If all the Indians simultaneously shouted at the ISS, could astronauts detect it?

[Reply]

The International Space Station is going to cross India soon. If everyone there looked up and shouted for 10 seconds as loudly as they could, would it be detectable from orbit? For the purposes of this question, let’s assume that the astronauts are given an 1-hour window to monitor, and from that they must determine the correct minute the shouting occurred in.

[Ranger_Jeff]

No. Sound needs air. The ISS, in LEO, is in a vacuum. No air begets no sound.

[Colibri]

The ISS orbit at 360 km is in high vacuum. No sound waves could propagate at that level.

[sco3tt]

According to Ridley Scott, no.

[zoid]

Only if all the Chinese jumped at exactly the same time.

[JBDivmstr]

@zoid

Only if all the Chinese jumped at exactly the same time.

While they were on a treadmill.

You know somebody was gonna say it.
Might as well get it over with.

[JBDivmstr]

@sco3tt

According to Ridley Scott, no.

<golf clap>

[Digital_is_the_new_Analog]

@Ranger_Jeff

No. Sound needs air. The ISS, in LEO, is in a vacuum. No air begets no sound.

I don’t think the question is specifically if it would be heard at the ISS. The question is could it be detected. Would there be any mechanism where they could determine that such an event happened? Something that could be measured in the atmosphere below them?

[don_t_ask]

what would they all shout?

[Koxinga]

“Get away from that magazine rack, this is not a reading room!”

[Just_Ed]

@Digital_is_the_new_Analog

I don’t think the question is specifically if it would be heard at the ISS. The question is could it be detected. Would there be any mechanism where they could determine that such an event happened? Something that could be measured in the atmosphere below them?

I don’t know, but I’d love to see Randall Munroe take a stab at this.

[Colibri]

@Digital_is_the_new_Analog

I don’t think the question is specifically if it would be heard at the ISS. The question is could it be detected. Would there be any mechanism where they could determine that such an event happened? Something that could be measured in the atmosphere below them?

It is theoretically possible to measure surface air pressure from satellites, but evidently a practical system has yet to be developed, even for the very great pressure differences found in hurricanes. Fromhere:

It’s hard to believe that, in this day and age, we don’t have a way to measure sea-level air pressure during hurricanes. NASA researchers, however, are working on a system that will improve forecasting of severe ocean weather by doing just that. The device measures sea-level air pressure, a critical component of hurricane formation – and one that has been extremely difficult to capture.

The Differential Absorption Barometric Radar (DIABAR) prototype is scheduled to make its second flight early this year.

DIABAR remotely senses barometric pressure at sea level, which is important in the prediction and forecasting of severe weather, especially hurricanes, over oceans.

But the ability to measure sea-level air pressure is a major missing link in storm observation, says Dr. Bing Lin, an atmospheric scientist at NASA Langley Research Center in Hampton, Va.

If it’s not possible yet to detect even such large pressure variations, it’s probably a long time off before we can measure the slighter and much smaller scale fluctuations produced by sound waves.

[smithsb]

Maybe if Christo had them all unfurl pink banners, it would be visible?

[Chessic_Sense]

@smithsb

Maybe if Christo had them all unfurl pink banners, it would be visible?

India has a population density of about 1,000/mi2. That’s a lot of ground to cover for each person, so I doubt it.

[chacoguy]

Laser Pointers.

[user_hostile]

@don_t_ask

what would they all shout?

Beat Pakistan!

(Re: Cricket)

[Colibri]

Sound waves generated by the 2011 earthquake in Japan have been detected by satellite. However, the GOCE satellite that detected them orbits at only 170 miles, or 270 km, much lower than the ISS, where there is still some atmosphere to carry sound waves.

GOCE orbits at the lowest altitude of any observation satellite but at less than 170 miles up it has to periodically use its thrusters to compensate for drag from the thin upper remnants of the atmosphere.

Also, the sound was extremely low frequency (infrasound) and very powerful, and thus not comparable to sound waves that would be generated by people.

[Fear_Itself]

@don_t_ask

what would they all shout?

“Thank you, come again!”

[smithsb]

@don_t_ask

what would they all shout?

“Welcome to Microsoft technical assistance, how can we help you?”

[Washoe]

@smithsb

“Welcome to Microsoft technical assistance, how can we help you?”

[Raj Koothrapalli]That’s so racist, dude.[/RajKoothrapalli]