--%>
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 : Why heat causes matter to expand What

    What is the reason that heat causes matter to expand? Briefly explain it.

    		•
  • Q : Describe Wiedemann-Franz law

    Wiedemann-Franz law: It is the ratio of the thermal conductivity of any pure metal (substance) to its electrical conductivity is just about constant for any specified temperature. This law holds pretty well apart from at low temperatures.

    		•
  • Q : Define Fermats principle Fermat's

    Fermat's principle: principle of least time (P. de Fermat): The principle, put onward by P. de Fermat that explains the path taken by a ray of light among any two points in a system is for all time the path which takes the least time.

    		•
  • Q : What is Arago spot What is  Arago

    What is Arago spot? The bright spot which appears in the shadow of a consistent disc being backlit by monochromatic light originating from a point source. &n

    		•
  • 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 : Procedure to define the Specific Gravity

    Briefly explain the procedure to define the Specific Gravity?

    		•
  • 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 : What is Hawking temperature Hawking

    Hawking temperature: The temperature of a black hole is caused by the emission of the hawking radiation. For a black hole with mass m, it is illustrated as: T = (hbar c3)/(8 pi G k m).

    		•
  • Q : Define Tardon Tardon : A particle that

    Tardon: A particle that has a positive real mass and travels at a speed very less than c in all inertial frames.

    		•
  • Q : Define Planck constant Planck constant

    Planck constant: h: The basic constant equivalent to the ratio of the energy of a quantum of energy to its frequency. This is the quantum of action. This has the value 6.626 196 x 10-34 J s.

    		•