• dmention7@midwest.social
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    2 days ago

    Nah, there is no way any astronomer studying orbital mechanics in our solar system is rounding pi to 1. There is virtually no practical calculation you could do on the mechanics of the sun or planets where rounding a known constant by a factor of 3 would yield any useful result whatsoever.

    Rounding pi to 1 only makes sense when the uncertainty in the numbers is large, not the magnitude of the numbers, and we know the masses and distances of the objects in our solar system to an amazing level of precision!

    Plus, the fact that Jupiter is massive enough to actually exert an influence that large on the sun is pretty fucking cool!

    • FuglyDuck@lemmy.world
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      2 days ago

      The reason being, that once you go large enough, a multiplier of three is irrelevant, and they only really care about orders of magnitude. You might be tempted to argue that that doesn’t happen inside the solar system, and you’d be right. Mostly.

      Except that astronomy doesn’t concern itself with just our system. So yes. Astronomers do frequently round to 1 because it really doesn’t matter that much in the scheme of things. (particularly talking about distances.) it’s even more so for cosmology.

      • dmention7@midwest.social
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        1 day ago

        Sure, I totally agree that when you’re dealing many with orders of magnitude, the factor of 3 is dwarved by the other uncertainties.

        But we’re talking about our solar system, and specifically the orbital mechanics of our planets and sun, where the quantities and scales only span a couple orders of magnitude in total. A factor of 3 absolutely makes a difference. That’s the difference between the orbit of Mercury and the orbit of Earth.

        Then there’s the practical point that, regardless of scale, rounding a known constant by that much makes no sense at all, unless you’re trying to estimate huge numbers in your head. If you’re using even the simplest of calculator, estimating pi as 1 is a deliberate choice to reduce accuracy.

          • FuglyDuck@lemmy.world
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            1 day ago

            Not when that definition of pi goes to all 300 trillion decimals that we have resolved. (To be fair, I don’t know of any that do… but eh…yeah. And I’m pretty sure it was defined by a masochist if one did.)

            That leads to unnecessary time spent calculating even simple equations. That level of precision is almost never actually needed.

            With fermi problems, usually that level of precision is moot and potentially a waste of time. (Particularly when the math is requiring some kind network cluster to do.)

            • mnemonicmonkeys@sh.itjust.works
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              23 hours ago

              Pi has it’s own button on most graphing calculators, and those that don’t usually only requure 2 button presses to get it. Meanwhile, there’s some iteration of ‘pi()’, ‘pi’, etc. in most programming languages

              • FuglyDuck@lemmy.world
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                11 hours ago

                Sure.

                But sometimes, the problems are complex enough that solve time becomes a concern. When they’re complex enough, you start asking “is everything these precise enough to justify that” and when the answer is “no”, then you don’t do that because runtime on networked clusters like AWS costs money.

                And when you’re talking about scales that encompass the galaxy…. Well. There’s just not a lot of precision there to begin with.

                • mnemonicmonkeys@sh.itjust.works
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                  6 hours ago

                  The counterpoint to that is that including a term for pi (or even rounding it to 3.14) would insignificant to add and look way more professional

                  • FuglyDuck@lemmy.world
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                    1 hour ago

                    …. Are you reading what I’m saying?

                    Yes. For simple, common problems. You are correct.

                    But sometimes they’re not running simple problems. Sometimes, the run time on servers costs money. Sometimes, there’s no value to be gained by being any more accurate- and it increases those costs.

                    Now, in those times…. Are you really going to tell me that costing your organization more money without any useful gains…. Is “way more professional”?

                    Also? Don’t get me wrong, that threshold is getting and higher every year. I have more computing power in my cell phone than they used to put a man on the moon.

                    None of that changes that astronomers sometimes use 1 instead of pi, and that the barycenter of Jupiter-sun orbit is close enough to say Jupiter orbits the sun.

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        2 days ago

        You’ve got to be a little bit careful, surely, because then one squared is ten in the sense that log pi is about half.