Recent content by adb

  1. A

    Deriving Velocity of Wedge Before Block Hits Ground

    There is obviously an error in your equation above. If the masses are equal, it implies the acceleration of the block is equal and opposition to the acceleration of the wedge, regardless of the angle of the wedge. If conservation of kinetic energy did not hold, heat would be produced ... but...
  2. A

    Deriving Velocity of Wedge Before Block Hits Ground

    It sounds very reasonable, although you have "a" on both sides. Taking a across gives quite a complex expression. I assume the acceleration on the block down the slope is g sin \alpha - a cos \alpha ... however in reality, the direction in which the block moves is NOT at the...
  3. A

    Deriving Velocity of Wedge Before Block Hits Ground

    Thank you for your thoughts however, Bruce, It is a closed system. Energy must be conserved. IDOGAWACONAN, 2 equations, 3 unknown velocities ... not enough for a solution. What is the basis for the "tan(angle of wedge) ..." equation ? Perhaps conservation of momentum as mentioned by...
  4. A

    Deriving Velocity of Wedge Before Block Hits Ground

    I've also come across this problem in the past few days and it has me puzzled. For a wedge angle 'alpha', how is the final velocity of wedge and block calculated ?
  5. A

    What's wrong with a bit of global warming?

    If there was a shed of evidence that man's CO2 is causing warming, I'm sure the IPCC would also like to hear about it. The rate of man's fossil fuel burning increased around 1200% after 1945 but the rate of warming from 1910 to 1940 is higher than any period after 1945. While the Arctic...
  6. A

    Falsifying the Atmospheric CO2 Greenhouse Effect: G. Gerlich & R.D. Tscheuschner

    In other words, you're taking half of the standard engineering equation for radiative transfer.
  7. A

    Falsifying the Atmospheric CO2 Greenhouse Effect: G. Gerlich & R.D. Tscheuschner

    Given : Th = temperature of a hot body Tc = temperature of a cold body ... what formula are you using for "back" radiative heat transfer from the cold body to the hot body ?
  8. A

    Falsifying the Atmospheric CO2 Greenhouse Effect: G. Gerlich & R.D. Tscheuschner

    None of the texts I have used or engineering collegues I have spoken to, make use of assumptions other than those based on the 2nd Law, in calculating heat flows an any situation we have encountered. The same as in a couple of posts back where you stated :
  9. A

    Falsifying the Atmospheric CO2 Greenhouse Effect: G. Gerlich & R.D. Tscheuschner

    Engineering takes a pragmatic view. Given 2 bodies at different temperatures, engineers calculate the heat flow between them. It the temperature of the atmosphere is the same at a given altitude, with or without greenhouse gases, I assume that this implies that if IR absorption becomes...
  10. A

    Falsifying the Atmospheric CO2 Greenhouse Effect: G. Gerlich & R.D. Tscheuschner

    From an engineering perspective this would be expressed as: 1000 downwards as sunlight. 150 upwards as reflected sunlight. 100 upwards as infrared surface emission. 750 upwards as convection and special heat. Another question: If the atmosphere was 100% "greenhouse" gas, that is...
  11. A

    Falsifying the Atmospheric CO2 Greenhouse Effect: G. Gerlich & R.D. Tscheuschner

    Instruments such as pyrometers bring the discussion full circle. They focus radiation from an object onto a thermocouple or an FPA array to determine its temperature by comparison to some standard, based on the amount of radiation it is emitting or absorbing. We point it at the sky and measure...
  12. A

    Falsifying the Atmospheric CO2 Greenhouse Effect: G. Gerlich & R.D. Tscheuschner

    Instead of a sunbather, suppose we have a box made of thin IR transparent material. The box is evacuated and has a thick insulated base. It is placed so that the top of the base can only view the sky. A shade is positioned some distance away to block the sun. Only 400 watts of back radiation...
  13. A

    Falsifying the Atmospheric CO2 Greenhouse Effect: G. Gerlich & R.D. Tscheuschner

    How about reflective foil, blackened on the sunbather side ? I'm an engineer, not a physicist ... I still find the concept of heat traveling from cold bodies to hot bodies difficult to get my head around.
  14. A

    Falsifying the Atmospheric CO2 Greenhouse Effect: G. Gerlich & R.D. Tscheuschner

    We're both intelligent people and I'd like to tie things down. I don't work in the industry and have nothing to gain whether greenhouse exists or not. No question that real greenhouses have no analogy with the atmosphere. The above is the crux on which I am trying to understand your...
  15. A

    Falsifying the Atmospheric CO2 Greenhouse Effect: G. Gerlich & R.D. Tscheuschner

    It is not a "bath" of IR radiation. According to greenhouse, there is a hemispherical emitter (the sky) providing as much radiation to the top of the sunbather, as the sun was, before she was put in the shade. Radiation shields are used everywhere. Your car exhaust is fitted with radiation...
Back
Top