper I > >> >> referenced end with the conclusion - > >> >> > >> >> "From a general perspective a phenomenon like the energy > concentration > >> >> in > >> >> a composite quantum system can indeed be motivated physically. There > >> >> exist > >> >> processes, where there is a redistribution of energy among different > >> >> system degrees of freedom making possible some amounts of system > >> >> self-organization. In particular, one could examine the possibility > of > >> >> concentrating the total energy of the system into a subset of degrees > >> >> of > >> >> freedom producing a decrease of its entropy, which in order to avoid > a > >> >> violation of the second law of thermodynamics, would compel the > release > >> >> of > >> >> energy to the environment, thus keeping the free energy constant. > This > >> >> is > >> >> possible only if the system is open..." > >> >> > >> >> "Concentrating Energy by Measurement" > >> >> http://arxiv.org/abs/1012.5868 > >> >> > >> >> Interesting theory. > >> >> > >> >> -- LP > >> >> > >> >> Harry Veeder wrote: > >> >>> Actually, I tend agree with Robin that measuring cannot increase the > >> >>> energy of the particle. My question reflects my own attempt to > >> >>> understand why it is so. Now that I have thought about it, it is > >> >>> because one doesn't measure energy per se. Most measurements are > >> >>> really the result of calculations based on measurements of length > and > >> >>> time plugged into a formula
