Imperial vs Metric

[AJB Temple]

This could be a long night........ if there was a multi-dot scenario then what do the scientists believe happened to the others - assuming only one (ours) made it to the big bang would they have been consumed after the event into our universe or would they have gone on to create parallel universes with their own attendant big bangs? I'm off to do some research - quite what this has all got to do with cutting the perfect dovetail I'm yet to discover....

There are almost as many theories as dots. The most plausible to me is an infinite number of dots all expanding and contracting simultaneously but not in synchronicity. I can see no real logic for just one dot as our beginning (the start of Big Bang) as if there was one why cannot there be two or an infinite number? Black hole theory seems to explain plausibly the expansion and contraction. If that can occur within one universe (as appears to be the case with many black holes sucking matter in within our universe) then I see no reason why not cannot be true of parallel universes. Time has no real meaning in this construct.

 

[billw]

Infinity is definitely one of those concepts that can keep people awake at night. However, I am pleased to say I have solved the issue of how to measure it - it's the amount of wastage I make from a piece of timber whilst machining it into what I thought was the right size.

 

[billw]

@AJB Temple To put your mind at rest, Before the Big Bang there was just Birmingham

Well, that might explain why there seems to be no escaping the place.

 

[Droogs]

IF has been postulated that there are infinite universes and each has it's own density, each akin to that of various species of wood. I'm content I live in an oak one, glad it's not a Lignum Vitae one and feel very sorry for those that live in the Ikea spruce chipboard one

 

[Andy Kev.]

This could be a long night........ if there was a multi-dot scenario then what do the scientists believe happened to the others - assuming only one (ours) made it to the big bang would they have been consumed after the event into our universe or would they have gone on to create parallel universes with their own attendant big bangs? I'm off to do some research - quite what this has all got to do with cutting the perfect dovetail I'm yet to discover....

The other dots are probably easy to deal with. Suppose our dot started roughly in the piece of space which your chair is occupying now and it expanded to occupy the space which our (still expanding) universe occupies now. Then suppose that just before our dot began expanding there was another one in roughly the space where your nearest neighbour's telly is standing now but it wasn't ready to expand.

Our dot (= our universe) expands and by definition it must push away anything which is outside it. As far as I can see it's not going to envelope your neighbour's or anybody else's other dots. And if one of those kicks off, it's not going to envelope our dot. That leaves the question of what happens if two dots are expanding in opposite directions head on to each other. Do they exchange material? Does a mixed border region appear? In any event the dots might all be gazzilions of light years away from each other and this whole thing is also in headache territory.

I'd recommend that book I flagged up to AJB. It won't do much to improve your dovetailing though.

 

[Andy Kev.]

IF has been postulated that there are infinite universes and each has it's own density, each akin to that of various species of wood. I'm content I live in an oak one, glad it's not a Lignum Vitae one and feel very sorry for those that live in the Ikea spruce chipboard one

I bet you've not even thought about worm holes.

 

[glenfield2]

Quite the opposite. The original definition of a Metre was 1 10millionth of the distance from the Equator to the North Pole along a Great Circle

Don’t forget the ‘through the Paris Meridian’ bit.
As usual we have to blame the French who decided that everything measurable In the universe should be neatly dIvisible by 1000. Them and their revolution, eh.
The rest of us were perfectly happy with our rods, poles and perches.

 

[Phil Pascoe]

Which actually are all the same.
I found an excercise book from about 1964 (I was ten) and the sums in it were in miles, furlongs, chains, yards, feet and inches - gallons, pecks and bushels - gallons, quarts, pints and gills - pounds, shillings, pence and farthings. All simple .............

 

[AJB Temple]

Which actually are all the same.
I found an excercise book from about 1964 (I was ten) and the sums in it were in miles, furlongs, chains, yards, feet and inches - gallons, pecks and bushels - gallons, quarts, pints and gills - pounds, shillings, pence and farthings. All simple .............

All that stuff belongs in the Middle Ages. Except feet and inches. Height of men should be measured in feet and inches. I also find that hands for horses makes far more sense than centimetres.

 

[AJB Temple]

It's also a weird fact that woodworkers don't like working in centimetres for some reason. They insist on mm except in America obviously as they clearly have a foot fetish. However when I get measured at the doctor, when they are telling me off about my BMI, they don't say you are 1900 mm tall, they say 190 cm. I quite like cm for woodwork.

 

[Felix]

I'd recommend that book I flagged up to AJB. It won't do much to improve your dovetailing though.

It might help prop up a drawer side whilst marking the pins though <lol>

 

[Tim Britton]

re measuring in metric or imperial... some time ago I took a break from writing about old motorcycles and instead did a short piece on my introduction to an alternative measuring system when I was an apprentice joiner in the 70s. The gist of it was the old lad teaching me used nothing more complicated than marks on a stick to deterine hights, widths and depths of whatever was being made. The lesson I learned all those years ago was not to rely on any one system, ergo it doesn't matter which system you use as long as you know what the marks mean. In any case I seem to recall learning in history the English 'yard' was originally classed as the distance from the ruling monarch's nose to the tip of his/her middle finger...

 

[AJB Temple]

History is full of old wives tales. It started with Henry VIII

 

[Andy Kev.]

re measuring in metric or imperial... some time ago I took a break from writing about old motorcycles and instead did a short piece on my introduction to an alternative measuring system when I was an apprentice joiner in the 70s. The gist of it was the old lad teaching me used nothing more complicated than marks on a stick to deterine hights, widths and depths of whatever was being made. The lesson I learned all those years ago was not to rely on any one system, ergo it doesn't matter which system you use as long as you know what the marks mean. In any case I seem to recall learning in history the English 'yard' was originally classed as the distance from the ruling monarch's nose to the tip of his/her middle finger...

That point has come up quite a few times. IMO the more you can liberate yourself from numerical measuring of bits of wood, the better the work proceeds. Sometimes it is of course handy to have a number e.g. if for some reason you can't use one piece of wood to mark another and then, as you point out, the System used doesn't matter.

I think that measured plans should only be taken as rough guides e.g. if something is specified at 125 x 63 x 67 mm (unlikely but it could reflect the writer measuring what he has ended up with), then it makes sense to be able to say, "OK, roughly 4 foot by 2 foot by 2 foot". Then you might want to measure your first rough cut of the pieces to 4' 1" but really after the cut to precise length (whatever you may finally settle on e.g. to fit a space) the rest of the measuring is probably a matter for dividers as you are going to be looking for proportionally harmonic bits of wood e.g. 1/2, 1/8, 1/16 of the inital roughly 4' length.

 

[Sheffield Tony]

It's all a simulation anyway. We aren't real. This very idea that quantum states only become determined when we observe them - why else would the universe work by lazy evaluation ? And is the speed of light limit a bit like fear of the water in the Truman show - an artificial limit to stop us discovering it's all not what it seems.

 

[PhilTilson]

I will not add to the arguments above. As an engineer, I deal almost entirely in metric measurements - and yet, having been schooled during the 50s - I still find that when estimating small distances, it is much more natural to think "that's about three inches", rather than "that's about 7.5cm". However, although I am perfectly happy in both systems, I grind my teeth when I use my favourite graphics program, Serif DrawPlus. This lets you choose either imperial measurements or metric for your drawings. But when you choose the metric scale, you find the sub-divisions are halves, quarters and eighths! Ye Gods!

 

[rafezetter]

Ah but … the speed of light is an absolute, a bit like a piece of wood: the units in which you choose to measure it- let us compromise on a piece of wood flying through the workshop at less than the speed of light due to frustration at mangling some dovetails - are entirely arbitrary i.e. anything but absolute.

Gotcha! ( er … I think.)

Come to think of it, the number of seconds in a year isn't very metric either.

Actually.... it isn't, and never was.

I read in the New Scientist that even though the speed of light is represented scientifically as the letter "C" - it was proven some time ago that the speed of light is altered depending on what it's traveling through - which is obvious when you take the time to think about it, because even photons have mass.

There was an article quite some years ago whereby scientists managed to reduce the speed of light down to a mere 38 mph iirc, a fact that's always stuck with me.

google fu shows this link has the gist of it:

Scientists Slow Down Speed of Light

abcnews.go.com

amazing what you can learn while waiting at the doctors!

 

[Dr Al]

Actually.... it isn't, and never was.

I read in the New Scientist that even though the speed of light is represented scientifically as the letter "C" - it was proven some time ago that the speed of light is altered depending on what it's traveling through - which is obvious when you take the time to think about it, because even photons have mass.

There was an article quite some years ago whereby scientists managed to reduce the speed of light down to a mere 38 mph iirc, a fact that's always stuck with me.

google fu shows this link has the gist of it:

Scientists Slow Down Speed of Light

abcnews.go.com

amazing what you can learn while waiting at the doctors!

The scientific symbol 'c' is specifically described as "the speed of light in a vacuum" - that's the thing that's a universal constant, not the speed of light generally. It's been understood for many years that it varies depending on medium.

 

[bjm]

... because even photons have mass.
...

No they don't

 

[britinfrance]

FYI here in France, the inch is referred to as "pouce" (pronounced puss) and features a lot in auto parts, wheel trims for example, and will often appear on powertools, eg bandsaws, where the throat depth will be given inmm and pouce.