--%>
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 : What is Geometrized units Geometrized

    Geometrized units: The system of units whereby certain basic constants (G, c, k, and h) are set to unison. This makes computations in certain theories, like general relativity, much simpler to deal with, as such constants appear often.

    Q : What is Meissner effect Meissner effect

    Meissner effect (W. Meissner; 1933): The reduction of the magnetic flux in a superconducting metal whenever it is cooled beneath the transition temperature. That is the superconducting materials imitate magnetic fields.

    		•
  • Q : What are Woodward-Hoffmann rules

    Woodward-Hoffmann rules: The rules leading the formation of products throughout certain kinds of organic reactions.

    		•
  • Q : Define Ohm or SI unit of electric

    Ohm: Omega: O (after G. Ohm, 1787-1854) The derived SI unit of electric resistance, stated as the resistance among two points on a conductor whenever a constant potential difference of 1 V generates a current of 1 A in the conductor;

    		•
  • Q : Define Hubbles law Hubble's law (E.P.

    Hubble's law (E.P. Hubble; 1925): The relationship discovered between radial velocity and distance. The further away a galaxy is away from is, the quicker it is receding away from us. The constant of proportionality is the Hubble cons

    		•
  • Q : Developing an algorithm to remove noise

    sir, Would you please help me to develop an algorithm to reduce noise and to detect weak signals under water using Green's function?

    		•
  • Q : Continuity of equation or Equation of

    Define Equation of continuity or Continuity of equation: An equation that states that a fluid flowing via a pipe flows at a rate that is inversely proportional to the cross-sectional region of the pipe. That is, when the pipe constric

    		•
  • Q : What is Bode's law Bode's law :

    Bode's law: Titius-Bode law - The mathematical formula that generates, with a fair quantity of accuracy, the semi major axes of the planets in out of order from the Sun. Write down the progression 0, 3, 6, 12, 24,

    		•
  • Q : Define Laue pattern Laue pattern (M.

    Laue pattern (M. von Laue): The pattern generated on a photographic film whenever high-frequency electromagnetic waves (like x-rays) are fired at the crystalline solid.

    		•
  • Q : What is Avogadro constant Avogadro

    Avogadro constant: L; NA (Count A. Avogadro; 1811) The total number of items in a sample of a substance that is equivalent to the number of molecules or atoms in a sample of an ideal gas that is at customary temperature and pressure. It is equivalent

    		•