--%>
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 : Fundamental principles of the regulation

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

    		•
  • Q : Scanning electron and transmission

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

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

    What do you mean by the term alloy? Briefly illustrate it.

    		•
  • Q : Calculate power consumed : A voltage v

    : A voltage v = 150 + j180 is applied across an impedance and the current flowing is I = 5 - j4 find ? A, impedance . B, resistance. C, reactance. D, power consumed. 

    		•
  • Q : What is Roche limit Roche limit : The

    Roche limit: The position about a massive body where the tidal forces due to the gravity of the primary equivalent or exceed the surface gravity of a specified satellite. Within the Roche limit, such a satellite will be interrupted by tides.

    		•
  • 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 : Explain Tachyon paradox Tachyon

    Tachyon paradox: The argument explaining that tachyons (should they subsist, of course) can’t carry an electric charge. For an imaginary-massed particle travelling faster than c, less energy the tachyon has, the faster it travels, till at zero e

    		•
  • Q : What is Peltier effect Peltier effect

    Peltier effect (J.C.A. Peltier; 1834): The modification in temperature produced at a junction among the two dissimilar metals or semiconductors whenever an electric current passes through the junction.

    		•
  • 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 : Magnetism what's the unit of Curie

    what's the unit of Curie constant and how to calculate Bohr magneton from the plot of 1/Khi vs Temperature(K)?

    		•