--%>
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 : How elevation and air pressure affects

    Briefly state how does the elevation and air pressure affects the boiling point of water?

    		•
  • Q : Problem on synchronous TDM We require

    We require using synchronous TDM and joining 20 digital sources, each of 100 Kbps. Each and every output slot carries 1 bit for each digital source, however one extra bit is added up to each frame for synchronization.

    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 : 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 : Bragg's law Bragg's law - Whenever a

    Bragg's law - Whenever a beam of x-rays strikes a crystal surface in which the layers of ions or atoms are often separated, the maximum intensity of the reflected ray takes place when the complement of the angle of incidence, theta (θ), the wave

    		•
  • Q : Define Ergosphere Ergosphere: The area

    Ergosphere: The area around a rotating black hole, among the event horizon and the static limit, where the rotational energy can be removed from the black hole.

    		•
  • Q : Law of Lamberts Cosine State the law of

    State the law of Lamberts Cosine? Describe briefly?

    		•
  • Q : Define Lux or SI unit of the illuminance

    Lux: lx: The derived SI unit of the illuminance equivalent to the illuminance generated by a luminous flux of 1 lm distributed consistently over a region of 1 m2; it therefore has units of lm/m2.

    		•
  • Q : What is Loschmidt constant or Loschmidt

    Loschmidt constant: Loschmidt number: NL: The total number of particles per unit volume of an ideal gas at standard pressure and temperature. It has the value of 2.687 19 x 1025 m-3.

    		•
  • Q : What is Pfund series Pfund series: The

    Pfund series: The series that explains the emission spectrum of hydrogen whenever the electron is jumping to the fifth orbital. Each line is in the infrared part of the spectrum.

    		•