Stylus as a bobsleigh in orbit.......!?

[Ldg]

As a rule I don't like analogies........but this one is pretty enlightening, methinks. How fast does the stylus move along the groove channel ? Pretty pedestrian, perhaps. Well, no.

Say we built a scale model, where the contact points on the stylus were spaced about 1m apart, like the runners on a bobsleigh. How fast would the bobsleigh have to run along its track to simulate motion of a stylus in the groove ?

About 7 miles per second, assuming I haven't gaffed the sums. Really !

That would just about get the bobsleigh into space, it's faster than earth's escape velocity, and comfortably into an earth orbit !

Not many people know that.

[Doug G.]

That would explain why, sometimes, my quad system sounds out of this world.



Doug

[dlaloum]

Capn the stylus canna handle it, the dilithium needle is at breaking point...

[Bran Kulez]

I think you just invented the ONLY Olympic sport that audiophiles can excel at.

Brilliant!

Should the protective helmet be conical or elliptical?

[Dismord]

I think you just invented the ONLY Olympic sport that audiophiles can excel at.

Brilliant!

Should the protective helmet be conical or elliptical?

Line contact.

[Alec124c41]

OK, how big is the record?

Cheers,
Alec

[dlaloum]

UFO's explained at last!

[Ldg]

OK, how big is the record?

Cheers,
Alec

7000 miles across..........with a 175 mile diameter spindle hole

About the same diameter as the earth !

[Bran Kulez]

it's late in the day so I may have missed a decimal place (or how to do math) but...

groove width = .1mil x 10,000 = 1" x 39" = 1 meter

record diameter = 12" x 390,000 (multiplier) = 390,000 ft

1 mile = 5,280 ft

390,000 ft x 1/5,280 ft/mile = 74 miles diameter

[whitesmoke]

Fascinating concept...
belt drive or direct drive?
tracking force in fractions of a metric tonne?
tangential acceleration expressed as furlongs per fortnight squared?
most importantly - how to flip the record over to listen to the "b" side?

[Ldg]

I make the scale factor is about 40000:1 [1m:25um]

Then groove speed scales up from about 0.3m/s to 12km/s, or about 7.5 miles/sec

And a record diameter scales up from about 0.28m to 11.2km, or about 7 miles

And the spindle hole scales up from 7mm to about 280m.

So my initial post about scale of styus speed in the groove seems correct. But in the 2nd post I'd overstated the scale size of the record by gaffing the conversion from m to km !

It remains that if one were small enough to sit inside the stylus like a passenger in a bobsleigh, the groove would seem about the same height/width as the bobsleigh track, but speed down the track would seem as though it were about 7 miles/second, like being in orbit. Now that would be a ride !

[thommo_work]

OK LD - if Canary Wharf was a Stylus, and you inverted it so the pointy top of the building was now the stylus tip, how far down into a similarly scaled up version of the groove would the building go?

The Building is 235m or 770ft tall.

[Ldg]

Canary Wharf is a bit of a trick question, because it has no curvature and the angle at the top means it either wouldn't fit at all, or the point would hit the bottom of the groove, or if it fitted perfectly you couldn't tell where the contact locations would be.....

But the Gherkin, is another matter ! I mean, really this just can't be a coincidence :



It's a markup showing how the very tip of the Gherkin would fit in a groove to scale. C'mon, these things don't happen by chance, someone has found the instructions we sent into space on how to build a record player, and has just got the scale a bit wrong

Contact locations are always exactly where the tangent is 45 deg, BTW.

[Bran Kulez]

ld wrote:...I make the scale factor is about 40000:1 [1m:25um]

I stand corrected, I used .1 mil instead of 1 mil.