--%>
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 : Semiconductors and magnetism I need

    I need well-explained answers on the questions in attached documents

    		•
  • 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 : What is Laplace equation Laplace

    Laplace equation (P. Laplace): For the steady-state heat conduction in 1-dimension, the temperature distribution is the explanation to Laplace's equation, which defines that the second derivative of temperature with respect to displac

    		•
  • Q : Define Trojan points Trojan points : L4

    Trojan points: L4 and L5 are the two dynamically stable Lagrange points (that is, beneath certain conditions).

    		•
  • Q : Water drain contradict problem Does

    Does water drain contradict clockwise in the northern hemisphere and clockwise in the southern hemi-sphere? Briefly explain it.

    		•
  • Q : Define Relativity principle Relativity

    Relativity principle: The principle, utilized by Einstein's relativity theories, that the laws of physics are similar, at least qualitatively, in all frames. That is, there is no frame which is better (or qualitatively any different) from any other. T

    		•
  • Q : What is Huygens construction Huygens'

    Huygens' construction: Huygens ‘Principle (C. Huygens): The mechanical propagation of the wave (specially, of light) is equal to supposing that every point on the wave front acts as a point source of the wave emission.

    		•
  • Q : What is No-hair conjecture No-hair

    No-hair conjecture (1960s): The conjecture (confirmed in the 1970s and 1980s) in general relativity that a black hole has merely three salient external characteristics: angular momentum, mass, and electric charge. All the other proper

    		•
  • Q : Define Cosmological redshift

    Cosmological redshift: The effect where light emanates from a distant source appears redshifted since of the expansion of the space time itself.

    		•
  • Q : Candela Candela : The basic SI unit of

    Candela: The basic SI unit of luminous intensity stated as the luminous intensity in a given direction of a source which emits monochromatic photons of frequency 540 x 1012 Hz and encompasses a radiant intensity in the direction of 1/683 W/

    		•