Finkeren Posted February 14, 2016 Posted February 14, 2016 Love this picture from 1908. Can you guess what it is? It's Alexander Graham Bell (yes, that Alexander Graham Bell) flying one of his many unorthodox tetrahedron-based kite designs. 1
sallee Posted February 14, 2016 Posted February 14, 2016 A device designed by the bloke on the right so the other yokels would stop staring and pointing at him for a change.
JG300_Olrik Posted February 14, 2016 Posted February 14, 2016 (edited) Have a look there http://www.carnetdevol.org/Bell/kite.html Edited February 14, 2016 by F/JG300_Touch
Finkeren Posted February 14, 2016 Author Posted February 14, 2016 High powered Ferris wheel accident? Best answer by far Just in case some of you didn't notice, I actually included the answer in the OP.
Uufflakke Posted February 14, 2016 Posted February 14, 2016 Like JimTM said, a kite. Constructed by mr. Bell. "Alexander Graham Bell discovered that the tetrahedral truss, created from three-dimensional triangles, could support considerable weight even when constructed out of light-weight materials. Bell made extensive aerodynamic studies with these kites before attempting to build airplanes. His Aerial Experiment Association achieved the first manned flight in Canada. The Library's extensive Gilbert H. Grosvenor collection of photographs documents Bell's work and family life."
Feathered_IV Posted February 14, 2016 Posted February 14, 2016 No no no. Can't be. And I refuse to be tempted by the spoiler tab. Let me try again... Special effects department at work for Stanislav Kubrick Senior's blockbuster moving picture film, 1901 - A Space Odyssey
unreasonable Posted February 14, 2016 Posted February 14, 2016 It is the British (or perhaps Irish?) contribution to the European Space Station.
Ace_Pilto Posted February 14, 2016 Posted February 14, 2016 Prototype Aerobie. The engineer obviously read the specifications wrong.
AndyJWest Posted February 14, 2016 Posted February 14, 2016 Like JimTM said, a kite. Constructed by mr. Bell. "Alexander Graham Bell discovered that the tetrahedral truss, created from three-dimensional triangles, could support considerable weight even when constructed out of light-weight materials. Bell made extensive aerodynamic studies with these kites before attempting to build airplanes. His Aerial Experiment Association achieved the first manned flight in Canada. The Library's extensive Gilbert H. Grosvenor collection of photographs documents Bell's work and family life." Alexander Graham Bell seems to have been quite the inventor, if he came up with three-dimensional triangles. All the ones I've ever seen fit quite happily into two dimensions... Nice kite though.
unreasonable Posted February 14, 2016 Posted February 14, 2016 Alexander Graham Bell seems to have been quite the inventor, if he came up with three-dimensional triangles. All the ones I've ever seen fit quite happily into two dimensions... Nice kite though. Take a football. Draw a line round the equator for part of the circumference. Draw a line from the end a of line 1 to the north pole. Same again for end b. Result is a triangle - a closed figure bounded by three straight lines. Added fun - check out what the three angles add up to. (Hint - it is not 180 degrees).
Monostripezebra Posted February 14, 2016 Posted February 14, 2016 Prototype Aerobie. The engineer obviously read the specifications wrong. you know that is bound to happen with people not using the metric system. fact. ;=) 1
Finkeren Posted February 14, 2016 Author Posted February 14, 2016 Take a football. Draw a line round the equator for part of the circumference. Draw a line from the end a of line 1 to the north pole. Same again for end b. Result is a triangle - a closed figure bounded by three straight lines. Added fun - check out what the three angles add up to. (Hint - it is not 180 degrees). Spherical geometry is a very reliable way to lose your will to live.
unreasonable Posted February 14, 2016 Posted February 14, 2016 Spherical geometry is a very reliable way to lose your will to live. I found it strangely liberating - the idea that a triangle could have angles adding up to almost 540 degrees was exciting and subversive. Not that I ever got into the maths of it much. I am lazy - once I think I have the hang of the concept and know who to ask if I need detailed workings or solutions, I move on to the next concept.
AndyJWest Posted February 14, 2016 Posted February 14, 2016 Take a football. Draw a line round the equator for part of the circumference. Draw a line from the end a of line 1 to the north pole. Same again for end b. Result is a triangle - a closed figure bounded by three straight lines. Added fun - check out what the three angles add up to. (Hint - it is not 180 degrees). Your definition of a straight line clearly differs from mine...
Finkeren Posted February 14, 2016 Author Posted February 14, 2016 Your definition of a straight line clearly differs from mine... So you wouldn't say an airliner flying directly from Orlando to Frankfurt is going in a straight line?
unreasonable Posted February 15, 2016 Posted February 15, 2016 Your definition of a straight line clearly differs from mine... Not really - it is simply the shortest route between two points on a surface, as Finkeren's illustration shows. Draw a straight line on a piece of paper. Then flex the paper or roll it up. Is the line you drew still straight? (Hint - Yes )
Ace_Pilto Posted February 15, 2016 Posted February 15, 2016 The line is still as straight as you drew it but the space it travels through has curved. If you curve the space you curve the also line so it is straight and not straight depending on your criteria of observation.
unreasonable Posted February 15, 2016 Posted February 15, 2016 Not quite how I would express it - the line you drew on the paper is still the shortest route between the end points on the paper however you fold it. If you draw a straight line on a sphere the same applies if you deflate the sphere. So not really to do with observation as such - more the specification of the dimensions in which the line exists. Of course you can add as many more as you like. Being pedantic here because the problem with adding "criteria of observation" in the explanation is that there may be a temptation to mix this with quantum effects where (perhaps) the criteria of observation really do matter. (Maybe - depending whether anyone is looking ). (Sorry for OT Finkeren - but it is true that there are stranger things out there even than your kite. I am waiting for some newspaper to report that some schoolkid has said "Sorry teacher, a gravitational wave ate my homework!". That is if they even have homework anymore).
Dakpilot Posted February 15, 2016 Posted February 15, 2016 Nothing pedantic, a line on a flat piece of paper is in two dimensions the second you pick up the paper and curve it you have created a third dimension and changed it's state, the observation has not changed the line has the last image shows why you don't fly along a line on a map http://www.flightradar24.com/blog/flight-paths-and-great-circles-or-why-you-flew-over-greenland/ I have to say I did not really enjoy my time in studies and exams in long range navigation, maths not being my strong point, remembering 1/2 a million formulas and how to apply them properly used to hurt my head. Practical navigation was more fun though https://en.wikipedia.org/wiki/Great-circle_navigation Cheers Dakpilot
unreasonable Posted February 15, 2016 Posted February 15, 2016 (edited) Nothing pedantic, a line on a flat piece of paper is in two dimensions the second you pick up the paper and curve it you have created a third dimension and changed it's state, the observation has not changed the line has Take an "F". Curving the paper does not create a new dimension, it was there all the time, as you can easily see for yourself if you pick up the piece of paper and rotate it around while still holding it flat. It is simply that for the purposes of approximating a genuinely two dimensional surface (a mathematical abstraction) one thinks in terms of flat sheets of paper. But it does not matter how you fold the paper - the shortest route on the paper between two points on the paper is still a straight line, you have not changed it at all. To change the shortest route you would have to stretch or distort the x and y axes - ie distort the sheet in 2 dimensions. What you do in the third has no effect on the first two. Edited February 15, 2016 by unreasonable 1
Dakpilot Posted February 15, 2016 Posted February 15, 2016 Back of the class....Probably why I should stick to Piloting and other simple tasks and avoid quantum effects and observation criteria when I take a foot long piece of aluminum and bend it over my knee it stays a foot long piece of aluminium, but I have changed its state Cheers Dakpilot
AndyJWest Posted February 15, 2016 Posted February 15, 2016 ...the shortest route on the paper between two points on the paper is still a straight line... There is only on shortest route, and it isn't on the paper...
Ace_Pilto Posted February 15, 2016 Posted February 15, 2016 Not quite how I would express it - the line you drew on the paper is still the shortest route between the end points on the paper however you fold it. If you draw a straight line on a sphere the same applies if you deflate the sphere. If you curve the paper it's still the shortest distance on paper but not through space.
sallee Posted February 15, 2016 Posted February 15, 2016 Where is Raaaid when you need him Right on cue.
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now