If space expands at a recession velocity ,then wouldnt the mass contents also move at the same velocity?

Answer 1

Because of the gross expansion of space involved in cosmological considerations, there is a preferred frame of reference locally that corresponds to that expansion. That is in a sense what the AVERAGE galaxy etc. is moving like, when the AVERAGE is taken over a SUFFICIENTLY LARGE local volume.

So you are right that in an average sense, the local (but sufficiently large region's) mass contents are not merely moving with, they actually DEFINE what the local universal frame is, at least in an idealized view of cosmological expansion. From this viewpoint, space is expanding, and the average local mass is simply "going along for the ride," somewhat like a surfer keeping in the same relative postionin a moving wave. That's why when we measure the redshifts of galaxies further and further away, we talk of the "measured expansion of the Universe" when the actual measurements are of the systematic increase in the so-called "recession velocities" of the galaxies.

However, each INDIVIDUAL galaxy will have its own so-called PECULIAR velocity with respect to that local universal reference frame. ("Peculiar" here means "of its own," not "odd" or "distinctly unusual if not perverse!") That peculiar velocity can be due to several factors, including the attraction of and interactions with relatively local galaxies (such as our Milky Way galaxy with the Andromeda galxy, or M31). Other effects include great streams of galaxies themselves moving towards things like "the Great Attractor," or the relative proximity of voids or "walls" of galaxies amidst the cosmic foam.

One interesting consequence of the discovery of the Big Bang relic or "three degree" microwave background radiation is this. We have MEASURED the Solar System's peculiar velocity relative to the local universal frame of reference! That is because, by hypothesis, the background radiation is coming at us equally from all directions. However, when fine angular measurements were made, it was found that SYSTEMATICALLY, the radiation was BLUE-SHIFTED by a minute amount in one particular direction, gradually going though its average wavelengths in an "equatorial belt" with respect to that direction, and was then ultimately RED-SHIFTED in the OPPOSITE direction from the blue-shifted direction. Accounting for the Earth's velocity round the Sun, the Sun's motion in our galaxy, our orbit relative to Andromeda, and the effect of the Great Attractor, we've been able to deduce what our own "peculiar velocity" actually IS, relative to the local standard of rest taking part in the Universal expansion.

If that isn't mind-blowing, what IS ?!

Live long and prosper.

Answer 2

A celestial body is what it is due to the space that supports it's existence.
When it moves through space it doesn't; carry the space along with it,the space is displaced,therefore space can outpace the matter in it.
If you take a two solar mass star and squeeze it,as it shrinks you are displacing some of the space that makes it what it is.
The surface gravity increases.
If you squeeze it down to 100 km in diameter it becomes a white dwarf.
The only difference between the giant star and the white dwarf is the space that you displaces from the interior.

Answer 3

If you assume the big bang theory to be correct, then all objects in space should be moving at the same relative velocity. The kicker is that absolute velocity is the sum of vectors. So, when the earth is in a elliptical orbit around the sun, there is a series of points in which the earth's relative velocity around the sun is directly opposite that of the vector produced by the big bang, the force driving universal expansion. if you think of our solar system as one unit, then yes it is traveling at a velocity which is comparable to those objects in our galaxy. i think you are asking about universal expansion, and if it is so, then yes, all major bodies such as galaxies and clusters are travelling at vectors with similar velocities. on objects that are orbitally reliant on other objects, the velocities are different when compared with other objects. you would also need to consider light. objects emitting light produce light in 360 degree fields. some of that light would be fighting the vector which produces universal expansion, resulting in a slower vector. the bottom line though, is that we do not have instrumentation that can view objects through different perspectives, making the determination of a constant velocity of massive objects comprehesible.

Answer 4

provide E S the "maximum suitable answer" Einstein's standard theory which replaced newtons assumptions gravity took him years and desires very state-of-the-artwork math to even start to comprehend the theory of area -time and lines being the shortest distance between 2 factors in an area container which has curvature is basically approximately previous mind's eye maximum suitable sensible word I even have ever pay attention: Mass tells area -time a thank you to bend, and the form of area time tells mass a thank you to flow! ( despite that extremely skill) Einstein's theory isn't nicely matched with Quantum Mechanics that's a exceptionally sturdy indication we mis-comprehend something. the observer is often at relax with appreciate to its own device. All measurements are the "relax "cost with v = 0 C is often C that's the 2nd observer in relative action that sees (measures ) the einstein- Lorentz transformation cost with the v^2/ C^2 time era the area of Einstein relativity is there is not any absolute physique of reference "the Mechanical Universe" television instruct of Cal tech physics ( annenburg Media) 1985 has an basically approximately comprehensible explaination