--%>
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 : Why Cadmium rods are given in a nuclear

    Cadmium rods are given in a nuclear reactor. Explain why?

    		•
  • 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 : Explain Boyle's law Boyle's law (R.

    Boyle's law (R. Boyle; 1662); Mariotte's law (E. Mariotte; 1676) - The product result of the volume and pressure of an ideal gas at constant (steady) temperature is constant.

    		•
  • Q : Define Steradian or SI unit of solid

    Steradian: sr: The supplementary SI unit of solid angle stated as the solid central angle of a sphere which encloses a surface on the sphere equivalent to the square of the sphere's radius.

    		•
  • Q : Define Planck equation Planck equation:

    Planck equation: The quantum mechanical equation associating to the energy of a photon E to its frequency nu: E = h nu.

    		•
  • Q : Define Rydberg constant Rydberg

    Rydberg constant (Rydberg): The constant that governs the relationship of the spectral line features of an atom via the Rydberg formula. For hydrogen, it is around 1.097 x 107 m-1.

    		•
  • Q : Define Occams razor or Ockhams razor

    Occam's [or Ockham's] razor (William of Occam [or Ockham]; c. 1340): It is the suggestion that the simpler a theory is the better. When two theories forecast the phenomena to the similar accuracy, then the one that is simpler is the better one. Furthe

    		•
  • Q : Fundamental principles of the regulation

    Describe the fundamental principles of the regulation? Briefly describe the principles?

    		•
  • Q : What is Edwards-Casimir quantum vacuum

    What is Edwards-Casimir quantum vacuum drive: The hypothetical drive developing the peculiarities of quantum mechanics by restricting permitting wavelengths of the virtual photons on one side of the drive (that is the bow of the ship); the pressure pr

    		•
  • Q : How fireworks turn to shapes similar to

    Briefly illustrate how do fireworks turn to shapes similar to hearts and stars?

    		•