
The unsolved secret of David Jones' perpetual motion machine [video] - rumcajz
http://www.bbc.com/news/av/uk-england-tyne-41638926/the-unsolved-secret-of-david-jones-perpetual-motion-machine
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larrydag
Apparently its known to be fake by David Jones. He did reveal how it was made
but the recipient is still keeping it secret.

[http://www.dailymail.co.uk/sciencetech/article-4762778/How-r...](http://www.dailymail.co.uk/sciencetech/article-4762778/How-
riddle-bike-wheel-finally-solved.html)

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jaclaz
As a side-side question, is it just me or "unsolved secret" doesn't sound
"right"?

I mean, "unsolved problem" or "unsolved mistery" or "unrevealed secret", but
"unsolved secret"?

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gerdesj
"Unsolved {riddle|puzzle|mystery}" are the usual forms for a headline of this
type in the UK. Part of the Beeb may have briefly lost the rule book.

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Zenst
Given the age of this creation,the era of crystal radio[1] as a power source
would be my first leap-to conclusion, whilst not enough to get it spinning
from a standstill, enough to maintain motion once at speed from an initial
hand-spin.

How could you test this - place in a faraday cage.

If that kept it running then my next thought would be some form of dry-pile
battery[2], which is equally old enough technology wise and also proven to
last many decades [3].

But certainly a fun puzzle to ponder.

[1]
[https://en.wikipedia.org/wiki/Crystal_radio](https://en.wikipedia.org/wiki/Crystal_radio)
[2]
[https://en.wikipedia.org/wiki/Zamboni_pile](https://en.wikipedia.org/wiki/Zamboni_pile)
[aka dr-pilebattery] [3]
[https://en.wikipedia.org/wiki/Oxford_Electric_Bell](https://en.wikipedia.org/wiki/Oxford_Electric_Bell)
[example of dry-pile battery operating for decades]

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userbinator
My first thought was also a long-lasting battery and an electrostatic motor
similar to those used in that bell. That along with the large moment of
inertia of the wheel and very good (possibly magnetic suspension?) bearings,
makes it possible for it to continue rotating for a very long time.

Also, for a second looking at the title, I thought it was going to be this
guy:
[https://en.wikipedia.org/wiki/David_L._Jones_(video_blogger)](https://en.wikipedia.org/wiki/David_L._Jones_\(video_blogger\))

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shad0wca7
Could it be something simple like a combination of measures designed to allow
it to rotate for an extremely long time: \- Vacuum enclosure (remove air
resistance) \- Perfectly balanced wheel (reduce bearing wear) \- Excellent
quality bearing / lubrication \- Small electric motor & battery to provide
enough force to allow for continuity once started externally

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Animats
When he first built that and wrote it up in his Daedalus column, I sent in my
guess as to how it works. He replied, and said that wasn't it.

Some students stole that wheel once, it continued to run, and they couldn't
future it out. They gave it back after three weeks, embarrassed.

He built four of those wheels. Here's another one.[1]

I'm really impressed that they are running long after his death.

[1]
[https://www.youtube.com/watch?v=2dpmP_H1LBM](https://www.youtube.com/watch?v=2dpmP_H1LBM)

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mhb
What was your guess?

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danmaz74
If it's not possible to access the machine and experiment on it, how can we
possibly know if somebody actually explained the trick correctly?

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tawm
Have they tried holding a geiger counter up to it?

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asmithmd1
My guess is it powered by changes in temperature and atmospheric pressure like
Cox's clock:

[https://en.wikipedia.org/wiki/Cox%27s_timepiece](https://en.wikipedia.org/wiki/Cox%27s_timepiece)

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alphabetter
I missed David Jones' work when he was alive. Does anyone know of online
resources about his inventions and writing? His books are out of print and
hard to get hold off.

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dcminter
They're available on AbeBooks last time I checked. Buy "The Inventions of
Daedalus" and if you like it also "The Further Inventions..." which are both
fantastic.

Alternatively you could read through his columns in back issues of New
Scientist and Nature at your local library but won't get the additional
commentary and goofy drawings.

Finally, there's a documentary on his perpetual motion machines (possibly
mentioned, haven't rtfa yet) which is more about the man than the machines. I
had to write to its creator to get a copy though!

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nerdponx
So is there only one in existence? I take it his family will not allow anyone
to dismantle the contraption.

~~~
larrydag
Supposedly this one was made by David Jones in 1999 in a Vienna museum.

[https://www.youtube.com/watch?v=2dpmP_H1LBM](https://www.youtube.com/watch?v=2dpmP_H1LBM)

~~~
Too
Heat sinks indicate sterling engine? The one from the first one is probably
also sterling although not as obvious.

~~~
larrydag
That's what I thought. Some sort of sterling engine. Yet sterling engines need
a heat source and sink. Perhaps the fireplace is a proper heatsink?

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ouid
Unsolved and unverified are different.

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cabaalis
I'm no expert, but every criticism I've ever seen of people's attempts at
perpetual motion always seem to involve the fact that some part will wear out
eventually. Such as "magnets will lose their pull over time" or "friction will
eventually wear down this gear."

I don't think those are valid criticisms of the machines. They are perpetual
motion machines, not perpetual no-maintenance machines.

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pvg
I can't think of any serious criticism of a perpetual motion machine that is
based on that. What are some examples you've run across?

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cabaalis
Well then you seem to agree with me? I'm quoting experience casually reading
various articles in my lifetime regarding the machines. Again, I am not a
scholar in this field.

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pvg
How am I agreeing with you? I'm asking you where you've seen that kind of
critique. It's not one that would be used in a middle school physics class or
article aimed at the general public.

