- #106
andrewj
- 33
- 0
are there three fixed points
Chronos said:All our knowledge of the universe is indirect. The long and the short of it is we think it's expanding because of redshift - a fairly well established scientific principle called the doppler effect. Wipe that concept from the blackboard of science and most modern models of the universe are dead on arrival. The problem is, it does not easily erase. All other independent indicators of distance strongly agree with the redshift interpretation. Halton Arp has railed against the redshift interpretation for many years, but his arguments have not been well received. That does not falsify his claim, but places it squarely within the fringe camp.
ummani said:My question is, why hasn’t there been a scientific revolution of unprecedented magnitude taken place?
Wallace said:Sure, that's a pretty clear argument you present and I agree with you. However, there are many, including Peacock, as well as Martin Reese and Steven Wienberg who wrote a New Scientist article about this some years ago who contend that thinking in this way misleads you and it's better to just think kinematically.
The classic test case is this. Imagine you are in an expanding universe and hold a galaxy at rest with respect to you but at a cosmological distance. According to Hubbles law a galaxy at that distance should be receding but you prevent this by using a chain or rockets or something to hold it in place. If you let go of the galaxy, what does it do?
[THINK ABOUT THIS FIRST THEN READ ON]
The answer you may assume is that since space is expanding the galaxy will start moving away from you, joining the Hubble flow eventually. However in a decelerating (but still expanding) universe the particle actually comes towards you! If you think about it it becomes clear why but Peacock argues in the link I posted that it is the idea of expanding space that leads to these misconceptions and hence should be abandoned.
nutgeb said:Yogi, please explain a little more about your idea. Are you saying that the increase in the number of granular units per volume creates a sort of positive pressure which in effect causes them to repel each other and solid matter, pushing everything apart? If so does that positive pressure bring additional gravity with it, like mass-energy does in GR? And how can positive pressure cause things to move apart if there isn't a pressure gradient somewhere (i.e., an outer 'edge' to the granule-filled universe, surrounded by a region devoid of granules)
Or are the granules just an instantiation of dark energy, characterized by negative pressure, which causes a sort of mutual anti-gravitational repulsion (as well as adding gravity)?
Dark energy of course is an explanation for the recent acceleration of the expansion rate, but it is not an explanation for the "original" expansion which was decelerating due to gravity until dark energy eventually became dominant. (Other than of course attributing inflation to some more powerful form of dark energy).
A model that requires both proliferating granules AND proliferating dark energy seems even more perplexing than the standard model.
I also note that the published analyses of the "tethered galaxy" exercise describe the idea of the untethered galaxy "picking up the Hubble flow" as a fallacy. Rather, unless dark energy dominates, the untethered galaxy moves counter to what the Hubble flow intuitively would cause. (Eventually the galaxy's peculiar velocity decays to the point where it arguably asymptotically "rejoins the Hubble flow", but this may be on the opposite side of the origin.) But you know that, so maybe I'm misinterpreting your comment.
nutgeb said:OK, I see. Yes there are still lots of fundamental questions about the standard model, so it is possible it will be overturned or significantly modified in the future.
I share your uneasiness about the assertion that gravity curves spacetime. It is a wonderful mathematical model and makes for very accessible graphical representations. But as you say the converse doesn't seem to be ruled out either. As has been mentioned before, an arrow flying through a crosswind could be described as traveling through curved spacetime, merely following a geodesic. But is that really a meaningful physical statement in this context? It may just come down to whichever approach makes the metric easier to calculate.
GR seems to justify the application of highly abstract methodologies because of its weirder aspects -- time dilation and spatial curvature. Either something is happening to this entity called 'spacetime' at a very deep level, or else we're missing a cornerstone of how to otherwise describe these observed phenomena.
Whitewolf4869 said:What proof is there that space expands at all
That is just an assumption since you can't see it touch it or sense it in any way.
Whitewolf4869 said:So you are saying that expansion will eventually be the end of all because the vacuum of space will overcome gravidly.
Whitewolf4869 said:Don't be insulted I am just rattling some chains
If Einstein hadn't dropped out of high school and become a free thinker who knows where we would be with this right now
Whitewolf4869 said:#1 The theory is all wrong vacuums don't expand
#2 So comparing space to balloons or bread is foolish
#3 Then an equation is created to explain what we see through our telescopes
#4 When that doesn't fit more equations are created to explain the faulty equations
because there isn't enough mater to explain movement and we add dark mater and dark energy and dark flow ignoring space itself the whole time
How do we know that space wasn't already here and mater and time was created by the negative energy of space and the space time distortion associated with mater is nothing more than surface tension.
Don't be insulted I am just rattling some chains
Whitewolf4869 said:Don't be insulted I am just rattling some chains ...
Whitewolf4869 said:Your absolutely right and I am working on it.
It just seems to be that every time someone thinks outside the box there is always some one that has to protect there ego. I realize that a lot of people have spent many years studying and teaching this subject and my own (bizarre) notions are based on common theory but if we don't constantly question popular belief we are doomed to failure.
Whitewolf4869 said:Your absolutely right and I am working on it.
It just seems to be that every time someone thinks outside the box there is always some one that has to protect there ego. ... if we don't constantly question popular belief we are doomed to failure.
steve watson said:I'm coming in on the tail-end of this, so forgive me, but I am fascinated by the topic of your discussion.
I think that a fundamental problem regarding the question of whether space is expanding is the fact that we treat "space" as a "thing", "something", i.e., a planet, a dog, a grain of sand, an atom, etc., etc., etc., rather than "nothing", i.e., the absenceof "something".
If we viewed "space" as "nothing", theabsence of "something", which it must be, then "space", which is "nothing" cannot be expanding.
steve watson said:I know that understanding the context of a statement is of the utmost importance. And I said so when I posted my note. So my apologies again, I didn't mean to inconveience you. Still, first, words shouldn't be used so loosely. Words have meanings or they would be useless. And next, "space" not being "something" cannot cause "something" to happen. Who set "space" up? What does that mean? I"m not be sarcastic or cute, I am asking real questions and I am curious as to your answers.
steve watson said:I understand, and I appreciate your response. These mathematical concepts trouble me. Math is trickey and can lead to strange and unverifiable notions and theories.
My problem is with the nature of "space" and what it is or rather what it is not. Nobody seems to be able to give me a straight answer. But everyone seems to think "space" is a "thing" rather than "nothing". If "space" were "nothing" wouldn't that turn a lot of these theories upside down?
steve watson said:Well you're way out of my league regarding math and the mathematical theories you speak of, but when you descirbe "space" as having a "shape", aren't the only things that have a "shape" things that exist? And if "space" has a "shape" doesn't that mean "space is a "thiing"?
steve watson said:anythat that exists: a planet, an atom, a needle, a haystack, a grain of sand, everythig except nothing, i.e., the lack of something. ...
steve watson said:I understand, but doesn't the "big bang" theory (which i don't subscribe to) and other theories setting out the beginning of time proclaim "space" to be a "thing" .. and if it is a "thing" where does it end, when does it end (if this is even a sensical question when it comes to matter, i.e., "things" and if things have no end, i.e., infinite, then how come you can identify one thing from another thing?
Whitewolf4869 said:Hears an alternative for you. Have you read any papers by William Tifft he and others found that c is not a constant.