--%>
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 : Explain Boyle's law Boyle's law (R.

    Boyle's law (R. Boyle; 1662); Mariotte's law (E. Mariotte; 1676) - The product result of the volume and pressure of an ideal gas at constant (steady) temperature is constant.

    		•
  • Q : Universal law of universal gravitation

    Describe the universal law of universal gravitation? Briefly describe it.

    		•
  • Q : State Kohlrauschs law Kohlrausch's law

    Kohlrausch's law (F. Kohlrausch): When a salt is dissolved in water, the conductivity of the solution is the addition of two values -- one depending on the positive ions and the other on negative ions.

    		•
  • Q : Define Faraday constant Faraday

    Faraday constant: F (M. Faraday): The electric charge fetched by one mole of electrons or singly-ionized ions. It is equivalent to the product result of the Avogadro constant and the absolute value of the charge on an electron; this i

    		•
  • Q : Define Olbers paradox Olbers' paradox

    Olbers' paradox (H. Olbers; 1826): If the Universe is infinite, consistent, and unchanging then the whole sky at night would be bright -- concerning as bright as the Sun. The further you stared out into space, the more stars there would be, and theref

    		•
  • Q : What is baryon decay Baryon decay - The

    Baryon decay -The idea expected by several grand-unified theories, those classes of subatomic particles termed as baryons (of which the nucleons -- neutrons and protons -- are members) are not eventually stable however indeed de

    		•
  • 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 De Broglie wavelength De

    De Broglie wavelength (L. de Broglie; 1924): The prediction that particles too contain wave characteristics, where the efficient wavelength of the particle would be inversely proportional to its momentum, where the constant of the pro

    		•
  • Q : Explain Joules laws and Joule's

    Joule's laws (J.P. Joule) Joule's first law: The heat Q generated whenever a current I flows via a resistance R for a specified time t is specified by: Q = I2

  • Q : On which gravitational force depends

    Explain in short on which the gravitational force depends on?

    		•