--%>
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 Cosmic censorship conjecture

    Cosmic censorship conjecture (R. Penrose, 1979): The conjecture, so far wholly undemonstrated in the context of general relativity, that all singularities (that is with the possible exception of the big bang singularity) are attended

    		•
  • Q : What is balmer series Balmer series (J.

    Balmer series (J. Balmer; 1885): An equation that explains the emission spectrum of hydrogen whenever an electron is jumping to the next orbital; four of the lines are in visible spectrum, and the remainder (residue) are in the ultraviolet.

    		•
  • Q : Describe the term ntu in thermodynamics

    Describe the term ntu in thermodynamics? Illustrate in short.

    		•
  • Q : Problem on beam For the beam

    For the beam illustrated below, we require to determine: (A) the support reactions

    		•
  • Q : Define Systeme Internationale d'Unites

    Systeme Internationale d'Unites (SI): The rationalized and coherent system of units derived from the m.k.s. system (that itself is derived from metric system) in common utilization in physics nowadays.

    		•
  • 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 : Branches of physics Briefly list out

    Briefly list out the name of all the branches of physics?

    		•
  • Q : What is Geometrized units Geometrized

    Geometrized units: The system of units whereby certain basic constants (G, c, k, and h) are set to unison. This makes computations in certain theories, like general relativity, much simpler to deal with, as such constants appear often.

    Q : Development of Missile technology Name

    Name the women scientist who played the essential role in the development of Missile technology of India and is nick named as the ‘Missile Woman’?

    		•
  • Q : What are Trojan satellites Trojan

    Trojan satellites: Satellites that orbit a body at one or the other Trojan points associative to a secondary body. There are numerous illustrations of this in our own solar system: a collection of asteroids that orbit in the Trojan points of Jupiter;

    		•