--%>
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 Coriolis pseudoforce Coriolis

    Coriolis pseudoforce (G. de Coriolis; 1835): The pseudoforce that arises since of motion relative to a frame that is itself rotating relative to the second, inertial frame. The magnitude of the Coriolis "force" is tot

    		•
  • Q : Define Luxon Luxon : The particle that

    Luxon: The particle that travels solely at c (that is the speed of light in vacuum). All luxons have a rest mass of exactly zero. Though they are mass less, luxons do take momentum. The photons are the prime illustration of luxons (that is the name it

    		•
  • Q : Weights in pounds of the liquid gallons

    Write down the weights in pounds of the liquid gallons? Briefly describe it.

    		•
  • Q : Define Josephson effects Josephson

    Josephson effects (B.D. Josephson; 1962): Electrical effects examined whenever two superconducting materials are separated by a thin layer of the insulating substance.

    		•
  • Q : Define Second or SI unit of time

    Second: s: The basic SI unit of time, stated as the period of time equivalent to the duration of 9 192 631 770 periods of the radiation analogous to the transition between the two hyperfine levels of the ground state of cesium-133 atom.

    		•
  • Q : Problem on Orbit cycle Calculate the

    Calculate the hot and cold temperature after 25 orbits. Assume a 100kg spherical spacecraft made of aluminum. Assume that the spacecraft is in an equatorial orbit. How is calculation 1 different for a spacecraft in a 90 degree (polar) orbit?

    		•
  • Q : Radar gun problem Whenever a radar gun

    Whenever a radar gun states the pitch is 90 miles per hour at what point in the balls travel to home plate is the radar gun evaluating the velocity?

    		•
  • Q : What is Transition temperature

    Transition temperature: The temperature (that is, dependant on the substance comprised) below that a superconducting material conducts electricity with zero resistance; therefore, the temperature above which a superconductor lose its superconductive p

    		•
  • Q : Explain Einstein field equation

    Einstein field equation: The cornerstone of Einstein's general theory of relativity, associating the gravitational tensor G to the stress-energy tensor T by the simple equation: G = 8 pi T<

    		•
  • Q : Solution Of Laplace’s Equation 1. Solve

    1. Solve Laplace's equation for the electrical potential between two infinite parallel plates, which have a charge density per unit area -on one plate and a charge density per unit area -! on the second plate, and determine the electric field between the plates from t

    		•