h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: Zero - A21345077
Author: Icy North - U225620

I was going to submit this a couple of weeks ago, but Fizzymouse got there first with 'Size Zero', and I thought it was too much of a good thing (insofar as you can have too much of nothing).

I want this to be comprehensive, so yell if I've missed anything.

Icy

This is the best Entry I've read for a long time!

Just time for a skim read at the present. I'll be back later with detailed feedback.

B

Thanks B!

(shudders at the thought of B's 'detailed feedback' - hope he doesn't bring the cane)

I was fascinated by this, Icy. brilliant idea for an entry.

I have to admit I got stuck on something though (my personal bias )

I have to go have a root around in my remote memory - I am thinking of Ptolemy and the Middle Eastern connection for zero in relation to Phoenicia. Wasn't Ptolemy Alexander the Great's general? Or am I centuries and generations out >

I'll go seek and bring back some proper dates if I find them (unless you two have the info already? )

'Scientists have also defined 'absolute zero' - the ultra-low temperature at which a substance has no heat energy, defined as -273.15°C or –459.67°F on those scales'.

I thinbk it's worth pointing out that 'Absolute Zero' is O degrees on the Kelvin scale (represented as 0K -without a 'degree sign').

This is excellent! I've only skimmed it too, but if it's any use you can show the omicron by a special character code: Ο

Ignore me. Wrong Ptolemy
http://www.alexander-the-great.co.uk/ptolemy.htm




In case you have not seen these:
http://www-groups.dcs.st-and.ac.uk/~history/HistTopics/Zero.html#s19
http://www.bbc.co.uk/radio4/science/5numbers1.shtml


W

Thanks All

I've added Skankyrich's Ο (looks identical to an uppercase O to me), and Al's zero degrees Kelvin.

I remember reading the first of those links Wilma. I think it confirmed a lot of what I had found elsewhere. Oddly, I can't access the second one at the mo - my employer's blocked it! I'll check when I'm at home.

Icy

What a wonderfully informative Entry Thanks once again Icy.

Just a couple of things;

I'd capitalise No Man's Land and Researcher

Plus, what about Nada? (?sp)

Great stuff.

Oh, and what about - 'Ground Zero' too?

Hi Matt

Es mejor que nada (translates as "what brilliant suggestions!" )

I've added those, with the exception of no-man's-land, which I've hyphenated instead.

Icy

Well done, Icy North (I can still hardly believe there was no such entry before.)

Footnote 2: You say that zero to the power of zero is undefined, but I think that, for various reasons, it is usually taken to be 1.

"We have no concept of minus zero": minus zero = zero. It is the only number with that property.

"Scientists have also defined 'absolute zero' - the ultra-low temperature at which a substance has no heat energy, defined as -273.15°C or –459.67°F on those scales, or zero degrees on the Kelvin scale, written as 0K." Er, I think it is slightly inaccurately formulated. The absolute zero is defined as the temperature at which a substance has no heat energy, and measured (or computed, I don't know), to be equal to -273.15°C, not defined (because you already defined it).

"[Nought] derives from from the Anglo Saxonnoht,": a space is missing after Saxon.

Interesting entry, very well written.
Some nitpicks:
George Cantor - Georg
colocated - collocated
celsius - Celsius
fahrenheit - Fahrenheit

'never depair' - despair
Nix - we use Nix in German, for example in saying: 'Null Komma nix', meaning: very fast, immediately, or: absolutely nothing (depending on the context)
spelt - spelled (house style)
1960's - 1960s'
German null - Null

Thanks Toy Box, Bel.

I think I've fixed all of those.

Icy

'Zero degrees fahrenheit is the freezing point of salt water'.

I think this is confusing.

In one view of how Fahrenheit came up with his scale, one of the fixed points was an UNSPECIFIED mixture of salt and water.

However, adding salt to water will bring the temperature down to -21.1 deg C - the eutectic point'. (At one time it was thought that, because salt-ater mixtures have fixed freezing points, they were definite compounds known as 'salt hydrates)

Different views exist on how Fahrenheit came up with his scale, but it's known that he took the melting point of an unspecified mixture of salt and ice (which he called 0 degrees) and the normal human body temperature (which he called 96 degrees) as the two fixed points. Hence, on this scale, water boils at 212 degrees F.

Thanks Al

I've changed it to 'Zero degrees on Fahrenheit's scale is the temperature of a particular salt-ice mixture.'

If you think it's still confusing, I'd be happy to remove it altogether.

Icy

No, I think it's fine as it is, but I would put:

'Zero degrees on Fahrenheit's scale is the temperature of a particular salt-ice mixture'. > Zero degrees on Fahrenheit's scale WAS the temperature of a particular, BUT UNSPECIFIED, salt-ice mixture.

Good entry as always, Icy!

I'm highly dubious of your paragraph about Ptolemy. Did he really use the Sumerian / Babylonian system? He was an Egyptian Greek; the Greeks had two systems of their own for writing numbers and the Egyptians had another one. It seems odd that he would have used the Babylonian system. I'm also doubtful of the slanted double wedge, as I was always told that the Sumerian/Babylonian system didn't have a symbol for zero. On the other hand, if it did have such a symbol, then surely that was the first example of zero?

You might like to mention that the mathematicians of Central America (the Maya) had a symbol for zero - they used a picture of a shell.

The sentence which starts with "The Indians cannot have known" is long and rambling, and uses 'however' in a sloppy way. It would be better as two sentences.

" If a car is at rest, it doesn't matter which direction it travels " -- I don't think that is clearly stated. You mean that if it is at rest, it can be considered to be travelling in any direction at zero speed.

"This is true of the Zeroth Law of Thermodynamics." -- you might like to add "and Bruckner's Symphony No. 0".

In some fonts, the zero symbol has been depicted with a line running through it -- although one manufacturer in the early days of computing, IBM, chose to put the slash through the letter O.

Gotta go.

Thanks Gnomon

That's really useful information, and I've made changes in those areas. I've made Al's last change too.

As for Ptolemy, I've seen two references to him using the Sumerian/Babylonian number system. One's in a general science book at home, the other is in the O'Connor/Robertson article on the St Andrews University site - Wilma's second link in posting 7 above. I'm confident that it's correct, but if you have any information to the contrary, let me know. I know you can't always trust what you read.

Icy

Traveller in Time searching for nothing
"Can not find a meaning for 'wiht', somewhere near nought. Probably it shout read 'whit'.

NIL (capitals) is used in many computer languages to define an empty vartiable, not specified. Used in cases where 0 is a value and would be wrong. Think of things like clearing the variable space for an image.

NULL is the bitbucket for not data not going to be used, sending the output to the null device voids any need to handle the data. "