--%>
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 Constancy principle Constancy

    Constancy principle (A. Einstein): One of the postulates of Sir Einstein's special theory of relativity that puts forth that the speed of light in vacuum is computed as similar speed to all observers, in spite of of their relative mot

    		•
  • Q : What is Hooke law Hooke's law (R.

    Hooke's law (R. Hooke): The stress exerted to any solid is proportional to the strain it generates within the elastic limit for that solid. The constant of that proportionality is the Young modulus of elasticity for that material.

    		•
  • Q : What is Lyman series Lyman series: The

    Lyman series: The sequence that explains the emission spectrum of hydrogen whenever electrons are jumping to the ground state. Each and every line is in the ultraviolet.

    		•
  • Q : Explain Twin paradox Twin paradox: One

    Twin paradox: One of the most well-known "paradoxes" in history, predicted by Sir Einstein's special theory of relativity. It takes two twins, born on similar date on Earth. One, Albert, leaves home for a trip about the Universe at very high speeds (v

    		•
  • Q : What is Simultaneity principle

    Simultaneity principle: The principle which all frames of reference will contain invariant simultaneity; that is, the two events perceived as simultaneous (that is, containing the similar time coordinate) in one frame will be apparent as simultaneous

    		•
  • Q : What is Huygens construction Huygens'

    Huygens' construction: Huygens ‘Principle (C. Huygens): The mechanical propagation of the wave (specially, of light) is equal to supposing that every point on the wave front acts as a point source of the wave emission.

    		•
  • 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 : Fission and Fusion What do you mean by

    What do you mean by Fission and Fusion?

    		•
  • Q : Explain Archimedes' principle What is 

    What is Archimedes' principle? A body which is submerged in a fluid is buoyed up by a force equivalent in magnitude to the weight of the fluid which is displaced, and directed upward all along a line via the c

    		•
  • 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?

    		•