Why the sky is dark in the night

We are not discussing the meaning of word darkness or brightness......all here who know basic Physics, understand what the darkness is in the context..

You made a statement that it is not dark, it is awashed with the radiation......technically correct but a pretty loose statement to kill the discussion........see how Paddo latched on to this.
The distinction is critical to your question and its answer.

As I pointed out:
pick one definition,and your post is answered in post 2.
pick another and we actually have a discussion, but it is not at all the one you are promoting about numbers of stars, etc.

You seem to be completely ignoring any EMR exact that which comes from current stars.
 
Hi TG
I am not sure as to the point you are trying to make may I ask you to outline it for me.
I live in a dark location and it seems the night sky is not visually dark as even on a moolness dark night I can read the head lines of a newspaper just from star light. Mostly the light is from the Milky Way.
We see M31 and the Magellan Clouds but mostly the stars of the Milky Way is what we see visually.
The Hubble Deep Field photographs show approx 2000 galaxies.To get an idea of the scale the Hubble shot covers a region that would be coveted if we held a grain of sand at arms length.
I am interested and want to understand the point you seek to make so please help me understand what it is you are trying to point out.
Thank you Alex
 
Hi TG
I am not sure as to the point you are trying to make may I ask you to outline it for me.
I live in a dark location and it seems the night sky is not visually dark as even on a moolness dark night I can read the head lines of a newspaper just from star light. Mostly the light is from the Milky Way.
We see M31 and the Magellan Clouds but mostly the stars of the Milky Way is what we see visually.
The Hubble Deep Field photographs show approx 2000 galaxies.To get an idea of the scale the Hubble shot covers a region that would be coveted if we held a grain of sand at arms length.
I am interested and want to understand the point you seek to make so please help me understand what it is you are trying to point out.
Thank you Alex

Ok, we will get into some basics......it gives me a feeling that people here are mixing up brightness/darkness with radiation. These are qualitative words....

See, the clear sun light is of the order of 100,000 Lux (measure of visible light intensity per unit area), the full moon brightness is of the order of 0.1 and moonless night brightness is of the order of 0.001, thats star light (we are not getting into further bifurcation here).

The point is simple.....that the sun could directly create 100000 lux, reflected light from moon can create a brightness of 0.1 Lux, then why trillions of trillions of stars could not even create 0.1 Lux ? This issue was known much before Big Bang was proposed.

Big Bang (a huge problem in itself) created a related problem of its own, but it got sorted out by the huge redshift (z = 1100 of BB light....The original question demanded an answer...

It was proposed that..

a. Universe is finite not infinite, thus not every line of sight from earth goes to a visible star.
b. Universe is expanding...redshift.
c. Finite speed of light.

This is well cateloged, answering this way is nothing but parrotising.......one particular poster messed up the same with radiation awashed, without understanding the definition of brightness/darkness. These three points do not prove a fact that visible light would be less than 0.001 lux in the clear night......one star is able to create 100000 lux, one moon is able to create 0.1 (both are in finite universe, expanding universe, with finite speed of light)....so caluclation is required that why 10^31 stars total brightness input to earth is << 0.1 ? That would be the answer, those three parrotised lines are just the lines.
 
So either we make up something that isn't true, or we "parrot" the mainstream?

Exactly what kind of answer do you want?
 
So either we make up something that isn't true, or we "parrot" the mainstream?

Exactly what kind of answer do you want?

I searched for your posts, when you posted earlier on this thread, I could not figure out any contribution by you, so far almost all the posts by you are contentless....this forum needs members, who bothers about content ? You justify that.

I like your 'we' above..twice.
 
TG
Thank you but I seem to miss your conclusion.
You suggest current explainations dont meet your expectation.
What does your model say about our observations.
Are you driving at the old tired tired light thing.
I just miss where you are going with this.
If its not mainstream you could open a thread in an appropriate section and put it forward.
Sorry I am tired I will reread your post when I am brighter and rested.
 
Ok, we will get into some basics......it gives me a feeling that people here are mixing up brightness/darkness with radiation. These are qualitative words....

See, the clear sun light is of the order of 100,000 Lux (measure of visible light intensity per unit area), the full moon brightness is of the order of 0.1 and moonless night brightness is of the order of 0.001, thats star light (we are not getting into further bifurcation here).

The point is simple.....that the sun could directly create 100000 lux, reflected light from moon can create a brightness of 0.1 Lux, then why trillions of trillions of stars could not even create 0.1 Lux ? This issue was known much before Big Bang was proposed.

Big Bang (a huge problem in itself) created a related problem of its own, but it got sorted out by the huge redshift (z = 1100 of BB light....The original question demanded an answer...

It was proposed that..

a. Universe is finite not infinite, thus not every line of sight from earth goes to a visible star.
b. Universe is expanding...redshift.
c. Finite speed of light.

This is well cateloged, answering this way is nothing but parrotising.......one particular poster messed up the same with radiation awashed, without understanding the definition of brightness/darkness. These three points do not prove a fact that visible light would be less than 0.001 lux in the clear night......one star is able to create 100000 lux, one moon is able to create 0.1 (both are in finite universe, expanding universe, with finite speed of light)....so caluclation is required that why 10^31 stars total brightness input to earth is << 0.1 ? That would be the answer, those three parrotised lines are just the lines.
As I stated many pages ago, this one is just one of those concepts you are just not going to be able to 'get'. All we are doing here and will continue to do is go round and round covering the same ground. My advice to you is to move on to a new subject.
 
TG
Thank you but I seem to miss your conclusion.
You suggest current explainations dont meet your expectation.
What does your model say about our observations.
Are you driving at the old tired tired light thing.
I just miss where you are going with this.
If its not mainstream you could open a thread in an appropriate section and put it forward.
Sorry I am tired I will reread your post when I am brighter and rested.

I have proposed no alternative on this.
How those 3 lines prove the lux < 0.001 ?
 
Ok, we will get into some basics......it gives me a feeling that people here are mixing up brightness/darkness with radiation. These are qualitative words....

See, the clear sun light is of the order of 100,000 Lux (measure of visible light intensity per unit area), the full moon brightness is of the order of 0.1 and moonless night brightness is of the order of 0.001, thats star light (we are not getting into further bifurcation here).

The point is simple.....that the sun could directly create 100000 lux, reflected light from moon can create a brightness of 0.1 Lux, then why trillions of trillions of stars could not even create 0.1 Lux ?

....
These three points do not prove a fact that visible light would be less than 0.001 lux in the clear night......one star is able to create 100000 lux, one moon is able to create 0.1 (both are in finite universe, expanding universe, with finite speed of light)....so caluclation is required that why 10^31 stars total brightness input to earth is << 0.1 ?
I offered to walk you through a couple of methods for calculating this and a simpler related problem that you yourself proposed. The offer remains on the table.
I have proposed no alternative on this.
No, you've just claimed based on nothing more than your own disbelief that the accepted model is wrong.
 
Last edited:
I offered to walk you through a couple of methods for calculating this and a simpler related problem that you yourself proposed. The offer remains on the table.

No, you've just claimed based on nothing more than your own disbelief that the accepted model is wrong.

So what are you waiting for ? Give the calculations which will prove the lux of the order 0.001....
 
I dont know so please explain how those three lines prove to be wrong and you offer no alternative.
Why suggest something is wrong if you cant point out what is right.

The question is how those 3 lines prove the lux of the order of 0.001...want to try ?
 
Well, think of it this way: How many degrees of an arc are we getting of light from the sun, compared to how many degrees of an arc are we getting of light from the other stars?
 
Back
Top