Castle Aching

[Compound2632]

1 hour ago, Edwardian said:

We have discussed this, I recall. 

 

Late Feb 2018 I think but it's all mixed up in the usual way with wiring and Baden Powell that I can't find where it begins. Apologies for going round in circles.

[Regularity]

1 hour ago, Compound2632 said:

 

Late Feb 2018 I think but it's all mixed up in the usual way with wiring and Baden Powell that I can't find where it begins. Apologies for going round in circles.

That’ll be the wiring: electricity can only go round in circles.

[Donw]

Perhpas this is an apt desription

 

Round like a circle in a spiral, like a wheel within a wheel
Never ending or beginning on an ever spinning reel
Like a snowball down a mountain, or a carnival balloon
Like a carousel that's turning running rings around the moon
Like a clock whose hands are sweeping past the minutes of its face
And the world is like an apple whirling silently in space
Like the circles that you find in the windmills of your mind!
Like a tunnel that you follow to a tunnel of its own
Down a hollow to a cavern where the sun has never shone
Like a door that keeps revolving in a half forgotten dream
Or the ripples from a pebble someone tosses in a stream
Like a clock whose hands are sweeping past the minutes of its face
And the world is like an apple whirling silently in…

 

Words and the Music by Noel Harrison

 

Don

[Northroader]

Spoken like a true poet, Don.

[Canal Digger]

 

1 hour ago, Regularity said:

That’ll be the wiring: electricity can only go round in circles.

Sorry but being pedantic no, it depends upon the shape of the conductor/ circuit board, could be triangular, rectangular... . I grant you that it returns to the same point  

[Compound2632]

... the alternative being to run round in ever diminishing circles until you disappear up your own particular, like the oozlum bird.

[Caley Jim]

4 hours ago, Donw said:

Perhaps this is an apt description

........

That pretty much sums up my understanding of electronics!  Current, voltage and resistance and the fact that you need a circuit I can cope with, after that.....

 

Jim

[Malcolm 0-6-0]

5 hours ago, Compound2632 said:

 

Late Feb 2018 I think but it's all mixed up in the usual way with wiring and Baden Powell that I can't find where it begins. Apologies for going round in circles.

 

That's interesting - I always thought Baden Powell was a little "wired" .........

[Regularity]

3 hours ago, Canal Digger said:

 

Sorry but being pedantic no, it depends upon the shape of the conductor/ circuit board, could be triangular, rectangular... . I grant you that it returns to the same point  

Ah, but circles in this instance refers to getting back to the starting point: but is almost a homophone for circuits...

[Nearholmer]

5 hours ago, Regularity said:

electricity can only go round in circles.

 

It can remain static, not going anywhere, too, although I guess it will all get home one day.

[St Enodoc]

13 hours ago, Donw said:

Perhpas this is an apt desription

 

Round like a circle in a spiral, like a wheel within a wheel
Never ending or beginning on an ever spinning reel
Like a snowball down a mountain, or a carnival balloon
Like a carousel that's turning running rings around the moon
Like a clock whose hands are sweeping past the minutes of its face
And the world is like an apple whirling silently in space
Like the circles that you find in the windmills of your mind!
Like a tunnel that you follow to a tunnel of its own
Down a hollow to a cavern where the sun has never shone
Like a door that keeps revolving in a half forgotten dream
Or the ripples from a pebble someone tosses in a stream
Like a clock whose hands are sweeping past the minutes of its face
And the world is like an apple whirling silently in…

 

Words and the Music by Noel Harrison

 

Don

Ah yes, and who can forget Hannah Gordon singing it on the Morecambe and Wise show...

[St Enodoc]

8 hours ago, Nearholmer said:

 

It can remain static, not going anywhere, too, although I guess it will all get home ohm one day.

Edited.

[Compound2632]

Beware the superconductor: resistance is futile.

[Donw]

14 hours ago, Nearholmer said:

 

It can remain static, not going anywhere, too, although I guess it will all get home one day.

 

Moot point that Say you have a telegraph circuit using earth return the current will travel along the wire but does it actually travel back through the earth or is it just absorbed in the giant storage of the earth'

It is rther like the banks you take your money in to pay a bill I doubt the same money goes to the electricity board or whoever. Your money could have been given to someone in the queue behind you.  The electricity board probably paid your money is wages to someone else but the notes he recieved would have come from yet another.

I wonder how often you get a note back that you have used before?

 

Same with electricity I have yet to recognise an electron that I used previously.

 

Don

[Compound2632]

24 minutes ago, Donw said:

Moot point that Say you have a telegraph circuit using earth return the current will travel along the wire but does it actually travel back through the earth or is it just absorbed in the giant storage of the earth'

 

There are return current flows through the earth. This was an issue for some precision measurements at the National Physical Laboratory, Teddington, as the cross-currents from the third rail earth returns from the Teddington loop and Hampton Court lines created varying magnetic fields. One of my colleagues succeeded in tracking down the half-hourly periodic fluctuations in the behaviour of his single trapped ion to the times at which trains crossed at the Shepperton level crossing - the fluctuation in magnetic field was linked to the gap in the conductor rail. 

 

30 minutes ago, Donw said:

I have yet to recognise an electron that I used previously.

 

You wouldn't; they're all identical. 

[Guy Rixon]

4 minutes ago, Compound2632 said:

 

There are return current flows through the earth. This was an issue for some precision measurements at the National Physical Laboratory, Teddington, as the cross-currents from the third rail earth returns from the Teddington loop and Hampton Court lines created varying magnetic fields. One of my colleagues succeeded in tracking down the half-hourly periodic fluctuations in the behaviour of his single trapped ion to the times at which trains crossed at the Shepperton level crossing - the fluctuation in magnetic field was linked to the gap in the conductor rail. 

 

 

You wouldn't; they're all identical. 

The return flows are sometimes an issue for S&T work, too. I once read an old article that spoke of problems on the Metropolitan Railway (the original bit, not the branch into darkest Buckinghamshire). This was built when London was an electrical desert. The telegraphs were earthed at both ends of the cable run --- i.e. return through earth --- and all was well for a while. Fast forward thirty years or so and London was majorly electrified, with motors (for lifts and such) appearing all over; and everybody was returning their current through the earth. The local earth-potential seen by the telegraphs went up and down like a whore's bloomers and the machines were not at all happy. Eventually, the S&T engineers were forced to install common-return wires for their telegraphs. Later, when the railway put in conductor rails, they put in return rails too.

 

As to electrons being identical remember that they are fermions, and therefore bolshy little so-and-sos. Put any two in the same orbital and they will insist on distinguishing themselves by having different spins.

[Compound2632]

2 minutes ago, Guy Rixon said:

As to electrons being identical remember that they are fermions, and therefore bolshy little so-and-sos. Put any two in the same orbital and they will insist on distinguishing themselves by having different spins.

 

Yes, of course, collectively they are naturally socially-distancing creatures but taken individually one can't tell one from another. It's the bosons that are the true collectivists.

Edited November 22, 2020 by Compound2632

[Guy Rixon]

1 minute ago, Compound2632 said:

 

Yes, of course, collectively they are naturally socially-distancing creatures but taken individually one can't tell one from another.

Are you allowed to say that these days? Sounds a bit disrespectful.

 

In truth, you are quite right and the spin-up/spin-down thing is of course about the states where the electrons live. Here, the thing that still I'm trying to get my head around is that after 115 years development in quantum theory of atoms we still don't have an exact-enough theory of atoms to precisely identify all those states (in anything more complex than a Helium ion). And when I say "get my head around", I mean that I'm currently cat-herding scientists to make a labelling scheme that's just approximate enough to work and can be coded into a software system. Sore point. Pray for my quantum soul.

[Nearholmer]

Stray traction currents have been causing upset for long enough to have their own body of literature.

 

This is a good start.

 

 

 

 

[webbcompound]

Of course "stray" traction currents can be quite useful, as I found when I was in charge of some of these things: a tram that has jumped the rails can usually be rerailed using only a crowbar and a bucket of water.

[Compound2632]

26 minutes ago, Nearholmer said:

Stray traction currents have been causing upset for long enough to have their own body of literature.

 

This is a good start.

 

I had a colleague - close to retirement when I started - who was responsible for precision magnetic measurements. He was also a steam railway enthusiast; he argued that the third-rail electrification had put the railway in breach of covenants entered into at the time NPL was established at Bushy House and that there should therefore be a return to steam traction. 

 

58 minutes ago, Guy Rixon said:

In truth, you are quite right and the spin-up/spin-down thing is of course about the states where the electrons live. Here, the thing that still I'm trying to get my head around is that after 115 years development in quantum theory of atoms we still don't have an exact-enough theory of atoms to precisely identify all those states (in anything more complex than a Helium ion). And when I say "get my head around", I mean that I'm currently cat-herding scientists to make a labelling scheme that's just approximate enough to work and can be coded into a software system. Sore point. Pray for my quantum soul.

 

The trouble is that the nice state labelling system breaks down for the heavier atoms, where there's always a bit of state mixing coming into play for the lower-lying states. I used to have to do with singly-ionised ytterbium, which is really two atoms rolled into one, with families of states of opposite parity that rarely and then only weakly spoke to each other. Montagues and Capulets was nothing to it.

[Northroader]

If I went into the ironmongers and asked for a pack of ytterbium, what could I do with it? (Yes, besides that)

[Donw]

All of which only proves my point  in the earth currents all get mixed together and some do stray. Yes they all balance out but talking of it all getting home missed the point.  Your battery may shove a few electrons into the ground  and pull some more out of the ground elsewhere but the ground current flows are to do with balancing the sum of all those actions there is no distinct flow through the ground driven by your battery .  

The effects of large power flows may seem more evident  but are not exactly matching the current causing them.

I know a bit about stray currents we had trouble with them with lead sheathed cables. 

 

It works rather like pooled railway wagons you might ship a wagon load from britol to leeds the wagon doesn't come back it gets sent to donacaster with another load however at times too many wagons are at one place and too few somewhere else so a balancing load of empties might be necessary.

 

Don

 

[Compound2632]

8 minutes ago, Northroader said:

If I went into the ironmongers and asked for a pack of ytterbium, what could I do with it? (Yes, besides that)

 

The ironmonger would send you on to a dealer in non-ferrous metals, I should think. 

 

Ytterbium is one of four elements named for the town of Ytterby in Sweden, it being from ore mined there that those elements were first identified.

[Nearholmer]

Be useful for the rivets in fork ‘andles, I reckon.

 

 

Edited November 22, 2020 by Nearholmer