--%>
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 Schroedingers cat

    Schroedinger's cat (E. Schroedinger; 1935): A thought experiment designed to exemplify the counterintuitive and strange ideas of reality that come all along with the quantum mechanics. A cat is sealed within a clos

    		•
  • Q : Radioactive dating-Determining of age

    In the radioactive dating we use half life to find out the age of a sample however not average life why? Describe.

    		•
  • Q : Define Luxon Luxon : The particle that

    Luxon: The particle that travels solely at c (that is the speed of light in vacuum). All luxons have a rest mass of exactly zero. Though they are mass less, luxons do take momentum. The photons are the prime illustration of luxons (that is the name it

    		•
  • Q : Scanning electron and transmission

    Give one benefit of a scanning electron microscope over the transmission electron microscope? Briefly explain it.

    		•
  • Q : Explain Ohms law Ohm's law (G. Ohm;

    Ohm's law (G. Ohm; 1827): The ratio of the potential difference among the ends of a conductor to the current flowing via it is constant; the constant of proportionality is termed as the resistance, and is distinct for different materials.

    		•
  • 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 are Woodward-Hoffmann rules

    Woodward-Hoffmann rules: The rules leading the formation of products throughout certain kinds of organic reactions.

    		•
  • Q : How fireworks turn to shapes similar to

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

    		•
  • Q : Define Permittivity of free space or

    Permittivity of free space: electric constant; epsilon_0: The ratio of the electric displacement to the intensity of the electric field generating it in vacuum. It is equivalent to 8.854 x 10-12 F/m.

    		•
  • Q : Describe the term ntu in thermodynamics

    Describe the term ntu in thermodynamics? Illustrate in short.

    		•