--%>
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 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

    		•
  • Q : Physics Assignement Answers and

    Answers and explanation to all the questions.

    		•
  • Q : Define Copernican principle Copernican

    Copernican principle (N. Copernicus): The idea, recommended by Copernicus, that the Sun, not the Earth, is at the center of the earth. We now know that neither idea is accurate (that is, the Sun is not even situated at the center of o

    		•
  • Q : Define Heat pumps Heat pumps move heat

    Heat pumps move heat from one place to another. They work similar to refrigeration. The movement of heat takes energy, either electrical energy as in the use of  vapor compression heat pumps or thermal energy as in the use of absorption heat pump

    		•
  • Q : Define the term wave fronts What do you

    What do you mean by the term wave fronts? Explain in short.

    		•
  • Q : Define Atwood's machine Atwood's

    Atwood's machine: The weight-and-pulley system devised to compute the acceleration due to gravity at Earth's surface by computing the total acceleration of a set of weights of identified mass about a frictionless pulley.

    		•
  • Q : What is Reflection law Reflection law :

    Reflection law: For a wave-front intersecting a reflecting surface, the angle of incidence is equivalent to the angle of reflection, in the similar plane stated by the ray of incidence and the normal.

    		•
  • Q : Explain Kirchhoffs laws or Kirchhoffs

    Kirchhoff's laws (G.R. Kirchhoff) Kirchhoff's first laws: An incandescent solid or gas in high pressure will generate a continuous spectrum.

    Q : What is baryon decay Baryon decay - The

    Baryon decay -The idea expected by several grand-unified theories, those classes of subatomic particles termed as baryons (of which the nucleons -- neutrons and protons -- are members) are not eventually stable however indeed de

    		•
  • Q : Polar Materials The molecules of many

    The molecules of many dielectrics possess an electric dipole moment without having an external electric field. In such molecules centres of their positive and negative charges are displaced with respect to each other and therefore form a dipole. Such materials are kno

    		•