--%>
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 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 : What is Refraction law Refraction law:

    Refraction law: For a wave-front travelling via a boundary among two media, the first with a refractive index of n1, and the other with one of n2, the angle of incidence theta is associated to the angle of refraction phi by:

    		•
  • Q : Explain Lamberts laws or Lamberts

    What is Lamberts laws or Lamberts first law, second law and third law: Lambert's laws (J.H. Lambert) Lambert's first l

    		•
  • Q : Define Pauli Exclusion Principle Pauli

    Pauli Exclusion Principle (W. Pauli; 1925): No two similar fermions in a system, like electrons in an atom, can contain an identical set of the quantum numbers.

    		•
  • Q : Procedure to define the Specific Gravity

    Briefly explain the procedure to define the Specific Gravity?

    		•
  • Q : Dynamic strain aging and the strain

    What is the basic difference among the dynamic strain aging and the strain aging?

    		•
  • Q : Explain Planck radiation law Planck

    Planck radiation law: The law which explained blackbody radiation better than its precursor, therefore resolving the ultraviolet catastrophe. This is based on the supposition that electromagnetic radiation is quantized.

    Q : Define Eddington limit Eddington limit

    Eddington limit (Sir A. Eddington): The hypothetical limit at which the photon pressure would surpass the gravitational attraction of a light-emitting body. That is, a body emanating radiation at bigger than the Eddington limit would

    		•
  • Q : Blackbody radiation What is Blackbody

    What is Blackbody radiation - The radiation - that is the radiance at specific frequencies all across the spectrum -- generated by a blackbody -- which is, a perfect radiator and absorber of the heat. Physicists had complexity exp

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

    What do you mean by the term fusion reaction?

    		•