--%>
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 Einstein field equation

    Einstein field equation: The cornerstone of Einstein's general theory of relativity, associating the gravitational tensor G to the stress-energy tensor T by the simple equation: G = 8 pi T<

    		•
  • Q : Explain Coulombs law Coulomb's law (C.

    Coulomb's law (C. de Coulomb): The basic law for electrostatics, equivalent to Newton's law of universal gravitation. It defines that the force between two point charges is proportional to the arithmetical product of their respective

    		•
  • Q : Rest mass energy of the electron What

    What do you mean by the rest mass energy of the electron?

    		•
  • 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 : Law of Machines Describe briefly all

    Describe briefly all the Law of Machines?

    		•
  • Q : Concept of nuclear reaction Describe in

    Describe in brief the concept of nuclear reaction?

    		•
  • Q : Problem on Orbit cycle Calculate the

    Calculate the hot and cold temperature after 25 orbits. Assume a 100kg spherical spacecraft made of aluminum. Assume that the spacecraft is in an equatorial orbit. How is calculation 1 different for a spacecraft in a 90 degree (polar) orbit?

    		•
  • Q : Explain Hawking radiation Hawking

    Hawking radiation (S.W. Hawking; 1973): The theory which black holes emit radiation similar to any other hot body. The virtual particle-antiparticle pairs are continuously being made in supposedly empty space. Infrequently, a pair wil

    		•
  • Q : Define Landauers principle Landauer's

    Landauer's principle: The principle which defines that it doesn't explicitly take energy to calculate data, however instead it takes energy to remove any data, as erasure is a vital step in computation.

    		•
  • 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

    		•