Theoretical limit for loud music??

[John Woodgate]

I read in sci.electronics.design that Kevin Aylward
lueyonder.co.uk>) about 'Theoretical limit for loud music??', on Sat, 4
Sep 2004:

have a look at
http://math.ucr.edu/home/baez/physics/Relativity/SR/mass.html

Having established that the rest mass of a photon is zero, it balks at
saying anything about its relativistic mass, which is apparently (to
teletubbies) infinity times zero, leading to brain-pain and the collapse
of civilization as we know it.

It also doesn't define gamma.

Since Kevin's own referenced page is about GR, it's not to surprising
that it doesn't introduce the 'relativistic mass' concept, since GR
doesn't need it.

 

[John Woodgate]

I read in sci.electronics.design that Mark Fergerson <[email protected]>

"No practical advantage"? What better than to set the bar for
Audiophools, in hopes they'll try to reach it?

A suitable goal for them would be 200 dB SPL, since that's twice as loud
as 100 dB SPL, isn't it? (;-)

 

[Kevin Aylward]

I read in sci.electronics.design that Mark Fergerson <[email protected]>

A suitable goal for them would be 200 dB SPL, since that's twice as
loud as 100 dB SPL, isn't it? (;-)

Not at all John At 200 dB SPL your hearing will be completely fried,
resulting in about 0.00001 of the level at 100 db spl.

Kevin Aylward
[email protected]
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[Kevin Aylward]

I read in sci.electronics.design that Kevin Aylward


Having established that the rest mass of a photon is zero, it balks at
saying anything about its relativistic mass, which is apparently (to
teletubbies) infinity times zero, leading to brain-pain and the
collapse of civilization as we know it.

It also doesn't define gamma.

Since Kevin's own referenced page is about GR, it's not to surprising
that it doesn't introduce the 'relativistic mass' concept, since GR
doesn't need it.

The other one is "length contraction". "Correct" descriptions in SR,
doesn't have it either, that is lengths don't physical shrink. Length is
an invariant. The length contraction is a rotation in time, just like a
large pole when tilted can get through a door smaller the length of the
pole. Its all about relativity of simultaneity of events in time.
Different observers see the ends of the pole going through at different
times etc... It took me a while before I cottoned on to all of this as
well. The issue is that 99.99% of descriptions, i.e the popular ones are
usually ignorant of what SR is really about.

Kevin Aylward
[email protected]
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[John Woodgate]

I read in sci.electronics.design that Kevin Aylward
..blueyonder.co.uk>) about 'Theoretical limit for loud music??', on Sat,
4 Sep 2004:

Not at all John At 200 dB SPL your hearing will be co

At 200 dB SPL, if you could get there, you wouldn't be worried about
being deaf. Not after your head exploded, anyway.

 

[John Larkin]

I read in sci.electronics.design that Kevin Aylward
.blueyonder.co.uk>) about 'Theoretical limit for loud music??', on Sat,
4 Sep 2004:


At 200 dB SPL, if you could get there, you wouldn't be worried about
being deaf. Not after your head exploded, anyway.

I wonder where the bodily-damage threshold really is. 190 dB is just 1
atm overpressure, which doesn't sound very severe to me. Escaping from
a submarine must be 50x as severe. In some of the early a-bomb tests,
soldiers crouched in trenches hundreds of yards from ground zero,
where the overpressures must have been immense, and they got through
uninjured.

(Grabs handy copy of "The Effects of Nuclear Weapons", DOD, 1977...)

Ah yes. At 1000 feet from ground zero, 20 kilotons surface blast, the
overpressure is about 140 PSI, about 10 atm. The 190 dB distance will
be roughly one mile.

Numbers are fun.

John

 

[John Woodgate]

I read in sci.electronics.design that John Larkin <jjlarkin@highlandSNIP
techTHISnologyPLEASE.com> wrote (in <7fvjj0hndmb0epi303ro0it0oimeieroe8@
4ax.com>) about 'Theoretical limit for loud music??', on Sat, 4 Sep
2004:

I wonder where the bodily-damage threshold really is. 190 dB is just 1
atm overpressure, which doesn't sound very severe to me. Escaping from a
submarine must be 50x as severe. In some of the early a-bomb tests,
soldiers crouched in trenches hundreds of yards from ground zero, where
the overpressures must have been immense, and they got through
uninjured.

(Grabs handy copy of "The Effects of Nuclear Weapons", DOD, 1977...)

Ah yes. At 1000 feet from ground zero, 20 kilotons surface blast, the
overpressure is about 140 PSI, about 10 atm. The 190 dB distance will be
roughly one mile.

Numbers are fun.

Yes, but *underpressure* is not. Your head won't explode in a diving
suit, but in a hard vacuum.....

 

[Rich Grise]

194 dB SPL, if the air pressure is 1 bar.

So, in other words, it's possible for sound to be so loud that it
actually breaks the air?

Shudder!

Thanks,
Rich

 

[Rich Grise]

Of course, it takes a _lot_ of energy to create extremely loud sound.
There was once a study of how loud sound affects various ear structures;
to get adequate sound levels, some experimental animals (think it was
in rats) were anaesthatized in cages in close proximity to the space
shuttle
rocket boosters. IIRC the sound of the boosters when they were later
fired was still below the 180dB mentioned in another posting. {Even
that was not enough -- at least in those animals -- to collapse lungs.}

Look at the spectral distribution of a shuttle motor, and look at the
spectral distribution of some of that nigger/spic rap noise. Make the
noise at the resonant frequency of the right body part, and you're dead.
Of course, they go for the resonant frequency of their dick.

Cheers!
Rich

 

[Rich Grise]

There's no limit on the positive-direction overpressure, if you don't
mind a bit of harmonic distortion (and who would, when you're being
homogenized to death.)

This brings to mind a little video snippet I saw at the St. Paul, MN
Science Museum, shortly after Mt. St. Helens went up. It was a satellite
video of the "event." There was a visible circle that expanded from
ground zero so fast that it went across two states in about a second.
I wonder if that was real-time, in which case the shock wave was going
about a thousand miles a second, or it was way slowed down. I assume
that the shock wave was visible from condensation of some kind - in
the famous ocean test where the ships look like toys, you can see
the shock wave go through the cloud layer, very fast.

But I think that might not qualify as "sound".

Cheers!
Rich

 

[Jim Thompson]

Look at the spectral distribution of a shuttle motor, and look at the
spectral distribution of some of that nigger/spic rap noise. Make the
noise at the resonant frequency of the right body part, and you're dead.
Of course, they go for the resonant frequency of their dick.

Cheers!
Rich

I know that a fellow suffered serious kidney damage while standing on
a shake table at Kodak (~1980), so we GenRad types, using Kodak's
shake table facilities to simulate shipping vibrations, were warned to
stay off of it.

Personally, I didn't like seeing CRT necks flexing when viewed with a
strobe, so I stood behind a pillar ;-)

Did the same thing at Sperry/Honeywell Aerospace while testing my
satellite spinner motor drive... 2 tons of satellite spinning at
6-8RPM, hanging from a test gantry, is just a wee bit scary ;-)

...Jim Thompson

 

[John Woodgate]

I read in sci.electronics.design that Rich Grise <[email protected]>

But I think that might not qualify as "sound".

Oh, it does. Acousticians get their extreme kicks from studying shock
waves and plasmas.

 

[Rich Grise]

I read in sci.electronics.design that John Larkin <jjlarkin@highlandSNIP
techTHISnologyPLEASE.com> wrote (in <7fvjj0hndmb0epi303ro0it0oimeieroe8@
4ax.com>) about 'Theoretical limit for loud music??', on Sat, 4 Sep
2004:

Yes, but *underpressure* is not. Your head won't explode in a diving
suit, but in a hard vacuum.....

Gee, John. Didn't you see "2001 A Space Odyssey"? Keir Dullea was clearly
holding his breath in vacuum when he popped the hatch on the pod. Yah,
right. Try going to 33 ft. on scuba, and do an emergency ascent, while
holding your breath. You'll get pneumothorax. You'd have to _exhale_ as
hard as possible to keep your lungs small, and let's not talk about
eardrums and eyeballs. But ISTR that they did do some test, and volunteers
survived hard vacuum for at least some seconds. That could have been when
I was reading Sci-Fi stoned, however. ;-)

But I don't think your head would actually explode, but whatever did
happen would be quicker than in "Total Recall." And you might fart blood.

Cheers!
Rich

 

[Rich Grise]

I know that a fellow suffered serious kidney damage while standing on
a shake table at Kodak (~1980), so we GenRad types, using Kodak's
shake table facilities to simulate shipping vibrations, were warned to
stay off of it.

Personally, I didn't like seeing CRT necks flexing when viewed with a
strobe, so I stood behind a pillar ;-)

Did the same thing at Sperry/Honeywell Aerospace while testing my
satellite spinner motor drive... 2 tons of satellite spinning at
6-8RPM, hanging from a test gantry, is just a wee bit scary ;-)

Is that Six to Eight RPM? That's not very fast. You should see them
spin up some of the parts here on the 84" vertical turning station.

Cheers!
Rich

 

[Jim Thompson]

Is that Six to Eight RPM? That's not very fast. You should see them
spin up some of the parts here on the 84" vertical turning station.

Cheers!
Rich

Imagine your car, hanging from the ceiling, spinning at 8RPM ;-)

...Jim Thompson

 

[Rich Grise]

Imagine your car, hanging from the ceiling, spinning at 8RPM ;-)

Yeah. Eight revolutions a minute. That means one revolution in one-
eighth of a minute, or 7.5 seconds. You could follow the bumper around
the circumference on foot. Now, if they were spinning the 2-ton item at,
say, 1200 RPM, now THAT would be impressive!

Cheers!
Rich

 

[Active8]

Have you heard of a weapon that puts you down with a strobe light
effect?

How about a sound weapon that makes you puke?

 

[Active8]

I wonder where the bodily-damage threshold really is. 190 dB is just 1
atm overpressure, which doesn't sound very severe to me. Escaping from
a submarine must be 50x as severe. In some of the early a-bomb tests,
soldiers crouched in trenches hundreds of yards from ground zero,
where the overpressures must have been immense, and they got through
uninjured.

But like someone else said, if you get the right part of the body
resonating, it'll break. They've managed to make jet airliners more
quiet by designing in members that resonate out of phase with the
vibrations.

(Grabs handy copy of "The Effects of Nuclear Weapons", DOD, 1977...)

Damn. I've got one of those stashed somewhere. Is it the one with
the circular effects computer in a pocket inside the back cover?

Ah yes. At 1000 feet from ground zero, 20 kilotons surface blast, the
overpressure is about 140 PSI, about 10 atm. The 190 dB distance will
be roughly one mile.

Numbers are fun.

I bet nukes are, too

 

[Active8]

So, in other words, it's possible for sound to be so loud that it
actually breaks the air?

Some music doesn't sound any better than breaking wind.

Shudder!

No, it's plbht.

 

[John Larkin]

Damn. I've got one of those stashed somewhere. Is it the one with
the circular effects computer in a pocket inside the back cover?

Good grief, it does! Cool blue-and-white circular slide rule, with one
scale calibrated in deaths. And a scale for "probability of a glass
fragment penetrating 1 cm of soft tissue." Creepy.

I also have "The Effects of Atomic Weapons" (Los Alamos, 1950),
"Atomic Energy for Military Purposes" (1945) and my favorite, "The Los
Alamos Primer", lectures to newbies on how to build a bomb. Both
Rhodes books, of course, and two recent books of gorgeous/terrifying
photographs of nuclear tests. There's lots of this stuff around, and
it's really interesting reading.

Oh, the Atomic Bomb Collection of CD's, narrated by William Shatner,
is pretty cool too.

I bet nukes are, too

Ted Taylor ("The Curve of Binding Energy") designed a lot of nukes,
including the biggest fission bomb and the only known bomb design that
wouldn't go off. After he became a peace activist, he said that he did
miss how much fun it was to design bombs.

John