--%>
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 : 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 : Simulation using VMD and NMD programes

    I need the homework to be finished in five days. and could you please tell me if you are familiar with VMD and NMD simulation programs or not? I will send you some docments that I think it could help to solve the homework questions. But please send me an email so I can attached both files. all b

    		•
  • Q : What is Speed of light Speed of light

    Speed of light (in vacuo): c: The speed at which the electromagnetic radiation spreads in a vacuum; it is stated as 299 792 458 m/s.

    		•
  • Q : Explain Thomson experiment or Kelvin

    Thomson experiment: Kelvin effect (Sir W. Thomson [later Lord Kelvin]): Whenever an electric current flows via a conductor whose ends are maintained at various temperatures, heat is discharged at a rate just about proportional to the

    		•
  • Q : How asteroids are formed Explain how

    Explain how asteroids are formed? Describe.

    		•
  • Q : Problem on dot equivalent Obtain the

    Obtain the “dot” equivalent for the circuit shown below and use it to find the equivalent inductive reactance. 2141_dot.jpg

    Q : What nucleons altogether in a nucleus

    Explain what does held the nucleons altogether in a nucleus?

    		•
  • Q : Define Weber or SI unit of magnetic flux

    Weber: Wb (after W. Weber, 1804-1891): The derived SI unit of magnetic flux equivalent to the flux that, connecting a circuit of one turn, generates in it an electromotive force of 1 V as it is decreased to zero at a uniform rate in a period of 1 s; i

    		•
  • Q : Why heat causes matter to expand What

    What is the reason that heat causes matter to expand? Briefly explain it.

    		•
  • 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

    		•