--%>
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 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 : What is Reflection law Reflection law :

    Reflection law: For a wave-front intersecting a reflecting surface, the angle of incidence is equivalent to the angle of reflection, in the similar plane stated by the ray of incidence and the normal.

    		•
  • Q : What is Arago spot What is  Arago

    What is Arago spot? The bright spot which appears in the shadow of a consistent disc being backlit by monochromatic light originating from a point source. &n

    		•
  • Q : How radiation emitted from the body

    Describe the procedure how radiation emitted from the body? Illustrate in brief.

    		•
  • Q : Meaning of Network Define the meaning

    Define the meaning of Network in brief.

    		•
  • Q : Explain BCS theory BCS theory -  The

    BCS theory - The theory put forth to elucidate both superconductivity and super fluidity. This suggests that in the superconducting (or super fluid) state electrons form Cooper pairs, where two electrons proceed as a single unit. This takes a non

    		•
  • Q : Explain Cosmological constant

    Cosmological constant (Lambda): The constant mentioned to the Einstein field equation, proposed to admit the static cosmological solutions. At the time the present philosophical view was steady-state model of the space, where the Universe has been aro

    		•
  • Q : Balanced field takeoff Describe the

    Describe the process of balanced field takeoff in brief?

    		•
  • 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 : Define Tau-theta paradox Tau-theta

    Tau-theta paradox (1950s): Whenever two distinct kinds of kaons, tau and theta (nowadays tau refers to a totally different particle) decay, tau decays into three particles, whereas the theta decays into two. The tau and theta vary onl

    		•