The first thing that I can think of is that space exploration becomes incredibly slow, because sending everything up there that is not pre-programmed needs a human pilot, and there would be no way of getting the data but to bring back the probe altogether. But what else?

This world is similar to the real world as far as astronomical bodies go; there's the moon, the sun, other planets, asteroids, etc. The major difference is that radio communications can only work in an atmosphere.


closed as too broad by Azuaron, sphennings, MozerShmozer, AngelPray, Josh King Sep 28 '17 at 21:20

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

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    $\begingroup$ so which law of physics did you breaks? and how does the revised one works? $\endgroup$ – user6760 Sep 28 '17 at 7:49
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    $\begingroup$ As I said in my answer: your premise — as stated — breaks the universe. However(!)... you can make a new question and make the much more specific — and realistic question — "How would space exploration be affected if radio will reflect off of the upper layers of the atmosphere?". Suppose we postulate that radio can work inside the atmosphere, and radio works outside the atmosphere. But radio cannot pass through some boundary of the atmosphere. That will be much more realistic since we are already today using the ionosphere to reflect radio waves. $\endgroup$ – MichaelK Sep 28 '17 at 8:51

There would never be life on planet Earth

Considering that radio is electromagnetic radiation, and that all light is also electromagnetic radiation...

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...and that life on planet Earth is dependent on light from our nearby star Sol...

...there would never be life on planet Earth if you have made it so that light cannot propagate anywhere but within an atmosphere.

This — naturally — puts a big dent in everyone's plan to explore space.

No really, you just reversed one of the most basic laws of physics — Classic Electromagnetism as described by Maxwell's Equations — in such a way that you essentially broke the universe. There is no way we can make it so that radio exists in a medium but not in a vacuum.

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    $\begingroup$ luckily I read your answer before posting mine, which would have been a neat duplicate. $\endgroup$ – L.Dutch Sep 28 '17 at 8:14
  • $\begingroup$ This doesn't answer the question about how space exploration, except by implication that dead planets don't do much space exploring. The question specified radio carried by atmosphere, but this doesn't necessarily apply to all electromagnetic radiation. Maxwell's equations assumed the medium of an ether, and still work without it, perhaps by rewriting Maxwell's equations so an atmosphere is the medium for radio. Although the resulting equations might mathematically quite weird. $\endgroup$ – a4android Sep 28 '17 at 10:38
  • $\begingroup$ @a4android "...except by implication...". That implication is strong enough. I wrote in a comment under the question how OP can make a question that works on the assumption that radio communication into space is not possible. But I will not answer this question as if that was what they asked. $\endgroup$ – MichaelK Sep 28 '17 at 10:40
  • $\begingroup$ Actually I like your radio boundary concept because it's more plausible. Figuring out a world where radio needs atmosphere as its medium is too hard to make sense of it. I think in your last sentence of your above comment, which was very puzzling, it should be that not this because that makes more sense. $\endgroup$ – a4android Sep 28 '17 at 10:51
  • $\begingroup$ @a4android No no, I meant "this". I will not answer this question — the one that graces the top of this page with its presence — as if it was instead asked as "What if radio cannot penetrate outside the atmosphere... what happens to space exploration?". OP will have to post that in a new post and then we can get to business with exploring what I assume is their object of curiosity: what happens to space exploration if you cannot communicate with mission control via radio. $\endgroup$ – MichaelK Sep 28 '17 at 11:02

You can probably work around this problem using some sort of laser (with a revised version of the morse code) to comunicate between the spacecraft and low earth orbit station and then the normal radio waves from the station to earth (ISS is still in the atmosphere after all).

So I think that once the system is setup, the space exploration will not be too much slower than today.

  • $\begingroup$ Well spotted! The question restricts EM propagation through the medium of an atmosphere to radio, light based signals like lasers could still work. Plus one. $\endgroup$ – a4android Sep 28 '17 at 10:40

Basically in your world radio transmissions are only possible if traveling through an atmospheric medium. A lot, like sound. Generally, I dislike this concept since radio waves are a form of radiation which does not need a medium, hence why we can observe distant radio waves from far-off stars and other heavenly bodies.

A better option would, in my opinion, be that the atmosphere of your planets have a characteristic that filters or blocks a lot of background radio interference that would otherwise make radio communication outside of the atmosphere very difficult since the interference levels could make broadcasting over radio frequencies limited to only short range.

EDIT: Since the atmosphere or the lack of one does not permit radio communication, another reasonable way that is relatively in canon with my previous entry; Use either Geostationary sattelites or some way that can stretch a cable out into space and do the information transfer between the surface and out into the close proximity space. From there, if only the radio frequencies are impossible to communicate over, use optical light transmission. This can be done in super simple morse, or more complex Li-Fi The latter, can be used in combination with satellites or other heavenly bodies as extenders that work in the same way as wifi-extenders. This way, you can theoretically attain extreme bandwidth. "Researchers have reached data rates of over 224 Gbit/s". I think I may have solved the issue of getting Earth-Lunar internet as well.

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    $\begingroup$ The OP is not asking how to improve his world. Your answer, though making sense, misses the point. $\endgroup$ – L.Dutch Sep 28 '17 at 8:15
  • $\begingroup$ If OP's question is wrong-headed, answers that address that and offer a solution that results in a substantially similar starting condition should be acceptable. That being said, @DannyBoy, while you've presented a much better scenario for how radio communication from ground-to-space isn't possible, you have not answered the question, "How would space exploration be different?" Please update your answer to address the core question being asked; this answer has entered the delete queue, so it's only a matter of time before someone less forgiving than me deletes it. $\endgroup$ – Azuaron Sep 28 '17 at 13:23
  • $\begingroup$ Edited @Azuaron $\endgroup$ – DannyBoy Sep 28 '17 at 14:39

If radio waves can’t be used then it would delay space exploration as there would be no easy means to communicate with space craft initially. However given a few more decades of technological advancement microwaves could be used instead or visible light by way of lasers, unless these were also blocked. Ultimately any electromagnetic wave might be used for communication, (some more easily than others). If all electromagnetic waves require an atmosphere to propagate then the earth would be a very different place as it would recieve no heat or light from the sun.


Radio propagation does not need an atmosphere. It is the Ionosphere which may reflect some radio waves back to Earth, so an earth-based station may send signals at some frequencies across the globe without a satellite to act as a relay station.

This wikipedia article on ionosphere explains the process

Now, the second part: Change the atmosphere of the planet (or you can just say it is different, without specifying its composition) and say that the ionosphere is more reflective and is so over a broader frequency range. The radio technology has evolved well before space exploration and satellite launching became feasible, so signaling relies on the ionosphere rather than satellites. You can complicate things by saying this reflective layer works in both directions, so future satellites will have difficulty communicating with earth-based stations.


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