On Sat, Feb 4, 2017 at 10:32 AM, Steve Summit <[email protected]> wrote: > Warner wrote: >> I think this is the crux of my problem with Tom's answer to my first >> leap second question. We have two times, that are obviously different >> that when subtracted produce 0 as the answer. x-y = 0 should only be >> true when x and y are the same. But we get that answer when they are >> different. > > So what about x = 100 degrees Celsius, y = 212 degrees Fahrenheit? > Two obviously different numbers. What should the difference be?
That's a bad analogy, because there's a 1:1, onto mapping between the two. There's also a unit shift involved. And no "leap degrees." And also, it turns out, universal agreement as to what the right answer is. A better analogy would be between Julian and Gregorian calendars. Does the offset for those increase on Feb 29, 2100 (Gregorian) or on March 1, 2100 (Gregorian)? I suspect we'd have a similar debate about that. > This is a suggestion, not a proof. The analogy between > Celsius-versus-Fahrenheit and TAI-versus-UTC is not at all > perfect. And we're dancing around between proofs from first > principles, versus demonstrations based on what makes the math > easier. But I'm afraid the "the numbers are different, so the > difference can't be zero" argument is not as compelling as you'd > like. I guess we're at logger heads then. Any "proof" that involves a lossy mapping is suspect, imho. Warner _______________________________________________ LEAPSECS mailing list [email protected] https://pairlist6.pair.net/mailman/listinfo/leapsecs
