studiot

Did your daughter scratch at the site of the splash? Not a good idea as that would rub the acid in. You didn't say if the teachers immediately washed tha acid off? Or did someone just wipe it off and then leave it? 1M is not that strong for a near adult, but what was an 11 year old doing with it and what was the supervision? By way of contrast car battery acid is 4M to 6 M and would definitely burn straight away. Here is a company Health and Safety document which regards 1M as "corrosive to skin" http://www.onboces.org/safety/msds/S/Scholar Chemical/Sulfuric_Acid_1.0M_740.00.pdf

Get hold of this book http://press.princeton.edu/titles/8861.html It exactly fits your bill. BTW Sears and Zemansky have various books that are streets ahead of the Resnick & Halliday, even as edited by Young and Freedman.

Your are too suspicious. I am trying to work through the physics of something with you so that that you can see for yourself what the facts are. It is fundamental to wave theory that a point source produces a spherical wave that spreads out in all directions. So a point source on the surface of the Sun (Point P in my fig1) creates an expanding spherical wavefront as I have shown dashed in Fig1. This has an average radius of 150 million kilometres by the time that front reaches Earth. The source at P does not have a choice in this, nor does it have collimators or focusing devices. But yes there are many such sources on the surface of the Sun and they are not coherently phased, like a laser. (Thank the Lord Huygens) or we would not be here if they were. I said that as a result of that distance that wavefront is effectively a plane wave so the (very simple) maths of this is shown in fig2. The deviation of a circular curve from a straight line is given by the formula (distance along the straight line squared) divided by (twice the circle radius) With the figures shown this works out at about one tenth of a millimetre over the linear distance of the radius of the Earth. So think how much straighter the wavefront must be over the size of a carbon dioxide molecule, whose bond lenght is 1.16 x 10-7 millimetres long. This is why we can say that in another model - that of geometrical optics which treats light as a series of 'rays', that the rays from the Sun are parallel. I mentioned bond length of carbon dioxide which is important because this determines the frequencies for the four fundamental modes of vibration of the molecule. The plan is to fully understand how a straight radio aerial works and see if we can use this to understand how the stretching modes of the carbon dioxide bonds comes to be in the IR and microwave bands and not other bands of the EM spectrum. But first we must look at your thoughts on how a radio aerial actually works. This is not far off the truth but just need a couple of amendments. I have underlined the relevant bits. Firstly and most importantly. Forget resonance - the word will get you into trouble when we consider charge separation in the carbon dioxide molecule. It has a specific and quite different meaning for chemists and bonding. The radio waves induce current in any conductor of any length. Resonance is not required. The issue is what happens to those currents when they have been induced. We shall see that conductor length then becomes vitally important. I prefer the phrase charge separation, rather than current because that is what happens in both the radio aerial and the carbon dioxide molecule. The effects are potential driven, not current driven. Finally we spoke about reflection, absorbtion and transmission. What about refraction and diffraction of waves? I think we are doing well and making real progress

I agree with iNow - to quote the old phrase "There's none so blind as those that won't see and none so deaf as those that won't listen."

Surely if he admits it doesn't have to then you can challenge him as deceitful. Ask why did he use something he knew to be false as a challenge, instead of offering proper evidence or reasoning.

Nor am I a biologist, but why does the genetic information have to increase? Why can't it simply change but stay the same quantity? Or heresy even, diminish if a trait is lost or dying out? BTW how does one measure the quantity of genetic information?

I like miracles. +1

Actually I'm very much against Hinkley C - it is a complete and enormous waste of public money, when there are much better options available, whcih are also 24/7. However the point about both solar and available wind is that they represent low density energy with substantial off periods. (With apologies to those in the Americas and Asia suffering from more powerful winds) You are close enough to Cruachan to understand the obvious implications of what to do about that.

Not on the solar panels I am familiar with, and not when there is no Moon to speak of.

I have it! There are (or used to be) certain radio /TV call-in shows where the presenters made a specific point of insullting or brow-beating the callers. The OP has escaped from radio GAGA where he was trained in these darkside arts. May The Force be with you all

Does anyone know what happened to Mitch? Seems strange that he would ask a question and not bother to come back for the answer.

I find it very comforting at night when I want to turn the lights on, cook my dinner and watch the BBC, that nuclear is constant, unlike solar.

So far you seem to think that there are three possibilities (though not mutually exclusive as with your chlorophyll example) when light approaches something. Transmission, reflection or absorbtion. That is not the case. Do you think that the radio wave is transmitted through the solid copper bar of the aerial? We have just agreed that the wave appears on the downstream side of the bar (it is not blocked by it) Having agreed that an aerial is frequency selective, do you understand how one works? I suggest you forget photons here. I have already suggested that for the purposes of this thread and your on topic question classical wave theory is adequate. I agree that there are many additional observable effects that require alternative theories, but they are not on topic here. Directionality is a not function of the wave alone, it is also dependent upon the source. The issue of a propagation medium is off topic here, but I would just observe that Faraday's notion that the wave generates its own medium as is goes along is adequate here. Finally your response to my observation that waves are larger than the obstruction leaves much to be desired. If the waves are propagating in the z direction then they are enormous in the x and y directions since they are so far from the source they are effectively plane waves. The 'waves' of light from the Sun are vastly bigger than the Earth itself. Hopefully you understand this much.

You have more faith in electronics than is warranted by my (passenger) experience of controlled rail systems think is warranted. There is a wonderful scen in the Norman Wisdom comedy where the hero is put into a centrifuge to practice Hi-gee. He is shown the safety cut out button to press if the stress gets too much. When they finally decide to stop the machine and drag him from it, they ask "Whys didn't you press the safety button?" He holds out the button with its connecting lead broken off. "I did" As to efficiency the figures were in the last post. The eurostar hauls around a ton of metal or more per passenger. Trams are no different. You can get 4 or more people in to a car that weights 1/4 to 1/2 ton That is one of many reasons why they are more efficient. The tractive effort of tyres on the road are also inherently more efficient than steel on steel. And of course you have to allow for the inefficiencies of generating that electricity for the tram motor.

Taken as a whole, trams (and other rail systems) are considerably less efficient than small IC engine cars. The price of lowering pollution is a reduction in efficiency. They are not necessarily safer either. The recent incident of the crashed Croydon tram on its side amply demonstrates that they can have bigger accidents. A few facts and figures: A single Eurostar train takes 800 passengers It weight 800 tonnes Putting all those passengers in cars would occupy 800 yards of the M25 London orbital motorwaY

https://en.wikipedia.org/wiki/The_Roads_Must_Roll

https://www.amazon.co.uk/Shorter-English-Dictionary-William-Trumble/dp/0198605757 Only £63

That is the shorter version, note the page number for the letter m. But is really is a good book. No I would not use a hyphen like that, although Americans do and it makes spell checkers a real pain. I might use the hyphen to separate two vowels say in re-edit, but not in remagnetization, it serves no pupose there.

Thank you for bringing this system to our attention. +1 I just expect that it would be far too expensive to run without enormous state subsidies. All the UK new tram projects have lost tens to hundreds of millions and been curtailed because they are so cumbersome. Personally I have heard from mechanical engineers that Robert Heinlein's 'rolling roads' are a more achievable proposition. We already have the beginnings of this in airports and shopping malls.

According to the bible (Oxford English Dictionary - OED) both are correct, but z would be the more common. That is certainly the case in my straw poll of British scientific authors in that field, especially post 1970.

No talking to you isn't all that bad, in fact you seem to be progressing towards proper discussion. I try very hard to read and address the contents of the posts of others inlcuding yourself. But when I asked for your comments on carbon dioxide in the atmosphere, you responded by talking about solid carbon dioxide. Which I hope you will agree is frustratingly irrelevant. But this last time you seem to be actually responding to what I wrote, so let us start again, without preconceptions. I think you seek a mechanism to explain how EM waves can pass by, or be absorbed by, or reflected by objects in their path. Ideally this mechanism should offer the conditions when each possibility will happen and concur with the results of real world observations. Please confirm that this is the case because I am trying to explain this to you. I also said that the easist explanation for this is wave theory. By this I meant classical wave theory, which in my opinion is sufficient to discuss the matter. My starting premises, based on real world observations, are: The structures of aerials for TV and radio broadcasts allow the broadcast waves to pass by and are sometimes reflected by these structures, but only extract the energy (ie absob at least some waves) for certain specific wavelengths which they are said to be tuned to. For simplicity I will take the simplest possible aerial, a length of conductor such as a straight aluminium or copper tube or wire. It is an observational fact that the wavelengths this aerial is tuned to depend upon its length in much the same way as and organ pipe can be tuned to a particular sound wavelength. Please confirm that you consider there observational facts. I am saying it like this because you chose to simply quibble by ignoring various helpful comments I made to enliven and enrich the discussion. I propose the development and extension of this theory to atmospheric carbon dioxide molecules. Working together this can be achieved. Continuing to work in seoparate compartments, it is unlikely the discussion can progress. The choice is yours.

J.C.MacSwell Since the OP hasn't thanked you for such a clear and complete answer I will. +1

Despite your unappreciative/unhelpful remarks in your last reply to me I will try one more time to help. The reason is best found in the wave theory of light and is the same reason we cannot see atoms or electrons with a light microscope. The wavelength of visible light is just too long by several orders of magnitude to resolve distance this small. The radius of an electron is of the order of 10-16 metres The radius of a carbon or oxygen atom is of the order of 10-10 metres The wavelength of visible light is of the order of 10-7 metres Since you like sound analogies, it is the same reason low frequency sound can diffract round objects, whilst higher frequencies sounds are blocked. In your sketch you have shown the wave being much smaller than the CO2 molecule. In fact it is the other way round. A visible light wave is ten thousand times larger.

This is where the engineering decisions and trial calculations come in. Yes the water could be pressurised to raise the temperature, or the transfer fluid could be steam or oil or a commercial high temperature 'refrigerant' such as you find in heat pumps. Yes a suitable piping loop could evaporate 3500 litres, but what is the recharge time? That would determine if it was fast enough.

Come on, are we talking sense or not? I asked why we could see through a carbon dioxide atmosphere, either as dilute as the Earth's atmosphere or pure, if carbon dioxide reflects visible light. Your answer apppears to be that we can't see a suspension of water droplets (clouds or fog) which is true but irrelevant. One of the important characteristics of wave motion is that reflection occurs at a boundary. The boundary is not at the atomic scale but water doplets provide an ideal boundary to disperse the light rays by reflection. I didn't notice much solid carbon dioxide around when I got up this morning either, so what is the relevance of the transparancy or opacity of the stuff?