Mathematical what-ifs

Obviously math in general is pretty constant: 2+2 will always equal 4 no matter what universe we're in. But what if people did math differently? What if we used a different system besides base ten, or Arabic numerals never came into use in Europe, or the plus sign was different, or that sort of thing? How different could math possibly be while still making sense?

This is a general thread for discussing that topic. I put it here because most PODs will be pre-1900, but post-1900 PODs are fine too.
 
I've wondered about earlier game theory and the like as those apparently affect political strategies, but don't know enough.:eek:
 
There is historically an other base that was used besides Base 10 in the Middle Ages : Vicesimal (Base 20).
Still used in French numeration (eighty is called four-twenties, ninety, four-twenties and ten, seventy, sixty and ten)
 

Jasen777

Donor
Well we still use base 60 for minutes, and when people have to look at the clock and compare their time to the computer's which does it in decimal most of my fellow employees can't handle it (for instance if the computer says 39.9 hours that means you have 6 minutes left to get to 40 hours).

I don't know what would happen exactly, but Roman numerals are just awful, they had to be able to benefit from Arabic ones if they could have developed something similar. And maybe Greek math could have advanced more.
 
There is historically an other base that was used besides Base 10 in the Middle Ages : Vicesimal (Base 20).
Still used in French numeration (eighty is called four-twenties, ninety, four-twenties and ten, seventy, sixty and ten)

We also used it in phrases like "four score and seven."

Well we still use base 60 for minutes, and when people have to look at the clock and compare their time to the computer's which does it in decimal most of my fellow employees can't handle it (for instance if the computer says 39.9 hours that means you have 6 minutes left to get to 40 hours).

I don't know what would happen exactly, but Roman numerals are just awful, they had to be able to benefit from Arabic ones if they could have developed something similar. And maybe Greek math could have advanced more.

We also use base 12 (dozens, and the words eleven and twelve, kind of) and for higher numbers, we count in powers of 1000 (1,000,000,000,000 rather than 1,0000,0000,0000 or 1,00,00,00,00,00,00 or 100,00000,00000). And of course computers use base 2, 8, and 16 for various things.

If Arabic numerals never became prominent though (like if Indian civilization somehow collapsed, or the Arab conquests never happened) then they would have had to have come up with something. Maybe "European numerals" would have been invented?
 
There is historically an other base that was used besides Base 10 in the Middle Ages : Vicesimal (Base 20).
Still used in French numeration (eighty is called four-twenties, ninety, four-twenties and ten, seventy, sixty and ten)

Don't forget the duodecimal system, which may have been even more popular during this period. Less for mathematics, than in everyday life (people guesstimated their age as 12, 24, 36 and such quite regularly).
It happens regularly that some stuff is sold à la douzaine (to say nothing about une grosse, which is a dozen of a dozen)

You could even have a mix between duodecimal and vicesimal bases : French livres is a good exemple : 1 livre = 20 sous, 1 sou = 12 deniers (which is exactly the same system than the old British pound or the medieval mark, all of them being issued from the carolingian system)
 

Driftless

Donor
Long, long ago, I had a math teacher opine in class that if humans had been born with six fingers on each hand that we would operate in the more mathmatically useful base-12; as opposed to base-10. I don't remember all of his examples, but I do remember the logic worked.
 
You don't need six fingers to count in base-12, it's really easy with our current ones and it's why it was used historically.
Basically, you just have to count your phalanxes with your thumb.

And this way, you can count on a base-60, which is only counting in base-12 as much times you have fingers on the other hand. 12x5 = 50.
 
No thumbs?

If we hadn't used our thumbs, we'd be using base 8--much handier when the electronics generation comes along.
 
Well, some people in south Asia use base 12, like some people have previously pointed out, it is actually superior to base 10.

This SETI Talk comes to mind.
https://www.youtube.com/watch?v=9MV65airaPA

There is a pattern in in the last 2 digits of squares, so that in decimal, 26^2 has the same 2 end digits as 24^2 and the same goes for 23 and 27 etc. In other basesl that pattern is much shorter, allowing anybody to mentally obtain squares and roots of very large numbers. So that would be different.
 
Obviously math in general is pretty constant: 2+2 will always equal 4 no matter what universe we're in. But what if people did math differently? What if we used a different system besides base ten, or Arabic numerals never came into use in Europe, or the plus sign was different, or that sort of thing? How different could math possibly be while still making sense?

Basically, the only one of these that would make any difference whatsoever is Hindu-Arabic numerals. And that's more due to 0 and a positional notation than anything else.

Using Greek (or Hebrew) letters for 1-9 with a new zero and positional notation would do just as well as OTLs numbers, really. And SOMETHING like that is going to happen eventually.

Heck, it might be a counting table/abacus based notation.
 
Well, some people in south Asia use base 12, like some people have previously pointed out, it is actually superior to base 10.

This SETI Talk comes to mind.
https://www.youtube.com/watch?v=9MV65airaPA

There is a pattern in in the last 2 digits of squares, so that in decimal, 26^2 has the same 2 end digits as 24^2 and the same goes for 23 and 27 etc. In other basesl that pattern is much shorter, allowing anybody to mentally obtain squares and roots of very large numbers. So that would be different.

superior? ehhh... maybe easier, in reality in there are pretty equal and for actual mathematicians it makes no real difference. Base 2 would be awesome though.
 
Geometry...

So far, we've looked at different bases that are used for exactly the same thing, producing the same answers with greater or lesser ease. But geometry, with its rigorous proofs, need not develop anything like it did today. For example, if Euclid or an analogue was also a long distance navigator, he might never have included the parallel postulate, or stated it to preclude the existence of parallel lines altogether. Or he might have developed both plane and spherical geometry in parallel.

For that matter, might geometry and its strict postulates and proofs take much longer to develop? If so, what does the delay do to the development of logic overall?
 
superior? ehhh... maybe easier, in reality in there are pretty equal and for actual mathematicians it makes no real difference. Base 2 would be awesome though.

Well yhea, when it comes to anything meaningful, base is meaningless. So when comparing bases we must focus on things were their differences mater, every day arithmetic, measures, and commercial transactions, etc.

Humans think of quantity ordinal rather than cardinally. That is why halves, thirds, fourths, sixths, fifths, are used with regularity in decision making and common activities. Most common tools are differentiated by a fractional gauge, and most natural measurement systems are somewhat duodecimal, with 12 inches to a foot, and 12 ounces to a pound, they are also more intuitive than metric units (and I say this as definitely not-a-Yank). When you go to the butcher shop you ask for a quarter of liver, not for 250 grams of liver (in fact I once did this and the butcher remarked it was an unusual way of asking for it)… because the mental estimation of quantity is easier.
But adding fractions takes more time than just adding numbers, so fractions that can be translated to whole numbers are “better”. The greater percentage of these the notation system has the easier it will be to use. Both bases have 4 fractions that are recurrent, yet since base 12 has 2 more fractions overall, this makes it a smaller percentage of recurring fractions.


We should also take into consideration that both a human’s sense of number is logarithmic. Entropy dictates that in our world smaller numbers are over represented. This means that all things being equal, 1/5 will be used less than that 1/2, 1/3, 1/4. The only reason we put things in groups of 10 is because it makes the calculations easier.

That is why; it is my belief that humans are more suited to base 12 or base 6 than base 10.
But yhea, base 2 would be awesome.
So far, we've looked at different bases that are used for exactly the same thing, producing the same answers with greater or lesser ease. But geometry, with its rigorous proofs, need not develop anything like it did today. For example, if Euclid or an analogue was also a long distance navigator, he might never have included the parallel postulate, or stated it to preclude the existence of parallel lines altogether. Or he might have developed both plane and spherical geometry in parallel.

For that matter, might geometry and its strict postulates and proofs take much longer to develop? If so, what does the delay do to the development of logic overall?

This is a very good point, particularly given the interlinking between earlier number theory and arithmetic proofs with geometry. The SETI video I liked to explore that point a little.

A more abstract mathematics rather than one based on geometry in the beginning would be interesting.
 
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most natural measurement systems are somewhat duodecimal, with 12 inches to a foot, and 12 ounces to a pound, they are also more intuitive than metric units (and I say this as definitely not-a-Yank). When you go to the butcher shop you ask for a quarter of liver, not for 250 grams of liver (in fact I once did this and the butcher remarked it was an unusual way of asking for it)…

maybe not-a-Yank but obviously not-a-Frog either. Here in Frog country, we definitely order 250g of something (one-fourth-of-a-kilogram would be very weird). I guess it is the same way in most of the civilized world. It is also definitely easier to use than the fraction system (if I want 200g/person for 3 persons, I will order 600g; I suspect that even in fraction-land, ordering 3/5th of something is a bit unusual, right? besides, sorting { 625, 600, 667 } is much easier than sorting the corresponding fractions {5/8, 3/5, 2/3}). (source: am a Frog).

For physics applications, using a number system adapted to the measure system is a good thing (for a simple explanation why: imagine computing the volume, in gallons, of a box whose dimensions are given in feet and inches. That is ugly. The same thing in metric is trivial enough that you can do a mental estimate).

However, it is hard to change the metric system (you have to set up a standard, as in Bureau International des Poids et Mesures), but even harder to change the number system since this one is already an international standard (a bit like we tried with decimal time, which failed miserably since there already was a standard). So it is the measure system which must be adapted to the number system.

The problem is that, historically, the measure system was not coherent in base 12 or 20 or 60 or whatever, but a real mess:
https://commons.wikimedia.org/wiki/File:English_length_units_graph.png
So, in order for base-12 to be really useful, you need to first sort out the measures themselves, which basically requires inventing the metric system.

Fore pure math, the choice of the basis is irrelevant. (Source: am a mathematician; computations in base 10, 2, 16, or p are really the same. We barely even write any numbers, actually). The big thing is the positional number system (including zero); without indo-arabic digits, it is likely that someone would eventually have added a zero to the Greek letters.

About the history of the development of math, it was actually very much invented “on the fly” depending on the needs. A few examples:
- basic arithmetic (positional number system, four operations, negative numbers) was invented for the accountants (XIII-XVIth centuries),
- probability theory for the insurance companies and gamblers (why am I making these two separate classes, I don't know) (XVIIth-XVIIIth centuries),
- calculus for the physicists (this is useless unless you have a good watch) (XVIIth-XVIIIth centuries),
- numerical methods for analysis were invented with the age of the computer (in a wider sense, as “human computer” and “mechanical computer” and “electromechanical computer” and finally “transistor computer”).
So I think that math developed more or less according to its age and time and that it could not have developed significantly faster. On the other hand, the fact that, in any of these instances, it did not come too late either, shows that this was probably the only way that it could develop.
 
About the history of the development of math, it was actually very much invented “on the fly” depending on the needs. A few examples:
- basic arithmetic (positional number system, four operations, negative numbers) was invented for the accountants (XIII-XVIth centuries),
- probability theory for the insurance companies and gamblers (why am I making these two separate classes, I don't know) (XVIIth-XVIIIth centuries),
- calculus for the physicists (this is useless unless you have a good watch) (XVIIth-XVIIIth centuries),
- numerical methods for analysis were invented with the age of the computer (in a wider sense, as “human computer” and “mechanical computer” and “electromechanical computer” and finally “transistor computer”).
So I think that math developed more or less according to its age and time and that it could not have developed significantly faster. On the other hand, the fact that, in any of these instances, it did not come too late either, shows that this was probably the only way that it could develop.

Certainly not. To take your examples, the Babylonians, Egyptians, Greeks, and so on obviously had accountants and accounts, yet they didn't accept negative numbers or other aspects of basic arithmetic until quite late (actually hundreds of years after the Chinese and Indians did). Similarly, gamblers clearly existed in the ancient world, yet they didn't invent probability theory, even the parts that don't depend on calculus or other advanced topics. And on that note, while the most prominent uses of calculus might have to do with time differentials, it is also intimately concerned with the calculations of areas and volumes (with integrals) and dealing with limits, sequences, and series, both of which were topics of great interest to ancient mathematicians. In ancient Egyptian, Greek, and Chinese sources, among others, these topics see many proto-calculus concepts developed, and it's obvious that a true theory of calculus would have been very useful to mathematicians of the time to base their ad-hoc calculations of areas or the like on a more solid foundation, yet, again, they didn't develop it.

The idea that mathematical theories were invented just when they needed to be, no earlier and no later, is simply not supportable from even a cursory examination of the history, where exceptions in both directions can be found. Some deeper explanation is needed as to why the ancient Greeks or Romans didn't invent calculus or probability theory than "they had no use for it".
 
I'm pretty sure the entire existence of gambling depends on people unaware of probability theory.

As Circonflexe notes, the early development of probability theory had a lot to do with mathematicians wanting to do things like figure out whether or not they're likely to win a bet or determining the fairest method of splitting a gambling pot if a game is interrupted or the like.
 
The Swedish King Charles XII wanted to reform the numeral system, going from base 10 to base 64 (no, that's not a typo, he wanted base sixty-four). His argument for this particular number wasn't as crazy as you think! Most people never seem to question the fact that a circle has 360 degrees, but when you think about it, you may start to wonder "Why 360? Who not 100, or 36, or any other number?" Well, it turns out that 360 is a very useful number when dealing with fractions, since it's a (relatively) small number that can be divided evenly in a number of ways that 100 cannot. For example, 360=180x2=120x3=90x4=72x5=60x6=45x8=40x9=36x10. Similarly, 64 has the added benefit that it can be evenly divided by 4 and 8, which 10 cannot.

Personally I'd say that if you're going to go above 50 when choosing your base, surely 72 would be superior to 64, since 72 can not just be evenly divided by 4 and 8, but also 3 and 6, but then again (thankfully) I'm not Swedish royalty.
 
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