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If we cant see all the spectrum does this mean that maybe exist objects we cant perceive? or it just the colors we cant perceive?

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Yes, it's possible for there to be objects which are invisible to human eyes but which would be detectable using wavelengths outside the visible range.

A simple example is index-matched beads, which become invisible when submersed in water because their refractive index for visible wavelengths matches that of water, and there is no longer refraction and reflection at the bead's surface (which is how you see them when they're in air). It is perfectly conceivable to retain this behaviour while also asking for a difference in refractive index from that of water in the ultraviolet or infrared regimes, in which case a UV or IR camera would be able to detect them.

Generally speaking, though, it would take a dedicated effort to manufacture such an object, and it would only work in limited circumstances.

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  • $\begingroup$ but how can we are sure that next to our chair or table isnt an invisible for us table ? its the common sense that lead us to minize such assumptions ? $\endgroup$ – ado sar Oct 11 '18 at 19:56
  • $\begingroup$ @adosar How can you be sure that the world won't end spontaneously in the next hour? How can you be sure that there isn't someone with a bat behind your shower curtain waiting to assault you? How can you be sure that you don't live inside the Matrix? $\endgroup$ – Emilio Pisanty Oct 11 '18 at 19:59
  • $\begingroup$ i am not sure and thats why i am asking...i wanted to say that what we see is only what we can see...i asked from a scientific point of view not a philosophy one... $\endgroup$ – ado sar Oct 11 '18 at 20:08
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    $\begingroup$ If you suspect an invisible object then you can always check by touch. $\endgroup$ – my2cts Oct 14 '18 at 21:04

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