Okay, as everyone knows (or at least I would hope so!) our eyes can't see infra-red or x-rays etc... how do we know that aliens might only be able to see infra-red or x-rays? Does anyone think that's possible or do you think they'd be able to see the same visible light that we can?

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"The stars are my home"
"I've seen things you people wouldn't believe... Attack ships on fire off the shoulder of Orion... I've watched c-beams glitter in the dark, near the Tanhauser Gate... all those moments will be lost, in time... like tears in the rain..."

It would depend on what they need to be able to see.

Yeah it depends on what kinda alien they are ^^

what they need to see and what environment they "evolved in". Perhaps they won't see in the light range... or that is particle waves, perhaps they will see gravitational effect? Even creatures from the depths of the ocean in total darkness tend to "see" light,(bioflouresence) and have huge pupils... Bats see mostly sound... They have eyes indeed, but navigate through another sense... Who knows?

considering the vast array of vision types on Earth (even using sonar...eg bats), I'm sure it is likely that alien species are equally diverse with how they perceive their surroundings. Like Parker said, it's all about evolution. These aliens would evolve to be able to see what they need to see in the way that they need to see it in order to survive.

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Climate Change Australia

Whatever environment they were brought up in. They would see what they were ment to see. See?

i find more possible that aliens react in a different way than earthlings than vice versa, same goes for human 'looking' at alines but being unable to 'see' them

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<span style='color:purple'><span style='font-family:Impact'>i dont know much </span></span>

Of course there is always the possibility that aliens live in the same universe but an a different plane of existance.

What do you mean by different planes of existence?

Yeah, I think you're right re environment

I'm curious to know about how aliens would exist in other dimensions too...

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"The stars are my home"
"I've seen things you people wouldn't believe... Attack ships on fire off the shoulder of Orion... I've watched c-beams glitter in the dark, near the Tanhauser Gate... all those moments will be lost, in time... like tears in the rain..."

To be alien on a seperate plane must be awfully frustrating. I would hope a clue or too would be left to inspire a motion for th0ught.

or indeed exist in a different wavelength than the range that we can 'see'

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Damien,
International Baccalaureate Physics teacher
Optics, Photogrammetry and Remote Sensing Instrumentation Major
Admin: Pacific Science and Art

I would think they don't need eyes and they proabley don't see.
After all they have that telepethy.

and may have manipulated light like in the Predator

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Damien,
International Baccalaureate Physics teacher
Optics, Photogrammetry and Remote Sensing Instrumentation Major
Admin: Pacific Science and Art

Though in "predator" he gave proof of earlier existance. :huh:

true, but i was referring to the technology

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Damien,
International Baccalaureate Physics teacher
Optics, Photogrammetry and Remote Sensing Instrumentation Major
Admin: Pacific Science and Art

Make-up, camoflauge(?checK) survival...light,heat,sound..., where does it begin?

from the beginning...it is hard to even predict what an alien civilisation has accomplished

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Damien,
International Baccalaureate Physics teacher
Optics, Photogrammetry and Remote Sensing Instrumentation Major
Admin: Pacific Science and Art

Well, I think visible light or echo ranging would be needed by all species. In order to be a space traveling bunch, sight would be essential. Sight, or the ability to see, in one way or another is one of natures greatest technological wonders. I don't forsee a species developing beyond the need of sight. On the contrary, it would probably be one of the senses that would be enlarged and improved upon.

I think any alien species would have the ability to perceive at a distance. On earth this includes sound (vibration of some medium), sight (electromagnetic detection) and smell (i.e. motion of small particles - I believe dogs' perception is primarily scent-based). Touch and taste need contact so would have limited use on their own so are unlikely to evolve as the main method of perception.

If you're looking at a space-faring species, they could perceive using almost any part of the electromagnetic spectrum. There is no reason why they'd be limited to just our visible wavelengths. Many of the astronomical images that are published are in other wavelengths (infra-red, radio etc.) so it all depends what local conditions exist on their planet. Whichever wavelengths are most prevalent would be the ones they considered "visible".

A species that, say, only perceived sound would never see any objects outside their atmosphere so it would be very difficult for them to start exploring their solar system, let alone other stars. So I think any species we bump into will be able to see some part of the electromagnetic spectrum. So we should be able to construct equipment to allow us to see the same things as them, and vice versa.

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Spike
:)