You're absolutely right in observing that the electromagnetic spectrum is incredibly vast, with wavelengths ranging from much smaller than an angstrom (on the scale of subatomic particles) to several kilometers long. The visible spectrum, which is what humans can see with the naked eye, represents only a tiny fraction of this entire range.
The reason we assign specific boundaries to the visible spectrum, despite the spectrum’s broad and undefined limits, is based on human perception. Our eyes are only sensitive to electromagnetic waves within a certain wavelength range, typically between about 400 nm (violet) and 700 nm (red). This range is a product of the biological evolution of human vision, and it’s a practical convention for discussing the range of light we can detect. However, as you mentioned, the boundaries of the electromagnetic spectrum extend far beyond this range. For instance: - *Gamma rays* have wavelengths shorter than about 0.01 nm. - *X-rays* range from about 0.01 nm to 10 nm. - *Ultraviolet (UV) light* spans wavelengths from about 10 nm to 400 nm (just shorter than visible light). - *Infrared (IR) light* ranges from about 700 nm to 1 millimeter. - *Microwaves* range from about 1 millimeter to 1 meter. - *Radio waves* can extend from 1 meter to many kilometers. Since the visible spectrum is so small relative to the total range of electromagnetic radiation, it’s often expressed as a percentage of the total spectrum in a very approximate way. If you consider the entire spectrum of wavelengths, the visible light range is less than 0.1% of the total electromagnetic spectrum. The lack of precise boundaries on either end of the electromagnetic spectrum only adds to the difficulty of assigning a specific percentage to the visible spectrum. We could never define exact "endpoints" for the range, but in the context of human vision, we apply convenient, agreed-upon boundaries for clarity and practicality. In short, the visible spectrum is just a small portion of the electromagnetic spectrum, and its boundaries are drawn from human perception, not from some natural, fixed cutoff in the broader spectrum. K Rajaram IRS 29325 ---------- Forwarded message --------- From: Srinivasan Sridharan <[email protected]> Date: Fri, 28 Mar 2025 at 23:12 Subject: Re: Percentage of the visible spectrum in the total electromagnetic spectrum To: Markendeya Yeddanapudi <[email protected]>, Rajaram Krishnamurthy <[email protected]> I understand that the total electromagnetic specteum has wavelengths. ranging from less than simgle armstrong units to even more than several kilometers. Infact nobody has found the boundary limits of the shortest and the longest wavelengths of electromagnetic waves! How can then be possible to give the visible spectrum any percentual boundary from the totality ofpossible range?! Sridharan. On Mar 28, 2025, at 12:03 AM, Markendeya Yeddanapudi < [email protected]> wrote: So what we cannot see is 99.9965% of the totality,where one has to practice feeling,to access the gigantic invisible spectrum or the feeling only arena. YM On Fri, Mar 28, 2025 at 11:47 AM Rajaram Krishnamurthy < [email protected]> wrote: > Yes true. Hence only knowledge is appreciated. Aviveki does not know about > it. K Rajaram IRS > > On Fri, 28 Mar 2025, 11:23 Markendeya Yeddanapudi, < > [email protected]> wrote: > >> The visible spectrum which enables seeing by the eyes is just 00.0035% of >> the total electromagnetic spectrum. >> Chat GPT >> >> >> >> -- >> *Mar*The visible spectrum represents only a small portion of the total >> electromagnetic (EM) spectrum. The entire electromagnetic spectrum spans a >> vast range of wavelengths and frequencies, from very long radio waves to >> extremely short gamma rays. >> >> The visible spectrum, which humans can see, ranges roughly from 400 nm >> (nanometers) to 700 nm in wavelength, covering all the colors of light. >> This range is a tiny fraction compared to the entire EM spectrum. >> >> To give you a sense of scale: >> >> - >> >> The entire electromagnetic spectrum includes radio waves, microwaves, >> infrared, visible light, ultraviolet, X-rays, and gamma rays, with >> wavelengths ranging from thousands of kilometers (for radio waves) to >> fractions of a nanometer (for gamma rays). >> - >> >> The visible spectrum occupies only about *0.0035%* of the entire >> electromagnetic spectrum. This is because the visible range of light >> (approximately 300 nm in total width) is very small compared to the vast >> range of wavelengths that the EM spectrum covers. >> >> In short, the visible spectrum is a very tiny part of the electromagnetic >> spectrum. >> > -- *Mar* -- You received this message because you are subscribed to the Google Groups "Thatha_Patty" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/thatha_patty/CACDCHCJ7W-%2BrS4_GhgXC6QWHi2dR6PWsxsLE4fqVzAXyBuB05g%40mail.gmail.com <https://groups.google.com/d/msgid/thatha_patty/CACDCHCJ7W-%2BrS4_GhgXC6QWHi2dR6PWsxsLE4fqVzAXyBuB05g%40mail.gmail.com?utm_medium=email&utm_source=footer> . -- You received this message because you are subscribed to the Google Groups "Thatha_Patty" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. 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