enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Vacuum energy - Wikipedia

    en.wikipedia.org/wiki/Vacuum_energy

    Using the upper limit of the cosmological constant, the vacuum energy of free space has been estimated to be 10 −9 joules (10 −2 ergs), or ~5 GeV per cubic meter. [3] However, in quantum electrodynamics , consistency with the principle of Lorentz covariance and with the magnitude of the Planck constant suggests a much larger value of 10 113 ...

  3. Earth's energy budget - Wikipedia

    en.wikipedia.org/wiki/Earth's_energy_budget

    Earth's energy budget (or Earth's energy balance) is the balance between the energy that Earth receives from the Sun and the energy the Earth loses back into outer space. Smaller energy sources, such as Earth's internal heat, are taken into consideration, but make a tiny contribution compared to solar energy.

  4. Shockley–Queisser limit - Wikipedia

    en.wikipedia.org/wiki/Shockley–Queisser_limit

    This places an immediate limit on the amount of energy that can be extracted from the sun. Of the 1,000 W/m 2 in AM1.5 sunlight, about 19% of that has less than 1.1 eV of energy, and will not produce power in a silicon cell. Another important contributor to losses is that any energy above and beyond the bandgap energy is lost. While blue light ...

  5. Atmospheric escape - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_escape

    One classical thermal escape mechanism is Jeans escape, [1] named after British astronomer Sir James Jeans, who first described this process of atmospheric loss. [2] In a quantity of gas, the average velocity of any one molecule is measured by the gas's temperature, but the velocities of individual molecules change as they collide with one another, gaining and losing kinetic energy.

  6. Zero-point energy - Wikipedia

    en.wikipedia.org/wiki/Zero-point_energy

    Energy density curves space, and an increase in energy density produces an increase of curvature. Furthermore, the zero-point energy density has other physical consequences e.g. the Casimir effect, contribution to the Lamb shift, or anomalous magnetic moment of the electron, it is clear it is not just a mathematical constant or artifact that ...

  7. Zero-energy universe - Wikipedia

    en.wikipedia.org/wiki/Zero-energy_universe

    Gravitational energy from visible matter accounts for 26–37% of the observed total mass–energy density. [15] Therefore, to fit the concept of a "zero-energy universe" to the observed universe, other negative energy reservoirs besides gravity from baryonic matter are necessary. These reservoirs are frequently assumed to be dark matter. [16]

  8. Solar panels on spacecraft - Wikipedia

    en.wikipedia.org/wiki/Solar_panels_on_spacecraft

    The International Space Station also uses solar arrays to power everything on the station. The 262,400 solar cells cover around 27,000 square feet (2,500 m 2 ) of space. There are four sets of solar arrays that power the station and the fourth set of arrays were installed in March 2009. 240 kilowatts of electricity can be generated from these ...

  9. Cosmic ray - Wikipedia

    en.wikipedia.org/wiki/Cosmic_ray

    The magnitude of the energy of cosmic ray flux in interstellar space is very comparable to that of other deep space energies: cosmic ray energy density averages about one electron-volt per cubic centimetre of interstellar space, or ≈1 eV/cm 3, which is comparable to the energy density of visible starlight at 0.3 eV/cm 3, the galactic magnetic ...