There are more stars in the heavens than all the grains of sands covering the world’s beaches — Carl Sagan
While watching Star Trek, once in a while I stop and think that while visiting far corners of the galaxy the Enterprise not only comes across biological forms, but they also share similar sensory traits as I do.
Us and the aliens Enterprise encounters share a common perception of the world. They have physiology for visual perception that is sensitive to same part of electromagnetic (EM) spectrum — the EM waves between 380 nanometers (nm) (violet) to about 750 nanometers (nm) (red). They have auditory senses that respond to compression (or longitudinal) waves between 20Hz to 20,000 Hz.
It could just be a construct of the mind of the script writers (it is a show made for entertainment). However, there could be a physical basis for it.
The previous posts (see links below) had discussed that in an energy constrained environment, emergence of the mechanism of natural selection is an inevitability. Following the principles of natural selection, the sensory traits of biological organisms on the Earth, including us, have evolved to best fit the environmental conditions.
The reason my eyes are sensitive to a particular part of the EM spectrum is that the Sun (that is the source of all energy for biological organisms on the Earth) emits radiation intensity of which peaks in the range biology of eyes is sensitive to. Evolving under the constraint of the characteristics of the Sun, the physiology of eyes developed accordingly.
Knowing a physical basis for the characteristics of my sensory physiology provides a clue why the Enterprise encounters biological organisms like me.
Let us consider some facts about stars and the Sun.
The Sun is one star among billions that reside in a galaxy called the Milky Way. The number of galaxies in the universe is estimated to exceed a trillion. By any estimate, the number of stars in the universe is staggering.
Astronomers have measured the distribution of various characteristics of stars like their size, brightness, surface temperature and have classified them in many ways. One way of classifying stars is according to their temperature.
The temperature of stars ranges from about 30,000 K to 3,000 K. The temperature of the star also determines the spectral power distribution (SPD) (which refers to amount of radiation a star emits at different wavelengths).
The relationship between the wavelength at which the SPD peaks and temperature is known as Wein’s law and states that the peak wavelength of emission is inversely proportional to the temperature of the star. The peak of emission wavelength of hot stars is towards shorter (bluer) wavelengths, while cooler stars peak at longer (redder) wavelengths.
The SPD of the Sun peaks around the wavelengths that the physiology of our eyes is sensitive to. No surprise there as natural selection shaped it to be so.
Among the billion or more stars in our galaxy about 3–4% of stars share the same SPD characteristics as the Sun. In the neighborhood of those suns if biology evolved and progressed to where we are today, the physiology of their eyes, by necessity of natural selection, would be somewhat similar to ours.
We would share organs for visual perception that will respond to similar wavelengths.
And so, the possibility that while visiting far corners of the galaxy, the Enterprise comes across biological forms that share sensory perceptions like I do, does not have to be a complete fantasy. Its plausibility is grounded in sound physical basis.
Ciao.
Of interest:
The reason I see and hear what I see and hear
Fitting in a Puddle
Natural Selection: Could there be any other alternative?
Inevitability of Natural Selection
Inevitability of Natural Selection (Take II)
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