--%>
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 : Why Cadmium rods are given in a nuclear

    Cadmium rods are given in a nuclear reactor. Explain why?

    		•
  • 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 : 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 : 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 : Define Sievert or SI unit of dose

    Sievert: Sv: The derived SI unit of dose equivalent, stated as the absorbed dose of the ionizing radiation multiplied by internationally-agreed-upon dimensionless weights, as various kinds of ionizing radiation cause various kinds of damage in the liv

    		•
  • Q : What is Meissner effect Meissner effect

    Meissner effect (W. Meissner; 1933): The reduction of the magnetic flux in a superconducting metal whenever it is cooled beneath the transition temperature. That is the superconducting materials imitate magnetic fields.

    		•
  • Q : Physics Assignement Answers and

    Answers and explanation to all the questions.

    		•
  • Q : Weak equivalence or principle of

    Weak equivalence principle: principle of uniqueness of freefall: The idea in general relativity is that the world-line of a freefalling body is sovereign of its composition, structure, or state. This principle, hold by Newtonian mechanics and gravitat

    		•
  • Q : What is Dulong-Petit law Dulong-Petit

    Dulong-Petit law (P. Dulong, A.T. Petit; 1819): The molar heat capacity is around equivalent to the three times the ideal gas constant: C = 3 R

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

    What do you mean by the term fusion reaction?

    		•