--%>
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 curvilinear motion What do you

    What do you mean by the term curvilinear motion? State in brief?

    		•
  • Q : What is Peltier effect Peltier effect

    Peltier effect (J.C.A. Peltier; 1834): The modification in temperature produced at a junction among the two dissimilar metals or semiconductors whenever an electric current passes through the junction.

    		•
  • 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 : Physics Assignement Answers and

    Answers and explanation to all the questions.

    		•
  • 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 : Define Josephson effects Josephson

    Josephson effects (B.D. Josephson; 1962): Electrical effects examined whenever two superconducting materials are separated by a thin layer of the insulating substance.

    		•
  • 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 : Explain Cosmological constant

    Cosmological constant (Lambda): The constant mentioned to the Einstein field equation, proposed to admit the static cosmological solutions. At the time the present philosophical view was steady-state model of the space, where the Universe has been aro

    		•
  • Q : Define Siemens or SI unit of an

    Siemens: S (after E.W. von Siemens, 1816-1892): The derived SI unit of an electrical conductance equivalent to the conductance of an element which has a resistance of 1 O [ohm]; this has units of O-1.

    		•
  • Q : What is the turnover number of the

    What is the turnover number of the enzyme? Is that forever an evaluation parameter of the action or activity of the enzyme?

    		•