--%>
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 Causality principle Causality

    Causality principle: The principle which cause must always precede effect. More properly, when an event A ("the cause") somehow persuades an event B ("the effect") that take

    		•
  • Q : Explain Ohms law Ohm's law (G. Ohm;

    Ohm's law (G. Ohm; 1827): The ratio of the potential difference among the ends of a conductor to the current flowing via it is constant; the constant of proportionality is termed as the resistance, and is distinct for different materials.

    		•
  • Q : Define Cosmological redshift

    Cosmological redshift: The effect where light emanates from a distant source appears redshifted since of the expansion of the space time itself.

    		•
  • Q : Define Luxon Luxon : The particle that

    Luxon: The particle that travels solely at c (that is the speed of light in vacuum). All luxons have a rest mass of exactly zero. Though they are mass less, luxons do take momentum. The photons are the prime illustration of luxons (that is the name it

    		•
  • Q : Physics Assignement Answers and

    Answers and explanation to all the questions.

    		•
  • Q : Explain Drake equation 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

    		•
  • 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 : Procedure to define the Specific Gravity

    Briefly explain the procedure to define the Specific Gravity?

    		•
  • 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 Farad or SI unit of capacitance

    What is Farad or SI unit of capacitance? Farad: F (after M. Faraday, 1791-1867): The derived SI unit of the capacitance stated as the capacitance in a capacitor that, when charged to 1 C, contains

    		•