Motion/speed is the measure of the space/distance that an object travels with respect to time.
v=d/t
A <--------vA=1/2C-------O-------vB=1/2 C-----------> B
Supposing an object "O" splits into two halves, A and B, wch then move away from each other
in opposite directions each at a velocity of v=0.5C.
The distance/space between A and B expands at a rate equal to the sum of the two velocities:
vA + vB = C/2 + C/2 = C
How is it possible to differentiate between these four scenarios:
In all four cases the space between A and B is expanding.
Does this mean they are equivalent descriptions of one phenomenon?...
or can a distant observor distinquish between the different kinds of motion responsible for the expansion?
(1)A is stationary ,and B is moving in relation to A : vB = C
(from the point of view of A , B is moving away from A at the speed of light)
(2)B is stationary and A is moving in relation to B : vA = C
(from the perspective of B, A is moving away from B at the speed of light)
(3)both A and B are moving in relation to each other. vA + vB = C
(4)both A and B are stationary, but the space between them is expanding at v = C
(the spatial separation between A and B is increasing or expanding at a rate or velocity equal to the velocity of light, C ) ( from the perspective of the space separating A and B ,this distance is increasing/expanding at the speed of light)
Spatial expansion can only be measured as a change in distance between two objects A and B.
If objects cannot travel faster than the speed of light,then it follows that space between objects also cannot expand faster than the speed of light.
If the expansion of space exceeded light speed,then the two objects embedded in the matrix of space
would separate at greater than light speed.
If this is forbidden by the laws of physics ,then it follows that when the expansion of space reaches the speed of light ,it reaches a barrier/limit, and ceases to increase beyond this speed.
But what happens in this case:
A <--------vA=3/4C-------O-------vB=3/4C-----------> B
vA + vB = .75C + .75C = 1.5 C
It appears that space between the two objects is expanding at 1.5 times the speed of light.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Let's make it simpler:
vA = c
<--------------------
A-------------------------------->B
--------------------->
vB = c
Supposing a photon, B, is emitted from the earth,A....and departs at the speed of light. vB = c
But supposing just before it leaves, we hop onto it and ride with it.
Now from the observational frame of reference of the photon ,we experience ourself as being at rest (stationary) . When we look forward in the direction of travel, the universe streams toward and past us at light speed. When we look back, the earth is receding from us at light speed! vA = c
Theoretically this sounds correct, but observationally it is wrong.
Even if the earth is continuosly emitting light ,that light can never catch up with us.
So when we look back from whence we came ,all we will see is darkness .
The earth will be invisible !
Cosmologists claim that the expansion of space is accelerating.
What happens when the rate of expansion (of the universe) reaches the speed of light?
Perception requires that light emitted by an object can be received by an observor.
In other words, light must reach the observor in order to be seen.
If the expansion rate of space between an object and an observor reaches or exceeds light speed
then any light emitted by the object cannot reach the observor ..and so the object will not be visible,
Anything traveling away from an observor at or greater than the speed of light disappears beyond
a "horizon of perceptibility" or a curtain of invisibility.
"Invisible" does not mean that it dematerializes or ceases to exist; it just means that we cannot see it because any light from it never catches up with us.
Perhaps the speed of light is not an absolute speed limit ,but more like a perceptual barrier.
Anything traveling away from an observor at the speed of light would fall outside the observor's field of perception and would therefor be unobservable
This gives rise to the question as to how much of the energy in the universe is moving away from us at the speed of light ...and is this enuf to account for the undetectable "dark energy"?
b
v=d/t
A <--------vA=1/2C-------O-------vB=1/2 C-----------> B
Supposing an object "O" splits into two halves, A and B, wch then move away from each other
in opposite directions each at a velocity of v=0.5C.
The distance/space between A and B expands at a rate equal to the sum of the two velocities:
vA + vB = C/2 + C/2 = C
How is it possible to differentiate between these four scenarios:
In all four cases the space between A and B is expanding.
Does this mean they are equivalent descriptions of one phenomenon?...
or can a distant observor distinquish between the different kinds of motion responsible for the expansion?
(1)A is stationary ,and B is moving in relation to A : vB = C
(from the point of view of A , B is moving away from A at the speed of light)
(2)B is stationary and A is moving in relation to B : vA = C
(from the perspective of B, A is moving away from B at the speed of light)
(3)both A and B are moving in relation to each other. vA + vB = C
(4)both A and B are stationary, but the space between them is expanding at v = C
(the spatial separation between A and B is increasing or expanding at a rate or velocity equal to the velocity of light, C ) ( from the perspective of the space separating A and B ,this distance is increasing/expanding at the speed of light)
Spatial expansion can only be measured as a change in distance between two objects A and B.
If objects cannot travel faster than the speed of light,then it follows that space between objects also cannot expand faster than the speed of light.
If the expansion of space exceeded light speed,then the two objects embedded in the matrix of space
would separate at greater than light speed.
If this is forbidden by the laws of physics ,then it follows that when the expansion of space reaches the speed of light ,it reaches a barrier/limit, and ceases to increase beyond this speed.
But what happens in this case:
A <--------vA=3/4C-------O-------vB=3/4C-----------> B
vA + vB = .75C + .75C = 1.5 C
It appears that space between the two objects is expanding at 1.5 times the speed of light.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Let's make it simpler:
vA = c
<--------------------
A-------------------------------->B
--------------------->
vB = c
Supposing a photon, B, is emitted from the earth,A....and departs at the speed of light. vB = c
But supposing just before it leaves, we hop onto it and ride with it.
Now from the observational frame of reference of the photon ,we experience ourself as being at rest (stationary) . When we look forward in the direction of travel, the universe streams toward and past us at light speed. When we look back, the earth is receding from us at light speed! vA = c
Theoretically this sounds correct, but observationally it is wrong.
Even if the earth is continuosly emitting light ,that light can never catch up with us.
So when we look back from whence we came ,all we will see is darkness .
The earth will be invisible !
Cosmologists claim that the expansion of space is accelerating.
What happens when the rate of expansion (of the universe) reaches the speed of light?
Perception requires that light emitted by an object can be received by an observor.
In other words, light must reach the observor in order to be seen.
If the expansion rate of space between an object and an observor reaches or exceeds light speed
then any light emitted by the object cannot reach the observor ..and so the object will not be visible,
Anything traveling away from an observor at or greater than the speed of light disappears beyond
a "horizon of perceptibility" or a curtain of invisibility.
"Invisible" does not mean that it dematerializes or ceases to exist; it just means that we cannot see it because any light from it never catches up with us.
Perhaps the speed of light is not an absolute speed limit ,but more like a perceptual barrier.
Anything traveling away from an observor at the speed of light would fall outside the observor's field of perception and would therefor be unobservable
This gives rise to the question as to how much of the energy in the universe is moving away from us at the speed of light ...and is this enuf to account for the undetectable "dark energy"?
b
I believe Einstein said that falling toward an object such as the earth under the influence of it's gravitational field ,and accelerating outward into space (thereby creating a G-force) would, without any visual cues, be an identical experience.
ReplyDeleteSupposing you were inside a rocket hurtling through space.
ReplyDeleteHow would you know that you weren't actually stationary and the external environment/space wasn't hurtling past you (as in a wind tunnel)
We on the earth's surface do not experience the earth's rotational or orbital motion.
We perceive ourselves to be stationary,while the sun is perceived to move across the sky from dawn to dusk and finally disappearing below the western horizon.
Contrary to our sensory experience ,we know this to be a "perceptual illusion" ,and the motion we experience is really due to the rotation of the earh on it's axis (a motion that we do not sense)!
Once while motoring across the prairies ,I had the strange sensation of standing still while the ribbon of highway rolled under me like a treadmill.
ReplyDeleteI realized I'd been driving too damn long ,and had to snap out of it,to shake the illusion.
DeleteDid the chicken really cross the road, or did the roadmove beneath the chicken?
What is the current rate of expansion of the universe?
ReplyDeleteaccording to this site:
Deletehttp://map.gsfc.nasa.gov/universe/uni_expansion.html
the current cosmic expansion velocity
has a value
between 66 and 82 (km/sec)/Mpc
At that critical threshold when a light-emitting object accelerates to the speed of light and crosses over into the "realm of the imperceptible" (that is,just before it plunges over the edge of perceptibility into darkness)
ReplyDeletewhat would it's Red Shift be?
Here's from Wikipedia:
ReplyDeleteHighest redshifts
Currently, the objects with the highest known redshifts are galaxies and the objects producing gamma ray bursts. The most reliable redshifts are from spectroscopic data, and the highest confirmed spectroscopic redshift of a galaxy is that of UDFy-38135539 [61] at a redshift of z = 8.6, corresponding to just 600 million years after the Big Bang. The previous record was held by IOK-1,[62] at a redshift z = 6.96, corresponding to just 750 million years after the Big Bang. Slightly less reliable are Lyman-break redshifts, the highest of which is the lensed galaxy A1689-zD1 at a redshift z = 7.6[63] and the next highest being z = 7.0.[64] The most distant observed gamma ray burst was GRB 090423, which had a redshift of z = 8.2.[65] The most distant known quasar, ULAS J1120+0641, is at z = 7.1.[66][67] The highest known redshift radio galaxy (TN J0924-2201) is at a redshift z = 5.2[68] and the highest known redshift molecular material is the detection of emission from the CO molecule from the quasar SDSS J1148+5251 at z = 6.42[69]
Extremely red objects (EROs) are astronomical sources of radiation that radiate energy in the red and near infrared part of the electromagnetic spectrum. These may be starburst galaxies that have a high redshift accompanied by reddening from intervening dust, or they could be highly redshifted elliptical galaxies with an older (and therefore redder) stellar population.[70] Objects that are even redder than EROs are termed hyper extremely red objects (HEROs).[71]
The cosmic microwave background has a redshift of z = 1089, corresponding to an age of approximately 379,000 years after the Big Bang and a current comoving distance of more than 46 billion light years.[72] The yet-to-be-observed first light from the oldest Population III stars, not long after atoms first formed and the CMB ceased to be absorbed almost completely, may have redshifts in the range of 20 < z < 100.[73] Other high-redshift events predicted by physics but not presently observable are the cosmic neutrino background from about two seconds after the Big Bang (and a redshift in excess of z > 1010)[74] and the cosmic gravitational wave background emitted directly from inflation at a redshift in excess of z > 1025.[75]
We observe the sun and the stars moving across the sky from east to west. This "motion" is a perceptual illusion arising from the rotation of the earth on it's axis --a motion that we do not experience.
ReplyDeleteMightn't the "observed" expansion of the universe have a similar alternative explanation?
Yes, the apparent "expansion of space" may have an alternative explanation.
ReplyDeleteBut it would be incumbent on us to identify that alternative explanation!
Calculations of astronomical distances are based on the assumptions that the speed of light is a constant,and the rate of time flow is also constant.
But if time fl0w exhibits the same plasticity as space ,then it can change;i.e. time flow can speed up and slow down.
Any such change in the rate of flow of time would drastically distort our calculations of astronomical distances
see post titled "Expansion of spce;contraction of time"
Since it was discovered that the universe, AKA "spacetime", was expanding, cosmologists formulated the Big Bang theory of the universe's origin.
DeleteIf we extrapolate backwards in time
(and take this extrapolation to the limit)
Cosmic expansion seems to imply that the universe began as a dimensionless point (point of origin), the universe must have been created.
Prior to the moment of creation, the universe was not there; afterwards, the universe was there.
This implies that the universe created itself!
But why does the evidence of spacetime expansion
require extrapolating to the extreme limit of zero time and a "dimensionless point" (zero space)?
In actuality there may be limit to how much spacetime can be contracted and how much matter/energy
can be compressed.
According to this scenario then, the universe started from a pre-existing something and not from nothing.
It is generally acknowledged that the contraction of "spacetime" and the compression of matter-energy under the influence of gravity
Deleteresults in the creation of a Black Hole.
So much for the idea of rewinding cosmic expansion back to a hypothetical Bing Bang!
Expansion requires an input of energy(work).
DeleteAn increase in the rate of expansion would require an additional input of energy to fuel/propel the acceleration in the speed of expansion:
According to Newton's first law of motion - sometimes referred to as the law of inertia. An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
Seeing is not always believing:
ReplyDeleteThe eye may see the large as small: the sun appears the size of a saucer...but reason tells us that the sun is many times larger than the earth. It's apparent "smallness" is a perceptual illusion arising from it's immense distance from us!
These are examples of the fact that our senses are not always reliable/ credible means of acquiring accurate knowledge about the world/universe!
ReplyDeleteMuch that appears to our senses to be real is in fact illusory!
...and blinds us to the true reality!
But if we can't trust our senses...what can we trust?
“The influences of the senses,” said Ralph Waldo Emerson “has in most men overpowered the mind to the degree that the walls of space and time have come to look solid, real and insurmountable; and to speak with levity of these limits in the world is the sign of insanity.”
DeleteEvery magician knows how easily our senses can be fooled/tricked!
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteWhat we "see" or "sense" depends on how yhe brain processes or interprets yhe information(sense data) it receives.
ReplyDeleteRaw sense data taken at face value is meaningless.
It is the brain's function to extract meaning,impose order,etc.
upon it.
Here's another exsmple of reality not being as it seems:
ReplyDeleteWe think of atomic matter (matter made of atoms) as being very solid and dense. But its density (mass/volume) is very small compared with the density of subatomic particles such as neutrons.
If we scale up an atom so thst its nucleus was the size of the earth the distance to its closest electron would be 2.5X the
distance between the earth and the sun!
So in reality the atoms of wch ordinary matter is made are
mostly empty space!
In other words matter is mostly emptiness!
This comment has been removed by the author.
ReplyDelete...and the parts that arnt "emptiness" arnt really matter, ...but highly condensed forms of energy!
ReplyDeleteAll of wch belies the evidence of our senses!
(just try kicking a big rock, or running through a wall)
Solidity may be illusory...
ReplyDeletebut when it comes to kicking a big rock or jumping off a tall building
I think it wise to believe in the evidence of one's senses!
Yes, it is true that our sensory experience seems more real than the Truth--wch often seems abstract and abstruse.
ReplyDelete