Rolle Rant

Well, if you want to go that far, what is a proof? What does "a proof exists" actually mean? Does a proof exist independent of someone proving it? Does it only exist after someone proves it?

Yes, Erdos

When he would read a particularly excellent proof, he would exclaim, "This one's from the Book!"

I'm supposing Rolle's isn't in said book.

Tim

-- Deep Friar: a very philosophical monk. Website:

Two can be as bad as one It's the loneliest number since the number one

Platonism leads to even stranger places. Such as "what is a calculation", given that all possible equations and all possible solutions already "exist".

The apples will rot before you reach infinity. :)

Roman/Greek/whatever letters _are_ pictures. Cosgrove's rule #1: Do _not_ let pictures get in the way of a good rant. ;-)

Ed

Ouch!

Double ouch!!

Ed

Check; forgot to mention that the operation + must also be defined for the field of interest...

Well, there is only ONE of me and who "needs" more than one (WinDoze) desktop?

A rack full of satellite comm gear might. Might need several.

...and what INDIVIDUAL would $$pend that kind of money, space and energy to do ???

Who said anything about an individual?

You? You're just a commoner. You don't get "individual" status.

Done anything noble?

No, really, if you could not see that me talking about VDMs and hardware control, and then about racks of gear was not about an individual, then you should probably find some way to give your soul back to the Hall of Souls, so it can be put to better use.

A proof is not a thing like a rock. It's a purely mental object. So saying that a proof exists generally means that a given proposition is both true and demonstrable. (Goedel showed that those two ideas are not identical.) A proof is only *known* to exist once somebody writes it down.

A proof is a logical demonstration that a given proposition is true. What level of detail the proof goes into depends to some degree upon the style of the given mathematician.

'Existence', for a mathematical object, means that it is not self-contradictory--i.e. non-Euclidean geometries are odd but do exist, whereas four-sided triangles are self-contradictory and so do not exist.

The rules of math are well-suited to the field, because they've been shown to work well for well over two thousand years now. If you don't like it, that's fair enough, but it's definitely a private taste of yours own.

Cheers

Phil Hobbs

The pyramids were built more than 2000 years ago, and Mayan calendars are older than that as well, and they are down to the second on planetary positions, and galactic positions as well. Not a small mathematical feat.

Compared to what? And measured how?

Even UTC averages more than 1 leap second per year.

ry

Sorry - should be "more than 1/2 leap second per year".

The science community is perfectly aware that the day is only 86,400 seconds long.

It (the year) is 31,557,600 seconds. That's 365.25 times 86,400.

Averages?

Now I now you are smoking Jimson weed. It is right on the money. Always has been. There are small arguments about crossing points on a given rotation, but it is pretty easy to look at centuries of time passage, and center right in on the figure. Just ask Newton.

The Mayan calendar is accurate to the day on a 13,000 year cycle. Pretty impressive. They describe the passage of three previous cycles already.

This is our last gig. Is your house in order? Does it even matter?

AlwaysWrong is *ALWAYS* wrong. You must be lonely this week, Dimbulb.

Clueless.

Try to learn *something* in your life, AlwaysWrong.

There is a nice graph of the difference and explanation at

You could legitimately believe that to be true during the period when the Julian calendar was still in regular use before the Gregorian calendar reforms. The Julian year is still defined that way, but it is only used for certain crude computations. You are clueless.

Averages - you also have to specify precisely which definition of year you are referring to - conventionally the tropical year is the civil definition measured from equinox to equinox and the equation for the average length of a year is

= 365.2421987 - 0.00000614T days or =31556925.97 -0.530496T seconds

Where T is time measured in Julian centuries of 36525 days from 1900

That is about 674 seconds shorter than you claimed. It was this discreprency that led to the 11 missing days when Pope Gregory finally had the Christian calendar sorted out.

Sidereal year (fixed star to fixed star) and anomalistic year (perigee to perigee) are both slightly longer at around 365.26 days.

Sidereal year is experimentally now the easiest to measure to very high precision and IERS look after the data if anyone is interested:

You are certainly B-Ark material. Don't forget to buy some more canned sausages and bread buns for when the 2012 Mayan calendar rolls over. Beware the mutant star goat!

Regards, Martin Brown