--%>
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 Correspondence limit or

    Explain Correspondence limit or Correspondence principle? Correspondence limit (N. Bohr): The limit at which a more common theory decreases to a more specialized theory when the situations that the

    		•
  • Q : What MeV in MeV photon signify What

    What does MeV in MeV photon signify? Briefly describe it.

    		•
  • Q : What is Hawking temperature Hawking

    Hawking temperature: The temperature of a black hole is caused by the emission of the hawking radiation. For a black hole with mass m, it is illustrated as: T = (hbar c3)/(8 pi G k m).

    		•
  • Q : What is De Broglie wavelength De

    De Broglie wavelength (L. de Broglie; 1924): The prediction that particles too contain wave characteristics, where the efficient wavelength of the particle would be inversely proportional to its momentum, where the constant of the pro

    		•
  • Q : Weights in pounds of the liquid gallons

    Write down the weights in pounds of the liquid gallons? Briefly describe it.

    		•
  • Q : Define Newton or SI unit of force

    Newton: N (after Sir I. Newton, 1642-1727): The derived SI unit of force, stated as the force needed to give a mass of 1 kg of an acceleration of 1 m/s2; it therefore has units of kg m/s2.

    		•
  • Q : Newtons laws of motion Briefly

    Briefly illustrate all the Newton s laws of motion?

    		•
  • Q : Explain Rayleigh-Jeans law

    Rayleigh-Jeans law: For a blackbody at the thermodynamic temperature T, the radiance R over a range of frequencies between the nu and nu + dnu is specified by: R = 2 pi nu2 k T/c2.<

    		•
  • Q : Define Faraday constant Faraday

    Faraday constant: F (M. Faraday): The electric charge fetched by one mole of electrons or singly-ionized ions. It is equivalent to the product result of the Avogadro constant and the absolute value of the charge on an electron; this i

    		•
  • Q : Formula for acceleration What is the

    What is the appropriate formula employed to compute the acceleration? Explain in brief.

    		•