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Evidence that the key assumption made in discovery of dark energy is in error

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Re: Evidence that the key assumption made in discovery of dark energy is in error

#131

Post by cthalupa »

ltbarcly3 wrote: post #92
ncmncm wrote: post #85

Earlier quoted context omitted.

Conservation of energy has only ever been observed in local conditions. The universe is not obliged to respect our local expectations, and has always turned out to violate them in uncomfortable ways. The ground looks flat near you (at least in Nebraska). The Sun seems to go around Earth.

Which is more likely, that you can have infinite free energy or that the very careful measurements of the distances to supernova that happened billions of years ago on the other side of the universe, and for which we have virtually no standard yardstick to compare against are not accurate? You are just making an appeal to ignorance. All of physics and astronomy is based on the assumption that the rest of the universe…

This is a false dichotomy. We have known energy is not (always) conserved since long before we began discussing dark energy.

This is such a misunderstood topic vis a vis dark energy that Discovery specifically has an article on it:

https://www.discovermagazine.com/the-sciences/energy-is-not-...

Re: Evidence that the key assumption made in discovery of dark energy is in error

#132

Post by sanxiyn »

PopePompus wrote: post #122
mannykannot wrote: post #81

Earlier quoted context omitted.

Do the current models of dark energy not have it changing over time? Or at least allow for the possibility? The idea that fundamentally, physical law does not change over time, is either a metaphysical or methodological assumption (or a bit of both), but it is certainly not an empirically-derived result, and it clearly does not rule out manifestations of those fundamental laws changing over time.

The issue is much more prosaic than the fundamental laws of physics changing over time. On average, very distant supernovae have a different composition than nearby supernovae. As the universe ages, more light element atoms are fused into heavier element atoms and expelled into space. That material is incorporated into the next generation of stars, so stars begin their lives with less and less hydrogen, as the univer…

That's what is weird about this: from the paper, "Unlike population age, we find no significant correlation between host metallicity and Hubble residual". So it correlates with age, but not metallicity!

Re: Evidence that the key assumption made in discovery of dark energy is in error

#133

Post by mikorym »

As a mathematician, I will inherently be biased against dark matter and dark energy (if you're calculations don't fit, then your mathematics is not suitable, so change the math before you change the physical description). What is the relationship between dark matter and dark energy, and does this have any effect on the r^2 law assumptions and the introduction of dark matter?

For example, does this mean that when we thought that r^2 was not strictly followed that in fact we had the positions of the bodies wrong?

Re: Evidence that the key assumption made in discovery of dark energy is in error

#134

Post by briantakita »

_bohm wrote: post #124
mathiasrw wrote: post #57

If you find things like this interesting I suggest you look on youtube for videos on the electric universe. The main take is that our current models having gravity as the main driving force shaping our universe is a misunderstanding - hence rejecting the idea of dark matter / dark energy that was "invented" to make for math for gravity work with the observations of expansion.

It should be noted that among cosmologists, electric universe is widely considered to be bunk science.

And Plasma Physicists think that "dark matter", "dark energy", & the assertion of gravity (ignoring plasma) being the dominant force in the Univese is mathematics without physical evidence. Thus "pathological science". Irving Langmuir, discoverer of the double layer effect in plasmas & coined the term "plasma" physics, came up with the definition of "Pathological Science". He was also around during the birth of the "Standard Model".

https://en.m.wikipedia.org/wiki/Pathological_science

Re: Evidence that the key assumption made in discovery of dark energy is in error

#135

Post by qyv »

bananabreakfast wrote: post #77
flashman wrote: post #34

To know if the universe is expanding, we need to know the following: how far away things are, and whether they're moving away from us. In an accelerating universe, there's evidence that things were moving away from us slower in the past. The evidence that things are moving away from us is that as the universe expands, the wavelength of any light travelling through it also expands, shifting it towards the red end of t…

Speaking from the pov as a former astrophysicist, that definition of redshift is not quite accurate. While we have observed the universe expanding since Edwin Hubble published his findings 90 years ago, it was in fact the Friedmann equations produced 10 years earlier that established how it would work within the context of general relativity. The Universe is expanding at every known point at the same time at the same…

> However, as you go further and further out from our galaxy the metric expansion of spacetime begins to dominate the relative motion of all bodies, leading to observing progressively redder and redder light curves. A galaxy billions of light years away is perceived to be moving away from our reference frame at a significant percentage of the speed of light!

Is this not because there is simply more space between things that are farther away and therefore more expanding space? So, more space = more magnitude of expansion?

Re: Evidence that the key assumption made in discovery of dark energy is in error

#136

Post by pedrosorio »

zaroth wrote: post #114
Tenemo wrote: post #108

Earlier quoted context omitted.

Your ruler is absolute distances, like the speed of light. You can inflate or deflate the balloon and the number of marks on its surface won't change. But the time required for the light to travel between them will.

Stupid question - How do you know for certain it isn’t just that light is slowing down? Relativity probably doesn’t work this way at all, but if light did actually slow down, would it be perceived by us as light moving at the same speed across a greater distance?

https://en.m.wikipedia.org/wiki/Variable_speed_of_light

Re: Evidence that the key assumption made in discovery of dark energy is in error

#137

Post by briantakita »

Jweb_Guru wrote: post #121
mathiasrw wrote: post #57

If you find things like this interesting I suggest you look on youtube for videos on the electric universe. The main take is that our current models having gravity as the main driving force shaping our universe is a misunderstanding - hence rejecting the idea of dark matter / dark energy that was "invented" to make for math for gravity work with the observations of expansion.

Despite the similar name, dark matter really has very little to do with dark energy, and the lines of evidence for them are totally different. AFAIK there is fairly overwhelming evidence for the existence of dark matter at this point, and it's mostly a question of what exactly it is rather than whether the effect is real.

Dr. Anthony Perat, protege of Hannes Alfven, has a cosmological model based on plasma, which is observable & subject to physically reproducible experiments & replaces the need for both Dark Matter & Dark Energy as mathematical artifacts.

https://www.amazon.com/Physics-Plasma-Universe-Anthony-Perat...

Re: Evidence that the key assumption made in discovery of dark energy is in error

#138

Post by ailideex »

ncmncm wrote: post #42
AnimalMuppet wrote: post #5

Earlier quoted context omitted.

It is my impression that dark energy is generally accepted in cosmology. Whether that counts as "proceeding as if dark energy is well evidenced" is perhaps a different question. If everyone believes it's there, but nobody knows what it is, well... there was still something that convinced them that it was there. That something should be evidence. Is it enough to count as "well evidenced"? Perhaps not, especially if th…

I don't know of any other evidence for dark energy, other than that mathematical physicists think the equations would be prettier with some, although they sort of wish there was more. It is quite embarrassing that the value was so close to zero without being zero, so that might be one embarrassment less. We already knew there was likely to be something fishy about the most distant supernovas, because we have two dive…

> I don't know of any other evidence for dark energy, other than that mathematical physicists think the equations would be prettier with some, although they sort of wish there was more.

https://en.wikipedia.org/wiki/Dark_energy#Evidence_of_existe...

Re: Evidence that the key assumption made in discovery of dark energy is in error

#139

Post by trhway »

ncmncm wrote: post #51
AnimalMuppet wrote: post #47

Earlier quoted context omitted.

Hmm. Is this new result in the right direction to solve the Hubble Constant problem?

Haha, it would be fun if we now have three Hubble constants.

my personal favorite value for the Hubble constant is the "c" divided by the age of Universe, it results in 70.8 km/s/Mpc, right in the middle of the other 2 established Hubble constant's values, a very nice coincidence that the objects at the Universe age distance are running away exactly with "c".

Re: Evidence that the key assumption made in discovery of dark energy is in error

#140

Post by fsh »

mikorym wrote: post #133

As a mathematician, I will inherently be biased against dark matter and dark energy (if you're calculations don't fit, then your mathematics is not suitable, so change the math before you change the physical description). What is the relationship between dark matter and dark energy, and does this have any effect on the r^2 law assumptions and the introduction of dark matter? For example, does this mean that when we t…

They are not related at all. Dark matter is visible on the scale of galaxies, dark energy on the scale of the universe.

Dark matter is currently the best model that can describe the rotational curves of galaxies under the assumption that general relativity is correct. Since GR has so far stood all tests extremely well, this is a very compelling argument for the existence of dark matter. There are also some more direct observations, such as gravitational lensing caused by dark matter.

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