--%>
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 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 : 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 : Radioactive dating-Determining of age

    In the radioactive dating we use half life to find out the age of a sample however not average life why? Describe.

    		•
  • Q : What is Eotvos law of capillarity

    Eotvos law of capillarity (Baron L. von Eotvos; c. 1870): The surface tension gamma of a liquid is associated to its temperature T, the liquid's critical temperature, T*, and its density rho by: gamma ~=

    		•
  • Q : What are Woodward-Hoffmann rules

    Woodward-Hoffmann rules: The rules leading the formation of products throughout certain kinds of organic reactions.

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

    What do you mean by the term positron? Explain in short.

    		•
  • Q : Define Brackett series Brackett series

    Brackett series (Brackett) - The series (or sequence) that explains the emission spectrum of hydrogen whenever the electron is jumping to fourth orbital. All of the lines are in the infrared segment of the spectrum.

    		•
  • Q : What is Lawson criterion Lawson

    Lawson criterion (J.D. Lawson): This is the condition for the discharge of energy from a thermonuclear reactor. This is usually stated as the minimum value for the product of the density of the fuel particles and the energy imprisonme

    		•
  • Q : Define Rydberg constant Rydberg

    Rydberg constant (Rydberg): The constant that governs the relationship of the spectral line features of an atom via the Rydberg formula. For hydrogen, it is around 1.097 x 107 m-1.

    		•
  • 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.

    		•