The Ghost In The Machine wrote:

Yes; now we use something else that sounds even worse. :-)
The current sounds remind me of some sort of low-speed
modem, as opposed to the two-toned whine used previously,
which sounded like a mutated dial tone.

That is EXACTLY what it is. An oddball, low baud rate modem. It was
done that way to make it addressable, and to keep it from being tampered
with by hackers or terrorists.

Radium wrote:

On May 28, 11:30 am, "TimPerry" <timpe...@noaspama.net> wrote:

EBS tones have been discontinued for many years now in the US.

Nope. Whenever an emergency occurs, first they play the boring low-
pitch square-wave tones.

you are perhaps referring to the Emergency Alert System (EAS).
after all, a pleasant sounding emergency sound wouldn't be very effective.
it's not really square waves either. look up AFSK (audio frequency shift
keying)

Radium wrote:

On May 28, 11:30 am, "TimPerry" <timpe...@noaspama.net> wrote:

EBS tones have been discontinued for many years now in the US.

Nope. Whenever an emergency occurs, first they play the boring low-
pitch square-wave tones.

you are perhaps referring to the Emergency Alert System (EAS).
after all, a pleasant sounding emergency sound wouldn't be very effective.
it's not really square waves either. look up AFSK (audio frequency shift
keying)

On May 29, 11:31 pm, The Ghost In The Machine
<e...@sirius.tg00suus7038.net> wrote:

In sci.physics, Radium
<gluceg...@gmail.com>
wrote
on 29 May 2007 21:50:16 -0700
<1180500616.639919.174...@r19g2000prf.googlegroups.com>:

On May 29, 7:46 pm, "Tomoko Kanazawa"
<T.Kanaz...@eodomo.gsfc.nasa.gov> wrote:

Radios dont work in space. It's a VACKYOOM.

Yes they do. Sound cannot travel through space, however,
electromagnetic representations of audio signals can. The spaceship
has air in it [duh!, otherwise those onboard wouldn't survive] so
loudspeakers attached to the radio and amplifiers should give out some
sound. Right?

Well, congrats on knowing the basics, though you forgot three additional
possibilities.

Thanks.

[1] The electromagnetic waves could be converted to light pulses, which
would then feed a video receiver.

In which case, I wonder what would be seen on the screen.

[2] The E/M waves could be fed directly into one's brain. This
admittedly slightly farfetched notion is presumably in the far future,
but it is theoretically possible.

Extremely unlikely. The brain is too poor of a conductor to process
any electromagnetic signals.

Mostly the brain uses proteins to
transmit, receive, record, playback, store, and process signals.

There
is a long list of what determines those signals. This includes - but
is clearly not limited to - the types of proteins, the amounts of
proteins, the rate at which the proteins move, whether they move at
all, and a many other variables regarding proteins. Most CNS signals
are based on proteins, though many sci-fi thrillers tend to spread the
myth that the brain is purely-electric.

[3] The E/M waves could be fed into piezoelectric crystals -- earphones
or earbuds.

Yes.

There is also the possibility that the ship has no air but those aboard
it are using space suits.

Yes but even in this case, the space suit contains air, which is
necessary for the astronaut to survive. This air is what conducts the
sound produced by the loudspeakers the astronaut is wearing. The
loudspeakers generate the sound based on signals they receive via
radio waves.

Paul Cardinale pointed out that AM carrier waves as weak as 10^-10,000
watt [i.e. 10-to-the-power-NEGATIVE-10,000 watt] would mean "expect
photons to arrive at a rate of about one every 10^9964 years."

I am
now aware that my power requirements are way too low to receive
anything in a human lifetime. So let's increase the initial wattage of
the AM carrier wave to where it is equivalent to one 150 KHz photon
per second. Now, I can expect - after super-amplification and
subsequent demodulation -- to hear those terrifying yet enjoyable high-
pitched, heterodyne-like, EAS-resembling tones while on the spacecraft.