--%>
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 : Explain Twin paradox Twin paradox: One

    Twin paradox: One of the most well-known "paradoxes" in history, predicted by Sir Einstein's special theory of relativity. It takes two twins, born on similar date on Earth. One, Albert, leaves home for a trip about the Universe at very high speeds (v

    		•
  • 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 : How fireworks turn to shapes similar to

    Briefly illustrate how do fireworks turn to shapes similar to hearts and stars?

    		•
  • Q : Define Pseudoforce Pseudoforce : The

    Pseudoforce: The "force" that arises as an observer is plainly treating an accelerating frame as an inertial one.

    		•
  • 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 : What is Edwards-Casimir quantum vacuum

    What is Edwards-Casimir quantum vacuum drive: The hypothetical drive developing the peculiarities of quantum mechanics by restricting permitting wavelengths of the virtual photons on one side of the drive (that is the bow of the ship); the pressure pr

    		•
  • Q : Define Zeeman Effect or Zeeman line

    Zeeman Effect: Zeeman line splitting (P. Zeeman; 1896): Zeeman Effect is the splitting of lines in a spectrum whenever the source is exposed to the magnetic field.

    		•
  • Q : Explain Ohms law Ohm's law (G. Ohm;

    Ohm's law (G. Ohm; 1827): The ratio of the potential difference among the ends of a conductor to the current flowing via it is constant; the constant of proportionality is termed as the resistance, and is distinct for different materials.

    		•
  • Q : Define Eddington limit Eddington limit

    Eddington limit (Sir A. Eddington): The hypothetical limit at which the photon pressure would surpass the gravitational attraction of a light-emitting body. That is, a body emanating radiation at bigger than the Eddington limit would

    		•
  • Q : Universal law of universal gravitation

    Describe the universal law of universal gravitation? Briefly describe it.

    		•