Why do chemical substances affect our senses differently?

  • Context: High School 
  • Thread starter Thread starter beste ulusoy
  • Start date Start date
  • Tags Tags
    Sound
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
Sign up Log in
24 replies · 4K views
beste ulusoy
Messages
5
Reaction score
0
i know this is a primitive question and to be answered in my head. eventually both light and sound are a wave carrying information and energy. is speed of light effective to we see it?
 

Discussion

Physics news on Phys.org
We have receptors in our eyes that are excited (chemically altered) when light of a certain wavelength of photons (440-770nm) impinges upon them. That is what we call "seeing".

The thing we call sound is actually pressure waves of molecules (not photons), usually of air. These waves have wavelengths on the order of metres (millions of times longer than light). Our receptors are not excited by moving molecules (of air or of retinal fluid).
 
  • Like
Likes   Reactions: Gcshiba
We do hear sounds. I think that some animals can form a pretty accurate representation of their surroundings using sound. They have suitable sensory organs to do that.
Due to the different nature of the sound and light waves, we need different organs (sensors) to reveal them (as DaveC426913 said better than me)
 
FranzDiCoccio said:
We do hear sounds. I think that some animals can form a pretty accurate representation of their surroundings using sound. They have suitable sensory organs to do that.
Did you want to edit that question? The OP was not asking about hearing sounds.
 
FranzDiCoccio said:
We do hear sounds. I think that some animals can form a pretty accurate representation of their surroundings using sound. They have suitable sensory organs to do that.
Due to the different nature of the sound and light waves, we need different organs (sensors) to reveal them (as DaveC426913 said better than me)

DaveC426913 said:
Did you want to edit that question? The OP was not asking about hearing sounds.

I think you're both right. Franz was speaking somewhat metaphorically and should have said "we do SEE sounds" ... well, not us really but bats for example are known to "see" using sound.
 
DaveC426913 said:
Did you want to edit that question? The OP was not asking about hearing sounds.

No I just tried to avoid interpreting too much the question. Perhaps I focused too much on the fact that there is more than revealing photons involved in "seeing".
I was trying to help, anyway.
 
Hyo X said:
you can see sound using the ruben's tube
Well, if you want to go that way, there are tons of light-display things that are sound-wave driven and even an oscilloscope let's you "see" sound.

I'm pretty sure this is not what the OP had in mind.
 
FranzDiCoccio said:
We do hear sounds. I think that some animals can form a pretty accurate representation of their surroundings using sound. They have suitable sensory organs to do that.
Due to the different nature of the sound and light waves, we need different organs (sensors) to reveal them (as DaveC426913 said better than me)
To some extent humans also form a kind of mental image of their surroundings from auditive cues, and this ability can be enhanced with training:
https://en.wikipedia.org/wiki/Human_echolocation

The longer wavelengths of sound impose a limitation to how precise this can be, but sound at say 3000Hz, has about 10cm resolution so it isn't that bad (echolocation relies on clicks which aren't pure frequencies)

Also the fact that we so not see the auditive image in the same way as a visual one is related to the physical process but also to the brain "post-processing"
 
  • Like
Likes   Reactions: atyy
atyy said:
were the echolocation experts blind from birth?
Some were, others lost their sight during childhood or later. Not sure about those included in that study.

Edit : From the article :
Two blind skilled echolocators participated in the current study. Participant EB (43 years at time of testing) had partial vision up to 13 months of age. At 13 months, his eyes were removed due to retinoblastoma (early onset blindness). Participant LB (27 years at time of testing) lost vision at age 14 years due to optic nerve
atrophy (late onset blindness).
 
Last edited:
  • Like
Likes   Reactions: atyy
Is it possible for animals that are deaf to see sound since they have more/less receptors in their eyes? Maybe flies? Sometimes when I shout at them they appear to be startled and fly away.
 
Shu Sheng said:
Is it possible for animals that are deaf to see sound since they have more/less receptors in their eyes? Maybe flies? Sometimes when I shout at them they appear to be startled and fly away.

Sound is nothing but vibrations in air. Bass drums move the air so much we feel this with our entire body. But any sufficiently thin sheet of matter, that can vibrate with the air, will be sensitive to sound. Membranes are optimized for this.

I'm not a fly expert, but I would expect their wings to be so thin that any noise would make them move just enough that the fly senses it. Maybe it's another part of of their body. There is no point in using the word "see". If something is sensitive to air vibrations, we use "hear", sense", or "receive".
 
beste ulusoy said:
i know this is a primitive question and to be answered in my head. eventually both light and sound are a wave carrying information and energy. is speed of light effective to we see it?

You are right they are both waves that carry information and energy but they are very different kind of waves. Light is a wave of the electromagnetic field and carries energy of electric and magnetic field. Sound on the other hand is a wave of matter (also referred to as mechanical wave) that carries kinetic energy of the molecules of the medium it is transmitted within (the medium for sound is usually air). Now our eyes can sense only waves of electromagnetic field that have a frequency between 1000-2000TeraHz. It is our ears that can sense mechanical waves in the air with frequency 4hz-22Kilohz. To emphasize it again it is not only the different range of frequencies it is that they are different kind of waves as i said in start. (1kilohz=1000hz, 1Terahz=1000 billion hz)

helpfull should be the following link, should be enough to read just the intro section http://en.wikipedia.org/wiki/Wave
 
Last edited:
Delta² said:
. Now our eyes can sense only waves of electromagnetic field that have a frequency between 1000-2000TeraHz. It is our ears that can sense mechanical waves in the air with frequency 4hz-22Kilohz. To emphasize it again it is not only the different range of frequencies it is that they are different kind of waves as i said in start. (1kilohz=1000hz, 1Terahz=1000 billion hz)
While this is true, I think the frequency is probably the key difference though : other differences mostly mean that we need different types of sensors to detect them, but the kind of perceptual image we can form depends only weakly on that (and studies of echolocation or synesthesis suggest there is some overlap between the two forms of perception).

EM waves in the kilohertz frequency range are VLF radio waves - and if we had sensors receptive to these, 'EM sensitive cochleas' so to speak (which we could actually get artificially by using a radio receiver connected to an earphone), we could hear EM waves.

(Note that while a radio set also converts EM waves to sound, it is differs from such an "EM ear" in that the the sound frequencies it produces do not directly correspond to the EM frequencies received)
 
Last edited:
Sound is a kind of disturbance, right?? It travels by vibrating molecules which can't be seen with a naked eye. So we can't see sound. I don't know whether this is true or not. But that's what my imagination is. I'm just in 9th grade. Please correct me if I'm wrong.
And I have another thought, sound is not a substance right?? It doesn't have any particles but it solely moves through molecules. Sound is a vibration / disturbance. We can see vibrating bodies but we cannot see vibrations..
 
Blackberg said:
I'm not a fly expert, but I would expect their wings to be so thin that any noise would make them move just enough that the fly senses it. Maybe it's another part of of their body.
Yup. Almost all insects and arachnids are covered in tiny hairs that are sensitive to vibration.
 
DaveC426913 said:
Yup. Almost all insects and arachnids are covered in tiny hairs that are sensitive to vibration.
Ah yes. If I remember correctly, these are actually quite similar (well, if not they at least perform the same function) to the "hairs" or ciliae that serve to detect sound in the human ear.
 
Animals which are blind, I guess, do not see sound but they image their surroundings with the help of sound... Isn't it??
 
I am not sure if some of the terms have been used in this thread are justifiable by biologists.
manogyana25 said:
Animals which are blind, I guess, do not see sound
By definition, sound is not seen, it's heard. Except of this issue, I guess you are right. But vibrations in air are actually not the only way with which certain species analyze their surrounding, some of them rely on chemical substance as well.
 
It's partly a matter of semantics here.
We and other animals can perceive light because eyes have photo receptors which produce signals which are then processed by the brain.
The result is what we call vision, or 'seeing'.
Similarly animals can perceive sounds because ears have receptors sensitive to air pressure waves.

Both are forms of perception, but generally the term 'seeing' refers only to perception of light.
 
blue_leaf77 said:
I am not sure if some of the terms have been used in this thread are justifiable by biologists.

By definition, sound is not seen, it's heard. Except of this issue, I guess you are right. But vibrations in air are actually not the only way with which certain species analyze their surrounding, some of them rely on chemical substance as well.
Chemical substances?? Sorry, I didn't get you.. Can you explain more clearly?
 
manogyana25 said:
Chemical substances?? Sorry, I didn't get you.. Can you explain more clearly?
The easiest example would be that human can taste and smell.
Basically all living creatures are sensitive to chemicals, if not they wouldn't have been able to identify their nutrition (food). Foods are not to be heard, are they? They are tasted, the way of tasting may differ for different species.