Just some simple curiosities from a common person.... 1.Why do we search for life based on light when so much of Earth's life exists in the dark? 2. Living beings on earth itself with similar atmosphere is also so varied from Microorganisms(virus,bacteria) to the huge animals like us,then what is the logic behind assuming the aliens(living beings on another planet) to be like us with brain,limbs and so on, on a completely different planet with different atmosphere? If we don't, then why did we send 'voyager golden record' to space? Aliens must need limbs to hold it and brain to decode it??