- #1
bobie
Gold Member
- 720
- 2
Hi,
what is the lowest visible frequency? can anyone see light with f less than 4*1014 Hz?
what is the lowest visible frequency? can anyone see light with f less than 4*1014 Hz?
Thanks, just out of interest, actually the bolded part is what interested me most. I must learn to "canvass", I regret I did not know that , and got a yellow card!Simon Bridge said:This is a very commonly asked question - did you try canvassing the answers?
The longest wavelength most people have a chance of seeing is 780nm ... with differences between individuals.
What do you want to know for?
Is there really a chance I could do that?, I'd love toSimon Bridge said:That wavelength is incredibly difficult to see - try it.
I am only a student and probably do not belong here.Simon Bridge said:Googling your question is a good tool
Read lots of replies.
780nm diodes are not inexpensive ... take care though.bobie said:Is there really a chance I could do that?, I'd love to
Nonsense. This site exists to help students struggling with this sort of material.I am only a student and probably do not belong here.
That is why you look at lots of answers - yu soon learn which sites are reliable.I tried googling but it is dangerous for me as I cannot distinguish good sites from bad :
I found a site on QM that explained things very clearly, I asked in a (probably my first) thread if it was reliable (how could I know?) : the thread was deleted and I was reprimanded as the answer, apparently, was "no"
hyperphysics is an educational site so it gives the standard limits ... more detailed information usually requires more detailed background knowledge.In this case I tried at a good site a mentor recommended:
http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html
and it gives ( like wiki and other sites) a figure of 700 nm, which I suspected to be a rounded figure. You confirmed that, but I could not possibly expect such a different figure of 790 , the one you gave me
Variation between individuals can be dramatic - with some people unable to see any red light at all.And then, I was curious to know if that can vary a lot with individuals.
The lowest visible frequency is the lowest frequency of electromagnetic radiation that can be detected by the human eye. It is commonly known as the color red and has a wavelength of approximately 700 nanometers.
The lowest visible frequency is determined by the sensitivity of the human eye to different wavelengths of light. The eye is most sensitive to green light, which has a frequency of approximately 540 terahertz, and becomes less sensitive to lower frequencies, such as red light.
Yes, the lowest visible frequency can be seen by everyone with normal color vision. However, some people with color vision deficiencies may have difficulty distinguishing between different shades of red.
In addition to the lowest visible frequency of red, the colors orange, yellow, green, blue, and violet are also associated with different frequencies of visible light. Violet has the highest frequency, while red has the lowest.
The lowest visible frequency, or red light, is commonly used in traffic signals, emergency vehicles, and warning signs due to its high visibility and contrast with other colors. It is also used in photography and film to create a warm or dramatic effect.