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uk.sci.weather (UK Weather) (uk.sci.weather) For the discussion of daily weather events, chiefly affecting the UK and adjacent parts of Europe, both past and predicted. The discussion is open to all, but contributions on a practical scientific level are encouraged. |
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#151
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On Mon, 10 Aug 2015 00:14:56 +0100
"Alastair McDonald" wrote: If you can't provide an answer to this then it's game, set and match I'm afraid. It has been game set and match for quite a while. There is no way that you will accept what I have to say. This is just a Kangaroo Court with me as a victim. Dawlish has persuaded every one to distrust me, and just look how much he is enjoying it. I don't read Dawlish so I wasn't influenced by him one way or the other. -- Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer] http://www.scarlet-jade.com/ I wear the cheese. It does not wear me. Posted with Claws: http://www.claws-mail.org/ |
#152
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![]() "Alastair McDonald" wrote in message ... . It has been game set and match for quite a while. There is no way that you will accept what I have to say. This is just a Kangaroo Court with me as a victim. Dawlish has persuaded every one to distrust me, and just look how much he is enjoying it. There is no need to 'play the victim' just because everybody disagrees with you. You give the impression that everybody is scared of Dawlish and he has brow-beaten everyone into agreeing with him. The reason that everybody disagrees with you is that everybody thinks you are wrong. It really is a simple as that. -- Col Bolton, Lancashire 160m asl Snow videos: http://www.youtube.com/channel/UC3QvmL4UWBmHFMKWiwYm_gg |
#153
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On Monday, August 10, 2015 at 12:21:30 AM UTC+1, Alastair wrote:
It not just about semantics. It is also about my reputation. It has been destroyed by Dawlish ridiculing me for maintaining that bodies absorb cold radiation. You have destroyed your own 'reputation' by maintaining that bodies absorb cold radiation. You have deserved the ridicule and I can assure you it has not all come from me. Scroll back and look at the number of people who have also called you foolish, of stupid, or ignorant for believing this. However, if blaming me makes you feel better, all well and good. Water off a duck's back to me, but I will always expose snake oil science - and that is exactly what you are proposing, if you say that heat transfers are capable of moving from cold to hot. Cold radiation does not exist; centrifugal force does not exist. Anything else you'd like to propose? Cheers, Alastair. |
#154
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"Alastair McDonald" wrote in message ...
It not just about semantics. It is also about my reputation. Well, if you absolutely insist on misusing long-established terminology then it's scarcely surprising that your reputation might suffer. (Are you _really_ that bothered about reputation on a newsgroup???). I suspect that you're snittermost. |
#155
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On 09/08/15 23:54, Alastair McDonald wrote:
"RedAcer" wrote in message ... How many do you know? Scores. I've got a degree in Physics and spent several years working on a PhD in low temperature solid state physics. When the photon reaches a body and is absorbed by an atom how does is it 'know' if that body is hotter or colder than the one it was emitted from. How does the absorbing atom 'know' the temperature of the body the photon came from? I am tempted to reply: "The photon and atom ask a passing PhD student." :-) The photon and the atom only "know" the photon's frequency and hence its energy. It is the difference between the absorbed photons' and emitted photons' energies which determines the objects change in temperature. That is drivel. You need to learn some physics. ? I didn't mention any emitted photons. Lets do one thing at a time. "When the photon reaches a body and is absorbed by an atom how does is it 'know' if that body is hotter or colder than the one it was emitted from" |
#156
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On 10/08/15 01:56, Tudor Hughes wrote:
On Sunday, 9 August 2015 16:47:13 UTC+1, RedAcer wrote: On 08/08/15 12:26, Alastair wrote: I learnt my Kinematics at University while studying for an engineering degree, not from some smart alec teacher. Yours wasn't Dawlish by an chance? OK the centrifugal force is not a force field like gravity, magnetism, etc., but the centrifugal force can be calculated, see your link which describe it http://scienceworld.wolfram.com/phys...ugalForce.html . That link is proof enough for me. Strange that one can get so many hits for centrifugal force if it does not exist. Nonsense. If you were in a seat on a roundabout facing inwards then you would feel a force pressing into you back forcing you to move in a circle. Try this experiment. Take a short piece of sting with a weight on the end and whirl it round in a vertical circle. As the weight is at the top of the circle, let go. If there was a centrifugal force it should move outwards. It doesnt though. It will move off horizontally at a tangent to the circle. Hmm, some doubtful stuff there. From the point of view of the rotating body centrifugal force certainly exists and is a useful if non-rigorous concept. When you let go of the string the body the body certainly does initially accelerate outwards at a rate determined by the previous centrifugal force. No that is not correct. When you let go/cut the sting the tension towards the centre forcing the ball to move in a circle stops. At that instant the velocity of the ball is horizontal. According to Newtons laws it will continue to have a horizontal velocity. |
#157
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On 09/08/15 18:20, Alastair McDonald wrote:
"RedAcer" wrote in message ... On 09/08/15 12:49, Alastair McDonald wrote: "JohnD" wrote in message ... "Alastair McDonald" wrote in message ... Stephen was right. I falsely accused you of committing the fallacy of ad hominem. It should have been the fallacy of Argumentum ad populum https://en.wikipedia.org/wiki/Argumentum_ad_populum . =============================================== Alastair, I'm sure I'm wasting my time here, but let me try just one more time: Not as much as I am :-( The reason for raising what you're termed an ad populum argument is that you are seemingly very resistant to agreeing to logical scientific argument. So all I was saying was that even if you dismiss all the scientific arguments against your theory then does it really cut no ice at all that no-one else in this fairly well informed forum is prepared to offer even a modicum of support for it? If so, I can only conclude that you're starting to show signs of a messiah complex, at least insofar as physics is concerned. But let's try one other approach: Science is generally content with the simplest theory that fits all of the observable facts. (What's sometimes referred to as Occam's Razor in some contexts.) Would you disagree with that? A new theory is only needed when there are certain observations that are not well-explained by the prevailing scientific orthodoxy. This isn't a new theory. What I didn't realise was that others are so unfamiliar with it. So (and leaving to one side all the potential theoretical objections to 'cold radiation'), why the need to postulate two types of radiation when all current observations can be perfectly well described by the standard concept of radiation? It is a shorthand term for "the raditation emitted by a cold body." What are these observations and experimental results that are at odds with the existing model? I have given two examples of observations: the cold baby in an incubator, and Pictet's experiment which is described in this paper http://www2.ups.edu/physics/faculty/...experiment.pdf (Or try googling "Pictet's experiment", but it doesn't get as many hits as centrifugal force. :-) That paper even explains how to carry out the experiment yourself. My detractors have given no examples of experiments, and have only presented what you call "theoretical objections", (and a few insults e.g. acusing me of having a "messiah complex". You will have to ask them how they conflict with their model. The existing model is the one I am using, which I will now describe. All bodies emit radiation based on their temperature (blackbody radiation). A cold object emits cold radiation. If that radiation falls on a hot object then the hot object will cool. NO!NO!NO!; radiation contains energy. The energy emitted by a cold body and absorbed by a hot body will heat the hot body. Are you saying that a cold body emits negative energy?? Please stop this stupidity. No, that is what Dawlish would claim I am saying, if he were bright enough. The energy arriving from a cold body is not enough to maintain the temperature of the hot body, which is emitting black body radiation at a greater intensity and so it cools. The hotter body will cool anyway whether the colder body is there or not. The radiation from the colder body means that the hot body will cool more slowly that it would have done if the cold body weren't there. It is not 'cold' radiation as you keep insisting. It does not cool the hot body, it warms it up.(I'm assuming no background bodies or source of radiation) Cheers, Alastair. |
#158
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On 09/08/15 18:21, Alastair McDonald wrote:
"RedAcer" wrote in message ... On 08/08/15 18:11, Alastair McDonald wrote: "Eskimo Will" wrote in message ... I really canot understand why this is being discussed at such length. The laws of thermodynamics state that heat energy (radiation is a form of heat) flows from warm to cold and entropy increases, end of, surely? I now realise that the problem is that we are talking at cross purposes. They are talking about the balance of radiation which results in a NET flow of heat from warm to cold. I am talking about the cooler of those two flows, which is called cold radiation. If there is a body at x^0 centigrade alone in space; is it emitting:- radiation, hot radiation, cold radiation, something else ? What would 99.999999999999999% of physicists' or maybe, engineers say? I think 100% of engineers and 99% of scientists would say it is emitting blackbody radiation. It is only cold radiation if/when it arrives at a warmer body which, from a 0C body, is most likely. So it would be hot radiation when it arrived at a tank of liquid nitrogen or a block of dry ice. WRONG! - explained elsewhere. |
#159
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On 10/08/15 00:21, Alastair McDonald wrote:
"Metman2012" wrote in message ... On 09/08/2015 18:24, Alastair McDonald wrote: "Metman2012" wrote in message .............snip bizarre stuff. It not just about semantics. It is also about my reputation. It has been destroyed by Dawlish ridiculing me for maintaining that bodies absorb cold radiation. You have NO reputation when it comes to understanding physics. I have just realised that his problem is he is misinterppreting the Second Law of Thermodynamics. He think it means that heat only travels from hot to cold, but of course as you have pointed out it, it states entropy increases. Heat does only flow from a hot body to a cold body!!! That is the DEFINITION. Heat is the NET flow of energy. Radiative energy leaves the cold body and is absorbed by the hot body. Radiative energy leaves the hot body and is absorbed by the cold body. The net flow of energy is from the hot to the cold body. That is the heat flow. As heat flows out of the hot body it cools down. Forget this 'cold' radiation nonsense. Hot becomes colder and cold becomes hotter. Heat travels in both directions, just as does radiation. Thanks! HTH, Cheers, Alastair. |
#160
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On 09/08/15 19:26, Alastair wrote:
On Friday, 7 August 2015 18:25:05 UTC+1, Stephen Davenport wrote: Your smart, so I don't understand why this is so difficult. Stephen. Because I was not smart enough to realise Dawlish thinks that because a cold body radiaties blackbody radiation it will warm an adjacent body. That is just unbelievable - wouldn't you agree? Surely even a fool like him can't think that. A 'cold' body emits radiative energy proportional to T^4, where T is its absolute temperature. So does a hot body. The energy from that cold body will be absorbed by a nearby hot body. This is just well known physics. Radiation from the hot body will be absorbed by the cold body and some of that will be re-emitted back to the 'hot' body!! So, far from the cold body cooling the hot body as you claim, it does the opposite. Do the experiment yourself. (I'm assuming no other sources of radiation) |
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