--%>
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 : Velocity of the particle Determine the

    Determine the Velocity of the particle in terms of component veocities?

    		•
  • Q : Define Hall Effect Hall Effect:

    Hall Effect: Whenever charged particles flow via a tube that has both an electric field and a magnetic field (that is perpendicular to the electric field) present in it, only assured velocities of the charged particles are favored, and will make it un

    		•
  • Q : What is Curie constant and Curies law

    What is Curie constant and Curies law? Curie constant: C (P. Curie): The characteristic constant, dependent on the material in question that points out the proportionality among its susceptibility

    		•
  • Q : Law of Lamberts Cosine State the law of

    State the law of Lamberts Cosine? Describe briefly?

    		•
  • Q : Steps to the scientific notation

    Illustrate the steps to the scientific notation? Briefly illustrate the steps.

    		•
  • Q : Explain Lagrange points Lagrange points

    Lagrange points: The points in the vicinity of two massive bodies (like the Earth and Moon) with each others' relevant gravities balance. There are five, labeled L1 via L5. L1, L2, and L3 lie all along the centerline among the centers

    		•
  • 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 : What do you understand by term ray

    What do you understand by term ray casting? Explain briefly?

    		•
  • Q : Dielectric Materials Dielectric is a

    Dielectric is a material in which energy can be accumulated. Ideally, it  is  a non-conductor  of  electric  charge  like  insulators, but  an  efficient   supporter  of  electrostatic  fields. The

    		•
  • Q : Faradays laws of electromagnetic

    Explain Faraday's laws of electromagnetic induction and explain Faraday's first, second and third law of electromagnetic induction? Faraday's laws of electromagnetic in

    		•