Those who have eyes, let them see.

Source:  Those who have eyes, let them see.    Tag:  longest wavelength visible to the human eye
The combined circumstance that we live on Earth and are able to see stars— that the conditions necessary for life do not exclude those necessary for vision, and vice versa—is a remarkably improbable one.

This is because the medium in which we live is, on the one hand, just thick enough to enable us to breathe and to prevent us from being burned up by cosmic rays, while, on the other hand, it is not so opaque as to absorb entirely the light of the stars and block any view of the universe.

What a fragile balance between the indispensable and the sublime.
—Hans Blumenberg

To truly appreciate our good fortune, [in being able to see quite far] at least once everyone should stand on a mountaintop under the open sky, on a clear, moonless night. The air is so clear, and the stars so vivid, that only your lungs will remind your eyes that you’re on a planet with an atmosphere.

Consider the atmosphere’s transparency, which is actually just part of the story. Our atmosphere participates in one of the most extraordinary coincidences known to science: an eerie harmony among the range of wavelengths of light emitted by the Sun, transmitted by Earth’s atmosphere, converted by plants into chemical energy, and detected by the human eye. The human eye perceives light of different wavelengths as different colors, ranging from violet blue (the shortest wavelengths in the visible spectrum) to red (the longest). Looking at a diagram of the electromagnetic spectrum, we see the visible light emerging gracefully from the ultraviolet, differentiating into the familiar colors of the rainbow, and disappearing seamlessly into the warm, invisible infrared. The visible wavelengths rise and fall at the nano-scale, the distances from their peaks measured in ten-billionths of a meter, called Angstroms (A). We see blue at approximately 4,800 A, green at 5,200 A, yellow at 5,800 A, and red at 6,600 A. Earth’s atmosphere is transparent to radiation between 3,100 to 9,500 A and to the much longer radio wavelengths. The radiation we see is near the middle of that range, between 4,000 and 7,000 A, the range in which the Sun emits 40 percent of its energy. Its spectrum peaks smack in the middle of this visible spectrum, at 5,500 A. This is but a tiny sample of the entire range.
As it happens, our atmosphere strikes a nearly perfect balance, transmitting most of the radiation that is useful for life while blocking most ofthe lethal energy.

(The Privileged Planet: How Our Place in
the Cosmos is Designed for Discovery,
by Guillermo Gonzalez and Jay W. Richards :65-67)

Those who have eyes, let them see. Stated another way, there is a lot of evidence, much more than that, that habitability (Life, those who have eyes.) is associated with measurability (Let them see, read. See the signs, read the signs...).

Yet in reading the Bible, Jesus and the prophets already said it. Those who have ears, let them hear. Those who have been designed and designated as seekers, let them find. Those who have a mind, let them think through their brain.

And the masses, the metaphoric "sand on the seashore" that was always meant to run the human race that is layed out for it, let them run. It all seems to be just so, everything layed out in patterns so that human civilization can rise quite high. But perhaps to those at the end of the race, to whom much is given, much is required.

For those who want knowledge and answers as to this part of the race, the human race, you probably will get some at the end of it. It seems that one way, or another way.... your mind will have its answer. The call of the prophets is to see the Sign and hear the Word now, yet even now your mind probably rejects it. Mine often does too, for that matter...

It seems, very sensible to try to see and hear it now. It makes sense. Besides, the absence of sense is nonsense.