--%>
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 : Engineering in brief Define the term

    Define the term engineering in brief.

    		•
  • Q : What is Gray Gray : Gy (after L.H.

    Gray: Gy (after L.H. Gray, 1905-1965): The derived SI unit of engrossed dose, stated as the absorbed dose in which the energy per unit mass communicated to the matter by the ionizing radiation is 1 J/kg; it therefore has units of J/kg

    		•
  • Q : Magnetism what's the unit of Curie

    what's the unit of Curie constant and how to calculate Bohr magneton from the plot of 1/Khi vs Temperature(K)?

    		•
  • Q : Define Tipler machine Tipler machine:

    Tipler machine: The solution to Einstein's equations of general relativity which permits time travel. A tremendously dense (that is, on the order of the density of neutron star matter), infinitely-long cylinder that rotates very quickly can form close

    		•
  • Q : What is Standard quantum limit Standard

    Standard quantum limit: It is the limit obligatory on standard techniques of measurement by the uncertainty principle in quantum mechanics.

    		•
  • Q : Explain Millikan oil drop experiment

    Millikan oil drop experiment (R.A. Millikan): A famed experiment designed to compute the electronic charge. The drops of oil were carried past a consistent electric field among charged plates. Subsequent to charging the drop with x-ra

    		•
  • Q : Define Sievert or SI unit of dose

    Sievert: Sv: The derived SI unit of dose equivalent, stated as the absorbed dose of the ionizing radiation multiplied by internationally-agreed-upon dimensionless weights, as various kinds of ionizing radiation cause various kinds of damage in the liv

    		•
  • Q : Define Faint Faint , young sun paradox

    Faint, young sun paradox: The theories of stellar evolution point out that as stars mature on the main series, they grow gradually hotter and brighter; computations propose that at as regards the time of the formation of Earth, the Su

    		•
  • Q : Define Hoop conjecture Hoop conjecture

    Hoop conjecture (K.S. Thorne, 1972): The conjecture (as so far unproven, although there is substantial proof to support it) that a non-spherical object, non-spherically compressed, will only form a black hole whenever all parts of the

    		•
  • 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.