Recent content by johnbbahm

  1. J

    Historic temperature data in New York/Greenwich on small and large time scales

    I cannot speak to the billion years, but the last decade of New York, is covered fairly well by NOAA's climate at a glance. https://www.ncdc.noaa.gov/cag/city/time-series
  2. J

    Wind chill -- How is it actually measured?

    I think of wind chill as how quickly heat is removed from an object, the object can be ether a person or a bowl of water. The persons perspective is subjective, the bowl of water freezing solid is not.
  3. J

    Wind chill -- How is it actually measured?

    Since how something feels is very subjective, I would hope the formula is based on empirical data. For me a type of real measurement would be the time difference between a bowl of water at say -5 C without air movement to freeze solid vs the time with a 10 knot wind. The moving air would cause...
  4. J

    Secondary Mirror in Solar Concentrator Dish Designs

    The only limitation I can think of would be a concern for air ionization. As the energy density increases in the ever tightening focused beam, you might pass the point where the air ionized and becomes less transparent. This can be observed with lasers or just a few watts, the power observed at...
  5. J

    B Recreation of Famous Japanese Rogue Wave

    I understand, I was simply trying to show that the possibility for rouge wave exists in the math as well. You are correct that the randomness of waves of different directions, amplitudes, and frequencies would make the actual peak interference very rare.
  6. J

    B Quartz vs. Glass -- why do they have different melting points?

    A word of caution, if you are used to working with glass, quartz looks like it has cooled off long before it actually has.
  7. J

    Where can I find historic daily average temperatures?

    I think NOAA's climate at a glance has what you may be looking for. https://www.ncdc.noaa.gov/cag/city/time-series/USW00094728/tavg/12/12/1895-2018?base_prd=true&firstbaseyear=1901&lastbaseyear=2000&trend=true&trend_base=10&firsttrendyear=1895&lasttrendyear=2018 It also can do maximum and...
  8. J

    Storing Heat from a Radiator

    You might try finding a 30 gallon barrel and filling it with rocks and water, and placing it in contact with the radiator. (Perhaps do not seal the barrel) The mass of the rocks and water would warm up with the radiator, but then take several hours to cool down after the source of the heat...
  9. J

    B Recreation of Famous Japanese Rogue Wave

    I think we think of waves and constructive interference in 2 dimensions, and with mostly 2 frequencies. In the ocean there can be several vectors of energy, and water supports a wide range of frequencies. I recall something I worked on a few decades ago, where the summation maxima s were not the...
  10. J

    How do we know electromagnetic waves are light?

    C/wavelength=frequency, C/frequency=Wavelength
  11. J

    How do we know electromagnetic waves are light?

    When it meets those criteria, it behaves like a wave, and works with the wave equations. You could say most of the same things for sound waves, but the "c" is different.
  12. J

    How do we know electromagnetic waves are light?

    I would say that if c(the speed of light) is divided by ether the frequency or wavelength, and the result is the one you did not divide by, then it counts as light.
  13. J

    Are there other variables that control climate change?

    You would think, but IPCC AR5 in 2013 cited Baede as the more comprehensive assessment. https://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter01_FINAL.pdf "Here, some of the key concepts in climate science are briefly described; many of these were summarized more comprehensively in...
  14. J

    Are there other variables that control climate change?

    The largest area of uncertainty in the climate models is based on our poor understanding of how clouds interact with radiation, Baede et al 2001 IPCC TAR, "It is believed that the overall effect of the feedbacks amplifies the temperature increase to 1.5 to 4.5°C. A significant part of this...
  15. J

    How do you run vacuum pumps in series?

    For high vacuum systems you use two pumps effectively in series. The roughing pump is attached at the bottom of the diffusion pump, and lowers the pressure to between viscous flow and molecular flow. The diffusion pump takes over, and collects molecules at the bottom for the roughing pump to...
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