--%>
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 : Explain Keplers laws or Keplers

    Explain Keplers laws or Keplers first law, second law and third law? Kepler's laws (J. Kepler) Kepler's first

    		•
  • Q : Balanced field takeoff Describe the

    Describe the process of balanced field takeoff in brief?

    		•
  • Q : What do you mean by the term fusion

    What do you mean by the term fusion reaction?

    		•
  • Q : What is Eotvos law of capillarity

    Eotvos law of capillarity (Baron L. von Eotvos; c. 1870): The surface tension gamma of a liquid is associated to its temperature T, the liquid's critical temperature, T*, and its density rho by: gamma ~=

    		•
  • Q : What is Maxwells demon Maxwell's demon

    Maxwell's demon (J.C. Maxwell): A contemplation experiment describing the concepts of entropy. We contain a container of gas that is partitioned into two equivalent sides; each side is in thermal equilibrium with the other. The walls and the separatio

    		•
  • Q : Explain BCS theory BCS theory -  The

    BCS theory - The theory put forth to elucidate both superconductivity and super fluidity. This suggests that in the superconducting (or super fluid) state electrons form Cooper pairs, where two electrons proceed as a single unit. This takes a non

    		•
  • Q : Define Hertz or SI unit of frequency

    Define Hertz or SI unit of frequency: Hertz: Hz (after H. Hertz, 1857-1894): The derived SI unit of frequency, stated as a frequency of 1 cycle per s; it therefore has units of s-1.

    		•
  • Q : Definition of Pascals principle Briefly

    Briefly state the definition of Pascal’s principle?

    		•
  • Q : Non-Parametric Tests Activity

    Activity 9:   Non-Parametric Tests    4Non-Parametric Tests While you have learned a number of parametric statistical techniques, you are also aware that if the assumptions related to

    		•
  • Q : Define Tau-theta paradox Tau-theta

    Tau-theta paradox (1950s): Whenever two distinct kinds of kaons, tau and theta (nowadays tau refers to a totally different particle) decay, tau decays into three particles, whereas the theta decays into two. The tau and theta vary onl

    		•