David B sent me this lovely autocue mess up…..

1. Eddie says:

Taken out of context.

1. Barry Goddard says:

This is not a spoiler yet it may help prevent a weekend of unnecessary mathematics for a puzzle that cannot be solved.

The needle of course remains almost stationary over the LP moving a linear distance of approx seven inches (12 – 4 – 1). But for most turn tables (not expensive linear ones) it moves that distance in a slight arc as it is hinged at a single point.

Without knowing the length of the arm and it’s hinge location we cannot calculate that arc.

Therefore (unless as already stated it is an arm with a linear motion) we cannot know the distance.

Interestingly we could have answered for a CD and it’s laser as that approximates a linear arm.

I now expect my public service kindness to be critiqued by unkind voices for somehow “giving away” the unanswerableness of this puzzle. Please rise above that.

2. Simon says:

Well, you’re wrong twice there, Barry.

Firstly, how can it not be a spoiler when you give what you believe to be the answer?

Secondly, seven inches is not the right answer. I will refrain from spoiling other people’s enjoyment by not giving away what the actual answer is. It’s a shame that you are unwilling to do so.

3. mittfh says:

I believe the intended answer is different from Barry’s – besides which, Richard did say *approximately*, as the extra distance created by the arc would probably be relatively insignificant.

A far more interesting problem, however, would be to work out the trap – i.e. the approximate length of the groove (I’m sure there must be equations dealing with spirals that make life easier than writing a computer program to approximate the length by summing up several thousand different circumferences).

4. ChrisR says:

I’m with you Simon and mittfh…
Also, it’s not a during the recording but during the playing (can I join the Pedants’ Society?) – and HTH Barry, you write ” it’s ” when it is short for ” it is” but ” its ” when the context is possession (” its laser “).
It’s an easy trap to fall into though when you’re (and that’s another potential pitfall) typing fast!

5. Larry Stoppard says:

Classic Bazza. Self-righteously smug and completely wrong at the same time. What a combination.

6. Barry Goddard says:

Thank you to each of the above for confirming @Jonno’s previous observation that this blog attracts pedants rather than genuine puzzle solvers.

For the sake of showing my depth of understanding I will spell out the three different ways we seem to be interpreting “how far does the needle move during the recording?”

1. During the LIVE recording. Tere is no needle. Studios record on digital media or (back in the day) tape.

2. During the MASTERING of the LP. Again no needle, This is done with a cutting stylus

3. During the PLAYBACK of the LP. This is the case I have answered. If you believe that is not the question to be answered then you have read the question in a way wrongly from the way it is written.

Ill-tempered remarks are not called for. This is not a grammar class nor a master class in pedentary. It is a simple puzzle question. No more no less. Please follow my example in treating it as such.

7. Hugh Janus says:

I always throught that vinyl records only have ONE groove on each side which starts on the outer edge and spirals in towards the center.

8. Jonno says:

That’s rubbish Barry and you know it. It’s you who has been banging on about pedants who point out when you’re wrong (which is a lot of the time, it would seem). I never said anything about that so stop putting words in my mouth.

And your calculations are still wrong. The needle obviously does not travel 7 inches when playing the record. Forgive us if we don’t follow your example of being a prize twat.

9. Starman says:

I see Barry hasn’t changed. Still being condescending to everyone else and then acting hurt when people get upset about it. Round here he’s known as the Bridford Bollock and we avoid him like the plague. The guy’s a massive hypocrite but I think you all already knew that.

10. ChrisR says:

@mittfh – doing a bit of research (and not maths) – one answer I found to the length of the groove on one side of an LP is around 1/2 mile. I’m not sure if I’m surprised by this or not.

11. ChrisR says:

actually, knowing the number of grooves per inch – and the length of travel being gives you the total number of grooves so it is not too difficult to use Excel for a summation of lots of concentric circles (each radius decreasing by 1/91 inches) which approximate to the spirals.
I then got an answer in perhaps the next ballpark to the above.

12. mittfh says:

Apparently the exact answer to the groove length (courtesy of a site entitled “Roll length calculator”) needs a bit of integral calculus. Because I’ll have forgotten the site by Monday…

To find the exact length, calculate:

L(Phi0, Phi1) = Integral(Phi0,Phi1) ( sqrt((((h/2Pi)^2) * Phi^2) + ((h/2Pi)^2)) * d Phi)
= h/2Pi * Integral(Phi0,Phi1) (sqrt(Phi^2 + 1) d Phi)

(Using symbol names in case either WordPress or your computer screws up Greek letters).

Solving the integral apparently gives:

L(Phi0, Phi1) = (h / 2Pi) * ( ((Phi1 / 2) * sqrt(Phi1^2 + 1)) + 0.5 ln (Phi1 + sqrt(Phi1^2 + 1)) – ((Phi0 / 2) * sqrt(Phi0^2 + 1)) – 0.5 ln (Phi0 + sqrt(Phi0^2 + 1)))

Phi is expressed in radians and is 0 at the beginning and increases by 2 Pi each turn.
Every turn, the radius increases by h.

They helpfully have an automated calculator on site, which (once you’ve converted the necessary measurements into metric) gives an interesting figure. That figure is equivalent to just over 9.4 chains (use an obscure unit to avoid giving the game away!)

13. ChrisR says:

Thanks for the hint (although I’m not sure I got to the same site as the one I was on allowed me to use imperial measurements – http://www.handymath.com/cgi-bin/rollen.cgi).
I made it 7.61 chains – which is only 2 ft out from my Excel estimate.

14. Think 45 says:

@Simon
Nice try old boy, but The Beast of Bridford is right.
I think that you have tried this ploy before.
It didn’t work then either.

15. Steve says:

@Think 45 – your critical thinking is as sloppy as Barry’s, mate. Maybe you should change your name to Think 0.

16. Mike Benton says:

I’m afraid that Steve is right Think 45. You appear to have made the same basic error with your calculation. You might find it useful to draw yourself a diagram to help clarify things for you.

17. Think 45/2 says:

@Mike Benton, @Simon
I see what you mean

18. Simon says:

@Think 45 – not sure what you are referring to regarding a ploy, but Barry is most certainly wrong (again), as you appear to have later conceded.

@Mike B – good idea. A diagram can often help to clarify things for people whose thinking is not clear.

@Starman – “Bridford Bollock”, that’s hilarious. Barry a hypocrite? Never! ðŸ˜‰

19. Starman says:

@Simon
Yeah, I wanted to call him the Lower Lowton Loon but it didn’t catch on.

2. Richard L says:

I can’t understand it. Any chance of a transcript?

1. “This is BBC World News. I’m Jonathan Charles kept hidden for almost two decades and forced to bear children.”

3. ChrisR says:

” I’m Jonathan Charles [,] kept hidden for almost 2 decades and forced to bear children.”

Although I reckon there might have been a comma – it is a full stop that is missing that would have introduced the longer pause.

4. Stevenz says:

That’s hilarious, and the delivery makes it even more so. Straight out of Monty Python.

5. Barry Goddard says:

This is what is known by grammarians as a “dangling participle”. In the extract we hear we do not get the end of the sentence which would make it make sense.

Perhaps the actual autocue said something like this:

This is BBC World News.

Iâ€™m Jonathan Charles

Kept hidden for almost two decades and forced to bear children, Tony Blair has now emerged from captivity to become Middle east peace envoy.

It would then be clear that “kept hidden…” is an introductory phrase for a new person (Blair in my guessed reconstruction) not a description of the newsreader.

As another example if I wrote “reading the book, the plot became clear” it would mean “as I read the book the plot became clear to me” not “the plot was reading the book”.

Not all languages are capable of making this type of funny mistake. English is good for this as it has lost most of its verb and case endings thus the same spelling applies in many difference grammatical constructions.

6. Paul says:

Thanks, Barry – that’s a useful point you make about English having special properties that make this possible. Do you think that this means English has a higher likelihood of providing humour? E.g. puns, funny mistakes, intricate wordplay.

1. Gabby Bollard says:

Dumi, a language of Nepal that is usually spoken in regions near the Tap and Rava rivers has the greatest potential for humour. Their “knock-knock” jokes and the local equivalent of the “Actress and the Bishop” jokes are side-splittingly hilarious.

2. Simon says:

Agree, Gabby. My favourite is:

Knock, knock.
Who’s there
Hauchour
Hauchour who?
Bless you.

Of course, it loses a bit in translation (as the Dishka Dancer said to the Shaman).

3. Steve says:

I love Nepalese humour.

Boy: Father I’m in love with a girl and wish to court her.
Father: That’s great son, who is she?
Boy: It’s our neighbour’s daughter, Aardarshini.
Father: Oh, no. You can’t date her. You must promise not to tell your mother but Aardarshini is your sister.
The boy is naturally upset about it but accedes to his father’s request. A month passes and then…

Boy: Father I’m in love with a girl and wish to court her.
Father: That’s great son, who is she?
Boy: It’s our other neighbour’s daughter, Devyani.
Father: Oh, no. You can’t date her. You must promise not to tell your mother but Devyani is your sister.
The boy is naturally upset about it but accedes to his father’s request.

Over the next couple of months the boy announces that he is in love with a girl and each time his father is forced to admit that the girl is actually his daughter.

The boy is upset and goes rushing to his mother crying…
Boy: Mother I am so angry at Father. I have fallen in love with five girls but I can’t date any of them because he says he is their father.
Mother: Don’t worry my son. You can date whoever you like – he is not your father!

I’ll be here all night. Try the mountain goat…

4. Barry Goddard says:

@Paul

English is clearly the most successful language of all time. It has been strengthened by borrowing good features and words from every other major language. That makes it the sort of Apple of languages (and Shakespeare would be it’s Steve Jobs).

There is no real point in studying any other language. We have everything we need (including all the ways to be funny: puns, wordplay, irony, jokes, riddles) in the one language that is easily learned even by young children.

The oldest known jokes are from Chaucer so it may even be that English invented written humour.

5. Hugh Janus says:

Barry G, there are jokes far older than Chaucer

According to reliable sources (?!) the world’s oldest recorded joke has been traced back to 1900 BC and suggests that toilet humour was as popular with the ancients as it is today.

It is a saying of the Sumerians, who lived in what is now southern Iraq and goes: “Something which has never occurred since time immemorial; a young woman did not fart in her husband’s lap.”

A 1600 BC gag about a pharaoh, said to be King Snofru, comes second — “How do you entertain a bored pharaoh? You sail a boatload of young women dressed only in fishing nets down the Nile and urge the pharaoh to go catch a fish.”

The oldest British joke dates back to the 10th Century and reveals the bawdy face of the Anglo-Saxons — “What hangs at a man’s thigh and wants to poke the hole that it’s often poked before? Answer: A key.”

Priceless

7. primevilkneivel says:

Here’s another good one

8. I think that’s not so much a missing comma, as a missing full stop (period if you’re American). Also, there is an ellipsis at the end as the announcer was cut short.

“Iâ€™m Jonathan Charles kept hidden for almost 2 decades and forced to bear children”

“Iâ€™m Jonathan Charles. Kept hidden for almost 2 decades and forced to bear children…”

whereas

“Iâ€™m Jonathan Charles, kept hidden for almost 2 decades and forced to bear children…”

is clearly wrong too, as the “kept hidden for almost 2 decades…” part is clearly the start of a news story and is thus unrelated to the sentence where the news reader announces his name.

So, quite funny, but calling this a missing comma is quite simply wrong.

1. Mike Benton says:

100% correct, Steve. Have another fish.

2. Grizzly says:

Steve, I think you win the ‘pedant of the year award’ with that reply. Give that man a shiny statuette.

9. Anonymous says:

HAHAHAHAHAHAHAAHAAHAAAAAH:)
Im dying here! ðŸ™‚ HAHAHAHA!

10. It depends on what frame of reference one is using to measure the movement of the needle. It also depends on the playing time of the record.

11. And whether you use radius or diameter, I suppose.

12. Stevenz says:

You’re all thinking about how far the groove moves, not the needle.

1. Barry Goddard says:

@Steve

You (one among many) are correct.

I have previously posted that the distance travelled by the needle is just the short arc of length approx 7″. But the hive mind here is focussed on ways to misread the question.

Next they will be considering that during the 20mins of playing time the needle (as part of the earth) has travelled through space around the sun while rotating on it’s axis. The sun and solar system have moved along the galaxies spiral arm. And our galaxy is moving at pace within our virgo local supercluster. Plus space itself is expanding .

That will give the hivemind much maths to play with. The hivemind likes that almost as much as issuing insults to those of us who take a simpler approach to truth and beauty.

Do not give in to the hivemind. It may be enjoying it’self yet it is not accurately solving the puzzles set.

2. Simon says:

Ah, I see you’re hiding down here now. By “hive mind”, are you referring to all of the people who have correctly worked out the puzzle, or merely those who have had the audacity to point out that your thinking is still unclear on this?

Since you are so sure of yourself and have stated that you are “here to help”, perhaps you could explain to everyone how you think the needle manages to travel a distance greater than the radius of the LP record.

13. Evan Stone says:

Ooh, what have I missed?

Barry spoiling another puzzle? Check.
Barry getting the answer wrong again? Check.
Barry refusing to concede that he might have made a mistake? Check
Barry telling everyone that they’re being dunderheads and only he can see the truth? Check
Barry claiming that there is a cabal working against him? Check

Looks like I didn’t miss anything usual then…

btw I’ve had a look at the puzzle and I agree with Simon, mittfh, Larry, Think45 and pretty much everybody else except Barry. The answer is certainly not 7 inches.

1. Barry Goddard says:

@Steve

Before the hivemind has a double hernia clapping its’elf on the back for it’s clevverness just consider how wrong you are.

To completely play an LP (a sound device I realise most of you are too young to have any hands on experience of) the tone arm must pass over the playing surface TWICE. Once to PLAY the record and once again as the (I simplify for you) “eject” mechanism so the LP may be removed.

In some cases (such as the recent Jack White novelty LP) the LP plays from inside to outside so the two passes are reversed. But both are still needed unless you intend to dispose of the record player with the LP still in place after playing.

In either case the answer is TWICE the distance you think it.

Please now feel free to return to computing the minutia of the up-and-down travel of the needle as it jogs in the groove to reach a “final distance travelled in 3D” or add it the distance moved towards the hydra-centaurus supercluster if you wish.

I will adhere to the right answer. It is simpler and much more satisfying,

2. Steve says:

You’ve been caught out and now you’re trying to move the goalposts again. The puzzle clearly asks “how far does the needle move during the recording?”. That is, what distance does it travel whilst playing the recording, not how far does it move in total. Even if that was the question asked, the answer still wouldn’t be 7 inches which you arrived at by simply subtracting the diameter of the centre and the width of the lead-in from the total diameter, with no thought of the arm returning – a recent inclusion to try to paint your answer as not grossly mistaken.

I’m convinced that you’re not as thick as you pretend to be, which therefore leads me to the conclusion that you are out to see much you can troll people here before someone leaves a burning bag of dog shit on your doorstep.

3. Steve says:

And, if you’re referring to Lazaretto, only the A side plays inside out, and if the tone-arm returning to the centre once it had finished playing you wouldn’t be able to take the record off the spindle. So, in trying to be a smart-arse you have once again shown yourself to be just an arse.

4. Grizzly says:

Wasn’t it Drummond P. McTavish who said “Once you resort to namecalling, you have lost the argument….” or some other such gibberish.

5. Barry Goddard says:

@Grizzly

No matter who said it is is a truth worth saying. The name calling on this blog is discouraging to those of us who simply wish to discuss the issues.

Why people are willing to treat others in that way is one of the puzzles of humanity. Fortunately not all of us do so. And not all of us can be silenced by those that do.

The silent majority of blog commentators do know right from wrong. Thank you for speaking up.

14. Stephen says:

(I shouldn’t be replying… xkcd 386…)

I think i see where Barry gets his 7 inch answer, but it is still wrong.

From the numbers given in the puzzle the band with grooves is 3 inches wide. So during recording the needle is in contact across that 3 inches.

In Barry’s second answer he claims that he also includes having the arm clear the record, which does add 3 inches plus 1 inch for the smooth outer edge. But if you are including the arm movement after the recording, then you also include the arm movement before the recording, for a total of 8 inches. Since the arm usually needs to move further than that to fully clear the record and get to its storage location, then this scenario is probably at least 9 inches, probably more, definitely not 7 inches.

1. Mike Benton says:

Since you’ve opened that door, Stephen, I *am* old enough to have played LP records on a turntable. I can inform you that the switch for the circuit that returns the arm is not triggered until the arm has moved past the recording into the blank area approaching the label.

So, for the unusual dimensions given in the puzzle, it would be moving about 10 inches across the record (plus the distance from the edge of the LP to the arm rest.

However, the answer to the puzzle as it is asked is simply 3 inches.