INFINITIES 12 – Infinities Left of the Decimal

Copyright M.W.F. Young


This is the twelfth in a series of posts exploring infinity, entities and ideas infinite, infinities larger than other infinities, infinity paradoxes, infinite perimeters, infinite regress and infinite sequences such as cyclic numbers.


In the previous post it was pointed out that an infinite string of nines to the right of the decimal (0.9999999 . . .) is equal to one but it was never proved. This post will start with a simple proof of that fact. Then there will be a demonstration of what an infinite string of nines to the LEFT of the decimal is equal to. The answer is ridiculous.

  • Let k = 0.9999999 . . .
  • 10k = 9.9999999 . . .
  • 10k – k = 9
  • 9k = 9
  • k = 1 = 0.9999999 . . .
  • Now, let . . . 999999.0 = m
  • Equation 1: . . . 999999 = m
  • Equation 2: . . . 9999990.0 = 10m
  • (. . . 999999) – (. . . 9999990) = m – 10m
  • 9 = -9m
  • m = -1
  • . . . 999999.0 = -1

To confirm this bizarre result, add 1 to m and if m is equal to -1 then adding 1 should give us zero. What is . . . 999999 plus 1 equal to? 9 +1 = 0, carry the 1 into the tens column, 1 +9 there equals 10 again, place the zero next to the first zero down below and carry the 1 into the hundreds column, 1 + 9 there equals 10 again, place another zero next to the two zeroes in the answer at the bottom and carry the 1 into the thousands column. Do this forever and you get an infinite string of zeroes. So, apparently, . . . 999999 = -1 . If we subtract 6 from each side, we get that . . . 999993 = -7, and if we subtract 40 we get that . . . 999959 = -41 and so on.

Now, consider what the following infinitely large number is equal to (this is a number consisting of an endlessly repeating chain of the six digits 857142, plus 1):

. . . 857142 857142 857143.0

What happens if you multiply this number by 7?

. . . 857142 857142 857143 x 7 = . . . 000000000000000001, i.e. simply 1

Therefore . . . 857142 857142 857143.0 = 1 / 7.

What do you suppose the infinitely large number . . . 666667 is equal to? If you multiply it by 3 you get 1, so . . . 666667 must equal 1 / 3.

What do you suppose . . . 888889 is equal to?

To find the negative of one of these numbers, you can either multiply it by -1 (which can be tricky), or you can find the number’s complement and add one to that complement. Two numbers are complements if they add up to nine. For example, the complement of 8 is 1, the complement of 4 is 5. The complement of . . . 857142857143 is . . . 142857142856. Adding 1 gives you . . . 142857142857 which theoretically equals – 1 / 7. How can we verify that? Since . . . 857142857143 equals 1 / 7 and . . . 142857142857 equals – 1 / 7, then if we add them together they should equal zero – and that’s exactly what does happen.


PIERRE DE FERMAT
By Unknown author – https://web.archive.org/web/20191028044928/http://www-groups.dcs.st-and.ac.uk/~history/PictDisplay/Fermat.html, Public Domain, https://commons.wikimedia.org/w/index.php?curid=36804

Andrew Wiles used a prime subset of numbers like these to solve Fermat’s Last Theorem, an infamous theorem which had gone unsolved for 358 years despite the fact that the greatest mathematicians of the last 358 years had attempted to prove it, all unsuccessfully. For more information on these numbers – https://www.youtube.com/watch?v=tRaq4aYPzCc&ab_channel=Veritasium

By the way, . . . 888888889 = 1 / 9 . To confirm this multiply the left side by 9 and see if you get 1.


PHILOSOPHICAL PERPLEXITIES ABOUT INFINITY

There are some Christian apologists who apparently are confused about what infinity is all about. A particularly prominent theist by the name of William Lane Craig gets infinity wrong in various ways in his defence of the Kalam Cosmological Argument for the existence of God. Similarly, the theist Alvin Plantinga’s defence of the Ontological Argument for the existence of God also rests on a misunderstanding of the nature of infinity.

William Lane Craig’s writings and speeches delve deeply into tensed and tenseless time, presentism and the nature of spacetime. He defends a neo-Lorentzian interpretation of Einstein’s Special Theory of Relativity, yet at the same time he is wrong about some basic mathematical concepts which I learned in high school. Craig also misses the point about Hilbert’s extraordinary Hotel Infinity (a topic dealt with in depth in the fourth post of this series of posts).

These philosophical treatments of infinity can become esoteric exercises in finitism and modal logic. I have gone into these matters in some detail at the end of this post if anyone is interested.

PREVIOUS POSTS

Post 1 – Infinity Everywhere – https://thekiddca.wordpress.com/2024/04/06/infinities-infinity-everywhere/

Post 2 – Snowflake Curve – https://thekiddca.wordpress.com/2024/04/13/infinities-2-theres-no-business-like-snow-business/

Post 3 – Ch’i Ch’iao T’u – https://thekiddca.wordpress.com/2024/04/20/infinities-3-infinitesimal-chi-chiao-tu/

Post 4 – Hotel Infinity – https://thekiddca.wordpress.com/2024/04/27/infinities-4-no-vacancies-but-rooms-still-available-at-hotel-infinity/

Post 5 – Pythagorean Infinity – https://thekiddca.wordpress.com/2024/05/04/infinities-5-pythagorean-infinity/

Post 6 – Rep-tiles 1 – https://thekiddca.wordpress.com/2024/05/12/infinities-6-welcome-to-the-rep-tile-house-part-1-of-5/

Post 7 – Rep-tiles 2 – https://thekiddca.wordpress.com/2024/05/18/infinities-7-welcome-to-the-rep-tile-house-part-2-of-5/

Post 8 – Rep-tiles 3 – https://thekiddca.wordpress.com/2024/05/25/infinities-8-welcome-to-the-rep-tile-house-part-3-of-5/

Post 9 – Rep-tiles 4 – https://thekiddca.wordpress.com/2024/06/01/infinities-9-welcome-to-the-rep-tile-house-part-4-of-5/

Post 10 – Rep-tiles 5 – https://thekiddca.wordpress.com/2024/06/08/infinities-10-welcome-to-the-rep-tile-house-part-5-of-5/

Post 11 – Cyclic Power –
https://thekiddca.wordpress.com/2024/06/15/infinities-11-cyclic-power/

SOME PHILOSOPHICAL PERPLEXITIES – MORE DETAILS

William Lane Craig is very sure of himself and when experts in fields outside his area of expertise (e.g. Mathematics, Cosmology and Astrophysics) challenge him he doesn’t like it. He has said with some impatience that there could never be such a thing as the David Hilbert’s Hotel Infinity, missing Hilbert’s point completely. Hilbert came up with the idea of Hotel Infinity to demonstrate that one must be careful when dealing with the concept of infinity because if you’re not careful you end up with bizarre impossible entities like Hotel Infinity. Hotel Infinity has an infinite number of rooms, each one occupied, but if a new guest arrives that guest can be given a room of her own while all the remaining guests can still remain in rooms alone. A thousand new guests could also be accommodated. So could an infinite number of new guests. So could an infinite number of sets of infinite numbers of guests.

Cantor did pioneering work with transfinite numbers and someone properly schooled in Mathematics would be fine with Cantor’s work. However, some Christian apologists seem to be unable or unwilling to understand something established mathematically 140 years ago. I have also heard Christian apologists misrepresent how probability works (I have no cites so you can accept this observation or not).

William Lane Craig argues that the universe had a beginning, everything has a cause, and that the only cause for the universe that makes sense is the Christian God. This is known as the Kalam Cosmological Argument. The argument is based on Craig’s misunderstanding of the nature of infinity (as well as various unwarranted assumptions). At one point he refers to infinity as the limit of an infinite series. He doesn’t seem to comprehend that infinity is not a number, nor does he understand the difference between a converging and a diverging infinite series. High school math.

His arguments also involve tensed and tenseless time, presentism and the nature of spacetime. He believes that the universe has not existed for an infinite amount of time in the past. He is convinced that God led a timeless existence, then He created the universe which included everything, even time itself. He believes in what metaphysicists refer to as the A-theory of time, i.e. that there are tensed facts (e.g. “it is now dinner time”) which cannot be reduced to tenseless facts (e.g. “it is dinner time at six P.M. on June 22, 2024”). He seems to think of the present as an individual infinitesimal slice of existence sliding along (his phrase is “absolutely becoming”) between the past and the future. This is at odds with Einstein’s demonstration that there is no such thing as simultaneity.

Unfortunately empirical science little by little continues to undermine Craig’s assertions. He argues that one can never have something come into existence from nothing, a conclusion which has been proven wrong by the discovery of quantum fluctuations leading to sub-atomic particles popping in and out of existence. More recently the discoveries of gravitational waves is also at odds with Craig’s beliefs. In 2011 noted astrophysicist Lawrence Krauss went as far as to accuse Craig of “disingenuous distortions, simplifications, and outright lies”.

One of the people whose views William Lane Craig is enamoured of is a theist named Alvin Plantinga. In 1960 Plantinga vigorously defended something called The Ontological Argument for the existence of God. That particular argument was proposed by St. Anselm (1033 – 1109) almost a thousand years ago, and yet before the ink was dry on St. Anselm’s manuscript Gaunilo of Marmoutiers, a contemporary of St. Anselm, was able to show that it was flawed. The Ontological Argument was also rejected by Thomas Aquinas (1225 – 1274), David Hume (1711 – 1776) and Immanual Kant (1724 – 1804). Aquinas and Kant, may it be noted, were two of the six or seven greatest philosophers who ever lived (IMHO). More to the point, Plantinga’s arguments also rest on a misunderstanding of infinity.


ST. THOMAS AQUINAS
By Bartolomé Esteban Murillo – Own work Amuley, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=33176874

As Keith Backman demonstrated in 2016, Plantinga’s treatment of infinite magnitudes and maximal greatness in his ‘proof’ of the Ontological Argument are fallacious. Backman explains how both St. Anselm and Platinga “propose that attributes of infinite magnitude should be manipulated, augmented or aggregated so as to obtain an entity with a magnitude distinguishable from the infinitely great properties of its starting components” (to quote the summary on the back of the book). Plantinga’s argument rests on several fallacies. One of the fallacies involves an invalid treatment of characteristics involving implicitly infinite magnitude as if they possess a definite measure. Plantinga also groups disparate appreciations of God’s existential status (introduced as imaginary), but then treats as substantive for purposes of reasoned argument (for more details see Creating God From Nothing: Fallacy and Subterfuge in Ontological Arguments for the Existence of God, by Keith Backman, Bookstand Publishing, 2016, page 55).

Tread the terrain of the infinite with great care.

INFINITIES 11 – Cyclic Power

Copyright M.W.F. Young 2024


This is the eleventh in a series of posts exploring infinity, entities and ideas infinite, infinities larger than other infinities, infinity paradoxes, infinite perimeters, infinite regress and infinite sequences such as cyclic numbers.

Different people have different favourite numbers. When I was but a child my favourite number was four because that was the jersey number of Red Kelly who was a high achieving hockey player on the Toronto Maple Leafs back when they were winning Stanley Cups a lot. Now my favourite number is 142857. A lot has been written about this number but this post will, in all probability, reference some little known properties of the number.

What do you get if you multiply 142857 by 2? You get 285714. Notice anything unusual about that? Yes, the digits in both 142857 and 285714 are not only the same but they are also in the same order. It’s just that they start with different digits. What do you think will happen if you multiply 142857 by 3? Here is what you get if you multiply 142857 by all of the digits from one to six:

  • 142857 x 1 = 142857
  • 142857 x 2 = 285714
  • 142857 x 3 = 428571
  • 142857 x 4 = 571428
  • 142857 x 5 = 714285
  • 142857 x 6 = 857142

Now what? We’ve generated six results using all six digits in 142857 as the leading digits in the answers, so what happens if we multiply 142857 by seven? Any guesses? 142857 is called a cyclic number and people have known about such numbers for quite awhile. Lewis Carroll, who is most famous for writing Alice in Wonderland and Through the Looking Glass, was also a mathematician and a pioneer in the field of symbolic logic. He was analysing cyclic numbers a century and a half ago.


Curiously, all of the cyclic numbers except 142857 have leading zeroes. For example, the next larger cyclic number is 0588235294117647 so we have

  • 1 x 0588235294117647 = 0588235294117647
  • 2 x 0588235294117647 = 1176470588235294
  • 3 x 0588235294117647 = 1764705882352941
  • . . .
  • 16 x 0588235294117647 = 9411764705882352


What do you get if you calculate the decimal expression of one seventh? You get 0.142857 142857 142857 . . . and that same group of digits, 142857, keeps repeating forever. You can guess what two sevenths, three sevenths and so on look like in decimal form:

  • 1 / 7 = 0.142857 142857 142857 . . .
  • 2 / 7 = 0.285714 285714 285714 . . .
  • 3 / 7 = 0.428571 428571 428571 . . .
  • 4 / 7 = 0.571428 571428 571428 . . .
  • 5 / 7 = 0.714285 714285 714285 . . .
  • 6 / 7 = 0.857142 857142 857142 . . .


But then when you multiply 142857 by 7 you get 999999 (a special case of Midy’s Theorem). So what does seven sevenths look like? It must equal 0.999999 999999 999999 and so on. But seven sevenths equals one. Therefore 1 = 0.999999 999999 999999 . . . After all 0.9999 . . . is equal to the infinite series nine tenths plus 9 hundredths plus nine thousandths plus nine ten thousandths and so on, and if you keep adding together these smaller and smaller amounts you get closer and closer to one. If you were able to keep adding these numbers forever (which is, of course, impossible) you would get to one. So we say that the limit of all these fractions is one, and a limit is something that you can get as close to as you like but you can never reach. This is a fundamental concept used in calculus.

Looking at the decimal expression of one seventh also helps to explain the cyclic property of 142857. Take a look at this:

1/7 = 0.142857 142857 142857 . . .

Multiply both sides by 10. 10/7 = 1.428571 428571 428571 . . .

10/7 = 7 / 7 + 3 / 7 = 1 + 3 / 7 = 1.428571 428571 428571 . . .

So 3/7 = 0.428571 428571 428571 . . .

Multiply by 10 again. 30/7 = 4.285714 285714 285714 . . .

30/7 = 28/7 + 2/7 = 4 + 2/7 = 4.285714 285714 285714 . . .

So 2/7 = 0.285714 285714 285714 . . . and so on.

999999 is also equal to 1000000 – 1, that is 106 – 1. Here are the first five cyclic numbers expressed using exponents:

  • (106 – 1) / 7 = 142857 (6 digits)
  • (1016 – 1) / 17 = 0588235294117647 (16 digits)
  • (1018 – 1) / 19 = 052631578947368421 (18 digits)
  • (1022 – 1) / 23 = 0434782608695652173913 (22 digits)
  • (1028 – 1) / 29 = 0344827586206896551724137931 (28 digits)


The generators of the first five cyclic numbers are 7, 17, 19, 23 and 29. These are all prime numbers. All cyclic numbers are also prime numbers but not all prime numbers are cyclic numbers. However we do know that 37.395 . . . % of all prime numbers are cyclic numbers. It would seem that cyclic numbers, like prime numbers, are infinite. There are also other pseudocyclic numbers whose digit sequence remains intact while the leading digit changes. However their multiples are not consecutive integers so they are not genuine cyclic numbers.
For example – 076923 x 1 = 076923, 076923 x 3 = 230769, 076923 x 4 = 307692, 076923 x 9 = 692307, 076923 x 10 = 769230, 076923 x 12 = 923076 .

Cyclic and pseudocyclic numbers can be generated by the expression (bp – 1 – 1) / p where b is the base being used and p is a prime number greater than 3 which does not divide evenly into b. Therefore, if b equals 10 (using the decimal system, i.e. base 10), and p = 7, this expression becomes (107 – 1 – 1) / 7 = (106 – 1) / 7 = 999 999 / 7 = 142857.

Sometimes it’s interesting just exploring number patterns, and then trying to figure out how the pattern is generated. The following pattern is sort of regular but isn’t quite, and I have no idea if it is significant:

  1. Divide the six-digit number 142857 into three two-digit parts and add them up (2 goes into 6 evenly): 14 + 28 + 57 = 99. 3 TWO-DIGIT NUMBERS – TWO NINES.
  2. Divide the six-digit number 142857 into two three-digit parts and add them up (3 goes into 6 evenly): 142 + 857 = 999. 2 THREE-DIGIT NUMBERS – THREE NINES.
  3. If you try to divide the six-digit number 142857 into four-digit parts you can’t do it since four doesn’t go into six evenly so instead divide the 12-digit number 142857142857 into four-digit parts, i.e. three of them (4 goes into 12 evenly, three times) and add those four-digit parts up: 1428 + 5714 +2857 = 9999. 3 FOUR-DIGIT NUMBERS – FOUR NINES.
  4. Divide the 30-digit number 142857142857142857142857142857 into six five-digit parts (5 doesn’t go evenly into 6, 12, 18 or 24, but it does go evenly into 30) and add them up: 14285 + 71428 + 57142 + 85714 + 28571 + 42857 = 299997. This is not the a string of nines, but at least 2 + 7 equals 9, so we sort of have five nines. 6 FIVE-DIGIT NUMBERS – FIVE NINES (SORT OF).
  5. Divide the 36-digit number 142857142857142857142857142857142857 into six six-digit parts (6 goes into 36 evenly) and add them up: 142857 + 142857 + 142857 + 142857 + 142857 + 142857 = 999999. 6 SIX-DIGIT NUMBERS – SIX NINES.
  6. Divide the 42-digit number 142857142857142857142857142857142857142857 into six seven-digit parts (7 doesn’t go evenly into 6, 12, 18, 24, 30 or 36, but it does go evenly into 42) and add them up: 1428571 + 4285714 + 2857142 + 8571428 + 5714285 + 7142857 = 29999997, and again 2 + 7 = 9 so we sort of have seven nines. 6 SEVEN-DIGIT NUMBERS – SEVEN NINES (SORT OF).
  7. Divide the 24-digit number 142857142857142857142857 into three eight-digit parts (8 doesn’t go evenly into 6, 12 or 18, but it does go evenly into 24) and add them up: 14285714 + 28571428 + 57142857 = 99999999. 3 EIGHT-DIGIT NUMBERS = EIGHT NINES.
  8. Divide the 18-digit number 142857142857142857 into two nine-digit parts (9 doesn’t go evenly into 6 or 12, but it does go evenly into 18) and add them up: 142857142 + 857142857 = 999999999. 2 NINE-DIGIT NUMBERS = NINE NINES.

Does this work for ten-digit parts?

The cyclic number 142857 contains the digits from 1 to 9 except for all the multiples of three. I wonder if that is significant? What do you get if you take the last three digits of 142857 and square it, and subtract the square of the first three digits? That is (857)2 – (142)2 = ?

Finally, here is a curious cyclic-related patterns which I stumbled across in a fascinating 2020 paper by Santanu Bandyopadhyay published in Mumbai, India – https://www.ese.iitb.ac.in/~santanu/RM3.pdf :

What happens if you insert 9 into the middle of 142857 giving you the seven-digit number 1429857, then multiply that number by the numbers from one to six? –

  • 1429857 x 1 = 1429857
  • 1429857 x 2 = 2859714
  • 1429857 x 3 = 4289571
  • 1429857 x 4 = 5719428
  • 1429857 x 5 = 7149285
  • 1429857 x 6 = 8579142

What happens if you insert two 9’s? I wonder why these things happen?


Next post: INFINITIES LEFT AND RIGHT

Post 1 – https://thekiddca.wordpress.com/2024/04/06/infinities-infinity-everywhere/

Post 2 – https://thekiddca.wordpress.com/2024/04/13/infinities-2-theres-no-business-like-snow-business/

Post 3 – https://thekiddca.wordpress.com/2024/04/20/infinities-3-infinitesimal-chi-chiao-tu/

Post 4 – https://thekiddca.wordpress.com/2024/04/27/infinities-4-no-vacancies-but-rooms-still-available-at-hotel-infinity/

Post 5 – https://thekiddca.wordpress.com/2024/05/04/infinities-5-pythagorean-infinity/

Post 6 – https://thekiddca.wordpress.com/2024/05/12/infinities-6-welcome-to-the-rep-tile-house-part-1-of-5/

Post 7 – https://thekiddca.wordpress.com/2024/05/18/infinities-7-welcome-to-the-rep-tile-house-part-2-of-5/

Post 8 – https://thekiddca.wordpress.com/2024/05/25/infinities-8-welcome-to-the-rep-tile-house-part-3-of-5/

Post 9 – https://thekiddca.wordpress.com/2024/06/01/infinities-9-welcome-to-the-rep-tile-house-part-4-of-5/

Post 10 –

INFINITIES 1 – Infinity Everywhere

Copyright M.W.F. YOUNG 2024

This is the first in a series of posts exploring infinity. There will be one infinity larger than another infinity, infinite perimeters, infinite regress, infinity paradoxes, an infinite set of bizarre things called cyclic numbers, and other infinity-related concepts.

Copyright M.W.F. YOUNG 2024

Infinities (and infinitesimals) are everywhere. Start counting (1 2 3 . . . ) and see how far you get. If the word “universe” means everything that exists, the universe must be infinitely large as well. It would also seem that Time is eternal, that is it consists of an infinite number of seconds or minutes or decades or whatever arbitrary unit of time you wish to use. Cosmologists are not all in agreement with these concepts, however, depending on how you define the words “exists”, “time” and “spacetime”.

Some infinities are different than others. If, for example, I start adding up the Natural Numbers (1 + 2 + 3 + 4 + . . . ), and did that forever, I would end up with an infinitely large number. This is a divergent infinite series. On the other hand, if I start adding up a series of ever smaller fractions ( 1/2 + 1/4 + 1/8 + 1/16 + . . . ) I could also do that forever, but in this case I would never get to the number one, let alone an infinitely large number. This is a convergent series, and involves the concept of being infinitesimally small.

Infinity is not a number but a condition of endlessness. It is a slippery concept. For example, infinity plus infinity equals infinity. The set of odd numbers is obviously infinite, and so is the set of even numbers, and if you combine the two sets you get the set of Natural Numbers which is also infinite. However the set of even numbers and Natural Numbers are the same size even though there seem to be only half as many even numbers as there are Natural Numbers. We know these two sets are the same size because we can match the Natural Number one up with the even number two, the Natural Number two with the even number four, three with six and so on, doubling each time, so we know that both sets have the same number of numbers in them.

What is even stranger is that some infinities are larger than others. I’ve understood the proof of that fact (it’s not a difficult proof) but I still can’t get my head around that idea. How can you have a number greater than the number of Natural Numbers? Georg Cantor proved it was possible, over a century ago. He showed that the number of Real Numbers is greater than the number of Natural Numbers, which means that the number of Transcendental Numbers (pi is a transcendental number, for example) is also greater than the number of Natural Numbers.

INFINITE SETS

Infinity is tricky. I can use infinite sets to prove that 1/2 = 0, and all the Natural Numbers (1, 2, 3 . . . ) not only add up to -1/12 but they also add up to -1/8 so I guess -1/12 = -1/8. The proofs use simple arithmetic and I have placed them at the end of this post if you want to take a look at them and try to figure out why they seem to be correct even though they “prove” something obviously false.

ACHILLES AND THE TURTLE

About 2500 years ago the Greek philosopher Zeno of Elea (490 BCE – 430 BCE) argued that if the great athlete Achilles was running a Kilometre long race against a turtle, and the turtle was given just a short head start of, say, ten metres, then Achilles could never catch up let alone pass the turtle. Zeno explains that if the turtle gets to start at some point A, ten metres ahead of the starting line, then as soon as the race starts Achilles will soon catch up and also reach point A but in the time it takes for him to do so, the turtle will have advanced to some further point, call it point B. Then as Achilles runs from A to B the turtle will have advanced once more to some further point, call it point C. As this same process unfolds over and over again Achilles never catches up to the turtle.


THE PLATONIC SOLIDS IN THE FORM OF DICE
By Tomruen – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=39985790

INFINITELY NESTED PLATONIC SOLIDS

There is a set of five fascinating three dimensional solids called the Platonic Solids. One of them, with six sides, is called a hexahedron which is just a mathematical name for a cube. If you find the centres of the six sides of a hexahedron and connect those centres using triangles you get another one of the Platonic Solids, an eight-sided figure called an octahedron and it looks like this:


AN OCTAHEDRON INSIDE A HEXAHEDRON
By 4C – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1049163

Now, if you find the centres of the eight sides of that inner octahedron and connect those centres using squares you get another, smaller, hexahedron. Then you can fit an even smaller, second octahedron inside that smaller hexahedron, and keep forming smaller and smaller Platonic solids forever, alternating between hexahedra and octahedra. The shapes become infinitesimal. You can do the same thing with two other Platonic Solids – the twelve-sided dodecahedron and the twenty-sided icosahedron. I wonder what happens if you connect the centres of the sides of the last and simplest Platonic Solid, the four-sided tetrahedron, using triangles?


TETRAHEDRON
By The original uploader was Cyp at English Wikipedia. – en:User:Cyp/Poly.pov, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=38709

PI UNEXPECTEDLY

Not only does pi equal an infinitely non-terminating non-repeating decimal, it also shows up in the most unexpected places, such as Buffon’s Needle Problem – https://en.wikipedia.org/wiki/Buffon%27s_needle_problem . It can also be expressed as an infinite series in a variety of ways which seem to have nothing to do with circle ratios. For example:

  • pi = 4(1/1 – 1/3 + 1/5 – 1/7 + . . . )
  • pi = 2(2 x 2 x 4 x 4 x 6 x 6 x …) / (1 x 1 x 3 x 3 x 5 x 5 x …)

AN INFINITE CONTINUED FRACTION

Here is a geometric proof that the square root of two is equal to an infinite continued fraction. This was taken from the book Through The Mathescope by Stanley Ogilvy.

ASYMPTOTES

Some curves when graphed get closer and closer to their asymptotes (which are usually, but not always, straight lines) and so they go on forever. The two branches of a hyperbola never reach their asymptotes. The witch of Agnesi, a curve analysed at length by Maria Agnesi (1718 – 1799), approaches asymptotes along the positive and negative x axes but never reaches them, as illustrated here:


By Dicklyon – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=118532845

In trigonometry the tangent function becomes infinite when x equals π / 2, 3π/2, 5π/2 and so on, getting ever closer to their asymptote positive and negatively but never getting there. I have illustrated that phenomenon in this illustration:

SOME NUMBER SETS THAT GO ON FOREVER

  • Natural Numbers (1, 2, 3, 4 . . . )
  • Integers (. . . -4, -3, -2, -1, 0, 1, 2, 3, 4 . . .)
  • Odd Numbers (1, 3, 5, 7 . . .)
  • Even Numbers (2, 4, 6, 8 . . .)
  • Prime Numbers (2, 3, 5, 7 . . .)
  • Perfect Squares (1, 4, 9, 16 . . .)
  • Perfect Cubes (1, 8, 27, 64 . . .)
  • and fourth powers, fifth powers and so on
  • Triangular Numbers (1, 3, 6, 10 . . .)
  • and Pentagonal Numbers, Hexagonal Numbers and so on
  • Perfect Numbers (6, 28, 496, 8128 . . .)
  • Cyclic Numbers (142857, 0588235294117647 . . .)

SOME INFINITE DECIMAL EXPANSIONS

The decimal forms of all sorts of numbers also go on to infinity.

  • 4 = 4.0000000000 . . .
  • 1/2 = 0.5000000000 . . .
  • 1/9 = 0.1111111111 . . .
  • 1/3 = 0.3333333333 . . .
  • 1/7 = 0.142857 142857 142857 . . .

Some go on forever without repeating and are the roots of a non-zero polynomial of finite degree with rational coefficients (i.e. algebraic numbers):

  • The square root two = 1.4142135623 . . .
  • The square root of three = 1.7320508075 . . .
  • The Golden Ratio / phi = 1.6180339887 . . . which is equal to one plus the square root of five all divided by two. It is the positive root of the equation x2 – x – 1 .

Some numbers go on forever without repeating but are not the roots of a non-zero polynomial of finite degree with rational coefficients (i.e. transcendental numbers):

  • Pi = 3.1415926535 . . . which is the ratio of the circumference of a circle to its diameter.
  • e = 2.7182818284 . . . which is the base of the natural logarithms aka Euler’s Number
  • The Liouville constant = 0.1100010000 . . .

FINALLY, DIVISION BY ZERO

In Mathematics division by zero is said to be undefined. Some people have got the impression that one divided by zero equals infinity, but this implies that infinity is a number but it is not. To say that the limit of one divided by x approaches infinity as x approaches zero makes more sense, but that still doesn’t make it clear exactly why division by zero is undefined. It is undefined because if you accept it you end up with inconsistent results.

To illustrate, take the equation y = 1 / x. Graph this on a Cartesian coordinate system. What happens to y as x gets smaller and smaller, i.e. it approaches zero, but along the positive x-axis? Is the limit simply infinity? No it isn’t. Set x equal to 1 / 2 and y equals 2. Set x equal to 1 / 3 and y equals 3. Set x equal to 1 / 1000000 and y equals 1000000. In other words, the limit is positive infinity. Again have x get smaller and smaller as it approaches zero, but have it approach zero along the negative x-axis this time. What happens? Set x equal to -1 / 2 and y equals -2. Set x equal to -1 / 3 and y equals -3. Set x = -1 / 1000000 and y equals -1000000. In other words, the limit is negative infinity. So, even if you try to figure out what the limit of 1 / x is as x approaches zero, you get that the limit is simultaneously positive and negative infinity, which is mathematically meaningless, inconsistent and ridiculous. If you graph the function you have two simultaneous curves, one going up forever and the other going down forever, both of them asymptotic to the y-axis. So don’t divide by zero. Just don’t.

NEXT POST: A curve with an infinite perimeter and a finite area.

PROOF THAT 1/2 = 0, AND -1/12 = -1/8 (AND THEREFORE EVERY WHOLE NUMBER IS EQUAL TO EVERY OTHER WHOLE NUMBER)

INFINITE SET 1. Let me show you that 1/2 = 0

  • Let A = 1 – 1 + 1 – 1 + 1 – 1 + 1 – 1 . . .
  • 1 – A = 1 – (1 – 1 + 1 – 1 + 1 – 1 + 1 – 1 . . . )
  • 1 – A = 1 – 1 + 1 – 1 + 1 – 1 + 1 – 1 + 1 . . .
  • 1 – A = A
  • 1 = 2A
  • A = 1/2

But wait a minute:

  • A = 1 – 1 + 1 – 1 + 1 – 1 +1 – 1 . . .
  • A = (1 – 1) + (1 – 1) + (1 – 1) + (1 – 1) . . .
  • A = 0 + 0 + 0 + 0 . . .
  • So A is also equal to 0. Apparently 1/2 = 0.

INFINITE SET 2

  • Let B = 1 + 2 + 3 + 4 + . . .
  • Let S = 1 – 2 + 3 – 4 + 5 – 6 . . .
  • B – S = (1 – 1) + (+2 – (-2) ) + (+3 – (+3) ) + (+4 – (-4) ) + . . .
  • B – S = 0 + 4 + 0 + 8 + 0 + 12 + . . .
  • B – S = 4(1 + 2 + 3 + 4 + . . . )
  • B – S = 4B

Now we need to find out what S equals. Add S to itself but when you put the second S under the first shift it over so that the 1 in the second S is under the 2 in the first S, the 2 in the second S is under the 3 in the first S and so on.

  • 2S = 1 + [(-2) + (+1)] + [(+3) + (– 2) ] + [(-4) + (+3)] + . . .
  • 2S = 1 – 1 + 1 – 1 + 1 – 1 + . . .
  • But we found out above that A = 1 – 1 + 1 – 1 + 1 – 1 . . . = 1/2
  • So 2S = A = 1/2
  • S = 1/4
  • Now go back to the line B – S = 4B
  • B – 1/4 = 4B
  • B – 4B = 1/4
  • -3B = 1/4
  • -12B = 1
  • B = -1/12 = 1 + 2 + 3 + 4 + . . .

You can also use infinite series’ to prove that B is also equal to -1/8 if you like:

  • B = 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + . . .
  • B = 1 + (2 + 3 + 4) + (5 + 6 + 7) + (8 + 9 + 10) + . . .
  • B = 1 + 9 + 18 + 27 + . . .
  • B = 1 = 9(1 + 2 + 3 + . . .)
  • B = 1 + 9B
  • B – 9B = 1
  • -8B = 1
  • B = -1/8
  • If -1/12 = -1/8
  • then 24(-1/12) = 24(-1/8)
  • -2 = -3
  • -2 + 2 = -3 + 2
  • 0 = -1

You can now multiply both sides by -1 (so 0 = 1), or by -2 (so 0 = 2), or by -3 (so 0 = 3) and so on, so every Natural Number equals every other Natural Number and they are all equal to zero.