Recent content by sf1001

I made a presentation where I derived, or at least attempted to derive, the formulae for the upper bounds of the efficiency/cop (cop = coefficient of performance) for a heat engine, work driven heat pump, and a heat driven heat pump with 3 thermal reservoirs, hot, warm, and cold. There are many...

I thought photons could have arbitrarily low energy as wavelength increases.

Thanks for the clarification

I’m aware gravitational energy and momentum can be difficult to define in general relativity, but I thought gravitational waves might be able to carry energy & momentum in some sense & that when they collide they could create a photon pair (or other particle pair if energetic enough) the same...

I thought the possibility that a resulting photon pair could propagate outward on differing alignments with the same initial colliding gravitational waves would mean that a test particle’s inertial path (eg one of the resulting photons) could be different with the same initial location in...

https://en.m.wikipedia.org/wiki/Ozsváth–Schücking_metric The article says this metric is not isometric to Minkowski space; but maybe this doesn't imply that it’s not locally the same as Minkowski space? Also maybe I misconstrued the metric to think that it implied a local rotational asymmetry...

According to wikipedia, the strong equivalence principle states “the gravitational motion of a small test body depends only on its initial position in space time and velocity, and not on its constitution, and the outcome of any local experiment (gravitational or not) in a freely falling...

@ mheslep Pu 240 has higher bare sphere (&reflected) fast critical mass than Pu239. But, the problem w/ Pu240 is that it lowers the time constant to become critical once mass has the right geometric configuration (I think because of Pu240's much shorter half life); the problem w/ Pu240 is that...

The plutonium used for modern nuclear bombs, which only use implosion type devices (similar to Fatman & Trinity), still needs to have <~7% Pu240 contamination, which can only be accomplished with <~90 days burn-up in a thermal nuclear reactor. Civilian (thermal) nuclear reactors typically have...

I know Pu239 produced in a thermal reactor is difficult or impossible to use for nuclear weapons if its fuel burn up is much greater than ~5 GW-d/tHM. But, could weapons grade Pu be produced from fast reactors w/ burn up > 30 GWd/t, since Pu 239 fission to absorption cross section ratio is much...

I've been reading about fast reactor designs lately (not necessarily ones that have actually been built). A few articles I've come across < https://drive.google.com/folderview?id=0B-MNeRy61MgpTVExcUQ3T3ZWWG8&usp=sharing > discuss the possibility of building fast reactors, fueled with molten U...

I read recently in my old ugrad 2012 solid state physics textbook, in its discussion of the attractive force between electrons in cooper pairs (in superconductors), that the attractive force between cooper pairs is explained mostly by the exchange of phonons (a quasiparticle associated with the...

I am aware the soviet reactors were cheap to build in part because they lacked the safety features of western reactors (I think the RBMKs laccked a reactor conainment vessel) and that candu reactors, which are prbly as safe as other commercial western reactors, have a slight positive void...

Is it possible to create a graphite moderated light water cooled reactor w/ at least 3 GW thermal power output and a non-positive void coefficient that runs on slightly enriched uranium (0.9-2%) w/ at least 60 GWd/tHM burn-up? If not, is it possible to create a graphite moderated light water...

The fuel composition was given in mole fractions.