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Old 10th November 2022, 03:33 AM   #161
Ziggurat
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Originally Posted by Mike Helland View Post
Why wouldn't it?
Because that's not possible. The photon has no "born with" tag, it only carries it's current energy. Anything that alters its energy will do so on the basis of it's current energy, not any other.
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Old 10th November 2022, 03:43 AM   #162
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Originally Posted by Mike Helland View Post
I answered the question thoroughly, eventually, and the results are here:

Code:
|-----------------7-------------|
A          B                    C
|---2.33---|---------4.66-------|

First photon
A (d=0,        z=0,    E=12 eV)
B (d=2.33 Gly, z=0.2,  E=10 eV)
C (d=7 Gly,    z=1,    E=6 eV)

Second photon
B (d=0,        z=0,    E=9 eV)
C (d=4.66 Gly, z=0.5,  E=6 eV)
This demonstrates that the expanding universe is internally inconsistent.
No, it doesn't.

In your calculation, a photon with 10 eV at B loses 4 eV to drop to 6 eV by the time it gets to C, while a second photon with 9 eV at B loses 3 eV to drop to the same 6 eV by the time it gets to C. If both events you refer to as B are the same, and both events you refer to as C are the same (which is something we could reasonably assume in a scientific presentation, but all bets are off when the presenter has a long and also recent history of using exactly the same letter to mean completely different things in consecutive sentences), then your calculation is inconsistent with an expanding universe.

That means any conclusions you may attempt to draw from your calculation have nothing to do with an expanding universe.
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Old 10th November 2022, 08:59 AM   #163
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Originally Posted by Mike Helland View Post
It doesn't. It's the same percent as the photon's original energy.

Say a photon redshifts over 100 million light years. But it doesn't redshift over 1 light second.

If you checked the photon's energy every second, and reset its distance to 0, it would never redshift.

Photons redshift per their original energy, not their energy at any arbitrary point.
I am probably being needlessly obtuse here, but it's hard to get behind a theory when it seems ordinary arithmetic doesn't work.

So maybe I'm misunderstanding the issue of percentages here, so correct me if I am.

We have a photon with a certain amount of energy. The exact amount seems irrelevant, as long as someone can measure it. It travels a certain distance. The exact distance seems irrelevant, as long as someone can measure it. We determine that a photon with energy n, when it travels a distance x, loses 50 percent of that energy. The exact cause of that loss seems irrelevant, as long as someone understands what it is. The choice of a distance that corresponds to a 50 percent loss is essentially arbitrary, based, one assumes, on long study of the rate of loss.

At the point we just measured, the photon now has an energy of n/2. In the next distance of x, one would, I think, expect that the energy of that photon would be halved again, becoming n/4. Yet in your statement, this is not the case. The photon loses ALL its energy, and is effectively extinguished.

Now maybe this is true, and maybe the rate of loss is not constant, but varies in some way, but the statement above,

Quote:
From d = 2 to d = 1 it loses 50%.

From d = 2 to d = 0 it loses 50% x 2.
looks from this vantage point like an arithmetical error, since it does not explain where that "50% x 2" comes from.
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Old 10th November 2022, 09:23 AM   #164
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Originally Posted by W.D.Clinger View Post
No, it doesn't.

In your calculation, a photon with 10 eV at B loses 4 eV to drop to 6 eV by the time it gets to C, while a second photon with 9 eV at B loses 3 eV to drop to the same 6 eV by the time it gets to C. If both events you refer to as B are the same, and both events you refer to as C are the same (which is something we could reasonably assume in a scientific presentation, but all bets are off when the presenter has a long and also recent history of using exactly the same letter to mean completely different things in consecutive sentences), then your calculation is inconsistent with an expanding universe.

That means any conclusions you may attempt to draw from your calculation have nothing to do with an expanding universe.
Then what is the proper calculation?

If the calculations are inconsistent with the expanding universe, either the calculations are wrong, or the expanding universe is internally inconsistent.

What are the proper numbers?
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Old 10th November 2022, 09:24 AM   #165
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Originally Posted by Ziggurat View Post
Because that's not possible. The photon has no "born with" tag, it only carries it's current energy. Anything that alters its energy will do so on the basis of it's current energy, not any other.
Sure it does. Eemit. That's what's in the equations.
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Old 10th November 2022, 09:29 AM   #166
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Originally Posted by bruto View Post
At the point we just measured, the photon now has an energy of n/2. In the next distance of x, one would, I think, expect that the energy of that photon would be halved again, becoming n/4.
When the energy is halved, z=1 (1/(1+z) = 1/2).

When the energy is halved again z=3 (1/(1+z)=1/4) so, but z=1 and z=3 are really close, compared to z=0 and z=1. Unfortunately, your intuition is not how z and distance are related.
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Old 10th November 2022, 10:32 AM   #167
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Originally Posted by Mike Helland View Post
When the energy is halved, z=1 (1/(1+z) = 1/2).

When the energy is halved again z=3 (1/(1+z)=1/4) so, but z=1 and z=3 are really close, compared to z=0 and z=1. Unfortunately, your intuition is not how z and distance are related.
I'll add that when you invert the redshift equations and use negative blueshift, then when energy is halved b=-0.5, and when it is halved again b=-0.75. *edit, was -0.25*

That's much more intuitive.

And the distance light traveled is -b * Hubble's length.

Last edited by Mike Helland; 10th November 2022 at 10:40 AM.
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Old 10th November 2022, 12:09 PM   #168
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Originally Posted by Mike Helland View Post
Sure it does. Eemit. That's what's in the equations.
Equations are descriptive. They work under certain circumstances, but it's easy to use them wrong, and you're using them wrong. Photons don't know how much energy they are emitted with. Hell, there isn't even a single value for that, it's reference frame dependent. The fact that Eemit appears in some equation does not mean that the photon itself keeps track of that. That's not how any of this works.
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Old 10th November 2022, 01:25 PM   #169
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Some people identify mathematics with arithmetic or calculation, but that's only a tiny part of what mathematics is about. Mathematics is about finding out what follows from what postulates, and about formulating postulates that are of some interest (usually because they correspond at some level to some situation that arises in the real world) and tracking down their often surprising consequences.

Mathematics is also about learning to think abstractly. By thinking abstractly, we can simplify our thought processes, leaving us less vulnerable to the mistakes we might make by pursuing a more concrete and more complicated process.

We have an example of that here.

Originally Posted by W.D.Clinger View Post
In your calculation, a photon with 10 eV at B loses 4 eV to drop to 6 eV by the time it gets to C, while a second photon with 9 eV at B loses 3 eV to drop to the same 6 eV by the time it gets to C. If both events you refer to as B are the same, and both events you refer to as C are the same (which is something we could reasonably assume in a scientific presentation, but all bets are off when the presenter has a long and also recent history of using exactly the same letter to mean completely different things in consecutive sentences), then your calculation is inconsistent with an expanding universe.

That means any conclusions you may attempt to draw from your calculation have nothing to do with an expanding universe.
Originally Posted by Mike Helland View Post
Then what is the proper calculation?
A calculation that relies on mainstream physics instead of Helland physics.

Originally Posted by Mike Helland View Post
If the calculations are inconsistent with the expanding universe, either the calculations are wrong, or the expanding universe is internally inconsistent.
Your calculations are wrong. Your calculations are wrong because they are based on Helland physics. Your calculation assumes photons behave as you think they behave, which is not how photons behave according to mainstream physics.

You started out by assuming photons behave in a way that is inconsistent with mainstream physics. It should come as no surprise that such calculations yield results that are inconsistent with mainstream physics. The only conclusion that can be drawn from the inconsistency of your calculation with mainstream physics is that Helland physics is inconsistent with mainstream physics.

You knew that at the outset, when you started by assuming mainstream physics is wrong about the behavior of photons. Your calculations based on Helland physics are mere obfuscation. You begged the question (in the original meaning of that phrase) by assuming mainstream physics is wrong, and then you relied on that assumption while embarking upon calculations designed to show that mainstream physics is wrong.

Originally Posted by Mike Helland View Post
What are the proper numbers?
We don't need numbers to understand what's wrong with your calculation. In mainstream physics, a photon that starts out at event B with energy X does not arrive at event C with the same energy as another photon that starts out at event B and follows the same world line to C.

Mathematically, the function that describes red shifts along any particular world line between events B and C is not many-to-one: You can't have two different starting energies end up at C with the same energy.

That last paragraph shows how much easier it is to think mathematically than to limit yourself to grade school arithmetic.
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Old 10th November 2022, 05:56 PM   #170
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Originally Posted by Ziggurat View Post
Equations are descriptive.
Indeed they are. The equations for redshift and distance describe a relationship between two measured values. They attempt to, at least.
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Old 10th November 2022, 06:00 PM   #171
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Originally Posted by W.D.Clinger View Post
A calculation that relies on mainstream physics instead of Helland physics.
False.

My calculations are standard mainstream stuff.

If you think I'm wrong, prove it.

Here's the chart. You put what you think is right.

Code:
|-----------------?-------------|
A          B                    C
|---?------|---------?----------|

First photon
A (d=0,        z=0,    E=12 eV)
B (d=?Gly,     z=?,    E=? eV)
C (d=? Gly,    z=1,    E=? eV)

Second photon
B (d=0,        z=0,    E=9 eV)
C (d=? Gly,    z=?,    E=? eV)
Fill in the ?'s.

Last edited by Mike Helland; 10th November 2022 at 06:02 PM.
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Old 10th November 2022, 10:12 PM   #172
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Originally Posted by Mike Helland View Post
Originally Posted by W.D.Clinger View Post
A calculation that relies on mainstream physics instead of Helland physics.
False.

My calculations are standard mainstream stuff.

If you think I'm wrong, prove it.
In mainstream relativity and electromagnetism, the following is true:
For any events B and C connected by a specific null geodesic W, and for any photon that departs from B and travels via W to C (without interacting with other particles etc), the relationship between the energy of that photon at B and its energy at C is described by a one-to-one mathematical function.
Your calculation assumes photons violate that fact about mainstream relativity and electromagnetism.

Your calculation is therefore based upon your against-the-mainstream brand of physics, which we might as well refer to as Helland physics.

QED
In mathematics, the following is true:
If f is a one-to-one continuous function from the positive reals to the positive reals, then f is either strictly monotonic or strictly anti-monotonic.
It so happens that the function alluded to above is strictly monotonic, but we didn't need that fact to prove that Mike Helland's calculation is inconsistent with mainstream physics.


Originally Posted by Mike Helland View Post
Here's the chart. You put what you think is right.

Code:
|-----------------?-------------|
A          B                    C
|---?------|---------?----------|

First photon
A (d=0,        z=0,    E=12 eV)
B (d=?Gly,     z=?,    E=? eV)
C (d=? Gly,    z=1,    E=? eV)

Second photon
B (d=0,        z=0,    E=9 eV)
C (d=? Gly,    z=?,    E=? eV)
Fill in the ?'s.
The specific numbers will depend upon the spacetime geometry and the specific world line W that represents a null geodesic from B to C. Your obsession with numbers at the expense of insight obscures the simple fact that two photons going from B to C via W cannot start out with different energies at B yet end up with the same energy at C.

By the way, that simple fact is easily proved using the time reversal of B, C, and W. Two photons that start out with the same energy and follow the same world line can't end up with different energies at the end of that world line unless they interact with some outside influence.
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Old 11th November 2022, 03:57 AM   #173
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Originally Posted by W.D.Clinger View Post
In mainstream relativity and electromagnetism, the following is true:
For any events B and C connected by a specific null geodesic W, and for any photon that departs from B and travels via W to C (without interacting with other particles etc), the relationship between the energy of that photon at B and its energy at C is described by a one-to-one mathematical function.
That seems like a reasonable assumption.

Ben m and jonesdave116 have detailed a scenario that demonstrates it is not true, however. Do the numbers.

Last edited by Mike Helland; 11th November 2022 at 05:27 AM.
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Old 11th November 2022, 06:11 AM   #174
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Originally Posted by Mike Helland View Post
Originally Posted by W.D.Clinger View Post
In mainstream relativity and electromagnetism, the following is true:
For any events B and C connected by a specific null geodesic W, and for any photon that departs from B and travels via W to C (without interacting with other particles etc), the relationship between the energy of that photon at B and its energy at C is described by a one-to-one mathematical function.
That seems like a reasonable assumption.

Ben m and jonesdave116 have detailed a scenario that demonstrates it is not true, however. Do the numbers.
ben m is no longer around to defend himself, but jonesdave116 is still here.

As I noted previously, jonesdave116 got confused by your habit of using exactly the same letter (e.g. "d") to represent completely different things, even in consecutive sentences. From what you wrote in the quotation above, and from things you have been writing throughout this thread, I suspect you have confused yourself as well.

Allow me, however, to note that you believe you are discussing these things in the context of red shift resulting from spatial expansion, which implies general relativity. That is why I have been careful to speak of events B and C rather than positions B and C, and why I have been careful to speak of some particular world line W (because there may be multiple null geodesics connecting events B and C). Even if you adopt the idealized simplifying assumption of an FLRW spacetime, the red shift is not uniform along W because the Hubble parameter H is not constant (because the scale factor a(t) is not a constant). To perform a proper calculation requires you to compute the value of a definite integral involving a(t). Even if you use approximations, how the red shift varies along W depends upon whether you are assuming a matter-dominated or energy-dominated FLRW spacetime.
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Old 11th November 2022, 06:40 AM   #175
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Originally Posted by W.D.Clinger View Post
ben m is no longer around to defend himself, but jonesdave116 is still here.

As I noted previously, jonesdave116 got confused by your habit of using exactly the same letter (e.g. "d") to represent completely different things, even in consecutive sentences. From what you wrote in the quotation above, and from things you have been writing throughout this thread, I suspect you have confused yourself as well.

Allow me, however, to note that you believe you are discussing these things in the context of red shift resulting from spatial expansion, which implies general relativity. That is why I have been careful to speak of events B and C rather than positions B and C, and why I have been careful to speak of some particular world line W (because there may be multiple null geodesics connecting events B and C). Even if you adopt the idealized simplifying assumption of an FLRW spacetime, the red shift is not uniform along W because the Hubble parameter H is not constant (because the scale factor a(t) is not a constant). To perform a proper calculation requires you to compute the value of a definite integral involving a(t). Even if you use approximations, how the red shift varies along W depends upon whether you are assuming a matter-dominated or energy-dominated FLRW spacetime.
Yep.

You can use this interactive version of LCDM to see the difference between matter and dark energy by adjusting the parameters.

https://mikehelland.github.io/hubble...other/lcdm.htm

If redshifts are caused by an expanding universe, then gravity plays a role in that by reigning it in a bit.

Since that is observationally incorrect, dark energy is employed to push it back.

Of course, if light just redshifts, none of that is right.

That's not to say general relativity has a flaw. Just the FLRW metric does not match reality. Does it have any purpose outside cosmology, BTW?
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Old 11th November 2022, 07:13 AM   #176
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Originally Posted by Mike Helland View Post
If redshifts are caused by an expanding universe, then gravity plays a role in that by reigning it in a bit.
In FLRW models of an expanding universe, gravity acts over time to reduce the second derivative of the scale factor a(t). In some FLRW models, where the matter-energy density of the universe exceeds a certain critical value, gravity will eventually make the first derivative of a(t) go negative, ultimately resulting in a Big Crunch.

The first derivative of a(t) is not negative at the present time, and observational evidence suggests the FLRW parameters that most closely fit the universe as we know it predict the first derivative of a(t) will never go negative. That of course remains to be seen, but I don't expect to be around as the universe dies from heat death (or collapses into a Big Crunch, if that's what you think will happen).

Originally Posted by Mike Helland View Post
Since that is observationally incorrect, dark energy is employed to push it back.
You don't know what you're talking about. What I wrote above is true even of FLRW models for which the cosmological constant (dark energy) is zero.

Originally Posted by Mike Helland View Post
That's not to say general relativity has a flaw. Just the FLRW metric does not match reality. Does it have any purpose outside cosmology, BTW?
If we consider arbitrary spacetime manifolds instead of limiting ourselves to idealized solutions such as FLRW, then the variation in red shift of a photon traveling from some event B to some event C along some null geodesic W can be just about anything you like. There are, however, a few fundamental constraints:
  • Two photons that start out with the same energy at B and travel to C along the same world line W can't end up with different energies at C.
  • Two photons that start out with different energies at B and travel to C along the same world line W can't end up with the same energy at C.
In other words, Mike Helland has been promoting a calculation that is wrong in one of the very few ways it is even possible for such a calculation to be fundamentally wrong.


ETA:
Originally Posted by Mike Helland View Post
Of course, if light just redshifts, none of that is right.
In that sentence, Mike Helland is telling us that, if we start with Helland physics instead of mainstream physics, then we reach conclusions that are inconsistent with mainstream physics. The reason for that is obvious: Helland physics is inconsistent with mainstream physics.

Last edited by W.D.Clinger; 11th November 2022 at 07:39 AM. Reason: added ETA
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Old 11th November 2022, 07:45 AM   #177
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Originally Posted by Mike Helland View Post
Indeed they are. The equations for redshift and distance describe a relationship between two measured values. They attempt to, at least.
You missed the point, which is that equations don't make reality. Eemit being in an equation doesn't mean that the photon actually carries that information. It doesn't. And you were using the equations wrong anyways.

Now, I don't know if any of your numbers are right, and I frankly don't care. But your claim of a contradiction was plainly wrong. So let's go through some numbers again. I'm not going to use d or z values here, we don't need them to see where you screwed up. I will use your energy values, though

Photon 1 starts at event A (I'm calling it an event because that identifies it as a specific point in both space and time), with an energy of 12 eV. It then travels to event B, where it has an energy of 10 eV. Then it travels to event C, where it has 6 eV.

Moving from A to B decreases energy by 16.7 %. Moving from B to C decreases energy by 33.3% of the energy it had at A, but that doesn't matter. What's happening between B and C has no access to any information about what happened at A. Between B and C, energy decreases by 40% of the energy it had at A.

Photon 2 starts out at event B and travels to event C. It starts with 9 eV, and experiences the same red shift as photon 1. How much does its energy decrease?

You wanted to use 33.3%, but this is wrong. Again, 33.3% was what you calculated as the percentage of the energy at A, but photon 2 didn't start at A, it started at B. You can't use 33.3% here and apply it to photon 2, that makes no sense. You have to use the equivalent, which is 40%, not 33.3%. So it will decrease its energy by 40%, not 33.3%, same as photon 1 when measured from event B, which is the proper way to do it. So its energy will decrease from 9 eV to 5.4 eV. As expected, photon 2 has 10% less energy than photon 1 both at event B and at event C.

If you don't **** up the math (which you did), there won't be any contradiction. Note that NONE of this required making ANY assumptions about expansion rates, distances, times, or anything of the sort.
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Old 11th November 2022, 08:16 AM   #178
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Originally Posted by Ziggurat View Post
You wanted to use 33.3%, but this is wrong. Again, 33.3% was what you calculated as the percentage of the energy at A, but photon 2 didn't start at A, it started at B. You can't use 33.3% here and apply it to photon 2, that makes no sense.
The second photon has a z=0.5, which 1/(1+z) means it has 66.6% of its energy.

Again, jonesdave116 was adamant that I did the math. I didn't see the point. Now it's pretty obvious your assumptions don't add up.

If you think I'm wrong, do the math.
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Old 11th November 2022, 08:20 AM   #179
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Originally Posted by W.D.Clinger View Post
In FLRW models of an expanding universe, gravity acts over time to reduce the second derivative of the scale factor a(t). In some FLRW models, where the matter-energy density of the universe exceeds a certain critical value, gravity will eventually make the first derivative of a(t) go negative, ultimately resulting in a Big Crunch.

The first derivative of a(t) is not negative at the present time, and observational evidence suggests the FLRW parameters that most closely fit the universe as we know it predict the first derivative of a(t) will never go negative. That of course remains to be seen, but I don't expect to be around as the universe dies from heat death (or collapses into a Big Crunch, if that's what you think will happen).


You don't know what you're talking about. What I wrote above is true even of FLRW models for which the cosmological constant (dark energy) is zero.


If we consider arbitrary spacetime manifolds instead of limiting ourselves to idealized solutions such as FLRW, then the variation in red shift of a photon traveling from some event B to some event C along some null geodesic W can be just about anything you like. There are, however, a few fundamental constraints:
  • Two photons that start out with the same energy at B and travel to C along the same world line W can't end up with different energies at C.
  • Two photons that start out with different energies at B and travel to C along the same world line W can't end up with the same energy at C.
In other words, Mike Helland has been promoting a calculation that is wrong in one of the very few ways it is even possible for such a calculation to be fundamentally wrong.


ETA:

In that sentence, Mike Helland is telling us that, if we start with Helland physics instead of mainstream physics, then we reach conclusions that are inconsistent with mainstream physics. The reason for that is obvious: Helland physics is inconsistent with mainstream physics.
There are no Helland physic here. Just standard redshift and lookback calculations.

Do the math. You won't get different results than I did.
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Old 11th November 2022, 08:39 AM   #180
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Originally Posted by Mike Helland View Post
The second photon has a z=0.5, which 1/(1+z) means it has 66.6% of its energy.

Again, jonesdave116 was adamant that I did the math. I didn't see the point. Now it's pretty obvious your assumptions don't add up.

If you think I'm wrong, do the math.
I just did the math. You ****** up. You can't use the same percentage applied to two different things (energy at A and energy at B) and expect them to match up. Of course that's going to cause inconsistencies.

ETA: OK, let's do this the other way around. Photon 2 goes from 9 eV at B to 6 eV at C, a decrease of 33.3%. Fine.

Photon 1 goes from 12 eV at A to 10 eV at B. Then it goes from B to C. It should decrease by 33.3% from B to C, just like photon 2. But not 33.3% of 12 eV, 33.3% of 10 eV. So it will end at C with an energy of 6.7 eV. At both B and C, photon 2 has 10% less energy than photon 1. No contradiction, if you don't **** it up.

You ****** it up.
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Old 11th November 2022, 09:24 AM   #181
W.D.Clinger
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Originally Posted by Mike Helland View Post
There are no Helland physic here. Just standard redshift and lookback calculations.

Do the math. You won't get different results than I did.
I've done the math:Those posts show the hard part of the math. The derivation of equations from the Friedman equations yields the definite integral I mentioned several posts above, ultimately yielding this equation for the redshift of a photon going from event B at time tB to event C at time tC in the FLRW coordinates:
1 + z = a(tC) / a(tB) = λ(tC) / λ(tB)
as derived in that same Wikipedia article.

Astute observers will observe that the red shift given by that equation does not depend upon the frequency a photon might have had at any event prior to B. The red shift depends only upon the photon's frequency at B (λ(tB)) and at C (λ(tC)), whose ratio depends in turn only upon the value of the scale factor at B (a(tB)) and at C (a(tC)).

The scale factors a(tB) and a(tC) are determined by the spacetime geometry, and are completely independent of which photons we might be discussing. From that it follows that the red shift given by that equation is the same for all photons traveling from event B to event C along a null geodesic.

Which means two photons that have different energies at B cannot have the same energy at C.

Which means Mike Helland's calculation is incorrect, no matter much he may stamp his feet and insist he's right.

Mike Helland's calculation is incorrect because it is based upon Helland physics, as opposed to mainstream physics.

Mike Helland hasn't done the math, and doesn't know enough physics and math to understand the mathematics laid out in the links I provided above.

That's why Mike Helland insists upon using numbers instead of equations and general principles of mathematics and physics. He does know how to use a calculator. He just doesn't know enough math to tell whether he's feeding correct numbers into that calculator.

Last edited by W.D.Clinger; 11th November 2022 at 09:29 AM. Reason: changed two words for clarity
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Old 11th November 2022, 11:25 AM   #182
Mike Helland
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Originally Posted by Ziggurat View Post
I just did the math. You ****** up. You can't use the same percentage applied to two different things (energy at A and energy at B) and expect them to match up. Of course that's going to cause inconsistencies.

ETA: OK, let's do this the other way around. Photon 2 goes from 9 eV at B to 6 eV at C, a decrease of 33.3%. Fine.

Photon 1 goes from 12 eV at A to 10 eV at B. Then it goes from B to C. It should decrease by 33.3% from B to C, just like photon 2. But not 33.3% of 12 eV, 33.3% of 10 eV. So it will end at C with an energy of 6.7 eV. At both B and C, photon 2 has 10% less energy than photon 1. No contradiction, if you don't **** it up.

You ****** it up.
How does a 12 eV photon with a redshift of z=1 get to 6.7 eV?

1/(1+z)=1/2

Perhaps it would help if you showed your work.
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Old 11th November 2022, 11:29 AM   #183
Mike Helland
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Originally Posted by W.D.Clinger View Post
From that it follows that the red shift given by that equation is the same for all photons traveling from event B to event C along a null geodesic.

Which means two photons that have different energies at B cannot have the same energy at C.
You assume your conclusion in your premises.

I understand why its hard to give actual answers to the problem posed by jonesdave116. It doesn't actually add up.
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Old 11th November 2022, 12:03 PM   #184
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Here's the problem.

You receive 2 photons, both 6 eV. One of them from a z=0.5 source. The other from z=1.

What energy were they emitted with? What distance did they travel?

And.... what energy did they have when they met up?

Code:
|-----------------?-------------|
A          B                    C
|---?------|---------?----------|

First photon
A (d=0,        z=0,    E=? eV)
B (d=? Gly,    z=?,    E=? eV)
C (d=? Gly,    z=1,    E=6 eV)

Second photon
B (d=0,        z=0,    E=? eV)
C (d=? Gly,    z=0.5,  E=6 eV)
Fill in the ?'s.

Last edited by Mike Helland; 11th November 2022 at 12:04 PM.
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Old 11th November 2022, 12:36 PM   #185
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Originally Posted by Mike Helland View Post
How does a 12 eV photon with a redshift of z=1 get to 6.7 eV?
Who said it had a z of 1? I didn't. I never said anything about z before, but see below.

I said it had a 12 eV starting energy and 10 eV at the meetup point, because that's numbers you used when trying to show a conflict.

Originally Posted by Mike Helland View Post
Here's the problem.

You receive 2 photons, both 6 eV. One of them from a z=0.5 source. The other from z=1.

What energy were they emitted with? What distance did they travel?

And.... what energy did they have when they met up?
I'm not going to bother calculating distances, they aren't necessary to disprove your claimed inconsistency. And they are model dependent, but consistency shouldn't be.

If photon 2 has a z of 0.5 and an energy of 6 eV at C, then it had an energy of 9 eV at B. If photon 1 has an energy of 6 eV at C, then it also had an energy of 9 eV at B. If its z is 1, then at A, it had an energy of 12 eV.

This means that at B, it had a z of 0.33.

Now here's where you're likely to run into confusion. You seem to be under the wrong impression about how z changes. If z for photon 2 increased by 0.5 when traveling from B to C, then any photon traveling from B to C should have z increase by 0.5, so that would make photon 1 go from z = 0.33 to z = 0.83. But that's not how it works, at all. The change in z doesn't have to be the same for each of them. It won't be, because z's don't add. z will change from 0.33 to 1.0 over that same distance.
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Old 11th November 2022, 12:45 PM   #186
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Originally Posted by W.D.Clinger View Post
That's a pretty amazing post, btw.
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Old 11th November 2022, 12:55 PM   #187
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Originally Posted by Ziggurat View Post
Who said it had a z of 1?
jonesdave. It was the basic stipulation of the problem.

Quote:
If photon 2 has a z of 0.5 and an energy of 6 eV at C, then it had an energy of 9 eV at B. If photon 1 has an energy of 6 eV at C, then it also had an energy of 9 eV at B. If its z is 1, then at A, it had an energy of 12 eV.

This means that at B, it had a z of 0.33.
Lookback time * c at z=1 is 7 Gly (say c/H0 = 14 Gly to make things easy).

Lookback time * c at z=0.5 is 4.66 Gly.

So the first and second photon traveled 4.66 Gly together.

That leaves 7 - 4.66 = 2.33 Gly the first photon traveled alone.

And it was z=0.33 when it met the second photon?

Lookback time * c at z=0.33 is 3.5 Gly.

4.66 + 3.5 > 7

Doesn't add up.

Last edited by Mike Helland; 11th November 2022 at 12:57 PM.
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Old 11th November 2022, 01:49 PM   #188
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Originally Posted by Mike Helland View Post
Lookback time * c at z=0.33 is 3.5 Gly.

4.66 + 3.5 > 7

Doesn't add up.
Because you're still doing it wrong. The quantity z is model independent, meaning its definition doesn't depend on how fast the universe is expanding. But the relationship between z and distance is NOT model independent. It depends on how fast the universe expands, and that's not constant in time. The relationship between z and distance that you're using is valid for z's calculated today. But the z you're using, 0.33, isn't a z that's valid today. It's a z from 4.66 billion years ago. You would need to use a different relationship between z and distance if you want to calculate how far photon 1 traveled between A and B based on z.

You keep using equations that you don't actually understand, and so don't realize when you're using them wrong.
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Old 11th November 2022, 01:55 PM   #189
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Originally Posted by Ziggurat View Post
Because you're still doing it wrong. The quantity z is model independent, meaning its definition doesn't depend on how fast the universe is expanding. But the relationship between z and distance is NOT model independent. It depends on how fast the universe expands, and that's not constant in time. The relationship between z and distance that you're using is valid for z's calculated today. But the z you're using, 0.33, isn't a z that's valid today. It's a z from 4.66 billion years ago. You would need to use a different relationship between z and distance if you want to calculate how far photon 1 traveled between A and B based on z.

You keep using equations that you don't actually understand, and so don't realize when you're using them wrong.
I understand pretty well.

If a photon travels for a billion years at the speed of light, it traveled 1 billion light years.

The source of the photon was less than that at the time of the emission. And it was greater than that when the photon was received.

That doesn't change anything though.

A photon that travels for 2.33 billion years will have a z=0.2. Not z=0.333.

Try filling out the chart.
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Old 11th November 2022, 02:15 PM   #190
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Originally Posted by Mike Helland View Post
I understand pretty well.
No, you absolutely do not understand.

Quote:
A photon that travels for 2.33 billion years will have a z=0.2. Not z=0.333.
Again, this is only for today. It was not valid in the past, it won't be valid in the future. You're applying it in the past as if the past was the same as today, but it's not.
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Old 11th November 2022, 02:26 PM   #191
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Originally Posted by Ziggurat View Post
Again, this is only for today. It was not valid in the past, it won't be valid in the future. You're applying it in the past as if the past was the same as today, but it's not.
So what you're saying is, this is right to you?

Code:
|-----------------?-------------|
A          B                    C
|---?------|---------?----------|

First photon
A (d=0,          z=0,    E=12 eV)
B (d=3.5 Gly,    z=0.33,    E=9 eV)
C (d=7 Gly,    z=1,    E=6 eV)

Second photon
B (d=0,           z=0,    E=9 eV)
C (d=4.66 Gly,    z=0.5,  E=6 eV)
Or how would you change that?
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Old 11th November 2022, 02:33 PM   #192
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Originally Posted by Mike Helland View Post
So what you're saying is, this is right to you?
No, it's not right. There's still a contradiction in there. You think that means that there's something wrong with the theory. In point of fact, it means you ****** up.

Again, distance vs. z relationship TODAY is different than it was in the past. I haven't bothered doing the distance/time calculations, but assuming that you did them right for photon 2 (since the calculations were done for today, that's more likely to be correct), then this is what they should be:

Code:
|-----------------?-------------|
A          B                    C
|---?------|---------?----------|

First photon
A (d=0,          z=0,    E=12 eV)
B (d=2.33 Gly,    z=0.33,    E=9 eV)
C (d=7 Gly,    z=1,    E=6 eV)

Second photon
B (d=0,           z=0,    E=9 eV)
C (d=4.66 Gly,    z=0.5,  E=6 eV)
z's don't match, but they don't need to. Elapsed times and changes in energy do match.
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Old 11th November 2022, 02:37 PM   #193
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Originally Posted by Ziggurat View Post
No, it's not right. There's still a contradiction in there. You think that means that there's something wrong with the theory. In point of fact, it means you ****** up.

Again, distance vs. z relationship TODAY is different than it was in the past. I haven't bothered doing the distance/time calculations, but assuming that you did them right for photon 2 (since the calculations were done for today, that's more likely to be correct), then this is what they should be:

Code:
|-----------------?-------------|
A          B                    C
|---?------|---------?----------|

First photon
A (d=0,          z=0,    E=12 eV)
B (d=2.33 Gly,    z=0.33,    E=9 eV)
C (d=7 Gly,    z=1,    E=6 eV)

Second photon
B (d=0,           z=0,    E=9 eV)
C (d=4.66 Gly,    z=0.5,  E=6 eV)
z's don't match, but they don't need to. Elapsed times and changes in energy do match.
So an observer at point B would receive the first photon at z=0.33 and conclude point A is 3.5 Gly away?
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Old 11th November 2022, 02:53 PM   #194
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Originally Posted by Mike Helland View Post
So an observer at point B would receive the first photon at z=0.33 and conclude point A is 3.5 Gly away?
NO! That is EXACTLY what I'm telling you is WRONG.

God damn it, Mike, how many times do I have to tell you? You CANNOT use an equation which is only valid TODAY for something long in the past. 4.66 billion years ago, the relationship between z and distance/age was DIFFERENT than it is today.
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Old 11th November 2022, 02:58 PM   #195
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Originally Posted by Ziggurat View Post
NO! That is EXACTLY what I'm telling you is WRONG.

God damn it, Mike, how many times do I have to tell you? You CANNOT use an equation which is only valid TODAY for something long in the past. 4.66 billion years ago, the relationship between z and distance/age was DIFFERENT than it is today.
Ok.

But you're confident an observer at point B would received a photon from point A at z=0.333?

Let's say 7 billion years ago 2 photons left point A.

One of them stops at point B 4.66 billion years ago.

The other continues to point C and gets there today.

Is the trip between point A and B uniform for both photons?
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Old 11th November 2022, 03:13 PM   #196
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Originally Posted by Mike Helland View Post
Ok.

But you're confident an observer at point B would received a photon from point A at z=0.333?
Yes. Why is that hard for you?

Quote:
Let's say 7 billion years ago 2 photons left point A.

One of them stops at point B 4.66 billion years ago.

The other continues to point C and gets there today.

Is the trip between point A and B uniform for both photons?
Yes. Why wouldn't it be?
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Old 11th November 2022, 03:18 PM   #197
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Originally Posted by Ziggurat View Post
Yes. Why is that hard for you?
Because it traveled for 2.33 billion years, and lost 25% of its energy (at z=0.333).

But if it traveled that same distance and was received today it would have lost just 16.66% of its energy (at z=0.2).

Since the universe is expanding faster now than in those times... they should have lost less energy in the past than now.

Not adding up.

Quote:
Yes. Why wouldn't it be?
Then why shouldn't their z and travel times and energy be equal?

You say the z's don't need to be equal. Kinda bailing on the whole consistency thing eh?
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Old 11th November 2022, 03:38 PM   #198
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Originally Posted by Mike Helland View Post
Because it traveled for 2.33 billion years, and lost 25% of its energy (at z=0.333).

But if it traveled that same distance and was received today it would have lost just 16.66% of its energy (at z=0.2).

Since the universe is expanding faster now than in those times... they should have lost less energy in the past than now.

Not adding up.
YOU came up with those ages, not me. The ages are model dependent. I don't know what model you're using. I don't know if that model is accurate. I don't know if that model produces acceleration.

What I do know is that you aren't handling red shifts correctly when there's more than one step.

Quote:
Then why shouldn't their z and travel times and energy be equal?
Travel times between events will be equal. z's won't be because they're in reference to things which aren't equal, since the photons started at very different times. Why would you expect them to be?

Quote:
You say the z's don't need to be equal. Kinda bailing on the whole consistency thing eh?
Uh, no. Consistency isn't the same as equivalence. Two things being different isn't an inconsistency if there's no reason they should be the same. The z CHANGE for the second segment of the trip for photon 1, which STILL REFERENCES event A, isn't going to be the same as z for photon 2, which was never at event A. There doesn't have to be any similarity. Don't compare z's between them. Compare their energies. Their energies are consistent.
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Old 11th November 2022, 03:48 PM   #199
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Originally Posted by Ziggurat View Post
The z CHANGE for the second segment of the trip for photon 1, which STILL REFERENCES event A, isn't going to be the same as z for photon 2, which was never at event A. There doesn't have to be any similarity. Don't compare z's between them. Compare their energies. Their energies are consistent.
Their energies are consistent because you assumed them to be, and then reached that conclusion. A consequence of which is that a photon that has traveled 2.33 billion years, has a z=0.3333. If you're happy with that, good for you.
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Old 11th November 2022, 03:58 PM   #200
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Originally Posted by Ziggurat View Post
What I do know is that you aren't handling red shifts correctly when there's more than one step.
Let's add another step. X:

Code:
|-----------------7-------------|
A          B                    C
|---2.33---|---------4.66-------|
A          B         X          C
|---2.33---|---------|----------|

First photon
A (d=0,        z=0,    E=12 eV)
B (d=2.33 Gly, z=0.2,  E=10 eV)
X (d=4.66 Gly, z=0.5,  E=8 eV
C (d=7 Gly,    z=1,    E=6 eV)

Second photon
B (d=0,        z=0,    E=9 eV)
X (d=2.33 Gly, z=0.2,  E=7.5 eV_
C (d=4.66 Gly, z=0.5,  E=6 eV)
What would you change on that?
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