studiot

You have yet to demonstrate there will be a freeze - thaw.

Since this is worrying you. Here is something to think about. Actually, no this is not possible. It is not possible becasue you have a length (and width and height) in space. You are not a point. Try to imagaine what would happen if you were a sausage and you said the sausage moves 3 units North, the two units West. Where is the sausage now ? Now ask the same question if you cut a slice from the middle of the sausage and moved it those idatances where is it now ? This second operation are what most people mean by time-travel, which is not the equivalent of space travel. Why not ?

Maxwell, Stokes and others worked all this out in great detail in the early to mid 1800s. But they rejected these mechanical models is unsatisfactory for a variety of reasons, and finally devised experiments to disporove aether models once and for all. How much less satisfactory do you think we now find them 150 years alter, armed with our greater knowledge and many, more refined experiments ?

Well you should not doubt it. Tensional forces from any source always aid the degradation due to chemical weathering, for instance by causing joints which allow the acid solvents to penetrate deeply into the body of the rock. Anyway as you say, your observations were side observations, and my comments were equally quick responses. I propose to do some reading up on the mechanical models I dubbed interesting and will report back when I have found more out.

Indeed I am just adding to my own observation that engineering predated science by perhaps thousands of years. Noelithic engineers had no science.

I'm glad you are beginning to do some thinking about it. Because your ice/water interface must have moved on many metres in that one second, depending upon the interface speed you take. If this does not happen then you will not have the required water for the hydroturbine to operate. It cannot do so in a slush. Also if you have used all the solar energy in your 100m strip for thawing the ice, how are you going to find the power to pump stuff around ? Finally all this area of solar collector, pipeline, pumps, controls, turbines, output electricl gear and storage must weigh millions of tonnes. How are you going to get it all there ?

Yes I wondered about some of the wording in the available extracts. For instance the idea of plates 'drifting' around the globe harps back to the theory of continental drift. As regards to 'damage', that may not be the best word but deformation does not tell the whole story either. Crustal (and other) rocks can and do continually degrade by various natural processes as well as specific event such as plate boundary activity.

What known science did the first neolithic engineer to build a clapper bridge 'apply' ?

No ridicule, but I'm pretty sure I didn't say your second line as you have rephrased it. I'm also pretty sure you fully understand the difference between power and energy. So what I said was that the solar energy incident on that area over a period of one second was eactly the amount you need to thaw a cubic metre of ice, if you could collect all of it and add it all to that ice. I was temporarily ignoring the inefficiencies of collection, distribution, storage etc and simply asking how you would transfer that amount of energy into a block of ice in one second, since you would need to do the same again with the next block of ice in the next second and so on. Given my own knowledge of this sort of thing from deicing of bridge structures I am doubting the practicality of that operation.

You could make an argument the other way round since engineering is by far the older discipline. In other words scientists are a particular type of engineer. However engineers sometimes 'do' science - when they want to find or try something out. Equally scientists sometimes do engineering when they want a particular piece of apparatus that does not already exist. When I cook the dinner I act as a chef not a scientist or an engineer. Which simply prooves that humans are more versatile than artificial categorisation.

Thank you @beecee that is enough to get the gist of it. Turkish - When I tried to follow your link the first time I saw mention of the Univesity of Istambul and examples in Turkey. The idea that the subducting plate is drawn ever more steeply downwards and eventually breks off has been around for quite some time. Ted Nield details the evidence for this in his 2007 book Supercontinent. The mechanical model of the dashpot, pulley and tension connections is new to me at least and interesting to consider. I wonder how many such situations there are (were) around the globe ? Thank you for a good response and an interesting article now I understand what it is all about. +1

So let me get this straight. You are envisaging using the entire output from a 100m wide strip, one quarter of the way round the martian globe to melt the ice in one metre of the pipeline ?

Yes, sorry. Quoting you instead of the OP was my mistake.

Unfortunately this article is subscription only. I would like to see at least a diagram in case something is lost in the translation from Turkish.

As an obviously competent engineer I am disappointed with the obviously politician's brush off when pressed for hard detail, more especially as you invited comment. Here is the problem I am trying to reconcile. You have mentioned several different pipe sizes, and somewhere a square metre of cross section. So let us consider 1 m2 section of pipe 1 metre long, at the frozen stage. This has a volume of 1 cubic metre. Ignoring, for the moment, the small difference in density between ice and water, this has a mass of 103 kg So to calculate the approximate energy reuqirement to raise this from ice at -4 C to water at +1 C ie to melt it we require 103(4*2050 + 334000 + 4200) = 3.464 105 x 103 Joules per m3 Now the rate of insolation on the mars is 590 w/m2 or 5.9 x 102 J/m2 per second So it requires ( 3.464 x 108 ) / (5.9 x 102 ) = 6 x 105 square metres of martian surface to receive this energy every second multiplied by the rate of movement of the ice/water interface as this was calculated on a 1m/s basis and assuming perfect energy conversion.

Sadly you are still not answering my question(s)

You are asking this question of the Physicists here. In most Physcis textbooks the authors are not to worried about charge so the equations presented do not generally observe conservation of charge. So the equations presented often have a beta minus or alpha positive charge on one side, but no charge on the other. So these equations do not balance in respect of charge. For example Chemists are more careful so here is an extract from a Chemistry textbooks that explains this in detail, balancing the charges as well. And yes the equations now balance for charge. Some reactants and/or products are now shown charged (eg as ions or whatever) Another way to compare is to understand that Physicists are talking about nuclear reactions and so use the chemical symbols to represent the nucleus, which always carries a positve charge equal to the atom ic number. Chemists use the same symbols to represent the electrically neutral atom so must always display the charge to refer to an ion. Does this help ?

Well perhaps you are not the only one being unclear since this post of yours describes exactly what is worrying me and I thought I had stated in my last post. Someone seems to have perhaps understood it, although your answer suggested that you did not catch it. Do you think that either Martian conditions allow either freezing or thawing at 18m/s ? That is driving along at 40mph. What sort of heat transfer coefficients are you envisaging for the pipline and what about the energy flows to accomplish this ?

Article about Tokomaks in Britain and America Interestingly set in the business section, not the science section of the BBC. However it does offer some useful up to date facts and figures. https://www.bbc.co.uk/news/business-56843149

After checking a few figures, I agree with your starting point about the length and rotational velocity of the pipeline in rounded numbers. But exchemist has a more supportable view of the rotational velocity of the interfaces. Have you thought about how long it takes for the thawing to occur ? Here is a table of measurements from Wikipedia. Note that at this site the temperature does not rise above the freezing point of water at any time of day or night from November to May

All good points pertinent to a much more in depth analysis than my offering. +1 However it should be noticed that the effect of blowing over soup is always cooling on the soup, however you blow. But the effect of blowing over the hands is cooling or warming depending upon how you hold you hands and how you blow.

Yes indeed it is possible to extract energy from the air. Wind turbines can turn this into electricity. Windmills or windpumps can turn this into useful work. Air pressure can be use this to raise and lower large steel pressure chambers or 'gasometers'. Heat pumps can turn this into useful heat. But none of these directly fit your description which appears to violate the First Law of Thermodynamics. Members here will happily discuss your invention and perhaps help you towards a practical revision that would actually function. I suggest you start by understanding the difference between loaded and unloaded machinery, both electrical and mechanical, and the importance of flow rate to the output of machinery.

I note you have posted this in Linear Algebra and Group Theory, not simply general Mathematics. So I assume you know what these terms are and that Groups are connected with symmetry. Well signed multiplication is an operation with a symmetry. The full list of possibilities is positive times positive makes positive positive times negative makes negative negative times positive makes negative negative times negative makes positive (The one you asked about) As you see this list is symmetrical: there are two ways for a positve result and two ways for a negative one.

Is this really a homework question or just a request for understanding of material you have been presented with in a course or read ? I ask because it looks much more like the latter and such questions can legitimately be asked in the main Chemistry sections. OK so there are several different classification schemes for chemical reactions. Each has its own point of view and the schemes are not mutually exclusive. So you first list is about reactants and products. That is what substances you start with and what substances you end up with. Say A + B = C - combination A = B + C - decomposition or dissociation AB + CD = AD + CB - replacement or elimination and so on. There are further reactions types than your first list in this viewpoint. Your second list narrows down these wider categories in some way. So Acid + Base = Salt + Water Is an elimination reaction where CB is always water and AD is always the salt. (This has been extended beyond water in more advanced Chemistry) If the reaction is in solution and AD is precipitated then this is also a precipitation reaction. So you can see some overlap in the categories beginning to appear. Oxidation is the addition of oxygen or the removal of hydrogen Reduction is the removal of oxygen or the addition of hydrogen Since combustion is one of these (which one ?) It is a redox reaction. Note that all these classification types start with substances and end with different substances. In more advanced Chemistry your will meet others views which are about what goes on during the reaction and the movement of electrons and/or protons from one substance to another. These may be called reaction mechnaism views. Where are you in your studies to have been given the first list as the basic 5 ?

What is meant by virtual (virtually is an adverb which refers to verbs, not nouns) is my point. Yes we do understand virtual and have been using it for centuries. Does you eye see the virual image obtained through a magnifying glass ? What is the difference between a real and virtual image ? If you understand the difference between pressure and force you are using a good example of another virtual phenomenon. Consider a gas. Imagine a frame somewhere in that gas defining an area. What is the pressure across that frame and is a force acting ? The frame and its area are virtual as pressure is only exerted on the boundaries of the gas. In other words it is only realised by the interaction with the real world around it, just like the quantum virtual particle.