Search results
Results From The WOW.Com Content Network
In the late 17th century, Sir Isaac Newton had advocated that light was corpuscular (particulate), but Christiaan Huygens took an opposing wave description. While Newton had favored a particle approach, he was the first to attempt to reconcile both wave and particle theories of light, and the only one in his time to consider both, thereby anticipating modern wave-particle duality.
Admission to undergraduate science programs (BS Four-year and BS-MS Dual Degree Five-year programs) in 7 IISERs, BS Four-year program in IISc, and BS Four-year program of MSE in IIT Madras only. Year started: 2010 (15 years ago) () Duration: 3 hours: Score range-60 to +240: Offered: once in a year: Restrictions on attempts
In theoretical physics, the dual photon is a hypothetical elementary particle that is a dual of the photon under electric–magnetic duality which is predicted by some theoretical models, [3] [4] [5] including M-theory. [1] [2] It has been shown that including magnetic monopole in Maxwell's equations introduces a singularity.
Schematic of energy levels involved in two photons absorption. In atomic physics, two-photon absorption (TPA or 2PA), also called two-photon excitation or non-linear absorption, is the simultaneous absorption of two photons of identical or different frequencies in order to excite an atom or a molecule from one state (usually the ground state), via a virtual energy level, to a higher energy ...
The types of radiation that can alter structural materials are neutron radiation, ion beams, electrons (beta particles), and gamma rays. All of these forms of radiation have the capability to displace atoms from their lattice sites, which is the fundamental process that drives the changes in structural metals.
The third class are matter waves which have a wavevector, a wavelength and vary with time, but have a zero group velocity or probability flux. The simplest of these, similar to the notation above would be cos ( k ⋅ r − ω t ) {\displaystyle \cos(\mathbf {k} \cdot \mathbf {r} -\omega t)} These occur as part of the particle in a box , and ...
Planck also noted that the perfect black bodies of Kirchhoff do not occur in physical reality. They are theoretical fictions. Kirchhoff's perfect black bodies absorb all the radiation that falls on them, right in an infinitely thin surface layer, with no reflection and no scattering. They emit radiation in perfect accord with Lambert's cosine law.
It is a purely mathematical fact that the characteristic polynomial of the Einstein tensor of any pp-wave spacetime vanishes identically. Equivalently, we can find a Newman–Penrose complex null tetrad such that the Ricci-NP scalars (describing any matter or nongravitational fields which may be present in a spacetime) and the Weyl-NP scalars (describing any gravitational field which may be ...