Sir,

I have a rhyme excelling in mystic force and magic spelling.

Celestial sprites elucidate all my own striving can't relate.

3.14159265358997323846

## Pi to 20 decimal places

### Pi to 20 decimal places

Mick F. Cornwall

### Re: Pi to 20 decimal places

There are several such mnemonics of varying lengths: two of the best known are:

All these systems would break down, seems to me, once we reach the 32nd decimal place which is the first '0' in the sequence. But we could adopt the system used in old-style telephone dialling: use a 10-letter word to represent a zero. In that case, how long (and how memorable?) could we make it?

Does anyone use a similar scheme to memorise their PIN [number]s? I do.

andHow I want a drink, alcoholic of course, after the heavy chapters involving Quantum Mechanics

This last one only works with American spelling, note.Now I - even I, would celebrate

In Rhymes unapt the great

Immortal Syracusan rivaled nevermore,

Who in his wondrous lore

Passed on before,

Left men his guidance

How to circles mensurate

All these systems would break down, seems to me, once we reach the 32nd decimal place which is the first '0' in the sequence. But we could adopt the system used in old-style telephone dialling: use a 10-letter word to represent a zero. In that case, how long (and how memorable?) could we make it?

Does anyone use a similar scheme to memorise their PIN [number]s? I do.

Suppose that this room is a lift. The support breaks and down we go with ever-increasing velocity.

Let us pass the time by performing physical experiments...

--- Arthur Eddington (creator of the Eddington Number).

Let us pass the time by performing physical experiments...

--- Arthur Eddington (creator of the Eddington Number).

### Re: Pi to 20 decimal places

Or one might adopt the Indiana Solution.

Have we got time for another cuppa?

### Re: Pi to 20 decimal places

Bonus point for anyone who can state what measurement or calculation would benefit from the 20th digit in this number.

(Do I need it to calculate my gearing correctly? )

(Do I need it to calculate my gearing correctly? )

### Re: Pi to 20 decimal places

Quite right - knowing pi to zillions of decimal places probably has no practical value - other than perhaps studies in randomness. The proof of Fermat's Last Theorem, likewise, probably conferred no practical benefits. Simply, pure knowledge.

If anyone should come up with a proof of Riemann's Hypothesis, on the other hand (no-one has - yet!), this might well have significant impact on practical matters. The hypothesis carries with it, assumptions about the distribution of prime numbers - knowledge which might affect such areas as cybersecurity. No-one would want their online banking to suddenly become less secure!

If anyone should come up with a proof of Riemann's Hypothesis, on the other hand (no-one has - yet!), this might well have significant impact on practical matters. The hypothesis carries with it, assumptions about the distribution of prime numbers - knowledge which might affect such areas as cybersecurity. No-one would want their online banking to suddenly become less secure!

Suppose that this room is a lift. The support breaks and down we go with ever-increasing velocity.

Let us pass the time by performing physical experiments...

--- Arthur Eddington (creator of the Eddington Number).

Let us pass the time by performing physical experiments...

--- Arthur Eddington (creator of the Eddington Number).

### Re: Pi to 20 decimal places

Incidentally, remember that the well-known sequence of digits for pi only applies in the decimal system. In other number systems, it would be quite different. For example, in hexadecimal, pi becomes 3.243F6A8885A308D313198A2E037073....

Suppose that this room is a lift. The support breaks and down we go with ever-increasing velocity.

Let us pass the time by performing physical experiments...

--- Arthur Eddington (creator of the Eddington Number).

Let us pass the time by performing physical experiments...

--- Arthur Eddington (creator of the Eddington Number).

### Re: Pi to 20 decimal places

661-Pete wrote:Incidentally, remember that the well-known sequence of digits for pi only applies in the decimal system. In other number systems, it would be quite different. For example, in hexadecimal, pi becomes 3.243F6A8885A308D313198A2E037073....

If you calculated that in your head, I am impressed

### Re: Pi to 20 decimal places

661-Pete wrote:Quite right - knowing pi to zillions of decimal places probably has no practical value - other than perhaps studies in randomness. The proof of Fermat's Last Theorem, likewise, probably conferred no practical benefits. Simply, pure knowledge.

If anyone should come up with a proof of Riemann's Hypothesis, on the other hand (no-one has - yet!), this might well have significant impact on practical matters. The hypothesis carries with it, assumptions about the distribution of prime numbers - knowledge which might affect such areas as cybersecurity. No-one would want their online banking to suddenly become less secure!

Not sure about that. The RH, though not yet proven, is widely assumed to be true, so proving it would in itself not affect cyber security. OTOH any new insights gained in achieving a proof might have some security implications.

The very highly respected professor Sir Michael Atiyah claimed to have a proof fairly recently, but it turned out to be a false alarm.

### Re: Pi to 20 decimal places

Yes I think you're spot on there. What it boils down to is, if anyone discovers a quick method of factorising a gargantuan number formed by multiplying two big primes together, this would throw the whole world of cryptography into chaos. I think there have been claims but no definite solution - yet.sjs wrote:Not sure about that. The RH, though not yet proven, is widely assumed to be true, so proving it would in itself not affect cyber security. OTOH any new insights gained in achieving a proof might have some security implications.

Let us pass the time by performing physical experiments...

--- Arthur Eddington (creator of the Eddington Number).

### Re: Pi to 20 decimal places

In in the Pi system, Pi = 1661-Pete wrote:Incidentally, remember that the well-known sequence of digits for pi only applies in the decimal system.

Mick F. Cornwall

### Re: Pi to 20 decimal places

Ha ha! Be impressed if you like! However, once you have it in Hex, it's easy enough to convert it into binary: it becomes 11.0010 0100 0011 1111 0110 1010.....etc.mattheus wrote:661-Pete wrote:Incidentally, remember that the well-known sequence of digits for pi only applies in the decimal system. In other number systems, it would be quite different. For example, in hexadecimal, pi becomes 3.243F6A8885A308D313198A2E037073....

If you calculated that in your head, I am impressed

Let us pass the time by performing physical experiments...

--- Arthur Eddington (creator of the Eddington Number).

### Re: Pi to 20 decimal places

661-Pete wrote:Ha ha! Be impressed if you like! However, once you have it in Hex, it's easy enough to convert it into binary: it becomes 11.0010 0100 0011 1111 0110 1010.....etc.mattheus wrote:661-Pete wrote:Incidentally, remember that the well-known sequence of digits for pi only applies in the decimal system. In other number systems, it would be quite different. For example, in hexadecimal, pi becomes 3.243F6A8885A308D313198A2E037073....

If you calculated that in your head, I am impressed

Now *that* bit I could have done!

(still not sure where I would use it … )

### Re: Pi to 20 decimal places

Not similar, but my (our) number is a long-time passed away dog's birthday.661-Pete wrote:Does anyone use a similar scheme to memorise their PIN [number]s? I do.

Border Collies .............. and the one we have now is our fifth. It's his first birthday the day after tomorrow.

Mick F. Cornwall

### Re: Pi to 20 decimal places

Mick F wrote:Not similar, but my (our) number is a long-time passed away dog's birthday.661-Pete wrote:Does anyone use a similar scheme to memorise their PIN [number]s? I do.

Border Collies .............. and the one we have now is our fifth. It's his first birthday the day after tomorrow.

On the 6th.

### Re: Pi to 20 decimal places

Sailor-the-dog will be one year old on the 6th of Feb.

The sooner he grows up, the better. One heck of a handful!

The birthday we use as a PIN was from a long-dead previous doggie.

The sooner he grows up, the better. One heck of a handful!

The birthday we use as a PIN was from a long-dead previous doggie.

Mick F. Cornwall