--%>
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 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 : Define Volt or SI unit of electric

    Volt: V (after A. Volta, 1745-1827): The derived SI unit of electric potential, stated as the difference of potential among the two points on a conductor fetching  a constant current of 1 A whenever the power dissipated between the points is 1 W;

    		•
  • Q : Define Newton meter What do you mean by

    What do you mean by the term Newton meter? Explain briefly?

    		•
  • Q : Explain Ideal gas equation Ideal gas

    Ideal gas equation: The equation that sums up the ideal gas laws in one simple equation, P V = n R T, Here V is the volume, P is the pressure, n is the

    		•
  • Q : What is basic SI unit of electric

    basic SI unit of electric current is termed as Ampere: A (after A.M. Ampere, 1775-1836) The basic SI unit of electric current, stated as the current that, when going via two infinitely-long parallel conductors of v

    		•
  • Q : Calculating current in magnetically

    For the magnetically coupled circuit in Figure a, calculate I1 and I2. If the dotted terminals in are changed so that the circuit now becomes that in Figure b, re-calculate I1 and I2.

  • Q : Polarization In a non-polar - molecule,

    In a non-polar - molecule, the centre of the nuclei and electron orbit overlap when such a molecule is positioned in electric field, the electrons are attracted with the positive charged of the anode and repelled by the negative charges of the cathode. Because of grea

    		•
  • Q : What is Chandrasekhar limit

    Chandrasekhar limit (S. Chandrasekhar; 1930): A limit that mandates that no white dwarf (a collapsed, degenerate star) can be much massive than around 1.4 masses solar. Any of the degenerate mass more massive should inevitably collaps

    		•
  • Q : What are Woodward-Hoffmann rules

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

    		•
  • Q : Define anti-aliasing What do you

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

    		•