https://answersingenesis.org/astronomy/cosmology/galaxies-unexplained-spirals/
After a short intermission, we are back on our series on whether YEC claims stand up to scrutiny. This Answers in Genesis article asserts that spiral galaxies prove that the universe cannot be as old as is commonly believed. Some excerpts:
In the 1930s astronomers realized a problem, though. The outer stars needed more time to complete their orbit than the inner stars. As the distance from the center of a galaxy increases, the spiral arms ought to become unstable. That is, after a few rotations, spiral arms ought to smear out.
Astronomers debated for years whether spiral arms wound up or unwound, depending upon the direction of rotation. No matter which view they adopted, however, if galaxies are at least ten billion years old, as is generally thought, then no spiral arms should be left.
While it is true that motion is relative, I am not sure it fixes the distant starlight problem...The relativity of motion is, however, a good thing to keep in mind when debating those who argue that the Bible says that the sun revolves around the earth...
Regarding the distant starlight issue... I’m no expert, but if time is relative, couldn’t speed be considered relative? Which would mean that the speed of light could be different in certain areas of the universe.
Now I’m sure there is something wrong with that argument, just something to think about.
"Evolutionary astronomer" probably wasn't the best term to use. My apologies.
https://www.ce-debate.org/glossary
We define evolution in 2 different ways here...One definition is the one the narrow, scientific term of which you speak, and the other is simply defined in the CE-DEBATE glossary as:
Now, this probably does not summarize your views if you are a theistic evolutionist, but it is often what some of us mean here when we say "evolution" (usually because it is simply much easier to write that than to say evolutionary/uniformitarian/millions-of-years). I think that "evolution" is an acceptable term for the definition quoted above, as that belief views the world as always changing and evolving (often from simple to complex). However, your critique does have a point (and we do sometimes use "evolution" as an umbrella term for the definition shown above).
First of all, what is an "evolutionary astronomer"? Astronomy is a completely separate discipline from biological evolution. Anyone who claims otherwise is either hopelessly confused or else is using the word "evolution" as a passive-aggressive umbrella term to mean "anything and everything about science that I don't like." Either way, they're simply not getting their facts straight.
Regarding your four assumptions. The first -- that the speed of light has always been constant -- can be tested. As I said, millisecond pulsars are just one of the many possible tests of this. If light had ever been different in the history of the universe (and certainly within the past six thousand years) we would observe their frequencies changing on a daily basis. But we don't. They are stable to within one part in 10^14 (one hundred trillion).
Besides, the speed of light is one of the most fundamental constants of nature. Just about everything in physics, chemistry and biology depends on it. If the speed of light had ever been different in the past, then the chemical properties of the elements would have been different, and life as we know it would not have been possible.
For what it's worth, the suggestions that the speed of light could have been different in the past only apply to the very early universe, and are not widely accepted by astronomers. Certainly, any possible variation in the speed of light is far, far, far too small to squeeze light travel times from the distant universe into just 6,000 years.
Regarding the second -- the effects of gravitational time dilation can actually be calculated. To produce the kind of time dilation that would squeeze 13.6 billion years of evidence into just six thousand, you would have to be just a couple of metres above the event horizon of a supermassive black hole the size of the earth's orbit.
Russell Humphreys' white hole cosmology is actually more complex and subtle than that -- in effect, he places the earth inside a black hole. Again, we know this doesn't work because it predicts that distant starlight should be blue shifted towards us. In reality, it is red shifted away from us.
Regarding the third -- the anisotropic synchrony convention (that light travels towards us at infinite speed but away from us at c/2) may be valid from a purely relativistic perspective, but it is not valid from an electromagnetic perspective. Light consists of electromagnetic waves, which are governed by Maxwell's Equations. They have a wavelength and a frequency, and the speed of light is determined by dividing one by the other. It is also determined by the electrical permittivity (ε0) and the magnetic permeability (μ0) of a vacuum, both of which are measurable quantities. Having light travel towards us at infinite speed and away from us at c/2 simply does not respect the physical nature of what light is actually made of.
Finally, regarding the fourth -- that light could have arrived supernaturally quickly. This is nothing more nor less than an "appearance of age" argument -- again, you're talking about the creation of evidence for a history of events that never happened, especially given that when they arrive, they have the appearance of depicting galactic collisions and relativistic jets that appear to have taken hundreds of millions of years.
As such, it is very, very different from the Resurrection of Christ. There is nothing about the Resurrection that requires us to believe in the creation of evidence for a history of events that never happened.
When I took an astronomy class in college 35 years ago, we were taught that "light years" was a measurment of distance, not time. "Those stars are many miles away from earth" NOT "the universe is billions of years old."
Also, in my experience evolutionary astronomers presuppose certain assumptions.
First assumption - light has always traveled at the same speed. (I think most creation scientists would affirm that this is probably a reasonable assumption—but it is an assumption, not an observable fact.)
Second assumption - the effects of gravitational time dilation are insignificant. According to Einstein’s theories, time can flow at different rates under different circumstances. Under the right conditions, light from the most distant galaxies could have arrived at earth in very short amounts of time. Many evolutionists seem to totally ignore this important principle of physics.
Third assumption - a particular synchrony convention. (The terrestrial equivalent of this fallacious assumption would be assuming that noon in Paris is the same as noon in Chicago.)
Fourth assumption - light always arrives entirely by natural means. Such reasoning is no different than those who reject the resurrection of Christ because it cannot be explained by natural forces.
Just a thought. Since God created the stars supernaturally on the fourth day of creation and made them to give light upon the earth, He may have used different means to get distant starlight here than the “natural” means by which He upholds the universe today.
I am certainly no astrophysicist, but it seems to me that both Biblical creationists and big bang evolutionists have proposed a variety of possible solutions to light-travel–time difficulties in their respective models. Big-bang evolutionists should not criticize creationists for hypothesizing potential solutions, since they do the same thing with their own model. The "horizon problem" remains a serious difficulty for evolutionists and they have many competing conjectures that attempt to solve it. That's why I think it is inconsistent for big bang theorists to use light-travel time as an argument against Biblical creation, since their own hypothesis has an equivalent problem.
It does not appear that the distant starlight problem is the same as the horizon problem...At least as you define them.
If I am not mistaken, the horizon problem is that 14 billion years is not enough time for heat to travel to all parts of the universe in such a way that it's temperature becomes uniform...It appears that some have even suggested that the speed of light changed in the past (https://arxiv.org/abs/astro-ph/9811018) in order to fix this problem...Considering your comment that the speed of light has never changed, I would be interested in hearing what you think of that idea...It is beginning to seem that big bang cosmology also has problems as YEC cosmology does (I mean, we can always play the "appearance of age" or "divine intervention" cards).
What the computer simulations show is that it is possible for spiral arms to persist for billions of years. This being the case, while they don't prove that the universe is 13.6 billion years old, they don't falsify it either. In other words, even if there are problems for the Big Bang and the scientific consensus on the age of the universe, galactic spiral arms are not one of them.
Regarding the horizon problem: regardless of what you make of it, it's simply ridiculous to claim that it's the same as the distant starlight problem. The two operate at completely different scales, involve completely different laws of physics, and concern completely different times in the universe's history.
To put it into perspective: if the visible universe were the size of your house, the horizon problem would only be a problem at the scale of your living room or greater. The distant starlight problem, on the other hand, would be a problem for everything bigger than the width of a human hair.
The YEC organisations have proposed a few solutions to the distant starlight problem, but none of them work. For example, we know that the speed of light has never changed because of millisecond pulsars. These are stars that emit X-ray pulses at very regular intervals -- in fact, they are more regular than modern atomic clocks, with a stability better than one part in 10^14. If light had ever been faster in the past, we would see them slowing down from one day to the next. We don't.
And then that gets into the realm of "appearance of age." After discussing this argument, it does not seem to be the best one for a young universe...It is evidence against an old universe in the same way however.
While we are on this topic, I would be interested in hearing what people think of the horizon problem (the fact that the universe's temperature is uniform, and the problems this poses for the big bang model) as well as perhaps some discussion of the distant starlight problem...
In this case, inferring that the universe is between 13-14 billions of years old, or using spiral galaxies to suggest the universe is only hundreds of millions of years old would pose the same challenge to the 6,000 year old universe.
What kind of scientific evidence?
There is more scientific evidence that supports a young universe as well, which we may end up discussing.
If spiral galaxies did happen to show (which I'm not conceding) that they were only hundreds of millions of years old, that would be just as much of a problem as a 14 billion year old universe for the position of a 6,000 year old universe. Either way, scientific evidence would suggest a MUCH older universe than a literalistic interpretation of Genesis 1 would allow.
Quick question: can these computer simulations count as evidence/observations (are they based on observations), or are they based on theory?
Thank you for posting these videos! Now that we can better visualize what we are talking about...
While these galactic spirals may not prove that the universe is less than 10,000 years old, surely they present a significant conundrum for the mainstream doctrine that the universe is around 13 billion years old? If it had to be admitted that these galaxies are only hundreds of millions of years old, would that not still be (comparatively) very young? To put it in perspective, (according to a millions of years timeline) life would have existed on earth for many millions of years before these galaxies even existed...
Now that these thoughts are squared away, I will be happy to discuss more reasons that spiral galaxies would possibly be able to last billions of years, and perhaps some productive conversations about virtual history will transpire as well.
I will be interested in reading your responses.
Here's a simplified one showing the basic idea:
Here's another one showing a much more detailed simulation:
As you can see, collisions and close encounters between galaxies will be one way in which spiral arms can re-form after they've been smeared out.
Here's a link to a Google search for more videos:
https://www.google.co.uk/search?q=spiral+galaxy+formation&client=firefox-b&dcr=0&source=lnms&tbm=vid&sa=X&ved=0ahUKEwj4sJjhsP7ZAhWBI8AKHWcyBUEQ_AUICygC&biw=1846&bih=1006
Regarding my second paragraph: it takes about 250 million years for the sun to orbit the centre of the galaxy just once. Stars closer in will orbit more quickly but it will still take tens of millions of years to make a single rotation. This being the case, it would take the spiral arms hundreds of millions of years at least to smear out. On the other hand, on a timescale of six thousand years, the change in the overall winding of the galactic spiral arms will be negligible.
This means that if they were created six thousand years ago, they must have been created almost exactly as they are today. Yet the fact that they have spiral arms in the first place makes them clearly look like they got that way from a different configuration, whatever that original configuration might be.
My apologies -- I should have included these videos in my original post.
Greetings! Just out of curiosity, would you mind posting one of these computer simulations for the gratification of all? You can imbed it directly into the thread by clicking on the video camera icon in the lower left of the post editor, and then pasting in the youtube link.
Also, would you mind providing some additional explanation of your second paragraph?
There's one thing the Answers in Genesis article doesn't seem to address about the density wave theory: computer simulations. There are several examples that you can see on YouTube, some of them quite detailed, and it seems that what happens in some cases is that galactic spiral arms smear out but then re-form.
The other problem with this argument was that even if there really were a problem with density wave theory, it would only reduce the maximum age of the galaxies by a factor of ten or so. The galaxies still have the appearance of being gravitationally bound, they still have the appearance of rotating, and unless you're going to argue for "appearance of age," getting into that configuration from whatever starting point is still going to take waaaaaaay longer than six thousand years.
There's another side to the question about galaxies though, and that is galactic collisions. The most prominent example is "The Mice" (NGC 4676. https://en.wikipedia.org/wiki/Mice_Galaxies) a couple of galaxies that have every appearance of being in the middle of a collision. The "tail" on the right hand galaxy is exactly what you would expect from tidal forces.
These two galaxies are about 290 million light years away, about 100,000 light years across, and moving past each other at about 200 miles a second. A quick back-of-the-envelope calculation suggests that they must have taken at least 100 million years to stretch out like that. Again, at the very least, you're looking at a pretty unambiguous appearance of age.
On a final note, I've never found the AIG claim that the distant starlight problem is the same as the horizon problem to be satisfactory for the simple reason that the two cover completely different scales of time and distance. The horizon problem relates to distances the scale of the entire universe, and laws of physics that are poorly known and difficult to reason about. The distant starlight problem relates to distances a fraction of the size of the Milky Way galaxy, and laws of physics that are far better known and far easier to investigate. Basically, it's like comparing a mountain to a molehill.