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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b>…</b>> <b>On Behalf Of </b>Mike Dougherty via extropy-chat<br><b>…</b><o:p></o:p></p></div><div><div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>>… I like math, but I don't think approaching the problem from equations is 'intuitive' for most people. We learned how a ball hit from home plate lands in the outfield by playing baseball; years later we have a physics class explaining the parabolic trajectory of a frictionless vacuum….<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Hi Mike, <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>For understanding baseball trajectories, Newtonian physics is perfect. For most of cosmology, Newtonian physicist is outta luck. There is no way to understand why black holes merge the way we see and why it creates a signal for which we already knew what it would look like before they ever started building an enormous expensive instrument to detect.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>>… Maybe you 'weren't into sports'? <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Played little league baseball. Always preferred racing sports, on foot, bicycle, motorcycle, etc. I played chess, but some claim that isn’t really a sport.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>>… So instead you had a computer game…<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Pong. Only. Game console only played pong. I predate personal computers.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>>…Flatland helped me think of analogies in higher and lower dimensions. I like the visualization of your 3d surface of 4d spacetime with the analogy of a 2d surface on a 3d balloon…<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Ja and even then, the analogy is kinda misleading in some ways. Once we visualize 4D spacetime as our existing on the 3D surface volume of 4D hypersphere, the obvious question is: OK then, where does the time dimension go? Well, you can think of it as if it were possible to look toward the center of the hypersphere, that is past, and the other direction is future, but that too is confusing to us as 3D beasts. Reason: if we look an any of the 3 space dimensions we can perceive, we are looking into the past. That works regardless of which direction we look.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>We think we can see the past, and some claim to see the future, but really we don’t. We can’t see the time axis any more than the Flatlanders could see above and below. They could only imagine it.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>>…Do they have to be Greek letters though?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Only if you want to look like a hipster mathematician. Otherwise they see those ABC letters and know you are an engineer and give you that pitying look as if to say: Primitive savage! You design three dimensional objects? Sorry these matters are simply beyond your understanding. Come back when or if you master multivariable calculus…<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>That sorta thing. Pisses ya off. Because in this case they are right. They remind you of Sheldon from Big Bang. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>spike<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div></div></div></div></body></html>