purintjp

I was thinking about the concept of time recently and came to the realization that for time to exist there must be some movement through space benchmark for it to exist. If you consider all the possibilites of the universe as it has supposedly existed from the 'primordial atom' as postulated on a recent showing of the 'Universe' series on TV to the current time and probably way beyond, it seems clear that there has always been movement through space and probably always will be. It would seem that the only way a 'beginning' of time could exist would be that the early universe consisted of nothing. Do we know how long the 'primordial atom' existed prior to the BBT ?

What is the 'G' in '8 pi G' ?

It would seem that black holes would also have to rotate to create the 'black hole eddy' effect shown in so many scientific programs and articles. It would appear that eddy is a twisting of space-time itself due to the rotation of the large mass singularity. Could a non-rotating black hole even exist ?

Actually, I went to Downey High in Downey, CA in 1962. My math is a bit rusty but I can do it. What does 'G' stand for in '8 pi G'. I noticed you said "If density is SIGNIFICANTLY greater than crit". Would we notice a not so significant greater crit ? It is pretty amazing that the key value seems to be the Hubble constant.

Is the average density of the universe one of the defining parameters ? If so, I was wondering how that number was derived. Could it be off more than we posit ? Was it adjusted to reflect recent discoveries like super-massive black holes in galaxy centers or is that to small to matter ? Does it reflect estimates from current time observations or does it compensate by calculating the actual positions of far distant objects in current time ? What about dark matter or energy affecting the density ?

Originally Posted by purintjp Maybe it's already started to contract and we don't know it yet... Well that's an entertaining idea, but it isn't consistent with our theory of gravity which has been tested rather thoroughly (since proposed in 1915) and it is not consistent with our dynamic model of the unverse which dates back to 1921 and has also been well tested (especially since the 1990s with a bunch of new space instruments.) Right now cosmology is in a mode of refining the parameters. (And finding out more about the physics underlying them.) Any damn fool thing is possible, but don't hold your breath. Does this mean that we now know exactly when the universe will start it's contraction ? How can we possibly know what the current state of the universe is when most of what we see is not current time ? It would seem that the biggest changes would start with the farthest objects. Would they collapse towards us faster than the speed of light in reverse of what is happening now ?

Maybe it's already started to contract and we don't know it yet. The light we see is pretty old. Our closest galaxy neighbor Andromeda is coming towards us now. Could be just gravitational attraction, though.

Reply to Martin ...... Thanks for the links to the Scientific American and others. It offers important help understanding some of the misconceptions. I guess that what was somewhat confusing to me was the balloon model which represents a sphere. I'm wondering if it might be more clear to use a cone where the big bang is a slightly rounded small end of the cone and the current state of the universe is now a slightly rounded large end (so large as to appear flat) to any observer. This would still allow for expansion in all directions with a constantly moving center. It was curious to me that the average density predicts a flat universe but the expansion would seem to indicate otherwise. Could it be so nearly flat that we could not detect the curvature ?

Reply to Martin and NowThatWeKnow ..... Thanks for your replies. I have not been able to get on the net lately due to hardware problems. If I understand what you are saying, the early expansion was happening at many times the speed of light so that at that time you probably could not have seen any light all ? Even the light coming from your own sun ????? I gotta tell ya, I start to get real skeptical when theories require that kind of speed. My calculus is really rusty so I'll take your word for the math. Are we sure that the red-shift method is really giving us the right numbers. I've read many articles that pretend to cast doubt on it. Do we know whether or not the light wave expansion is due to acceleration away or could it just be a natural wave expansion simply from the long trip or a gravitational anomaly or something else. I posted a blog on this forum about 2 months ago concering light. It was titled "Is there more to light than meets the eye". I think it's on Page 3 now. I was somewhat disappointed that not more people had comments. I postulated that light completely permeates the cosmos and as a result space is a vacuum but nowhere near empty. I had read an article concerning a couple of satellites in distant orbit near the outer planets that had orbit anomalies that were not as calculated by scientists. I was wondering if the push it got from our sun's light to the 'light ether' I speculated on had anything to do with it. I also wondered if light itself is the driver for universe expansion. I expected that wherever the limits of the universe where that light would get there first and finding nothing to stop it would continue to expand the universe until all the galaxies burned out. Based on your comments about multi-c expansion speeds I suppose that idea is history. If you feel like reading it, I would sure appreciate any comments.

In reply to Martin.... I understand the balloon concept and have seen the applet on the net. I have a little difficulty mentally translating a 2d surface to a 3d world we actually live in. Since the light from the far distant object is not all that far away at an earlier time the speeds of the far distant expansion should not be an issue as with a closer proximity expansion. Light from nearby galaxies has no problem getting here. Why would it be any different ? It still seems that it should exceed the speed of the early expansion and reach us in fairly short order in the distant past. Which begs the question of being able to see the same light photons at two widely separated time intervals.

After reading a number of scientific articles about far distant galaxies and the estimated age of the universe I began wondering how we could supposedly see light from objects that are 12 billion light years or so away. This is supposed to be light from nearly the beginning of time and space. If we agree to believe that the big bang actually happened then this would mean that at some point we were much closer (cosmologically speaking) to those distant objects. Since matter travels at a mere fraction of the speed of light is seems somewhat dubious that any light emitted from that object at the beginning of time, as we know it, would not already have passed us a long, long, long time ago. We have developed many tools for measuring distance from relatively nearby objects. I suspect that these work well up to a point, at which they start to break down somehow. Could it be that using light to measure distance works well when objects have been relatively close together since the beginning and then breaks down when objects become very far apart ? Maybe the big bang never happened and objects that are far away have always been far away ? Doesn't the fact that these supposed far distant objects are 12 billion light years away mean that the universe is far older than 14 billion light years or have these objects been moving at the speed of light ? I found an article in Wikipedia which attempts to explain this but I'm not sure I buy it. Look for 'Metrical_expansion_of_space'.

Reply to Transdecimal I suppose I could be overstating the number of physical laws. After surfing through many scientific searches on the web I came to the conclusion that many of these laws are hotly debated as to accuracy. It just seems that we really don't know enough about things that are so far away to set hard and fast rules. I suspect that any one theory of cosmology is probably not right but may contain some valid ideas. History is replete with discredited theories. I don't believe that light could be dark matter but it could have something to do with dark energy since it would most decidedly be a repulsive force. Reply to Moth The light that I am talking about has been propagating for 14 billion years. Remember that high mass stars have a fraction of the life span of stars like our sun so they have been created and reborn many times over releasing vast amounts of light throughout the cosmos. In any case, how can you refute the obvious evidence ? It may even be that light is the force and not matter that is expanding the universe. Light has to get to the cosmos limits faster than matter. Given that light is coming from all directions in my hypothetical sphere I guess that is would be inertial mass neutral where all stars and galaxies look like points of light. It would be more like an ocean where high lumination areas would create tidal repulsive forces. These would be areas close to or within galaxies and stars or star clusters. Thanks to both of you for your comments. This is a new experience for me. Most people's eyes glaze over when I talk about this.

I am a layman when it comes deep scientific theory but I have a keen interest in Astronomy and especially Cosmology and have learned much over my 62 years. I was hoping someone might be able to comment or answer questions on my observations. First question ...... With all the latest theories pointing to seemingly outlandish ideas about the nature of our Universe, i.e. The Big Bang, Black hole singularities, String theory (requiring upwards of 12 dimensions), Dark Energy, Dark Matter etc. etc. etc. I can't help but wonder it there is a fundamental problem with one of our thousands of accepted physical laws. Since many of these theories are founded on layers of Mathmatical equations it would seem like a giant house of cards needing only one mistake to topple it. Using the principle of Occam's razor I would expect a far more simple explanation for what is wrong or missing. I wonder what you think. Some further observations and questions ......... I have given much thought to one of our assumptions concerning light itself and have come up with what I believe to be one possible explanation for a novel solution to gravity effects. I think we underestimate the effect light has on our Universe. It is generally accepted that there is only a handful of mass particles in a given outer space volume, however, using a thought problem (ala Einstein) I imagine an abitrary volume in deep space, for simplicity's sake, of say a sphere with the diameter of the distance a light photon travels in just one second (about from here to the moon). I then imagine that I can take a simultaneous observation from all points within that sphere to some arbitrary star or galaxy. The amazing thing is that all those observations would indicate that a light photon from that distant object is penetrating that volume completely at all locations. This would indicate a staggering amount of light within the observed volume. Add up all the visible light sources in the Universe and it would seem that light utterly permeates the Cosmos no matter where that volume is located. In other words, we are just too small to visualize and grasp the significance since we can only be at one place at a time and can only see light coming straight at us. If we could stand back from the cosmos and view it from outside it would probably be a solid mass of light. So what ! , you say. According to Einstein's theory of Relativity text (see reference) the gravitational mass of a body is equal to it's inertial mass. Light is deemed to have no 'rest mass' but it does have 'inertial mass'. If that is the case then, given the sheer size of cosmos volume, the light it contains must surely have a gravitational effect over great distances giving rise to many questions. In fact, the greater the local light amplitude and volume the greater the gravitational effects ought to be. I suspect that neutrinos are somehow also involved in this since neutrinos can go where light can't. Does "empty" or "0" exist or is it just a tool to balance equations ? Could this be a possible explanation for some of the unknown forces in our Universe ? Is the Universe, in fact, based on light as the ultimate smallest unit ? Could this be the 'cosmological constant' ? An off topic question - I have a real problem with singularities. Can we be absolutely certain that the same effects we observe could not be caused by an extremely dense and small object as with a singularity ? If we can't see it how can we be so sure ? (Reference 'Relativity' by Albert Einstein published by Pi Press in 2005. See pages 84 and 85. This is a translated version) Hope you find these thoughts stimulating. Yours, John P. Purinton 22672 Shady Grove Circle Lake Forest, CA 92630 purintjp@cox.net