User talk:Dalekoepp

July 2020
Welcome to Wikipedia. We appreciate your contributions, but in one of your recent edits to Lorentz factor, it appears that you have added original research, which is against Wikipedia's policies. Original research refers to material—such as facts, allegations, ideas, and personal experiences—for which no reliable, published sources exist; it also encompasses combining published sources in a way to imply something that none of them explicitly say. Please be prepared to cite a reliable source for all of your contributions. You can have a look at the tutorial on citing sources. Thank you. DVdm (talk) 07:51, 12 July 2020 (UTC)

Note re my revert: if there is no reliable source for something, even if correct, that usually is sign of lack of wp:notability in the literature, so there is no place for it in Wikipedia. - DVdm (talk) 07:56, 12 July 2020 (UTC)

By the way, why on Earth would one get the idea of calculating
 * $$\gamma - 1 = \frac{\beta^2}{\sqrt{1 - \beta^2} \left (1 + \sqrt{1 - \beta^2} \right )}$$

when, given the definition of gamma, $$\gamma = \frac{1}{\sqrt{1 - \beta^2}},$$ it is clearly much easier to calculate
 * $$\gamma - 1 = \frac{1}{\sqrt{1 - \beta^2}} - 1$$?

- DVdm (talk) 08:10, 12 July 2020 (UTC)


 * I appreciate the clarification of "reliable source" and why it is necessary.
 * As to your question, "Why on Earth...", the answer is computer floating point round-off error. Perhaps I should have made that more clear. A floating point number on most computers has 53 bits accuracy. It is a known problem in software engineering that subtracting two numbers that are nearly the same, such as $$\gamma - 1$$ when $$\gamma$$ ≈ 1, results in a loss of accuracy. And it would be a significant loss of accuracy for low speeds. But the equation for $$\gamma - 1$$ in the form that I gave, when programmed into a computer, would retain the full 53 bits of accuracy, and the resulting software would give more reliable and accurate results.
 * No need to respond.
 * Dalekoepp (talk) 23:10, 12 July 2020 (UTC)


 * Ah, yes, you are right. I should have looked more closely. My apologies. Please consider the on Earth clause struck . Still, we'd really need a proper source for this, alas. Cheers - DVdm (talk) 14:28, 13 July 2020 (UTC)