I’ve been reading along, impressed with your patience.
With the holidays, a new baby, and a book I’m nursing along, I haven’t been my usual prolific contributor. That should change by January.
I’ve been reading along, impressed with your patience.
With the holidays, a new baby, and a book I’m nursing along, I haven’t been my usual prolific contributor. That should change by January.
I would like to second that you and also @dga471 have been patient as well as knowledgeable. You obviously enjoy questions about cosmology and most importantly you care that people make good use of mathematics. I was drawn in to reading all of this. I only followed some of the math - I am just a programmer at work (and an amateur astronomer). There wasn’t anything I was qualified to comment on. But how you both were so patiently helpful was impressive.
So just before this topic dies naturally, or is closed, I am going to include here some of my remarks about why it is not surprising that in light of the astrophysics evidence we have, scientists prefer to posit the existence of dark matter rather than modify gravitational laws like @Joe_Bakhos or even MOND does. This is adapted from what I wrote to Joe in a PM in response to his more specific remarks - I thought it would be beneficial to have it accessible to everyone else.
This shouldn’t be taken as an authoritative opinion universal to all physicists, but merely one physicist’s take on why the idea doesn’t seem far-fetched. In the course of writing this post I came across this excellent recent review article (Bertone & Hooper, History of Dark Matter) which has a more complete picture of how this paradigm came to be developed. I learned several interesting facts from this paper. If Joe or anyone else interested in learning in greater depth how dark matter became the dominant paradigm, please read this paper instead.
You can read my summary here: Why do Scientists Believe in Dark Matter?.
[@moderators: removed duplicate content, find it at the inserted link]
Thank you for this writeup, @dga471! I think that this perhaps deserves its own thread. I am sure that there are people here who are interested about dark matter, but won’t go through this long thread to find your writeup.
This absolutely should be kept somewhere prominent as a reference and not buried at the end of a long thread. It was a pleasure to read. It ties everything together. It is a great “big picture” look at things.
With a great deal of help, I have substantially re-worked my entire hypothesis. It also has bearing on the recent Oumuamua mystery. For any that might be interested, here is an abstract along with a link to the full article:
ABSTRACT
Galactic rotation rates, the distribution of matter in the early universe shown by the scale of anisotropies in the CMB, and cosmological expansion present problems that current theory attempts to resolve by positing dark matter and dark energy. This paper posits that gravitational force is a dampened wave function dependent upon mass and distance. Therefore gravity reverses at regular dampened intervals. This reversal would also be in effect at smaller scales such as our own solar system, implying that current theory may have overlooked evidence of this in the data from various probes that have been launched.
LINK: https://redd.it/ao8vfo
@Joe_Bakhos… it looks like your new theory has the gravitational acceleration due to the sun oscillating wildly in the space between planetary orbits? I hate to be the bearer of bad news, but I can assure you this is false. Humanity has sent a lot of interplanetary probes out into those spaces. We would have noticed. I’m pretty sure the differences between your theory and Newtonian gravity are orders of magnitude more than something like the Pioneer anomaly (and haven’t they figured that one out? I thought they’ve pinned it on thermal recoil).
Also, your expression \sin(0.00004\sqrt r) is meaningless without some units of inverse square root length attached to the .00004.
Also, calling your equation for a a wave function would probably not be considered correct usage, especially not without a wave equation (like, the Schrodinger equation, or the Klein-Gordon equation) that a satisfies.
@structureoftruth: “oscillating wildly” : There might be large oscillation near to the sun, but by the time you get to planetary distances we’re talking about an oscillation in acceleration of between .04ms^-2 to -.02ms^-2. This slight oscillation would be spread over tens of millions of miles. I guess “wild” is in the eye of the beholder.
Likewise with your comments about “orders of magnitude” differences in acceleration. I don’t think you are realizing the probes travel at speeds like 15,000 meters per second, while at these distances the differences in acceleration I am talking about are very, very slight – as I noted above.
About units: When you take the sin function of something, that something is considered an angle, and it is not necessary for it to have units since angles are dimensionless. All that is necessary is that you use the same units for r that you use in the outer equation.
@Joe_Bakhos, I’m too busy right now to look at your work in detail. Here’s some comments:
First, you need to clean up your equation and provide details on what each of the symbols meant. What is G here, what is its units and numerical value? What is x here? Also, as @structureoftruth already said, your \sin(0.00004 \sqrt{r}) makes no sense unless you attach a unit to the 0.00004.
Second, you need to fix your model so that it gets 9.8 m/s^2 on Earth. 11.8 m/s^2 is too far off; as it stands, even high-school experiments can falsify your model.
Third, in general you need to demonstrate your claims mathematically and quantitatively. Here are some examples in which you need to do this:
I’m sorry, but you are mistaken. I am not an astrophysicist trying to publish in a journal.
I am not able to “prove” anything.
I am here in an informal way floating a speculative hypothesis. This is what you need to do:
You need to stop pretending that you’re shooting down a thesis or playing gatekeeper for some journal.
You need to consider the basic proposition I’m putting forward. The general idea. And then respond to the general idea.
If you are too busy or you don’t want to, that is fine too.
Excuse me @Joe_Bakhos, he did respond. @PdotdQ laid out precisely what is necessary to convince him your idea has merit. He did respond to the general idea, telling you that you have much more work to do.
I thought you were trying to publish this in a journal. If you are not then you are free to write whatever you want.
Just trying to be helpful. Apparently constructive criticism is shooting down a thesis and gatekeeping.
I think I will respond with the same points I listed.
@PdotdQ: We are talking past each other. In my opinion, you’ve listed the obvious work that needs to be done to turn a speculative hypothesis into a theory. I am not disagreeing at all with your list.
I am disagreeing with the idea that it’s not worth discussing until it is proven.
Science obviously goes in stages. In the early stages, a researcher needs to discern what is worth investigating and what is not worth investigating.
If at a very early stage I say, “Hey, what about this? Might this be worth investigating?” You are basically saying: “Well Joe, complete your investigation, and prove that it’s true, and then I’ll tell you whether it’s worth investigating.”
So to try to be clear, you outlined a sensible course of action – but I already knew most of that list. That really wasn’t what I was asking. What I was asking was this:
Being an expert in the field, given your first impression of the general idea, would it be worth my time to go through that entire course of action to validate this? Or, in your opinion as an expert, can you see obvious flaws in the idea that tell you there is no possible way it can be true and is therefore not worth pursuing?
Now as I said before, if you’re not interested in answering this type of question, or if you do not have the time to look into it that deeply, I understand.
It is difficult to figure out whether your theory is worth further investigation given the details are so sparse - which is why this is a chicken or egg problem. If you can answer some of the comments (perhaps not all) that I outlined previously, then the theory will have more meat that I can evaluate to see whether it is worth it to continue or not.
I don’t know what you mean by “obvious flaws”. Perhaps the first two points I mentioned qualifies:
Here are a couple more that perhaps what you mean by “obvious flaws”:
An additional observation: your equation for acceleration is
a = \frac{GMr^2}{x^4+GM}(1 + 2 \sin (0.0004 \sqrt{r}))
Am I getting this correctly? What is x? If I assume that x^4 has the same units as GM, your formula will result in a having units of r^2 or length squared, which doesn’t make sense. (In addition to the units anomaly inside the sine function which others have mentioned.) Can you explain what is going on?
OK, so now your formula is
a = \frac{GMr^2}{r^4+GM}(1 + 2 \sin (0.0004 \sqrt{r}))
That still doesn’t make sense, as in denominator now we have r^4, which has units of m^4, added to G M, which has units of m^3 s^{-2}.
So you have discrepancies on the order of 10^(-2) ms^(-2). The Pioneer anomaly was a discrepancy on the order of 10^(-10) ms^(-2). It took maybe a decade, around 10^9 s, to become noticeable. Your anomalous acceleration would become noticeable somewhere on the order of seconds to days, at most.
@PdotdQ: G is numerically, the gravitational constant with appropriate units. What “appropriate” means, I don’t know yet. Same goes with your other concerns about units; put in whatever units make it work for you.
When you say the model needs to get 9.8 m/s^2 on Earth … please. This is obvious. I’m putting forward a general, rough idea in its rudimentary stages. Hey, how would MOND theorists feel if they got their predicted accelerations to within 20% of the observed value? As I keep explaining, I would appreciate a comment on the general idea rather concentrating on details. About Newton: Yes, it contradicts Newton. It also contradicts Einstein.
About Bertrand’s theorem: The entire point of my citing Bertrand was to point out that I think the gravity law does NOT follow his theorem. Newton followed his theorem based on observations. What I am saying is that over the course of billions of years, the dust, gas, and other matter around the sun eventually settle in a way consistent with Bertrand’s theorem, because the matter has sometimes been pushed further out, and sometimes pulled nearer in. You are very correct in that I certainly have not proven this mathematically – this must certainly be done before I can claim to have an actual theory.
[@moderators note: @dga471 does NOT endorse his idea]
@dga471: I would like to thank you for your ringing endorsement of my idea. The concept of triage is applicable here. It is natural to gravitate to the most glaring defects that an idea has, before moving on to the details. I’ve put forward an idea whose fundamental concept contradicts both Newton’s and Einstein’s theories. For you to look at it and conclude that the most glaring defect that needs most immediate attention … is appropriate units … seems like a huge endorsement to me.
@structureoftruth: The boundaries for acceleration I gave were maximums and minimums around Mercury. By the time you get to Pluto, the differences would be on the order of what you’re talking about.
As far as researchers “noticing” other deviations: In fact, they have: