(This is a carry on from my previous question about Oxygen pooling)

I am creating a world that is made up of Oxygen - in deep caves/sink holes, and Hydrogen/Helium (possibly Methane) in the higher levels.

I would like my characters to be able to visually see the different gasses as they travel the world, through the use of goggles or a helmet.

I know we can distinguish the atmosphere and makeup of different planets by the colour. But isn't that usually based on the colour of the surface? As in - what the gas has done to the surface is what we are looking at, rather than the gas itself?

Oxygen, Helium and Hydrogen all have different absorption wavelengths in nm. e.g.

Hydrogen 433, 486, 656

Helium 447, 502, 587, 668

Oxygen 464 to 467, 559, 626, 760

Does this mean (theoretically) that you could create a filter (helmet/goggles) that could be tuned to these specific spectrum's so you could "see" the different gasses on planets?

  • $\begingroup$ Well, if you used a proper frequency laser, but I don't think that is what you had in mind. $\endgroup$ – Jimmy360 Jun 17 '15 at 2:39
  • $\begingroup$ Thanks @Jimmy360 do you think that would work if you looked through a frequency laser? e.g. if the laser was bounced back and forth across/inside the viewport of a helmet? $\endgroup$ – JimDiGriz Jun 17 '15 at 2:44
  • $\begingroup$ No, it would have to hit the gas. $\endgroup$ – Jimmy360 Jun 17 '15 at 2:44
  • $\begingroup$ Consider rephrasing the question. I believe technically this is off-topic as currently worded but the spirit of the question falls into the realm of the board. "What color would I see on a planet with XYZ atmosphere?" "Could I make goggles to distinguish the different gasses in an atmosphere?" etc. $\endgroup$ – Jim2B Jun 17 '15 at 4:06
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    $\begingroup$ FLIR makes a camera that can identify gasses. It could easily be incorporated in to a pair of goggles through the power of scifi magic- $\endgroup$ – Magic-Mouse Jun 17 '15 at 6:26

With some effort, yes.

This wouldn't be a filter, specifically, but a very sophisticated imaging system. I doubt we have the engineering ability to build such a thing currently, but performing realtime (60 FPS), very high resolution, pixel by pixel spectroscopy different gases could be mapped as different colors on a user's head mounted unit.

However. It wouldn't have atomic resolution, so if you're in something like Earth's atmosphere you'll just see the combination of gases right in front of your face. Making gases opaque is not a great way to view the world.

  • $\begingroup$ Actually samuel, this is a thing, and it is being produced today. I don't know how much is public but the latest in the tech is pretty impressive. $\endgroup$ – Magic-Mouse Jun 17 '15 at 7:38
  • $\begingroup$ @Magic-Mouse Sorry I know it's used in space and for photos. I mean making a video version that processes in real time and is head mounted. That's hard. $\endgroup$ – Samuel Jun 17 '15 at 14:28

Plausible. Look up the spectra of those gasses, as used by space probes. A sense could hace a tuned peak to be sensitive to oxygen. This might be separate from the normal visual sense, with distinct organs that have directionality but no resolution, like a pit viper does with IR. I expect it would need to be in the UV range.

The different absorbsion peaks you mention are complicated by the fact that gas is almost completely clear in visible range, so how can you tell if the air is darker?

You could handwave a differential brightness between the peak and adjecent frequency that is sensitive to very low levels. Maybe you can only see it if sighting the sun through it.

If you are looking for oxygen seeps, perhaps they use smell to detect higher than ambient concentration and gradient, to locate the source.

Also, you could detect all the other stuff that goes with the microbiome. Think about the abyssal plane: if you could not detect the hydrogen sulfide directly, you will still notice the dense fauna growing around it: enter image description here

Another idea follows from the deep sea vent analogue: the hydrogen sulfide is emitted through vents at very high temperature. Certain shrimp at the vents can sense the IR, which finds the vents which just happen to emit the gas of interest. You will have a complete package of geological effects that go with the phenomenon of oxygen seeps.

  • $\begingroup$ Thanks @JDługosz - this is all great stuff. I like the idea of the creature being able to smell the difference. Didn't consider that. $\endgroup$ – JimDiGriz Jun 17 '15 at 22:11

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