Spyman

I would think Einsteins Theory of General Relativity deservs a little better notion than "a little mumbo-jumbo". Modern physics describes gravitation using the general theory of relativity, in which gravitation is a consequence of the curvature of spacetime which governs the motion of inertial objects. The simpler Newton's law of universal gravitation provides an accurate approximation for most calculations. http://en.wikipedia.org/wiki/Gravitation General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1915. It is the current description of gravitation in modern physics. It unifies special relativity and Newton's law of universal gravitation, and describes gravity as a geometric property of space and time, or spacetime. In particular, the curvature of spacetime is directly related to the four-momentum (mass-energy and linear momentum) of whatever matter and radiation are present. The relation is specified by the Einstein field equations, a system of partial differential equations. http://en.wikipedia.org/wiki/General_relativity General relativity's predictions have been confirmed in all observations and experiments to date. http://en.wikipedia.org/wiki/General_relativity General relativity has emerged as a highly successful model of gravitation and cosmology, which has so far passed every unambiguous observational and experimental test. http://en.wikipedia.org/wiki/General_relativity The tests of general relativity included: * General relativity accounts for the anomalous perihelion precession of Mercury. * The prediction that time runs slower at lower potentials has been confirmed by the Pound–Rebka experiment, the Hafele–Keating experiment, and the GPS. * The prediction of the deflection of light was first confirmed by Arthur Stanley Eddington in 1919. The Newtonian corpuscular theory also predicted a lesser deflection of light, but Eddington found that the results of the expedition confirmed the predictions of general relativity over those of the Newtonian theory. However this interpretation of the results was later disputed. More recent tests using radio interferometric measurements of quasars passing behind the Sun have more accurately and consistently confirmed the deflection of light to the degree predicted by general relativity. See also gravitational lens. * The time delay of light passing close to a massive object was first identified by Irwin I. Shapiro in 1964 in interplanetary spacecraft signals. * Gravitational radiation has been indirectly confirmed through studies of binary pulsars. * Alexander Friedmann in 1922 found that Einstein equations have non-stationary solutions (even in the presence of the cosmological constant). In 1927 Georges Lemaître showed that static solutions of the Einstein equations, which are possible in the presence of the cosmological constant, are unstable, and therefore the static universe envisioned by Einstein could not exist. Later, in 1931, Einstein himself agreed with the results of Friedmann and Lemaître. Thus general relativity predicted that the Universe had to be non-static—it had to either expand or contract. The expansion of the universe discovered by Edwin Hubble in 1929 confirmed this prediction. http://en.wikipedia.org/wiki/Gravitation

"The Local Interstellar Cloud ... is very tenuous, with 0.1 atoms per cubic centimeter" http://en.wikipedia.org/wiki/Local_Interstellar_Cloud

You can lead a horse to water, but you can't make it drink...

Hubble's law needs a cosmological model to correctly predict the redshift for distant objects, because the rate of expansion and thus the Hubble constant is changing over large timescales. The Hubble value H0 tells us how fast a spinning reel on a gigantic fishing rod with the hook stuck on a galaxy far away would spin, while deploying more fishing line because of expansion, in relation to how distant the galaxy is or how much fishing line there are streached between the rod and the hook. However if the distant galaxy would send information towards us, either by a spaceprobe or with a lightray, the information would have to travel through more space than the current distance during the time of transmission, since the distance would increase while the information is on its journey. This longer distance would also cause the "delay" time to be greater and without corrections for this the "acceleration" model will predict wrong receding speed. In the OP you said: "So, IF (if) we are accelerating, and IF (if) we are accelerating at the same rate..." But IF the Hubble constant is changing over time, then we are accelerating with a different rate than the object transmitting the image reaching us from over a large time and distance. "Hubble's law is considered a fundamental relation between recessional velocity and distance. However, the relation between recessional velocity and redshift depends on the cosmological model adopted, and is not established except for small redshifts. For distances D larger than the radius of the Hubble sphere rHS , objects recede at a rate faster than the speed of light: [math]r_{HS}=\frac{C}{H_o}[/math] Inasmuch as the Hubble "constant" is not constant at all, but varies with time in a manner dictated by the choice of cosmological model, the radius of the Hubble sphere may increase or decrease over various time intervals. The subscript '0' indicates the value of the Hubble constant today." "A variety of possible recessional velocity vs. redshift functions including the simple linear relation v = cz; a variety of possible shapes from theories related to general relativity; and a curve that does not permit speeds faster than light in accordance with special relativity. All curves are linear at low redshifts." http://en.wikipedia.org/wiki/Hubble's_law

Well, I interpret that as D is the distance light has to travel through space from object q to object p. The distance D you are using in your calculations is thus not the same distance as mentioned in the Hubble Law. As I said back in post #9, the Hubble constant yields the value of how much space is expanding over a certain distance today, as in right now, it does NOT tell you how much space expanded several Billions years ago or how much it has expanded during the last Billions of years. Using the Hubble constant wrongly does not give redshifts corresponding to observations.

The current model of Big Bang and expanding space does not include any "Continuum" that surrounds the Universe, allowing it to expand into something. The expansion is thought to be internal, it is like a scale factor changing the distance between the meter marks on the ruler. "Into what space is the universe expanding? Over time, the universe is expanding in space. The words 'space' and 'universe', sometimes used interchangeably, have distinct meanings in this context. Here 'space' is a mathematical concept and 'universe' refers to all the matter and energy that exist. The expansion is in reference to internal dimensions only. Finite space theory does not suppose space has an edge, but rather that space wraps around on itself. If it were possible to travel the entire length of space without going faster than light, one would simply end up back in the same place, not unlike going all the way around the surface of the balloon (or a planet like the Earth). The notion of more space is local, not global; we do not know how much space there is in total. The embedding diagram has been arbitrarily cut off a few billion years past the Earth and the quasar, but it could be extended indefinitely, even infinitely, provided we imagine it as curling into a spiral of constant radius rather than a circle. Even if the overall spatial extent is infinite we still say that space is expanding because, locally, the characteristic distance between objects is increasing." http://en.wikipedia.org/wiki/Metric_expansion_of_space You should also read this article: "Misconceptions about the big bang".

"The Big Bounce is a theorized scientific model related to the formation of the known Universe. It derives from the cyclic model or oscillatory universe interpretation of the Big Bang where the first cosmological event was the result of the collapse of a previous universe." "According to some oscillatory universe theorists, the Big Bang was simply the beginning of a period of expansion that followed a period of contraction. In this view, one could talk of a Big Crunch followed by a Big Bang, or more simply, a Big Bounce." "One of the main problems with the Big Bang theory is that at the moment of the Big Bang, there is a singularity of zero volume and infinite energy. This is normally interpreted as the end of the physics as we know it; in this case, of the theory of general relativity. This is why one expects quantum effects to become important and avoid the singularity. However, research in loop quantum cosmology purported to show that a previously existing universe collapsed, not to the point of singularity, but to a point before that where the quantum effects of gravity become so strongly repulsive that the universe rebounds back out, forming a new branch. Throughout this collapse and bounce, the evolution is unitary." "This work is still in its early stages and very speculative." http://en.wikipedia.org/wiki/Big_Bounce

Which distance is D, the distance between them when the light was emitted, the distance light has to travel between them or the distance they have between them when the light is received? If the two objects are accelerating then the distance will not stay constant during the time interval T. ---------- IF the speculated acceleration represents something real, it has implications that needs to fit with observations otherwise it is wrong. To put forth this spekulation and make the claim, you also need to explain how this acceleration is able to give rise to measured redshifts from distant galaxies.

Your math is missing a very important piece, your model includes an acceleration so you should realize that the receding speed and distance between the cars would also depend on the duration of previous acceleration and not only on the delay caused by their distance to each other. Without considering the previous acceleration your "car" model fails to explain expansion, because then both the preceding car and the car behind would be at the same distance from the middle car. A car that has been accelerating for 5 seconds looking back at a car 1 second behind will measure a different distance than a car that has been accelerating for 6 seconds looking back at a car 1 second behind. The Hubble constant is not a fixed constant like lightspeed, the Hubble value is constant over distance but it changes over a duration of time. The Hubble constant of 71 km/s/Mpc tells us how fast space is expanding today, how a galaxy placed at a certain distance is receding now, it does not directly tell us how fast something was receding at that distance a very long time ago. According to current models of expansion A1689-zD1 was receding from us with the speed of ~2.90-3.26×c and was ~3.29-3.96 Gly distant when the the light that reaches us now was emitted 12.8 Billion years ago. According to how you use the equations A1689-zD1 was 12.8 Billion lightyears distant and receding from us with the speed of ~0.93×c when the light was emitted, which does not match observations.

The Hubble constant is the rate of cosmic expansion.

The equation in post #2 seems to be in conflict with equation (2) in post #6.

Due to both the aircraft and the rope being indestructible and the high speeds involved when the rope gets streached, the tied end of the rope will tear a huge rip in the fabric of the Universe, causing a flow of galaxies and stars pouring out into hyperspace, which effectively will deflate and destroy the Universe as we know it. :D

There is no special situations when gravity acts as opposed to normal situations when gravity is passive. Earths gravity don't suddenly turn on or off. Just like gravity caused by matter, gravity caused by energy is always present. All photons in every cind of situations does always bend spacetime. Photons don't have rest mass but they have momentum, they do carry energy and according to Einstein's theory, mass and energy are related by E=mc2 and it is predicted that energy will have an equivalent gravitational effect. General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1915. It is the current description of gravitation in modern physics. It unifies special relativity and Newton's law of universal gravitation, and describes gravity as a geometric property of space and time, or spacetime. In particular, the curvature of spacetime is directly related to the four-momentum (mass-energy and linear momentum) of whatever matter and radiation are present. http://en.wikipedia.org/wiki/General_relativity As I understand GR, if all the matter Earth consists of was converted to radiation, trapped but evently spread out inside a huge spherical mirror with the same radius as the surface we have today, like a giant inside out disco ball, then we would be able to walk around as normal on its outside.

It is not the first time, the Jupiters South Equatorial Belt, (SEB), has disappeared before and it seems to happens at irregular intervals: This is not the first time that the SEB has disappeared from view. "The SEB fades at irregular intervals, most recently in 1973-75, 1989-90, 1993, 2007, 2010," said John Rogers, director of the British Astronomical Association's Jupiter Section. "The 2007 fading was terminated rather early, but in other years the SEB was almost absent, as at present." http://www.space.com/scienceastronomy/missing-jupiter-cloud-belt-mystifies-scientists-100521.html

I didn't ask about the age of the galaxy, I wanted to see a calculation from your "car" model how fast it was receding from us when it emitted the light we observe now.

"Astronomers have glimpsed what may be the farthest galaxy we've ever seen, providing a picture of a baby galaxy born soon after the beginning of the universe." http://www.space.com/scienceastronomy/080212-farthest-galaxy.html The galaxy A1689-zD1 has an estimated distance of 12.8 billion lightyears. What is the young galaxy's receding speed from Earth?

The values are small enough to be far below our observable limit with current technology, but I think there would also be problems with finding reference points and couping with equipment being affected by the phenomen under measurement. In the theory of general relativity both energy and matter bends the geometry of spacetime which causes gravity, thus if the vacuum energy of empty space is negative, it would bend spacetime in the opposite directions as positive energy or mass, which would be like a gravitational repulsion.

Nature of dark energy The exact nature of this dark energy is a matter of speculation. It is known to be very homogeneous, not very dense and is not known to interact through any of the fundamental forces other than gravity. Since it is not very dense — roughly 10−29 grams per cubic centimeter — it is hard to imagine experiments to detect it in the laboratory. Dark energy can only have such a profound impact on the universe, making up 74% of universal density, because it uniformly fills otherwise empty space. The two leading models are quintessence and the cosmological constant. Both models include the common characteristic that dark energy must have negative pressure. http://en.wikipedia.org/wiki/Dark_energy

Yes, it is normally considered that the expansion of space only happens on very very large scales. But, as I have tried to explain, on smaller scales, things like galaxies, solar systems, molecules and atoms are bound systems, they are held together by forces much stronger than the expansion. The force from Dark energy is not able to continue to expand them, instead bound systems only expands until they reach a slightly larger size where the forces that holds them together counter and stop the expansion. So bound systems don't continue to expand but they are a tiny bit larger due to Dark energy, this tiny bit is so teeny-weeny that it is not measureable and esteemed unimportant. The reasoning is not my personal idea, it's a valid scientific conclusion and even mentioned on Wikipedia: "A cosmological constant has the effect of a repulsive force between objects which is proportional (not inversely proportional) to distance. Unlike inertia it actively "pulls" on objects which have clumped together under the influence of gravity, and even on individual atoms. However this does not cause the objects to grow steadily or to disintegrate; unless they are very weakly bound, they will simply settle into an equilibrium state which is slightly (undetectably) larger than it would otherwise have been." http://en.wikipedia.org/wiki/Metric_expansion_of_space

No, this is wrong and not the current scientific explanation. The Big Bang was NOT an explosion of matter that flung apart pieces through space in different directions from a central point. According to observation, everything at large distances are expanding apart from us equally in all directions. If we look at any distant galaxy which are swept away from us due to expansion, the distance is increasing in directly opposite direction from us, there is no intersecting path of light through the three normal dimensions of space as if we where moving through space at different trajectories. If the Universe continues to expand at an accelerated rate there will be less and less matter left within our observable part of it, since the expansion already exceeds the speed of light at greater distances. Merged post follows: Consecutive posts merged A recent value for the Hubble constant is around 71 km/sec/Mpc which gives an expanding speed of 2.3×10-12 m/s per meter and the Helium atom has an electron cloud with a diameter of around 1×10-10 m so on this scale the expansion of space is 2.3×10-22 m/s without any forces at all countering it. Size comparison: a) If the atomic nucleus was 0.05 mm and the cloud was 5000 mm then the expansion for the electron from the core would be of 0.0000000115 mm/s without counter forces. b) If the nucleus was 400 mm and the electron some 4 000 000 mm distant then it would move away from the nucleus with 0.0000092 mm/s, without counter forces. I think we can safely conclude that the forces causing expansion is not affecting the sizes of atoms much.

The bigger part of stars won't turn into black holes and the supermassive black hole in the center can contribute to formation of new stars and planets from dust clouds within the galaxy. Most stars will become white dwarfs which much much will later cool and become black dwarfs. The merging with Andromeda will cause some disturbance and give us two supermassive black holes that will eventually merge into a large one. But after a few billion years, Andromeda and the Milky Way will have completely merged to form Milkomeda and everything will calm down to normal again. If there is true singularities then the Big Bang was likely torn apart from a massive singularity by some cind of force and as such it seems possible that lighter black holes can be torn apart too. But I think the common interpretation of singularities in general relativity is that our mathematical model breaks down and that there are no singularities inside black holes or at the start of the Big Bang. There might be other forces that rules over gravity on very small scales due to quantum mechanics, in this case our Universe could have been formed from a previous contracting Universe in a Big Bounce and the center of black holes would consist of highly compressed matter and energy around a border where quantum gravity are in equilibrium. "One of the main problems with the Big Bang theory is that at the moment of the Big Bang, there is a singularity of zero volume and infinite energy. This is normally interpreted as the end of the physics as we know it; in this case, of the theory of general relativity. This is why one expects quantum effects to become important and avoid the singularity. However, research in loop quantum cosmology purported to show that a previously existing universe collapsed, not to the point of singularity, but to a point before that where the quantum effects of gravity become so strongly repulsive that the universe rebounds back out, forming a new branch. Throughout this collapse and bounce, the evolution is unitary." http://en.wikipedia.org/wiki/Big_Bounce

The scientific view and observations clearly disagrees with your idea of greater gravitational energy with lesser mass. Also Newton was very able to reason and speculate of different theoretical universes. I suggest that you read more about the Big Bang and Newton's gravity: "The Big Bang is the cosmological model of the initial conditions and subsequent development of the Universe that is supported by the most comprehensive and accurate explanations from current scientific evidence and observation." http://en.wikipedia.org/wiki/Big_Bang "Newton's law of universal gravitation states that every massive particle in the universe attracts every other massive particle with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between them." http://en.wikipedia.org/wiki/Newton%27s_law_of_universal_gravitation

I think the comparison to whirlpools is due to that gravity causes matter to spiral inward towards the black hole and create a accretion disc and NOT because black holes suck like vacuum cleaners, which they are not able to do. If the Sun should turn into a black hole then the Earth would continue to orbit as normal, because the formed black hole would have the same mass as the Sun it formed from and therefor also continue to have the same gravitational influence on its surroundings. Similar, if the Sun should be replaced with a star three times as massive as the Sun, this heavier star would pull in the Earth with its stronger gravity in exactly the same manner as a black hole with three times the Suns mass would if it would replace our Sun. Gravity is weakening with larger distance but never goes down to zero or stop effect matter entirely. The Earth is not falling into the Sun because we have orbital speed matching the gravity and distance, likewise since stars in the galaxy are encircling the center, their orbital speed are in balance with the gravity. The process how galaxies and supermassive black holes are formed is not fully known but there are strong indications that they might form and develop together. Some galaxies have a very active core region in the center where a supermassive black hole is turbulently consuming matter but others like the Milky Way have a fairly passive core as if the supermassive black hole there is starved. It's not hard to imagine that a young galaxy or a older one but recently disturbed has plenty of matter for the supermassive black hole in the center to consume, while an older and/or more settled one has less matter left because the black hole has already consumed most of the matter within its reach.

The singularity in a Black Hole is not the breaking point of the fabric of Space, but rather the breaking point of our knowledge and models of gravity.

I said: So if the lightray is "the wheel" then it is affected as "made from rubber". But if you mean that objects made of matter don't swell due to expansion, I think that it is considered that they do, but the measurable expansion in space takes place over tremendous vast distances while the distances on atomic level is infinitesimal puny. If the force from Dark energy expanding space is acting inside matter too, slightly increasing the distance between particles, then on this scale the nuclear forces are large compared to the force from Dark energy which is dwindling down to a vanishingly tiny level. The particles are "placed" inside matter with a distance that is due to the nature of the nuclear forces and when the force from Dark energy is offsetting the distance, this offset only causes the nuclear forces between the particles to rebalance with a slightly larger distance. When comparing the distance between two particles in an expanding space and a non expanding space the differense is insignificant and negligible. We are not able to measure so diminutive distances and even if we could we don't have a lab with non expanding space to compare with.