# Superman goes supersonic: What would people below him experience? **URL:** \ **Category:** Factual Questions\ **Created:** [December 6, 2024, 4:25pm UTC](https://boards.straightdope.com/t/superman-goes-supersonic-what-would-people-below-him-experience/1011260 "2024-12-06T16:25:23Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Caribbean\_cruiser](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/caribbean_cruiser/32/9349_2.png) [@Caribbean\_cruiser](https://boards.straightdope.com/u/Caribbean_cruiser)\ **Post date:** [December 6, 2024, 4:25pm UTC](https://boards.straightdope.com/t/superman-goes-supersonic-what-would-people-below-him-experience/1011260/1 "2024-12-06T16:25:23Z")
Let’s say Superman is standing in a crowd of people and suddenly flies straight up into the sky, as quickly as he can, reaching supersonic speed at an altitude of, say, 100 feet, as he flies straight up, high above Earth. Would the people on the ground who were standing next to him experience the full sonic boom effect, given that his flight path is straight upward? Would the sonic waves be asymmetrically distributed? Clearly, they wouldn’t feel the full brunt of the rushing air, so can we assume the same about the sound produced? ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [December 6, 2024, 4:27pm UTC](https://boards.straightdope.com/t/superman-goes-supersonic-what-would-people-below-him-experience/1011260/2 "2024-12-06T16:27:51Z")
Superman is not very big. I can’t imagine the sonic boom is dangerous to anyone. Just a loud noise. Especially if he flies straight-up. The sound waves would spread out in a cone which would be a lot less impactful right below him. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [December 6, 2024, 4:54pm UTC](https://boards.straightdope.com/t/superman-goes-supersonic-what-would-people-below-him-experience/1011260/3 "2024-12-06T16:54:08Z")
Superman may not be very big but accelerating even something the size of a human body to supersonic speed within 30 meters is going to release _a lot_ of energy in the form of acoustic shock and aeroheating as most of the air in front of him is compressed. Although the standing shock front will be proceeding in front of the body, the shock wave will propagate outward in all directions with the potential for interacting shocks waves impinging and being reflected off the ground to create areas of shock amplification, especially if there are structures around to reflect the waves radially. It _probably_ wouldn’t kill anyone but you’d certainly feel the pressure wave, and unless wearing hearing protection it will probably damage hearing if not rupture eardrums of people directly below within at least a 100 meter radius. Also, it is never made clear exactly what the nature of Superman’s propulsion is; it does not appear to be rocket-based propulsion but unless he is capable of completely violating the laws of physics there is some kind of momentum exchange and associated thermodynamics with work being done to accelerate him. So, even if he is using ‘force fields’ or some other kind of alien technology, it seems likely that the people around him would be affected by the transformation of that energy release into unavoidable ‘waste heat’ per the Second Law of Thermodynamics. Superman is probably pulping innocent civilians any time he takes off, or spins through a phone booth, or even when he sneezes, and you can just imaging what would happen if he consummated his romantic relationship with Lois Lane with his powers intact. Stranger ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [December 6, 2024, 5:11pm UTC](https://boards.straightdope.com/t/superman-goes-supersonic-what-would-people-below-him-experience/1011260/4 "2024-12-06T17:11:15Z")
> [@Stranger\_On\_A\_Train](#): > > and you can just imaging what would happen if he consummated his romantic relationship with Lois Lane with his powers intact. > **[Man of Steel, Woman of Kleenex](https://en.wikipedia.org/wiki/Man_of_Steel,_Woman_of_Kleenex)** > > "Man of Steel, Woman of Kleenex" is a 1969 essay in which science fiction author Larry Niven details the problems that Superman would face in sexual intercourse and reproduction with a human woman, using arguments based on humorous reconciliation between physics, biology and the abilities of Kryptonians as presented in Superman comic books. > The issues discussed include Superman's loss of physical control during intercourse, the presumed "super powers" of Superman's sperm cells, genetic incomp... ---
**Author:** ![jnglmassiv](https://avatars.discourse-cdn.com/v4/letter/j/f07891/32.png) [@jnglmassiv](https://boards.straightdope.com/u/jnglmassiv)\ **Post date:** [December 6, 2024, 5:43pm UTC](https://boards.straightdope.com/t/superman-goes-supersonic-what-would-people-below-him-experience/1011260/5 "2024-12-06T17:43:03Z")
> [@Stranger\_On\_A\_Train](#): > > or even when he sneezes I loved the peanut flicking scene when I was a kid and just getting into flicking things myself. ---
**Author:** ![yendis](https://avatars.discourse-cdn.com/v4/letter/y/ed8c4c/32.png) [@yendis](https://boards.straightdope.com/u/yendis)\ **Post date:** [December 6, 2024, 6:46pm UTC](https://boards.straightdope.com/t/superman-goes-supersonic-what-would-people-below-him-experience/1011260/6 "2024-12-06T18:46:02Z")
Using Henry Cavil as a metric, Superman is a bit wider than a battleship shell but narrower than the biggest shells thrown by a number of railway guns. Those shells are supersonic so will have similair shockwaves, subtract the blast effect from the gun and you’ll get an empiricalish answer. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [December 6, 2024, 6:52pm UTC](https://boards.straightdope.com/t/superman-goes-supersonic-what-would-people-below-him-experience/1011260/7 "2024-12-06T18:52:22Z")
> [@Stranger\_On\_A\_Train](#): > > he is capable of completely violating the laws of physics He’s an alien. Earthly laws do not apply to him. I think he once got a certificate from the United Nations to that effect. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [December 6, 2024, 11:56pm UTC](https://boards.straightdope.com/t/superman-goes-supersonic-what-would-people-below-him-experience/1011260/8 "2024-12-06T23:56:12Z")
Coincidently, a YouTuber recently posted a video about why you won’t hear a sonic boom from a rocket going straight up. Yeah, it has a lot of filler, but [here](https://youtu.be/liKe0kg3agY?t=599) is where she gets down to brass tacks. She does gloss over objects other than sleek rockets though. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [December 7, 2024, 2:11am UTC](https://boards.straightdope.com/t/superman-goes-supersonic-what-would-people-below-him-experience/1011260/9 "2024-12-07T02:11:32Z")
> [@Stranger\_On\_A\_Train](#): > > and you can just imaging what would happen if he consummated his romantic relationship with Lois Lane with his powers intact. I remember from decades ago a Mad Magazine spoof of Superman, with Lois complaining, " do you have any idea how many birth control pills it takes to prevent a super-baby?!?" ---
**Author:** ![Measure\_for\_Measure](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/measure_for_measure/32/557_2.png) [@Measure\_for\_Measure](https://boards.straightdope.com/u/Measure_for_Measure)\ **Post date:** [December 7, 2024, 3:06am UTC](https://boards.straightdope.com/t/superman-goes-supersonic-what-would-people-below-him-experience/1011260/10 "2024-12-07T03:06:29Z")
In Frank Miller’s DK2, Superman explains some of the details to his daughter, birthed by Wonder Women. Dialogue from memory: “What about sex?” “Excuse me?.. Never with Terrans. They are too fragile.” ---
**Author:** ![ZonexandScout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zonexandscout/32/544_2.png) [@ZonexandScout](https://boards.straightdope.com/u/ZonexandScout)\ **Post date:** [December 7, 2024, 8:29am UTC](https://boards.straightdope.com/t/superman-goes-supersonic-what-would-people-below-him-experience/1011260/11 "2024-12-07T08:29:03Z")
While his current-day method of flying is subject to debate, I think it would be interesting to consider a situation more similar to pre-1940 Superman, when he basically jumped or “leaped.” If he is simply a very good jumper, and able to control himself after a jump by twisting and positioning his body, then he would have maximum power and velocity at the moment he leaves the ground. He would be ballistic. He would have to “go supersonic” before his feet even leave the ground, rather than 100 feet in the air. I imagine this would be a shock to the bystanders. (I am not a physicist, so having at me is fair game.) ---
**Author:** ![Loggins](https://avatars.discourse-cdn.com/v4/letter/l/74df32/32.png) [@Loggins](https://boards.straightdope.com/u/Loggins)\ **Post date:** [December 10, 2024, 6:18pm UTC](https://boards.straightdope.com/t/superman-goes-supersonic-what-would-people-below-him-experience/1011260/12 "2024-12-10T18:18:29Z")
So if many normal men use Viagra pill before having sex, perhaps Superman need a Kryptonite pill before mounting Lois Lane? ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [December 10, 2024, 6:20pm UTC](https://boards.straightdope.com/t/superman-goes-supersonic-what-would-people-below-him-experience/1011260/13 "2024-12-10T18:20:06Z")
Or Kryptonite in the mattress/ bedding. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [December 10, 2024, 6:52pm UTC](https://boards.straightdope.com/t/superman-goes-supersonic-what-would-people-below-him-experience/1011260/14 "2024-12-10T18:52:19Z")
Could you tell a Man of Steel sonic boom from a Superfart? Once the plume drifts down to ground level it should be obvious…