Physics: Problems and Solutions
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Granpa Granpa 1 May 2019
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Primary colors

The primary colors that the brain (not the retina) perceives are

yellow
red
blue

combining these gives the secondary colors

orange
purple
green

One can see that these secondary colors are intermediate between the primary colors

One would assume then that combining a primary color and a secondary color would result in a color intermediate between the primary and the secondary. And indeed most do. Except for cyan. Cyan is produced by combining blue light and green light but the color we perceive is not intermediate between blue and green.

The color we perceive as cyan is clearly a combination of blue and something. But what that something is is just not clear.


in a bird's cone cells.]]

I suggest that there were originally four primary colors and that cy…


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Granpa Granpa 14 April 2019
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Natural units

See also: Dimensional analysis and Nondimensionalization

In physics, natural units are physical units of measurement based only on universal physical constants. For example, the elementary charge e is a natural unit of electric charge, and the speed of light c is a natural unit of speed.


  • 1 Fundamental units
    • 1.1 Uncertainty principle
  • 2 References
  • 3 External links


A set of fundamental dimensions is a minimal set of units such that every physical quantity can be expressed in terms of this set and where no quantity in the set can be expressed in terms of the others.


  • https://www.ias.ac.in/article/fulltext/reso/004/02/0020-0023
  • Uncertainty principle
  • Gaussian function



  • The Spectrum of Riemannium
  • wisc.edu
  • Stoney Scale and Large Number Coincidences






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Granpa Granpa 7 March 2018
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Weather

Earth's weather is primarily driven by rising air in three Low-pressure areas.

  • The northern hemisphere polar front.
    • Extratropical cyclones form along the front and move eastward at 12-15 m/s (43-54 km/h) and last 3-5 days. (3600-6000 km)
  • The Intertropical Convergence Zone. Sometimes, a double ITCZ forms, with one north and one south of the Equator.
    • Tropical cyclones (Hurricanes) form here and move westward.
  • The southern hemisphere polar front.
    • Extratropical cyclones form along the front and move eastward

And to a lesser extent by descending air in two High-pressure areas:

  • Northern hemisphere subtropical ridge (horse latitudes)
    • The Sahara desert is here.
  • Southern hemisphere subtropical ridge (horse latitudes)
    • The Kalahari (in south Africa), the Atacam…
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Granpa Granpa 9 February 2018
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Superconductors and supersolids

Many people wonder how it is possible for a current of electrons to flow forever through a superconductor without any loss. The simplest explanation is that it doesn't. Instead a field is set up inside the superconductor which behaves as though charge was flowing.

The same is true of supersolids except that instead of behaving as though charge was flowing it behaves as though inertial mass was flowing. If we could learn to control this then we could create reaction wheels that have no moving parts.


http://www.open.edu/openlearn/science-maths-technology/engineering-and-technology/engineering/superconductivity/content-section-3.1

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Granpa Granpa 9 February 2018
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Transistors


The triangle in the diode symbol points in the forward direction, i.e. in the direction of conventional current flow. Electrons flow in the opposite direction.

An n-type semiconductor only conducts negatively charged electrons. A p-type semiconductor only conducts positively-charged holes.

When the diode is forward biased current flows easily and electrons and holes move toward each other and combine at the junction. In the case of a light emitting diode the combining of electrons and holes results in the creation of light.

When the diode is reverse biased current doesn't flow at all. However, in the case of a photodiode current can be induced to flow by shining a light on the junction. When the light is absorbed electrons and holes are created at the…


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