Jump to content

studiot

Senior Members
  • Posts

    18269
  • Joined

  • Last visited

  • Days Won

    104

Everything posted by studiot

  1. I can't think of any other technique they could have used, which is why I offered this as an explanation for the trough of water apparantly surrounding the pyramid. Further they would have had to carry this trough under the first (bottom) coursing to lay the base correctly. I also observed that there is no evidence they had the more sophisticated level equipment used by the Roman Agrimensores. the Romans also invented a device for setting right angles, called a groma, which I don't see evidence of, so I wonder how they did this.
  2. I know not cubits but when I was at school there were 5280 feet in a mile so your figure of 10,600' implies the dimension of a pyramid was 2 miles. Is this correct? 16.65 feet to be precise, but the figure is not proportional as you have it. The deviation or offset of a circular curve from a tangent is [math]offset = \frac{{{L^2}}}{{2R}}[/math] Where L is the distance along the straight line (tangent) and R is the radius of the circle which = 20 925 525 feet for the Earth. Of course a sensible builder will halve this by working from the centre (see the recent thread on centre lines in Engineering) Edit according to the internet the dimensions of the Great Pyramid are 755' side and 1069 feet diagonal, Over these distances the Earth's curvature works out at side 0.16" or 4mm diagonal 0.33" or 8.3 mm So my original guess was pretty close.
  3. No, it would be fair, if all that were, true but please accept that you are taking things more strongly than intended. Please also accept my apologies if you were offended, especially as not all I said was about your input(s).
  4. Please don't. Yes a level (or horizontal) line is curved. I would need the long or diagonal (horizontal) dimension of a pyramid is to calculate the effect of the curvature of the Earth, but I suspect it is of the order of 10mm deviation from a straight line I mentioned a modern day story earlier in this thread about a very serious error due to failure to take this into account.
  5. I am trying to keep to the topic in this thread, and please note I also said that no defense is needed. No, I didn't find your answer in the other thread defensive at all, I was referring to post#108 here.
  6. As davidivad said, it's also about presentation. I don't find your response confrontational, but I wonder if it is a trifle (you didn't like the word tad last time) defensive, where none is needed? Surely we are 'scientists' discussing ways and means in an adult manner?
  7. In the light of what has been said in this thread, it will be interesting to see what response is made to this new proposition that has just arisen http://www.scienceforums.net/topic/86154-energy-conservation-violation/ Obviously conservation is not violated, but are we going to frighten the OP off with an immediate strongly worded outright denial? Im am hoping that the OP is actually young, enthusiastic and interested in science and would therefore like to lead him/her to reach that conclusion for themselves.
  8. In order to make this statement you must have measured (or at least estimated) the input energy. Where do you think the input energy came from?
  9. This is an unsupported claim citations and references needed (I provided mine and they refer to more than one respected publication) Further you have taken absolutely no notice of what I said about oxide layers, which must exist on your simple test parts.
  10. So my comments about foundations have some foundation basis in reality. (I was tempted to make a pun here ) Thank you for the information. But my comment on levelling also referred to the survey techniques necessary to achieve a line, horizontal over a distance the size of a pyramid.
  11. Does this mean you don't approve of encouraging those with learning disabilities or other educational challenges? I think we have some here who really try very hard, although their responses are sometimes rather trying.
  12. As swansont noted, it is the relative velocity that is important here. B says that A travels away with r. velocity +V and makes the return trip with r velocity -V. However A could say that B travels away with r.velocity -V and returns with r.velocity +V. This makes no difference since the gamma factor depends upon the velocity squared.
  13. One thing to remember is there is a difference between the way length, mass and time work. If you take a twin on a round trip length, mass and time will measure differently during the trip. But when they return and the two twins are again side by side only age is different. Both mass and size return to their original figures (space diets aside) but the twin's ages are now different.
  14. Thanks for the additional info cnewton.
  15. Hello gwiyomi Well it is the reaction between two molecules can you name either or both, Because the name of one should give you a big clue as to what sort of reation it is. I think also that there needs to be a lot more of one of the reactants than is written on your board.
  16. Yes that's correct. Number of moles = Mass / molar mass Molar mass = Sum of the individual atomic masses taking account of numbers of atoms Mass concentration = total mass of substance per litre = total mass/ litres Molar concentration = number of moles per litre = number of moles / litres Have you studied balancing chemical equations yet? I'm doing a chemical preparation at the moment (cooking the dinner) so I will keep going away and coming back. So keep watch, others may also offer help meanwhile.
  17. Well your experiment was more complete than the ones I linked. Did you take the measurements youreselves or were they given to you? First we need to settle the chemical formulae. Can you write down the formulae for ammonium chloride, sodium chloride and water? Can you then calculate the molar masses?
  18. Was your coursework anything like these? http://www.scienceforums.net/topic/85620-chemistry-coursework-2014/ http://www.scienceforums.net/topic/85585-gcse-coursework-2014/
  19. I think there is a considerable difference between the tone of post#98 and post#101, although both argue against Michael's points. Thank you, sunshaker for your observations, perhaps some whow ahve attended formal schools should note the motto of this ancinet school, Peter Symonds School, Winchester 'Manners Maketh Man'
  20. This doesn't only affect baseball, it applies to all bat and ball sports. I can think of at least four reasons, others may add more. Two affect the quality of the strike and two affect the batsman. The first reason is that it is easier and more reliable to carry through a smooth path that does not end at the ball, ie it starts with the backswing point and carries on towards a point beyond the strike point. This path should be such that the bat is travelling at the best speed and in the most appropriate direction for the strike. The second reason is that attempts to change this path can result in 'jerky' action that diverts energy away from the optimum hit. The batsman may even attempt to pull up too soon thereby reducing the power of the strike. Note that some bat ball sports require wrist action as well as arm action. Timing of this is easier with a full swing. In some sports the batsman needs to immediately (rapidly) recover his 'ready' position. You will find that the follow through includes an optimum path to this. Finally the batsman doesn't want to hurt himself. Checking a travelling weight will result in reactions within his body, and contiually doing this may cause injury.
  21. Post#96 That's an interesting and insightful post, Michael. I wondered where you were going and had some sympathy with your some of your earlier comments. Unfortunately hackles do sometimes rise, particularly about certain subjects, a bit quickly here. Although this forum seems better than most, due in good measure to relaxed moderation. @elfmotat I asked a similar question some while back but drew nowhere near the size of discussion we are heading towards 100 posts and still going strong. Take courage from that.
  22. Why wait till Monday? I published one in June 1986, just for you in "The Survey Review", although I liked the rag better when it was "The Empire Survey Review". My article was entitled "The Use of the Fifth Quadrant" Well I don't have a PhD, though I do sport other postgrad qualifications that I don't bandy about, and I have been know to help modern PhD students with their studies. My feelings on the PhDs and Msc is that the qualifications have become devalued in recent years with the plethora of mediocre takers we now see and I cringe at some of the things that they are awarded for. After all that is what Albert got for Relativity. You are nearer the truth than you think. In 3D differential geometry one of the first things to recognise is that a line can twist or curve in two perpendicular directions at the same time, or not as the case may be. So it may be straight in one of these directions and curved in the other! Never mind the clever stuff, the animation showing this is good http://en.wikipedia.org/wiki/Frenet%E2%80%93Serret_formulas
  23. I like this simple way to put it. I hope those red blooded physicists note that no maths was needed and no mathematicians were harmed in the production of this post. +1
  24. 9.6% I wish my bank gave me that much interest!
  25. studiot

    Refraction

    elfmotat is pampering you - I was going to ask for a diagram. This statement probably needs further explanation. We are approximating arc PQ to the perpendicular from P tp OC. The smaller alpha is the more nearly exact this is. Which brings me to the sort of conditions we are talking about. We assume all rays meet the curved surface near the axis OC. That is alpha small. Such rays are called paraxial rays. These conditions are typical of eyes. We are also approximating the curved surface by a circle. This is true in spherical lenses and paraxial rays, but not true in tall thin lenses. CP is a normal because it represents the radius of curvature at P and is therefore perpendicular to the tangent at P.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.