--%>
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 Transition temperature

    Transition temperature: The temperature (that is, dependant on the substance comprised) below that a superconducting material conducts electricity with zero resistance; therefore, the temperature above which a superconductor lose its superconductive p

    		•
  • 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 : Define anti-aliasing What do you

    What do you understand by the term anti-aliasing? Describe briefly?

    		•
  • Q : Faradays laws of electrolysis or

    Explain Faradays laws of electrolysis or describe Faradays first law and Faradays second law? Faraday's laws of electrolysis (M. Faraday):

  • Q : Biot-Savart law Biot-Savart law (J.B.

    Biot-Savart law (J.B. Biot, F. Savart) - The law which explains the contributions to the magnetic field by an electric current. This is analogous to the Coulomb's law. Mathematically: dB = (mu0 I)/(4 pi r2) dl cross e

    		•
  • Q : Problem on multi level TDM Ten sources,

    Ten sources, six with a bit rate of 200 Kbps and four with a bit rate of 400Kbps are to be combined using multi level TDM  with no sync bits. Answer the questions below about the final phase of multiplexing: a

    		•
  • Q : What is Farad or SI unit of capacitance

    What is Farad or SI unit of capacitance? Farad: F (after M. Faraday, 1791-1867): The derived SI unit of the capacitance stated as the capacitance in a capacitor that, when charged to 1 C, contains

    		•
  • Q : Branches of physics Briefly list out

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

    		•
  • Q : Define Weiss constant Weiss constant :

    Weiss constant: The characteristic constant dependent on the substance, employed in computing the susceptibility of the paramagnetic materials.

    		•
  • Q : Why electron and proton encompass

    Explain in short why electron and proton encompass similar charge while the proton is 1836 times heavier?

    		•