EdEarl Posted June 15, 2013 Share Posted June 15, 2013 (edited) [&+-] Edited June 16, 2013 by EdEarl Link to comment Share on other sites More sharing options...
imatfaal Posted November 15, 2013 Share Posted November 15, 2013 [acr=Laughing Out Loud]LOL[/acr] LOL Link to comment Share on other sites More sharing options...
EdEarl Posted December 8, 2013 Author Share Posted December 8, 2013 test1... [math]a[/math] test2... [math]{a}[/math] test3... [math]123a[/math] test4... [math]123.45\cdot a[/math] test5... [math]123.45\cdota[/math] test 6... [math]123,45a[/math] test7... [math]abc[/math] test8... [math]a \cdot b \cdot c[/math] test9... [math]a_b[/math] test10... [math]{a}_{b}[/math] test11... [math]a_{b}^{c}[/math] test12... [math]{abc}_{d ef}[/math] test 13... [math]a b /c[/math] (PN: not enoguh space between variables 'a' and 'b') test14... [math]a _{b }+3.1 \cdot {10 }^{-12}[/math] (PN: minus sign is a bit too long and exponent should be placed a bit higher) test15... [math]3 \frac{x }{y }[/math] (PN: too much space between fraction line and numerator/denominator) test16... [math]2 \sin x \cos y[/math] test17... [math]2 \, \mathrm{sin }\, x \, \mathrm{cos } \, y[/math] (PN: I had to add \, space to make this look nice) test 18.. [math]a \bar{b }c[/math] test 19... [math]x \mathbf{y }z[/math] test20... [math]a b \mathtt{c }\delta \mathcal{Y } [/math] (PN: \mathcal{} works with uppercase letters only) matrix test1... [math]\left[ \begin{array}{ccc}s & b & c \\ x & y &z \\ a & & \end{array} \right][/math] limes test1... [math]\lim _{x \rightarrow \infty }\left( x +1 \right)[/math] underline/overline test.... [math]\underline{a b}\overline{c d}[/math] sqrt test... [math]\sqrt{x }\sqrt[3 ]{y }[/math] 'd' test... [math]d x[/math] (PN: what about partial derivation sign??) Link to comment Share on other sites More sharing options...
imatfaal Posted December 10, 2013 Share Posted December 10, 2013 (PN: what about partial derivation sign??) [latex]\partial x[/latex] Link to comment Share on other sites More sharing options...
EdEarl Posted December 10, 2013 Author Share Posted December 10, 2013 (edited) [latex]\partial x[/latex] Thanks. Please forgive me, I copied a post to get some examples and did not remove the questions and comments. Edited December 10, 2013 by EdEarl Link to comment Share on other sites More sharing options...
imatfaal Posted January 19, 2014 Share Posted January 19, 2014 You have mentioned time and time again that there is a singularity at the event horizon - this is an artifact. Your argument from post one, repeated many times and even spelled out in post 29 (sorry my post numbers might not match as I see all posts) relies on the fact that r_s/r will become the root of a singularity. The Scchwarzchild Spacetime Geometry can be represented as follows [latex]ds^2 = -(1-2M/r)dt^2+\frac{dr^2}{1-2M/r}+r^2(d \theta^2+sin^2 \theta d\phi^2)[/latex] This clearly hits problems when r=2M - ie at the Event Horizon where [latex]g_{tt}[/latex] becomes zero and [latex]g_{\tau \tau}[/latex] becomes infinite. This was originally thought to be evidence of a physical singularity at the EH - but Eddington showed that it was merely an artifact of the coordinate system being used - ie Schwarzchild Coordinates Link to comment Share on other sites More sharing options...
imatfaal Posted February 3, 2014 Share Posted February 3, 2014 [latex]\frac{d^2\theta}{dt^2} + C\frac{d\theta}{dt} + \kappa\theta = \tau(t)[/latex] If the damping is small, [latex]C \ll \sqrt{\frac{\kappa}{I}}\[/latex],, as is the case with torsion pendulums and balance wheels, the frequency of vibration is very near the natural resonant frequency of the system: [latex]f_n = \frac{\omega_n}{2\pi} = \frac{1}{2\pi}\sqrt{\frac{\kappa}{I}}\,[/latex] Therefore, the period is represented by: [latex]T_n = \frac{1}{f_n} = \frac{2\pi}{\omega_n} = 2\pi \sqrt{\frac{I}{\kappa}}\,[/latex] The general solution in the case of no drive force ([latex]\tau = 0\,[/latex]), called the transient solution, is: [latex]\theta = Ae^{-\alpha t} \cos{(\omega t + \phi)}\,[/latex] where: [latex]\alpha = C/2I\,\omega = \sqrt{\omega_n^2 - \alpha^2} = \sqrt{\kappa/I - (C/2I)^2}[/latex] Link to comment Share on other sites More sharing options...
EdEarl Posted January 29, 2018 Author Share Posted January 29, 2018 (edited) \Delta What am I doing wrong? Edited January 29, 2018 by EdEarl Link to comment Share on other sites More sharing options...
Mordred Posted January 29, 2018 Share Posted January 29, 2018 (edited) 35 minutes ago, EdEarl said: \Delta What am I doing wrong? You need to place [math] on each side in the latter half so I don't activate the command tags replace the % with a / [math] \Delta [%math] [math]\Delta[/math] You will need to refresh the page to see if it worked as well Edited January 29, 2018 by Mordred Link to comment Share on other sites More sharing options...
EdEarl Posted January 29, 2018 Author Share Posted January 29, 2018 ty I see, the preview button when replying does not do math. Link to comment Share on other sites More sharing options...
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