studiot

I have already referred you to post#281, byiNow, where the figure 200m is writ large. Who do I report these unseemly attacks to, since they now appear to be personal?

Well correct me then. Prove your claim. I was not attacked like this when, earlier in this thread I corrected a statement by Tim, although I did not join in the hounds baying at his heels in what seems to me to be a witchhunt.

How many million years ago was the cretaceous? So you have an accurate topographical/barymetric map of that time? You are a scientist so how can you compare data from millions of years ago with an event predicted to happen within 200 years? How can you be so certain that the topography will change so that such a rise is possible? If the topography does not change where will water equivalent to double the total ice come from, to bring this rise about?

I find this very disappointing and the rest of your post rather biased, especially considering this statement I made immediately after post#281 What about it? What about the quantity of ice that is floating above the current float line? There are probably quite a few factors that will affect the final figure in either direction, a small amount. I am supporting neither side in this discussion. Unfortunately climate change arguments always seem to end in tears. But I do like to see facts accurately represented. Perhaps, but if that is the case why did the originator not say so? I have seen him or her online her since that statement was made.

No I don't think you did, but I am fed up with verbal fencing for the sake of pointless argument.

Yes indeed that is true. But overall machine efficiency (and therefore fuel economy) is measured in terms of heat or work out against the calorific value of the fuel, not in terms of how well the fuel burns. What do you think of my distinction between a boiler and an internal combustion engine? One produces heat, the other work. Not only this but the IC engine has a large speed variation, so time available for fuel distribution varies with speed. Is the proposed method using sound capable of accomodating this? So I am querying whether it would be more appropriate to consider this for boilers. Yes comments from a mechanical engineer would be welcome, by why restrict to auto and? why not also turbines, gas engines, oil engines etc? It may be of interest to note that before loudpeakers were invented there was a device called the ionophone that performed the reverse operation. https://www.google.co.uk/search?hl=en-GB&source=hp&q=ionophone&gbv=2&oq=ionophone&gs_l=heirloom-hp.3..0j0i10l9.1562.4343.0.5812.9.9.0.0.0.0.140.1048.1j8.9.0....0...1ac.1.34.heirloom-hp..0.9.1048.DaYQEsg3jH8

Yes you said you wanted it to spread out, but why do you think that will increase the explosion? And even if it does why do you think that will help an engine that depends upon the expansion of gas? The smaller the start volume the bigger the final expnasion and the more the work that can be extracted. This is the reverse situation from heating a working fluid in a boiler or heat exchanger.

Airbrush, now your rocking! +1

Welcome soil engineer I look forward to some interesting posts. As regards combustion, why would you want to spread out the fuel? Boiler Plant that burn fuel would certainly benefit as the heat of controlled combustion is transferred in the heat exchanger. But combustion engines need to burn the fuel as quickly as possible since the wanted energy transfer is not thermal but mechanical in the work done by the expanding gases. Thus concentration is required. Timing also plays a part.

Do sensationalist replies help? Let us look at the figures. (Well spotted Greg H, yes obviously the units of volume are in cubic kilometres. But the numbers were correct.) Arete your reference has much the same figures as those from the US geological Survey official figures http://water.usgs.gov/edu/watercycleice.html But theirs have some additional material that is worth studying. So let us tabulate Total Water volume 1.33 x 109 cubic kilometres Total ice volume 24 x 106 cubic kilometres Current water surface area 361 x 106 square kilometres Curent average depth 3.68 km So if all the ice melts and the area does not increase that corresponds to an additional depth of water of (24 x 106) / (361 x 106) = .066km = 66m, say 60 m to allow for the spread as the depth increases. We can also expect a hotter earth to push more water into the atmosphere, reducing this still further. So what is the source of your figuring, iNow? don't you think 200m is excessive?

You could claim the same about being unable to discover what happens in the sky, without leaving the planet's surface. But it has probably been known since prehistoric times that clouds cast shadows. You could say the same about what happens in nearby space without leaving the planet. Again eclipses and other occlusions have been observed since antiquity. You could say the same about outer space without leaving the solar system. But what about the prediction and subsequent discovery of Le Verrier's Planet? So I could continue to extend outwards, you get the drift.

The rate of chemical reactions increases with temperature increase. So processes which involve chemical weathering will speed up. If you are interested the effect is called the Arrhenius equation. http://en.wikipedia.org/wiki/Arrhenius_equation

Matters are more subtle than this, although personally keeping cool when it is very hot is no subtle matter. Standard body temperature is 37 degrees centigrade. So for ambient below this temperature the body has to burn ingested fuel to stay alive Conversely, above this temperature survival requires the body has to reject heat. Having lived and worked in places where this barrier is regularly crossed for extended periods I can attestify that crossing this temperature barrier makes quite a difference.

No offence meant. but does T stand for ( the biblical) Thomas? Nothing I like more than to think my reply will be received with an open mind. OK On your wrist you have a gadget that performs exactly this miracle every hour. Let us take a line and connect the ends together into a circle. Now I can divide the line into (as many) infinitely small bits as I like, but the end result is still a finite circle, with a finite circumference. If I were to say I could not draw my circle or my watch hand could not pass the 12 because if I assemble an infinite number of these infinitely small bits of circumference will take an infinite amount of time, would I be right? Now extend that idea to the infinite number line. This time the circumference is infinite, but any point (as King Arthur said) on a round table can be taken as the start point, and is also the end point. So I can see both ends of my infinite number line. So there you have infinity without the maths. This was a very quickly dashed off exposition since It is well past my midnight and I am toddling off now. Final point the last step in an infinite sequence that reduces to zero must have zero length. I do not need to be able to count to infinity to know that. I did ask, a while back, that since your original post did not contain a question, whether you wanted to discuss infinities or the deficiencies in Zeno's logic. The deficiencies are not about infinities.

Confusion over terms seems rather common.

Well surely that has also to depend upon where your place your generator? solar is not much use at the North Pole, but then again wind is not much good in the doldrums nor is wave power in the Sahara.

Whilst I have offered you alternatives to thinking about infinities and you have eschewed them, the above is not true. So it is up to you if you wish to know more about what I mean or just continue to condemn the thought processes of others.

No of course not, why should I ? But I would contend that a block of pure steel containing a motor is different from one that does not. Just as any object with a hole is different from a similar one without. Of course the hole has defining limits. The ones I offered before have material boundaries. Various attempts have been made to create sustained artificial fusion reactors. Do you know of any where the containment was within a material body? In this case the containment (hole) was non material. But thank you for your thoughts.

The general cubic y = x3 + ax2 + bx + c is shown below for various values of coefficients a, b & c. For values of x that are very large and positive [math]y \mapsto \left( { + \infty } \right)[/math] For values of x that are very large and negative [math]y \mapsto \left( { - \infty } \right)[/math] So it must cross the x axis at least once on its continuous journey from negative infinity to positive infinity. imatfaal has pointed out that a cubic has three roots so if it crosses the x axis a second time ie left to right or from x negative to x positive it must cross back again to y positive. So a general cubic has one or three real roots. By evaluating the signs at the hinted points you can establish whether there is one or three crossings and where they are, following the same logic within each interval as others have indicated. Should this not be in homework help?

Without the existence of holes, you could not tie a knot and Topology would be a very different branch of Mathematics. Just as number theory would be very different without a solution to the equation x2 = -1

Roughly speaking material is translated as made of matter and no material is made of something else. Perhaps you missed this post in the time thread but here is something made of absolutely nothing (ie non material) If you wish to deny the existence of the hole, try using one without a hole. You didn't say that in your precious post. You need to be accurate and precise in Science. Particularly if you are testing the logic of someone else's deductions or statements.

You asked me what I meant by material and non material and I told you. Since I introduced the terms material and non material into the thread, quite deliberately to distinguish from any terms others might use, I claim the right to define them. We cannot have a conversation about anything I have said subsequent to my definition if you wish to use a different one since anyyhing I have said must be contingent upon my original definition. So are you arguing with my conclusions, drawn commensurate with my definitions, or are you arguing about my definitions? I did indeed, and I have several times in this thread distinguished between real as having existence and imaginary as not having existence. Further I have distinguished between material and non material items, which I have defined as a different concept, as indicated about, to prevent confusion with real v imaginary. I have even accomodated you in altering my use of the term 'object' to item and explained why I did that - again to avoid confusion stemming from conflicting definitions. So are you just palying with words or do you have a substantive point to make? If so, please be good enough to make it properly. Actually this is not strictly true, since there are other circumstances where a soleoid is not inert. If you look more carefully at my statement, I said Now a solenoid possesses calculable self inductance whether or not electric current applied. So once again. are you playing with words or do you have a reasoned objection? If so please state your reasoning.

Useful tips, thanks John, +1

http://www.eeweb.com/toolbox/wire-inductance

For those interested in theoretical thermodynamics (non engineering) I recommend. Elements of Classical Thermodynamics for Students of Advanced Physics : Pippard : Cambridge Thermodynamics and Statistical Mechanics : Wilson : Cambridge Basic Thermodynamics : Carrington :: Oxford Chemical Equilibrium : Denbeigh : Cambridge I do not advise Thermodynamics and and Introduction to Thermostatistics : Callen : Wiley.