2010年10月31日 · The macroscopic cross-section (Σ) has units of cm-1 is derived from the microscopic section according to Σ = N σ, where N is the atomic density of a particular nuclide. The reaction rate for a give interaction = Σ Φ, where Φ is the neutron flux. These forumla work well for average or thermal neutron energies.

2004年11月23日 · No one is saying that GR is only a macroscopic theory, just that on the microscopic scale quantum effects become significant and also have to be taken into account. Of course the macroscopic scope of GR becomes microscopic in the earliest stages of the Big Bang and so it then becomes imperative to have an integrated quantum gravity to find out ...

2020年1月15日 · Did theoretician understood how a wavefunction with such a small wavelength could arise from the wave functions of the smaller particles inside the macroscopic objects that have larger wavethengthes ? Or is the wavefunction of the big object just a kind of heuristic tool that no one should try to understand in term of the subparts wavefuntions ?

2013年7月12日 · macroscopic cross section=1/mean free path for water 1-cos(theta)=0.324 and 0.116 for heavy water Its not right to use theta in thermal energy because in thermal area of energy scattering is isotropic!

2020年8月13日 · Quantum Mechanics seems to explain phenomenon happening on a microscopic scale, where measurements aren't definite and probability plays a role. Classical physics explain macroscopic phenomenon where measurements are definitive without probability of that event happening. Is it happening just...

2015年12月1日 · The uncertainty principle applies to macroscopic objects in the sense that it sets a limit on our ability to measure their properties accurately. This means that even for objects that are large enough to be seen with the naked eye, there will always be a degree of uncertainty in our measurements of their position and momentum.

2025年1月19日 · Any macroscopic object is made up of an enormous number of particles, each of which individually behaves quantum mechanically. We can show mathematically that these quantum effects tend to average out so that the object as a whole behaves classically even though everything it is made of is behaving quantum mechanically (google for "quantum ...

2025年1月10日 · On large scales, the matter appears as a fluid-like "dust" with properties such as angular momentum and torsion that emerge from the collective behavior of galaxies. This approach aligns with ideas from Einstein–Cartan theory, where the macroscopic geometry of the universe reflects the average properties of finer structures.

2016年3月25日 · perhaps you meant micrscopic and macroscopic level. Uncertainty principle works/operate at microscopic level- in classical world -macroscopic level the uncertainties are not important as its value is so small(due to Planck's constant h) that it becomes meaningless. a few examples are there -but i can not vouch for its simplicity-

2011年10月6日 · Attempt to use De Broglie waves to macroscopic objects always leads to beyond-Universe scale: either in time, distance, energy, or to incredible densities of matter (beyond black hole densities). In both cases we know that Quantum Mechanics is not applicable - in such areas it must be extended by more general theory of Quantum Gravity.