--%>
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 : Fundamental principles of the regulation

    Describe the fundamental principles of the regulation? Briefly describe the principles?

    		•
  • Q : Define Hertz or SI unit of frequency

    Define Hertz or SI unit of frequency: Hertz: Hz (after H. Hertz, 1857-1894): The derived SI unit of frequency, stated as a frequency of 1 cycle per s; it therefore has units of s-1.

    		•
  • Q : Define Atwood's machine Atwood's

    Atwood's machine: The weight-and-pulley system devised to compute the acceleration due to gravity at Earth's surface by computing the total acceleration of a set of weights of identified mass about a frictionless pulley.

    		•
  • Q : Explain the procedure to compute the

    Briefly explain the procedure to compute the tensile strength?

    		•
  • Q : Problem on beam For the beam

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

    		•
  • Q : Define Rydberg constant Rydberg

    Rydberg constant (Rydberg): The constant that governs the relationship of the spectral line features of an atom via the Rydberg formula. For hydrogen, it is around 1.097 x 107 m-1.

    		•
  • 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 : Measure of the force of gravity Briefly

    Briefly explain the measure of the force of gravity on the object?

    		•
  • Q : What is Roche limit Roche limit : The

    Roche limit: The position about a massive body where the tidal forces due to the gravity of the primary equivalent or exceed the surface gravity of a specified satellite. Within the Roche limit, such a satellite will be interrupted by tides.

    		•
  • Q : Define Carnots theorem Carnot's theorem

    Carnot's theorem (S. Carnot): The theorem that states that no engine operating between the two temperatures can be more proficient than a reversible engine.

    		•