| The laws list: F |
The laws list F
faint, young sun paradox to Fizeau method.
Jump links.
A
| B
| C
| D
| E
| F
| G
| H
| I
| J
| K
| L
| M
| N
| O
| P
| Q
| R
| S
| T
| U
| V
| W
| X
| Y
| Z
F.
- faint, young sun paradox
-
- Theories of stellar evolution indicate
that as stars mature on the main sequence, they grow steadily hotter and
brighter; calculations suggest that at about the time of the formation of
Earth, the Sun was roughly two-thirds the brightness that it is now.
However, there is no geological evidence on Earth (or on Mars) for the Sun
being fainter in the past. At present there is no clear resolution for this
paradox.
-
- farad; F (after M. Faraday, 1791-1867)
-
- The derived
SI unit of
capacitance, defined as the capacitance in a capacitor that, if charged to 1
C, has
a potential difference of 1
V; thus,
it has units of
C/V.
-
- Faraday constant; F (M.
Faraday)
-
- The electric charge carried by one mole of
electrons (or singly-ionized ions). It is equal to the product of the
Avogadro constant and the (absolute value of the) charge on an electron; it
is 9.648 670 x 104
C/mol.
-
- Faraday's law (M. Faraday)
-
- The line integral of the electric field around a
closed curve is proportional to the instantaneous time rate of change of the
magnetic flux through a surface bounded by that closed curve; in
differential form,
curl E = -dB/dt,
where here d/dt represents partial
differentiation.
-
- Faraday's laws of
electrolysis (M. Faraday)
-
-
-
Faraday's first law of electrolysis
-
- The amount of chemical change during electrolysis is proportional to
the charge passed.
-
- Faraday's
second law of electrolysis
-
- The charge Q equired to deposit or liberate a mass m
is proportional to the charge z of the ion, the mass, and
inversely proprtional to the relative ionic mass M;
mathematically,
Q =
F m z/M.
- Faraday's
laws of electromagnetic induction (M. Faraday)
-
-
-
Faraday's first law of electromagnetic induction
-
- An electromotive force is induced in a conductor when the magnetic
field surrounding it changes.
-
-
Faraday's second law of electromagnetic induction
-
- The magnitude of the electromotive force is proportional to the rate
of change of the field.
-
-
Faraday's third law of electromagnetic induction
-
- The sense of the induced electromotive force depends on the
direction of the rate of the change of the field.
-
- Fermat's principle; principle
of least time (P. de Fermat)
-
- The principle, put forth by P. de
Fermat, that states the path taken by a ray of light between any two points
in a system is always the path that takes the least time.
-
- Fermi paradox (E. Fermi)
-
- E. Fermi's conjecture, simplified with the
phrase, "Where are they?" questioning that if the Galaxy is filled with
intelligent and technological civilizations, why haven't they come to us
yet? There are several possible answers to this question, but since we only
have the vaguest idea what the right conditions for life and intelligence in
our Galaxy, it and Fermi's paradox are no more than speculation.
-
- Fizeau method (A. Fizeau, 1851)
-
- One of the first truly relativistic experiments,
intended to measure the
speed of light. Light is passed through a spinning cogwheel driven by
running water, is reflected off a distant mirror, and then passed back
through the spinning cogwheel. When the rate of running water (and thus the
spinning of the cogwheel) is synchronized so that the returning pulses are
eclipsed,
c
can be calculated.
|
