TonyMcC

I wonder what would happen if the coin was wide and thin and a force was calculated to make it land on edge? I am thinking of imponderables such as air currents.

I can't really agree wth you. Military history follows an unending path of this nature :- One group develops an advantage. The other group then developes a means of counteracting that advantage, often in the process gaining an advantage themselves. This spurs the first group to counteract the new advantage and find a way to get an advantage for themselves etc..etc.. Think sword - spear - gun - missile to get the idea. Equality doesn't last for long. Sometimes the countermeasure comes from improving present technology, sometimes someone develops a new idea completely. I'm sure at the present time boffins around the world are working on means to detect stealth bombers. I personally think that the solution may well tie in with radar development that could detect clear air turbulence at long range. After all the "invisible" aircraft must leave a turbulent trail of disturbed air behind it. That of course is just speculation. If one side finds they can get an advantage by tampering with the human body and succeed in that, they would be starting another "arms race" of a different sort! Having said all that - I can't see it happening!

I have a history of high blood pressure which is controlled by drugs. I was experiencing some pain during some dental treatment, my dentist said he couldn't (or wouldn't) use anaesthetics containing adrenaline because of my condition. He didn't say whether it would raise or lower my blood pressure. I have had a little look around the web and found this http://www.ncbi.nlm.nih.gov/pubmed/1158539

No, you have one question and must go through the door you chose. - you can't have a look and change your mind.

I think I appreciate how you must feel. The very first course I ran as a college lecturer was known as a Youth Training Scheme (YTS). I was given 6 teenagers who had acheived absolutely nothing at school. I lost 2 along the way, 1 to the police for some crime and the other I suppose just got fed up. 4 of them passed a City and Guilds exam in electricity and electronics. The next year I was running a course for unemployed people and arranged a visit to an electrical company in a nearby town. At the door were my 4 ex-students who formed a sort of guard of honour and gave me a cheer as we entered. They then insisted on escorting me and my class around the factory and showing us the work they were doing. Quite honestly it was the proudest moment of my life. http://en.wikipedia.org/wiki/Youth_Training_Scheme

I voted "No". I have heard it said that time itself started for this universe at the "big bang". By the same argument I suppose time will end for this universe when the universe comes to the end of its existence. Perhaps this will happen if the expansion is cyclic and everything goes over a maximum and then eventually shrinks back to nothing.

Well, as unlikely as I think it is, surely one has to say "never say never"? First glimpses of possibilities occur with athletes such as Oscar Pistorious. Oscar has no legs but can run so quickly that he has had able bodied athletes claim that he has an unfair advantage! I recently saw a programme on TV where an athlete with one leg amputated below the knee said that he has a special leg for cycling competitions which was more aerodynamic than his everyday leg. I can't see the dramatic changes you mention ever being used but I have to repeat "never say never"!

I think developmentwill take things in the opposite direction - take the frail human out of the equation entirely. For example a computer controlled aircraft with sufficient ability to detect enemy aircraft and decide to attack could pull much tighter turns than a human controlled aircraft and would not experience human emotions such as nervousness or fear. we are partway there with cruise missiles and also drones flown by "pilots" on the ground.

I did say "in general". To be more precise I should have said "The most widely used system in modern computing". There is always more than one way to skin a rabbit! I thought I would leave the conversion of 1/2, 1/4, 1/8 ........into 1/10, 1/100, 1/1000.......... and the question of scientific notation until after the first part was sorted. I am pleased to see that aspect has been standardised since my time by IEEE 754. See "Two's complement" in the link. http://en.wikipedia.org/wiki/Computer_numbering_formats#Two.27s_complement As a lecturer at a College of Further Education the two's complement method of representing negative numbers was the only method looked at in detail because it was the most widely used. I have been looking up some details from when I spent some time working as a computer hardware engineer (1978). The systems I worked on did in fact use one's compliment for negative numbers to the surprise of some software engineers. For floating point they used 36 bits for single precision and 72 bits for double precision and did use a 1 bit sign digit. KasunL - Best if you ignore my post - and have a good look at D H's, if you can digest it in one go!

Can't really add much more. Analogue computing doesn't get much of a look in these days. If interested looking up Babbage's difference engine and perhaps an early application might provide you with some ideas. http://en.wikipedia.org/wiki/Difference_engine http://en.wikipedia.org/wiki/Analog_computer#Mechanical_analog_computer_mechanisms On second link go to section "Mechanical analogue computer mechanisms". Then click on link "World War 11 mechanical fire control computer mechanisms". Then click on "section 2 op1140-2 . pdf" and you will get some information regarding use of mechanical differential gearing.

In general digital computers perform subtraction by a form of addition. The method uses a method called "two's complement". You can find a lot of information at http://en.wikipedia.org/wiki/Two's_complement

Worthwhile - but hardly unique lol. Though I suppose nobody else planted those particular trees!

In my dreams I often "see" people that I have known and who have died. In my dreams they are alive and I enjoy meeting them. I don't know that they are dead. I take this as quite a natural thing as all generations in my family older than me are dead. However I don't see corpses thank goodness.

Do you think you have done something of benefit to others that possibly nobody else has ever done? In my case I ran a course to prepare a group of students for a recognised academic qualification. At the end of the course I sat down with my students and sat the same exam with them because I didn't have the qualification myself. That has to be unusual! I am glad ,and at the time was not a little relieved, to find when the results came through that I had passed! The course was run in 1974. The exam was for the UK General Certificate in Education at "O" level, the subject Electricity/Electronics. I was serving at R.A.F. Gan in the Maldives at the time and had been posted before the results were published. To this day I don't know how my students did. They would be around 60 years old now. If you recognise yourself then post to say how well you did!

Would you take that door?

Freedom of speech is not without its limits. Otherwise what is slander and libel all about?

This is an old puzzle, but if you haven't seen it before it should make you think. You stand before two identical doors. On door leads to a long and rewarding life, the other door leads to sudden death. Before each door is a guardian who, if you ask him the correct question will tell you which door to take. However one guardian always lies and the other always tells the truth. You don't know which one lies. You are only allowed one question. You walk up to a guardian and ask him the one question you are allowed and he tells you which door to take. What is your question?

One analogy uses the idea of a long train of carriages on a railway line. If you push the last carriage the effect is felt almost immediately by the first carriage, which moves. For an a.c. circuit imagine the train is as long as the circuit of rails. Pushing and pulling the train over a small distance will be felt at any point around the circuit.

I think ajb is being sassy

Strictly speaking you are correct. A combination of letters doesn't have to make sense to be a palindrome.

Sorry tto be a spoilsport. Its a good puzzle but taking the first letter away and putting it at the end does not make a palidrome. Whichever end it is placed you are still one letter short of a palindrome.

What about necrophilia? Some like it hot, some like it cold!

There is a unit of time called "The radar mile". It is the time an EM wave takes to travel 2 miles. Easily found on google. EM waves travel at the speed of light. The radar mile is the same for radar transmitters of any power. Typical radar powers could be 1 MW to 10 MW, but this does not change the radar mile and therefore does not change the speed of EM waves (or light).

Yes you are correct in that they set out to prove the existence of aether and failed. They expected light to change speed according to movement through the aether. However the results of their experiment had a bearing on the acceptance of Einsteins work as the part of the link headed "Einstein and General Relativity" shows. I knew their experiment eventually had something to do with the speed of light, but sorry I was not completely accurate. http://en.wikipedia.org/wiki/Michelson%E2%80%93Morley_experiment