Could sonic showers actually work?

We've all heard about sonic showers many times on Trek (and, on Voyager, actually seen them in action). But is the theory behind them, actually legit? Meaning, could sound waves theoretically work as a cleaning device, as Trek suggests?

I foresee some problems:

- Some people can't stand hearing high frequency sound waves. It might even give them headaches or seizures. I'd imagine sonic showers would be even more dangerous for people like this.

- Even if a sonic shower would shake the dirt off you, that's not all that makes you dirty. What about the sweat? Smell? How could soundwaves get rid of those? If you're sweaty and dirty, and you get into a water shower, that's easy, since the water sluices both of those off. I don't see how sound waves could. (Dirt, yes; sweat, not so sure.)

 

The sonic shower introduced in ST:TMP was conceptually based on a real-world "hydrosonic shower" prototype unit developed at - IIRC - McDonnell Douglas Astronautics' Huntington Beach, California facility circa 1976 under a study contract to Jesco von Puttkamer's office at NASA-OSF in order to minimize the amount of liquid water storage required for long-duration manned space missions. A description of the system was also published by its designers in one of the early AIAA Space Manufacturing volumes edited by Jerry Grey. I don't have my copy handy, but the mechanism employed steam jets and high-frequency (ultrasonic), low-amplitude acoustic generators to bathe the user in a thin film of water condensate which would then be vibrated, thus initiating the cleansing function. A few drops of liquid soap was all that was required to dissolve whatever sweat and dirt had accumulated since the last "shower", but further development of the hardware was apparently never pursued due to the excessive mass, complexity and cost of the original, to say nothing of the catastrophic budget cuts during the 1970s that destroyed NASA's plans for manned spaceflight beyond STS. The idea itself is absolutely sound (heh) though, as none of the MDA engineers who subjected themselves to the prototype reported any discomfort or injury during testing.

TGT

 

Yeah... that's exactly right.

The problem with the "Trek" incarnation of these things is that they're inconsistent with the REAL science it's based upon. Trek "sonic showers," supposedly, use no water. This is illogical and irrational, but not too surprising... the folks writing about it most often had no idea of the science behind it.

The idea of a sonic shower, as TGT said, isn't that it's WATERLESS... but that it's "water-efficient." Basically, the "sonic" part simply provides a very efficient SCRUBBING action of the soapy water... getting the job done without requiring ongoing, constant running water. It still does require water, and soap. THAT is what the Treknology writers seem to have gotten all confused about.

As for headaches and seizures and so forth... it has to do with intensity and frequency. You'd need to closely control the sonic excitation frequencies used. I mean... ultrasonic scanners (which, as the name implies, use high-frequency sonics) are by far the safest way to look at developing fetuses, for instance, and it's implied that many of Dr. McCoy's sensing devices are sonic-based technologies. It's unlikely that a sonic device would be inherently hazardous... though it WOULD be possible to sabotage the system and cause injuries to the crew (possibly even injuries that wouldn't show symptoms immediately, only over a significant length of time... which, if you think about it, would make for some interesting storytelling possibilities!)

 

To be fair, water droplets are clearly visible on the Ilia-Probe's shoulders, and if one has the iTunes version of ST:TMP (my copy is of the 1979 cinema edit but I believe Apple has since changed it to the DE) on their computer pressing the fast-forward on the QuickTime Player during that segment reveals - at least to me - steam being blown down on Khambatta which is otherwise almost completely obscured by the "mood light" animation effect.

TGT

 

No argument there. TMP was, however, much more well-thought-out, TECHNICALLY at least, than the TNG-and-later series (or any of the later movies). While TMP's ENTERTAINMENT value is subject to debate, it's technical value is not. It is, by far, the most technically reasonable of the various shows (sets not fitting within the hull structure notwithstanding). Something I attribute, heavily, to the involvement of Dr. Von Puttkamer (sp?) as technical advisor.

I'm fairly certain that the use of sonic showers is something he contributed to the mix (just like wormholes and other semi-factual science presented in the film).

Unfortunately, later Trek writers missed this point entirely, and simply reused the term as "technobabble" without really bothering to try to understand what they were talking about.

 

Also, I should point out that the Zero Gravity Toilet Instructions in 2001: A Space Odyssey contain references to a 'pure' sonic shower (one that doesn't use water at all) as well. The bathroom that Dr. Floyd is about to enter, has such a sonic shower, and also a sink that cleans your hands using only sound waves.

So don't blame Trek for getting the science wrong, blame Stanley Kubrick.

 

"Zero-gravity toilet instructions. These were purposely exaggerated to add a note of humor to scene showing a perplexed passenger Floyd trying to decide if he should attempt to use the facility." - Frederick I. Ordway, III (2001's Scientific Advisor) in his paper, 2001: A Space Odyssey in Retrospect, reprinted in Science Fiction and Space Futures: Past and Present, edited by Eugene M. Emme (American Astronautical Society, 1982).

Besides, was it possible for anybody in the audience actually read the full text even during the film's original 70mm Cinerama presentation?

TGT

 

No way. I saw 2001 in L.A. during its first run in ideal conditions, and again in San Jose (and many times since in a variety of venues, both in 35 and 70mm.) You could read some words, but I don't see how a speed reader could discern this stuff, it isn't like the EXPLOSIVE BOLTS signage that is MEANT to be read.

 

I guess the on-screen gag was just that the instructions were soooooo damn long and complicated!

They were printed in the making-of book soon after the film, for those of us who really wanted to read them.

 

For those who are interested, here is a link to a truncated version of the Ordway paper.

 

There are 2 choices that would indicate an advancement in the technology. Either, there is some material floating around when a sonic shower is used or there isn't any at all.

Without any additional material, the air around the user would be what's used to vibrate the gunk off the body. Or, with their force field technology, they might project EM energy around the user and that's what vibrates to clean them off. An alternative would be that the user's body is what's made to vibrate to get the stuff off. We've all had buzzing feelings before, so it could be something like that.

With before, seeing what looks like water droplets, Picard in TNG: Inner Light mentions atmospheric condensors. That technology could be used to take the air and form it into a fine mist that would be used in the shower to vibrate the gunk off.

 

It occurs to me that, when we sweat, we are releasing a mixture of water and body salts through our skin. This only has an unpleasant odour when it goes 'stale'. I believe it is the bacteria that develops in the sweat that is the main cause of the odour and not the sweat itself. So my thinking is that if vibration and/or heat could be used to also stimulate sweat glands then, combined with a surfacant (or in less scientific terms "soap"), you could feasibly have a sonic shower that produces no water of its own.

The Romans used oil and a metal scraper to remove dirt (including dead skin cells) from the body (Although I think they used water afterwards) so potentially an synthetic oil based substance could be used with some kind of sonic wave as the "scraper".

I'm sure with a combination of different methods (sonic waves to remove dirt, UV rays to kill bacteria) a no-water shower system might be possible.

I know in the series Babylon 5 they also had "Vibro showers" and JM Strazynski was very keen to have all the Human tech on that series as Scientifically feasible as possible based on current knowledge (The only exceptions being the Anti-g in a ship in spinoff series "Crusade" which relied on Minbari tech and the Jumpgates which were copied by all races off Ancient Jumpgates from a presumed extinct, unknown race) so the inclusion of "Vibro showers" would seem to suggest that it's possible but I suppose there are two other options:
!, They're based on the hyrdrosonic showers previously mentioned or
2. JMS got lazy at this point and just borrowed an idea from Star-Trek assuming that it was scientifically viable,

Even if a no-water system is never devised it would be interesting to see if the Hydrosonic idea was ever revisited. Minituarisation is a common thing over time in technology as is increased efficiency and reduced cost. So maybe at some point in the future we will have Hydrosonic showers in use in space. Maybe even just sonic ones.