Hi,

 

I got this question in my head....... Of course it seems quite true that there is no sound in space. But there might be exceptions. So is our universe completely silent??

What do you mean?

Where there are particles, there can be sound. There is no sound in a vacuum as sound propagates as movement of particles.

The less dense your area of particles are (i.e. air), the slower sound moves. The more dense it is (i.e. water), the faster it moves.

 

So no, the universe is not completely silent. It is for the most part simply because there are very few particles in deep space.

Hmmm...... The density of our universe is too small and therefore negligible. So we can assume that the universe is silent.

It depends how you look at it. The question is not as straightforward as you think it is.

If you want a simple answer, then yes, for the most part, the universe is silent as there are very few particles which would create sound.

I think there is 'noise' in the microwave range as cosmic background radiation.

Hi,

 

I got this question in my head....... Of course it seems quite true that there is no sound in space. But there might be exceptions. So is our universe completely silent??

It isn't "silent", there is noise in the 13 Mhz range. See here

Hmmm...... The density of our universe is too small and therefore negligible. So we can assume that the universe is silent.

 

You just disappeared in a puff of logic. You were too small a part of the universe to exist.

There is of course an easy answer to this , the Universe is always silent unless there is hearing to hear it.

Ok. But those sounds can't be picked by our ears. I consider the human ear as the receiver.

Ok. But those sounds can't be picked by our ears. I consider the human ear as the receiver.

 

Human ears don't exist. They're too small and therefore negligible. Or do I detect some goalpost moving?

 

You seem to be purposely setting up conditions for some kind of paradox.

Hmmmm.... I see . Moreover the sound of 13 MHz can't be detected by our ears. Our ears can detect only 20Hz to 20kHz.

Ultrasound and infrasound are still sound.

 

The clue is in the name.

Well if you are changing the question to human ears then the whole thing falls apart anyway no? - human ears? In space?

Hmmmm.... I see . Moreover the sound of 13 MHz can't be detected by our ears. Our ears can detect only 20Hz to 20kHz.

You do not understand the notion of "noise". Try studying it.

There is of course an easy answer to this , the Universe is always silent unless there is hearing to hear it.

Ah...the age old question...if I say something in the forest and my wife is not around to hear it...am I still wrong?

There are pressure waves in space, that is what causes the galactic spiral arms but we cannot hear them. Sound is the movement of matter, matter moves in space, from the galaxies spiral arms to the bow shock wave of the sun moving through space, all of them are far too low or weak or both for us to hear...