--%>
Assignment Help - homework help

Explain Drake equation

Drake equation (F. Drake; 1961): The method of estimating the number of intelligent, scientific species (that is, able to communicate with other species) in subsistence in our space.

N = R fp ne fl fi ft L.

Here,

N is the number of species explained above at any specified moment in our Galaxy. The parameters it is evaluated from are as follows:

R = the rate of star formation in our solar system (in stars per year);
fp = the fraction of stars that contain planets;
ne = the total number of habitable planets per system with planets;
fl = the fraction of habitable planets on which the life arises;
fi = the fraction of such planets on which the life develops intelligence;
ft = the fraction of such planets where the intelligence grows into a technological civilization which is capable of communication; and
L = the mean life-time of such a scientific civilization.

Out of these quantities, only the first -- R -- is recognized with anything like any reliability; this is on the order of 10 stars per year. The others, most particularly the fractions, are approximately totally pure speculation at this point. Computations made by respectable astronomers vary by something like ten orders of magnitude in the last estimation of the number of species out there.

   Related Questions in Physics

  • Q : Solution Of Laplace’s Equation 1. Solve

    1. Solve Laplace's equation for the electrical potential between two infinite parallel plates, which have a charge density per unit area -on one plate and a charge density per unit area -! on the second plate, and determine the electric field between the plates from t

    		•
  • Q : Explain Malus law Malus' law (E.L.

    Malus' law (E.L. Malus): The light intensity I of a ray with primary intensity I0 travelling via a polarizer at an angle theta among the polarization of the light ray and the polarization axis of the polarizer is specified by:

    Q : Define Watt or SI unit of power Watt: W

    Watt: W (after J. Watt, 1736-1819): The derived SI unit of power, stated as a power of 1 J acting over the period of 1 s; it therefore has the units of J/s.

    		•
  • Q : What is Boltzmann constant Boltzmann

    Boltzmann constant: k (L. Boltzmann) - The constant that explains the relationship between kinetic energy and temperature for molecules in an ideal gas. This is equivalent to the 1.380 622 x 10-23 J/K.

    		•
  • Q : Candela Candela : The basic SI unit of

    Candela: The basic SI unit of luminous intensity stated as the luminous intensity in a given direction of a source which emits monochromatic photons of frequency 540 x 1012 Hz and encompasses a radiant intensity in the direction of 1/683 W/

    		•
  • Q : Define Spin-orbit effect Spin-orbit

    Spin-orbit effect: The effect that causes atomic energy levels to be split since electrons contain intrinsic angular momentum (that is spin) in summation to their extrinsic orbital angular momentum.

    		•
  • Q : Polarization In a non-polar - molecule,

    In a non-polar - molecule, the centre of the nuclei and electron orbit overlap when such a molecule is positioned in electric field, the electrons are attracted with the positive charged of the anode and repelled by the negative charges of the cathode. Because of grea

    		•
  • Q : What is Universal age paradox Universal

    Universal age paradox: The two most straightforward techniques of computing the age of the Universe -- via red-shift measurements, and via stellar evolution -- outcome incompatible outcomes. Recent (in mid 1990s) measurements of the distances of far-a

    		•
  • Q : Explain Maxwells equations and its

    Explain Maxwells equations and its four elegant equation? Maxwell's equations (J.C. Maxwell; 1864): The four elegant equations that explain classical electroma

    		•
  • Q : What is Refraction law Refraction law:

    Refraction law: For a wave-front travelling via a boundary among two media, the first with a refractive index of n1, and the other with one of n2, the angle of incidence theta is associated to the angle of refraction phi by:

    		•