--%>
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 : Why sun emerge flat throughout sunrise

    Briefly explain the reason why does sun emerge flat throughout sunrise and sunset?

    		•
  • Q : Why is heavy water employed as a

    Describe why is heavy water employed as a moderator? Illustrate.

    		•
  • 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 : What do you mean by the term positron

    What do you mean by the term positron? Explain in short.

    		•
  • Q : Define Static limit Static limit : The

    Static limit: The distance from a rotating black hole where no spectator can possibly stay at rest (with respect to the far-away stars) since of inertial frame dragging; this area is external of the event horizon, apart from at the poles where it meet

    		•
  • Q : Define Copernican principle Copernican

    Copernican principle (N. Copernicus): The idea, recommended by Copernicus, that the Sun, not the Earth, is at the center of the earth. We now know that neither idea is accurate (that is, the Sun is not even situated at the center of o

    		•
  • 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 : Problem on beam For the beam

    For the beam illustrated below, we require to determine: (A) the support reactions

    		•
  • Q : Explain Tachyon Tachyon: The purely

    Tachyon: The purely speculative particle that is supposed to travel faster than light. According to Sir Einstein's equations of special relativity, a particle with imaginary rest mass and a velocity more than c would contain a real momentum and energy

    		•
  • Q : Information in physics What do you mean

    What do you mean by the term information in physics?

    		•