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mattjouff t1_iqsoich wrote

That’s usually not a limiting factor since you would lose the resolution of features smaller than IR wavelength so unless you are trying to resolve ants on Jupiter it won’t matter too much for astronomers!

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exoplanetaryscience t1_iqsxnyj wrote

That's not the same principle. The diffraction limit pertains to angular size, not physical size. You are correct that you wouldn't be able to resolve things smaller than a given wavelength, but the diffraction limit can apply to arbitrarily large objects as long as they appear small. A 100,000-light-year-across galaxy will simply appear lower resolution in an IR telescope than a visible-light telescope of the same aperture/focal length.

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Davidjb7 t1_iquic47 wrote

Exactly. The diffraction limit has to do with the limiting spatial frequency of the system, so for telescopes it's usually their apertures.

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