# Why can’t transverse waves travel through a gas or liquid?

1. Dec 23, 2015

### Barclay

1. The problem statement, all variables and given/known data
Why can’t transverse waves travel through a gas or liquid?

2. Relevant equations

3. The attempt at a solution
I understand that transverse waves require rigid medium through which to transfer their energy so they can travel through solids.
I'll just accept that transverse waves can travel through a vacuum.
I accept that transverse waves cannot travel through a liquid or gas because the medium is not solid BUT the light is a transverse wave and it passes through through the air (a gas) in our atmosphere. Also can see the torch light of a scuba diver in the ocean (a liquid).

This is high school physics level.

2. Dec 23, 2015

### Staff: Mentor

Who says transverse waves can't travel through a liquid or a gas?

Chet

3. Dec 23, 2015

### SteamKing

Staff Emeritus
This looks like transverse waves to me:

4. Dec 23, 2015

### Barclay

I've read it in text books and been searching the Internet and have seen the same information. I don't understand (don't believe it) because: we can see the torch light of a scuba diver in the ocean (a liquid).

Here;s a link to someone else asking the same sort of question but the answer does not make sense:

5. Dec 23, 2015

### SteamKing

Staff Emeritus
Well, Yahoo! Answers is not a reputable scientific source. People vote on the correct answer.

BTW, that thing about they can't put something on the internet if it's not true, well, it's not true.

6. Dec 23, 2015

### Barclay

I wasn't using Yahoo answers to study, only to give me an answer for a question similar to mine.

I knew that I could post my question here but was fearful of doing so. I've posted many on this forum and just get bogged down with riddles. Takes days and days to decipher an answer. Some of my questions I've just abandoned because I just can't get a straight answer. This is not a criticism. I know the forum rules and the intention is to make me learn more .... but I'm of simple mind and sometimes can't do it.

7. Dec 23, 2015

### SteamKing

Staff Emeritus
Well, if you have general questions which aren't course related, posting them in the Homework Forums is probably not a good idea, since the Rules for these Homework Forums prohibit people from simply giving you 'straight' answers.

There are several different technical forums, such as the General Physics forum, where the rules aren't as strict.

8. Dec 23, 2015

### Staff: Mentor

When they say that transverse waves cannot travel through a liquid or a gas, what they really mean is that shear waves cannot exist in a liquid or gas. This is because it is often believed that a liquid or a gas cannot support a shear stress. However, we know from Newton's law of viscosity that liquids and gases can support shear stress. This is because all real liquids and gases have non-zero viscosity. Only ideal inviscid fluids have zero viscosity. But, in the real world, there is no such thing as an ideal inviscid fluid.

Chet

9. Dec 23, 2015

### Barclay

Thanks. So is it best to say : Transverse waves do not travel as well through gases and liquids as they do through solids. They travel best through a vacuum where they are unhindered by collisions between particles?

10. Dec 23, 2015

### Staff: Mentor

When they are referring to transverse waves in this context, they are not referring to electromagnetic waves. They are referring to mechanical waves. Electromagnetic waves travel just fine through liquids and gases.

11. Dec 23, 2015

### Barclay

Hello I understand that electromagnetic waves are transverse waves but what are mechanical transverse waves.

Are water waves are mechanical transverse waves? Are there any examples?

12. Dec 23, 2015

### Barclay

Just found these examples of mechanical waves: vibration of string, , the surface wave produced on the surface of solid and liquid, sound waves, tsunami waves, earthquake P-waves, ultra sounds, vibrations in gas, and oscillations in spring, internal water waves, and waves in slinky .

13. Dec 25, 2015

### Jimmini

Extremely low frequencies are used for sub to surface communications.

14. Dec 25, 2015

### Barclay

Thanks all for your replies. I just needed to be told about mechanical transverse waves and electromagnetic transverse waves. Didn't know about the mechanical. When I found out it all clicked into place.

Longitudinal water waves are used in submarine sonar and by dolphins.
Transverse water waves are surface water waves.
Thanks