TonyMcC

Almost certainly an indication ripples in the atmosphere. Usually forms to the lee of hills and mountains when there is a strong steady wind. Glider pilots love it when they get a chance to fly in these conditions. They call it "wave lift" and it is often indicated by clouds like you describe. The link is given for information (not advertising). It describes wave lift. http://www.scottishglidingcentre.co.uk/lift.htm

From what I remember from physics lessons at school if you look carefully at steam issuing from a boiling kettle the steam will seem to appear to form a little distance away from the spout. Therefore it cannot be seen until it starts to condense. That was in the days when kettles were boiled on a gas ring and could be kept boiling for the observation. These days with electric kettles which automatically shut off it's not so easy! (Not to mention 'elf an safety)

Maybe, but this tank was made of copper and on entering her house she attempted to run water before lighting her solid fuel boiler trying to make sure water could flow through the system. On the typical UK system there is not a pressure relief valve, but instead there is an expansion pipe feeding back to a header tank in the loft. The water in this pipe must also have been frozen. It is fortunate that she hadn't lit the boiler which could have caused an explosion.

Not exactly the water pipe, but my mother in law (no jokes please she is no longer alive) several years ago had her hot water tank collapse inwards. She had been away from home in freezing weather and the feed to her tank, which was in the loft, had frozen. She turned on the hot tap and as water flowed from the tank the tank just collapsed. Quite powerful stuff air pressure!

You got out of those by lifting the canopy on one side. I read a report of someone who made himself a mini garage about three feet high. He drove into his little garage and didn't have enough height to lift the canopy. Having no reverse gear he was stuck for some hours before friends came and pulled him out backwards! There were a lot of these small vehicles about - many known as Bubble cars. http://en.wikipedia.org/wiki/Bubble_car

Back in the 1960's I owned a Bond Minicar. You would have difficulty making anything practical that was more simple. It had a two stroke engine (more simple that a 4 stroke), fuel gravity fed from a tank on the bulkhead, rear brakes rod actuated and front brake cable actuated (no hydraulics). No rack and pinion for steering - a simple arrangement swung the whole engine, gearbox and wheel assembly through almost 180 degrees (worm and sector). No heater. I must admit that when I later bought an Austin Mini it was truly luxurious by comparison!! http://en.wikipedia.org/wiki/Bond_Minicar

If things are that bad it may be worth considering mobile broadband using a "dongle". Quite expensive and not so fast (generally speaking) - but may be better than you have.

I don't see why not. For various "tasks", some illegal, many computers already work together to achieve a common aim. It seems a simple step to just have many processors connected to the same bus bars and hardware. http://en.wikipedia.org/wiki/Computer_cluster

It looks to me that you heat the air by compression and then cool it back to the temperature it was by decompression. That means you don't achieve an overall drop in temperature. Perhaps you could use cooling fins on the outside of the narrow part holding compressed air so that decompression then further cools the air? Not my field so this is just a suggestion.

There was a young man from Midwest, Who wanted to get off his chest, Thoughts very profound, About laws very sound, That govern both motion and rest.

PHDwannabe - Perhaps I have got hold of the wrong end of the stick but your post No.25 seemed to be looking for evidence that schizophrenic patients are at greater risk from suicide and suicide attempts. My apologies if I misunderstood.

I'm afraid that it is a sad fact that suicide attempts by schizophrenics are much more numerous than non-schizophrenics. http://www.schizophrenia.com/suicide.html

I don't know about the actual taste, but Sweeney Todd's customers seemed to find it palatable!

SMF - I deduce that you too have been a "teacher" with a responsibility to your students. I hope and sense that you will have done your best for your students, as indeed I did. The old joke says "half" and perhaps I should have said there is "some truth" rather than "a lot of truth". Strangely enough there were occasions during my working life when I worked with little or no margin of knowledge above that of my students. For a time I worked as a civilian for a Company manufacturing military products. My job was to teach customers the theory and practical maintenance of equipment I had never seen. That meant liaising with designers, gathering technical information, examining the equipment on the production line and planning the course I was to run. Later on in life I became a lecturer at a college of education and life became much more stable (and knowledge more certain) as I experienced the relative luxury of teaching basic and rarely changing principles! If, like me, you are retired then I wish you happiness and happy memories.

The simple truth is that nobody knows absolutely everything about anything! I learnt a lot from my students and over the years I am not too proud to say that I tripped up sometimes. I believe that my willingness to consider my students thoughts and allowing them to influence my thoughts through open discussion engendered more respect than a more stilted response might have done. In any case, my students seemed to do well in their efforts to achieve their aims and qualifications!

I used to be a college lecturer. There is an old joke that says "Only half of what a lecturer says is true - the problem is even he/she doesn't know which half". The joke works because there is a lot of truth in it!

Is it true that sine waves are actually defined using the exponential function or is this really only another way at looking at them or of developing other ways of using them? I am not a mathematician but I have always accepted that the sine and cosine waves are the X and Y components of a rotating phasor. I also would not call them "life" in any sense, but feel that they, together with squares and square roots, have a very important place in the "grand scheme of things". This is just a feeling I have developed because they appear so often in the sort of work I have been involved with.

I have always thought there is something very special about sine waves. They do occur throughout nature and keep cropping up in formulae to do with physics, science and all branches of engineering. If you draw any triangle it can be used as a triangle of forces (from parallelogram of forces) which has its uses for a wide range of "additions" (vector diagrams). In the same way, for sine waves any triangle can be used for the addition of sine waves of the same frequency but with any phase shift (phasor diagrams). This only applies to sine waves. These are basically why I think that sine waves are special and an understanding of them is probably essential in understanding how the universe "works".

Sounds rather like an animal - or a human!

There is a commonly held belief that women multitask better than men. http://www.telegraph.co.uk/science/science-news/7896385/Scientists-prove-that-women-are-better-at-multitasking-than-men.html Perhaps that explains why I, as an older than average male, don't do very well if I play poker at the same time as giving attention to this site. (lol).

lemur - Not all the energy contained in the em wave is reflected, some is absorbed. Also, particularly in the case of metal structures such as aircraft, re-radiation occurs where the aircraft itself can be considered an aerial. In this case currents flow in the structure and this will cause some of the incident power to be absorbed. I repeat, this idea of water changing its properties is something I haven't heard of before - but it does seem possible to me.

Although this is new to me I am not so sure that it is crap. Heavy rain and clouds consisting of ice crystals can be detected by radar and submarines cannot use microwaves under the sea. If water absorbs microwaves then it seems to me quite possible that in the absorption some changes in the water properties may occur. Changes in water properties certainly occur in microwave ovens!

You might like to mention that the origins for programming are quite obscure. Items like punched card and punched tape were controlling quite a lot of devices long before electronic computers.(Fairground organs, weaving looms for example). I would think you would give mechanical computers some mention especially Babbidge's difference engines. I am sure you would want to include analogue computers which can incorporate mechanical and/or electronic components and had quite a following in the early days of computer development. Picking out key words from the above and googling them will get you plenty of information. For something more light hearted I have been told that the following is true (but cannot guarantee that!). A computer engineer was called several times to a computer terminal which kept entering spaces at random. He could find no fault with the terminal. He decided to watch closely as the terminal was used and discovered that the operator was a rather buxom, short sighted woman who was inadvertently pressing the space bar with her ample bosom as she leaned forward for a closer look!

As someone who has worked with military electronics I think you might be surprised about the possibility of recovering intelligence through a background of noise. My experience mainly concerned radar equipments which worked with very small signals often accompanied by noise which was larger in amplitude than the signal itself.

Who thays we Englith have a lithp? I must thay I have nether notithed it!