--%>
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 No-hair conjecture No-hair

    No-hair conjecture (1960s): The conjecture (confirmed in the 1970s and 1980s) in general relativity that a black hole has merely three salient external characteristics: angular momentum, mass, and electric charge. All the other proper

    		•
  • Q : What are Woodward-Hoffmann rules

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

    		•
  • Q : Define Radian or SI unit of the angular

    Radian: rad: The supplementary SI unit of the angular measure stated as the central angle of a circle whose subtended arc is equivalent to the radius of the circle.

    		•
  • Q : Explain Newtons law of universal

    Newton's law of universal gravitation (Sir I. Newton): Two bodies exert a pull on each other with equivalent and opposite forces; the magnitude of this force is proportional to the product result of the two masses and is too proportional to the invers

    		•
  • Q : What is Super fluidity Super fluidity :

    Super fluidity: The phenomenon by which, at adequately low temperatures, a fluid can flow with zero (0) viscosity. These causes are related with the superconductivity.

    		•
  • 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 : 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 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.

    		•
  • 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 : Calculate power consumed : A voltage v

    : A voltage v = 150 + j180 is applied across an impedance and the current flowing is I = 5 - j4 find ? A, impedance . B, resistance. C, reactance. D, power consumed. 

    		•