--%>
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 : Define Newton or SI unit of force

    Newton: N (after Sir I. Newton, 1642-1727): The derived SI unit of force, stated as the force needed to give a mass of 1 kg of an acceleration of 1 m/s2; it therefore has units of kg m/s2.

    		•
  • Q : Black-hole dynamic laws or laws of

    Explain  laws of black-hole dynamics or First law of black hole dynamics and Second law of black hole dynamics? 

    Q : Fundamental principles of the regulation

    Describe the fundamental principles of the regulation? Briefly describe the principles?

    		•
  • Q : Define Cosmic background radiation or

    Cosmic background radiation: primal glow: The background of radiation is generally in the frequency range of 3 x 1011 to 3 x 108 Hz discovered in space in the year 1965. It is believed to be the cosmologically re

    		•
  • Q : Define Rydberg constant Rydberg

    Rydberg constant (Rydberg): The constant that governs the relationship of the spectral line features of an atom via the Rydberg formula. For hydrogen, it is around 1.097 x 107 m-1.

    		•
  • Q : Define Superconductivity

    Superconductivity: The phenomenon by which, at adequately low temperatures, a conductor can conduct the charge with zero (0) resistance. The current theory for describing superconductivity is the BCS theory.

    		•
  • Q : Procedure to define the Specific Gravity

    Briefly explain the procedure to define the Specific Gravity?

    		•
  • Q : Explain Coanda effect Coanda effect:

    Coanda effect: The effect which points out that a fluid tends to flow all along a surface, instead of flowing via free space.

    		•
  • Q : Explain Lamberts laws or Lamberts

    What is Lamberts laws or Lamberts first law, second law and third law: Lambert's laws (J.H. Lambert) Lambert's first l

    		•
  • Q : Atomic model which the Erwin

    Briefly state the atomic model which the Erwin Schrodinger creates?

    		•