Search results
Results From The WOW.Com Content Network
To create an electron-positron pair, the total energy of the photons, in the rest frame, must be at least 2m e c 2 = 2 × 0.511 MeV = 1.022 MeV (m e is the mass of one electron and c is the speed of light in vacuum), an energy value that corresponds to soft gamma ray photons.
Photons can be scattered by matter. For example, photons scatter so many times in the solar radiative zone after leaving the core of the Sun that radiant energy takes about a million years to reach the convection zone. [116] However, photons emitted from the sun's photosphere take only 8.3 minutes to reach Earth. [117]
This fermion pair can be leptons or quarks. Thus, two-photon physics experiments can be used as ways to study the photon structure, or, somewhat metaphorically, what is "inside" the photon. The photon fluctuates into a fermion–antifermion pair. Creation of a fermion–antifermion pair through the direct two-photon interaction.
The minuscule mass difference is the energy needed to split the molecule into three individual atoms (divided by c 2), which was given off as heat when the molecule formed (this heat had mass). Similarly, a stick of dynamite in theory weighs a little bit more than the fragments after the explosion; in this case the mass difference is the energy ...
The wavelength of the station is λ = c/ν = 3 m, so that λ/(2π) = 48 cm and the volume is 0.109 m 3. The energy content of this volume element at 5 km from the station is 2.1 × 10 −10 × 0.109 = 2.3 × 10 −11 J, which amounts to 3.4 × 10 14 photons per ().
Photons with high photon energy can transform in quantum mechanics to lepton and quark pairs, the latter fragmented subsequently to jets of hadrons, i.e. protons, pions, etc.At high energies E the lifetime t of such quantum fluctuations of mass M becomes nearly macroscopic: t ≈ E/M 2; this amounts to flight lengths as large as one micrometer for electron pairs in a 100 GeV photon beam, while ...
For example, a massive particle can decay into photons which individually have no mass, but which (as a system) preserve the invariant mass of the particle which produced them. Also a box of moving non-interacting particles (e.g., photons, or an ideal gas) will have a larger invariant mass than the sum of the rest masses of the particles which ...
An FM radio station transmitting at 100 MHz emits photons with an energy of about 4.1357 × 10 −7 eV. This minuscule amount of energy is approximately 8 × 10 −13 times the electron's mass (via mass–energy equivalence). Very-high-energy gamma rays have photon energies of 100 GeV to over 1 PeV (10 11 to 10 15 electronvolts) or 16 nJ to 160 ...