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  2. Faraday cage - Wikipedia

    en.wikipedia.org/wiki/Faraday_cage

    Some buildings, such as prisons, are constructed as a Faraday cage because they have reasons to block both incoming and outgoing cell phone calls by prisoners. [9] [10] The exhibit hall of the Green Bank Observatory is a Faraday cage to prevent interference with the operations of their radio telescopes. [11]

  3. Electromagnetic shielding - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_shielding

    A conductive enclosure used to block electrostatic fields is also known as a Faraday cage. The amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of holes in a shield to an incident electromagnetic field.

  4. List of physical quantities - Wikipedia

    en.wikipedia.org/wiki/List_of_physical_quantities

    Mass of a substance as a fraction of the total mass kg/kg 1: intensive (Mass) Density (or volume density) ρ: Mass per unit volume kg/m 3: L −3 M: intensive Mean lifetime: τ: Average time for a particle of a substance to decay s T: intensive Molar concentration: C: Amount of substance per unit volume mol⋅m −3: L −3 N: intensive Molar ...

  5. Solar radio emission - Wikipedia

    en.wikipedia.org/wiki/Solar_radio_emission

    A radio wave can be reflected in the solar atmosphere when it encounters a region of particularly high density compared to where it was produced, and such reflections can occur many times before a radio wave escapes the atmosphere. This process of many successive reflections is called scattering, and it has many important consequences. [47]

  6. Electromagnetic radiation - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_radiation

    A monochromatic wave (a wave of a single frequency) consists of successive troughs and crests, and the distance between two adjacent crests or troughs is called the wavelength. Waves of the electromagnetic spectrum vary in size, from very long radio waves longer than a continent to very short gamma rays smaller than atom nuclei.

  7. Radiation - Wikipedia

    en.wikipedia.org/wiki/Radiation

    Radiation used for cancer treatment is called ionizing radiation because it forms ions in the cells of the tissues it passes through as it dislodges electrons from atoms. This can kill cells or change genes so the cells cannot grow. Other forms of radiation such as radio waves, microwaves, and light waves are called non-ionizing.

  8. List of common physics notations - Wikipedia

    en.wikipedia.org/wiki/List_of_common_physics...

    Cartesian y-axis basis unit vector unitless kinetic energy: joule (J) wave vector: radian per meter (m −1) Boltzmann constant: joule per kelvin (J/K) wavenumber: radian per meter (m −1) stiffness: newton per meter (N⋅m −1) ^ Cartesian z-axis basis unit vector

  9. SI base unit - Wikipedia

    en.wikipedia.org/wiki/SI_base_unit

    "The kilogram, symbol kg, is the SI unit of mass. It is defined by taking the fixed numerical value of the Planck constant h to be 6.626 070 15 × 10 −34 when expressed in the unit J s, which is equal to kg m 2 s −1, where the metre and the second are defined in terms of c and ∆ν Cs." [1] The mass of one litre of water at the temperature ...