[WendelBuhbi (OP)]

Cosmology is based on this idea of redshifting light, that light from very very far away is shifted toward the color red.

It seems intuitive to think that shifting toward red, or shifting away from blue would be equal no matter how you slice it.

It turns out, that's not true. Because of how redshift is quantified there is a "divide by zero" at z=-1.

I've found how to use that to an advantage, by making a distance relationship:

d = z / (1 + z) * c / H_0

That closely matches LCDM and FLRW.

More info here:

https://mikehelland.github.io/hubbles-law/presentations/redblue/redblue.htm [nofollow]

Video here:

[Origin]

Cosmology is based on this idea of redshifting light, that light from very very far away is shifted toward the color red.

I think it is much more accurate to say redshift is part of cosmology.

It turns out, that's not true. Because of how redshift is quantified there is a "divide by zero" at z=-1.

How so?

[WendelBuhbi (OP)]

It turns out, that's not true. Because of how redshift is quantified there is a "divide by zero" at z=-1.

How so?
[/quote]

If redshift is:

1 + z = E_emit / E_obs, z can be any positive value,

But it can't be -1. For z=-1, the energy observed would have to be 0, which you can't observe a zero energy photon, and it would be a divide by zero error anyways.

See attached, which is the observed energy (% of original) for z. You'll see the vertical asymptote at z=-1. 

[Origin]

But it can't be -1

Of course not.  Z is valid for red shifts if there isn't a red shift, don't use Z.
Edit:
I was not completely right on that.  You can of course get a -Z, which simply means that the galaxy is moving towards you.  The andromeda galaxy has a Z = -0.00042 or in other words a blue shift.

[pzkpfw]

Cross reference for history:

http://www.internationalskeptics.com/forums/showthread.php?t=362150

[WendelBuhbi (OP)]

But it can't be -1

Of course not.  Z is valid for red shifts if there isn't a red shift, don't use Z.
Edit:
I was not completely right on that.  You can of course get a -Z, which simply means that the galaxy is moving towards you.  The andromeda galaxy has a Z = -0.00042 or in other words a blue shift.

Right.

Redshift is z > 0, and blueshift is -1 < z < 0.

Redshift is infinite, and blueshift is finite.

But the situation reverses when the equations are inverted.

"z" is used by convention for redshift and blueshift.

My proposal is to use "b" for both instead:

1 + b = 1 / (1 + z)

[Bored chemist]

1 + z = Eemit / Eobs, z can be any positive value,

But it can't be -1.

What physical conditions would correspond to z=-1?
As far as I can tell, it's the case where the light source is moving at the speed of light.
Since that's impossible, it doesn't matter if the equation doesn't give a proper answer for that (non existent) case.

[WendelBuhbi (OP)]

1 + z = Eemit / Eobs, z can be any positive value,

But it can't be -1.

What physical conditions would correspond to z=-1?
As far as I can tell, it's the case where the light source is moving at the speed of light.
Since that's impossible, it doesn't matter if the equation doesn't give a proper answer for that (non existent) case.

The key insight is that is z > 0 is redshift, and -1 < z < 0  is blueshift, meaning the range of redshifts is infinite, and the range of blueshifts is finite.

When inverted and represented as b (ie, 1 + b = 1 / (1 + z)) then the situation is reversed: b > 0 is blueshift, and -1 < b < 0 is redshift.

Having a finite range of redshifts leads to a different distance relationship:


z-distance-compare.png (77.76 kB . 990x663 - viewed 1481 times)

See the full argument here:

https://mikehelland.github.io/hubbles-law/presentations/redblue/redblue.htm [nofollow]

[Bored chemist]

meaning the range of redshifts is infinite, and the range of blueshifts is finite.

So, a bit like "hot" and "cold" then?
You can get infinitely hot (in principle) but you can only get as cold as absolute zero.

This is true, but not very exciting.

[WendelBuhbi (OP)]

meaning the range of redshifts is infinite, and the range of blueshifts is finite.

So, a bit like "hot" and "cold" then?
You can get infinitely hot (in principle) but you can only get as cold as absolute zero.

This is true, but not very exciting.

That's a great analogy.

When light redshifts, it loses energy. Think of that as getting colder.

As redshift z goes up, temperature goes down.

Now with the alternative quantification, when light blueshifts, it gains energy. Getting warmer.

As blueshift b goes up, temperature goes up.

Using redshift z is like using a temperature scale that goes down as it gets warmer. Technically, it can be done. But its "backwards" from reality.

Using blueshift b is like using a temperature scale that has an absolute zero (at b=-1, the photon would have zero energy).

The exciting part is when you try to make a redshift-distance relationship with them. You can get:

Code: [Select] [nofollow]

d = z c/H_0
or

Code: [Select] [nofollow]

d = -b c/H_0
Since:

Code: [Select] [nofollow]

1 + b = 1 /  (1 + z)
b = 1 /  (1 + z) - 1
b = 1 / (1 + z) - (1 + z) / (1 + z)
b = (1 - (1 + z)) / (1 + z)
b = -z / (1 + z)
-b = z / (1 + z)

So:

Code: [Select] [nofollow]

d = -b c/H_0
Becomes:

Code: [Select] [nofollow]

d = z/(1+z) * c/H_0
This is a huge improvement over the traditional redshift-distance relationship (d=z c/H₀) which is only a valid approximation at z << 1.

[WendelBuhbi (OP)]

Here is the manuscript I am trying to get peer reviewed:

https://docs.google.com/document/d/1D3VOxhgIeONMfjQh3SllT0EbvvuLhMP9OFIFarhxyYI/edit?usp=sharing [nofollow]

Any comments or criticisms are welcome.


red_blue_lcdm.png (50.91 kB . 1011x610 - viewed 1358 times)

[Christylalge]

Im at the point where I doubt those who are not vaccinated will be missed.

Also, if this is a bio-weapon, why wouldnt you get vaccinated against it?

[Origin]

Im at the point where I doubt those who are not vaccinated will be missed.

Also, if this is a bio-weapon, why wouldnt you get vaccinated against it?

That is a rather weird hijack...