Universal Time

From our perspective. It is the only thing that makes sense.

or the easiest concept to grasp.

We just worked backwards from the time it takes for the sun to orbit the earth.

The time came in waves and change going faster and slower. Because that, we look the universe expanding faster and faster. The big bang is no true. It do not make sense with the natural laws. We cannot say a set of laws start the universe and then change. It should be something that is same from the beginning and stay the same all the time. We will need rethink everything in the right way. Albert did everything relative but the time and that is no possible.

I wonder if the universe really is expanding faster and faster. It seems to me that the farther objects are from us the faster they should be going because we are looking backwards in time and those objects are closer to their initial velocities than we are.

"... we are looking backwards in time and those objects are closer to their initial velocities than we are."

True, but we do not really measure the recession velocities of distant objects - all we can do is measure their redshifts. In cosmic terms, that simply gives us the ratio of by how much the universe has expanded while the light were en route to us. The expansion stretched the wave lengths.

Using some ingenious methods, a conversion factor is found for redshift to distance - not really for speed. By observing near and far, which also means for later and earlier emission times, and using solutions to Einstein's general relativity, we can deduce the rate of expansion at various distances. IF our modeling is correct, we are then forced to interpret modern observations as an increase in expansion rate over the last 5 billion years or so.

Our models may however be wrong. I touched upon one alternative in reply #4 above.

-J

Using some ingenious methods, a conversion factor is found for redshift to distance - not really for speed.

So why is Hubble's constant Ho then expressed as a speed to distance ratio: km/s per megaparsec? I thought they convert redshift to speed like in Doppler shift and then use Ho to calculate distance.

This is the exact idea I have. Because our time is contracting due to the place of the wave we are the universe look like expanding and the light that originate when the time was slower look like with a redshift to us. The universe is eternal and is hard for us to understand the idea or eternity

Then you also have to know if time has always passed the same since if the universe is expanding at an accelerating rate is not time slowing down?

Sjw40364 asked in #6: "... if the universe is expanding at an accelerating rate is not time slowing down?"

Since nobody offered an answer, I'll try. For as far back as we can observe natural events with some rhythm, like pulsars, accretion disks, supernovae, etc., it seems that the rate of time has been roughly the same over the last few billion years than it is today.

-J

Additionally, there is evidence of a hyper inflationary period early after the Big Bang.

That evidence, as I understand it, comes from the microwave background radiation. There are about 400 million of these microwave photons racing through each cubic meter of space at any one instant.

However, anywhere we should hope to "glance" the background radiation is always 2.7 Kelvins.

The uniformity by which the the cosmic radiation speaks says that at some point about 370 K years after the Big Bang that the universe has to be of a size where every other particle and photon could "interact" with each other so that each area in the universe would be of uniform temperature. Sort of like pouring hot water into a cold pitcher of water, the two reach an equilibrium. The 370 K year period and earlier is the period where the universe's temperature had to be so high that not even photons could penetrate the soup of energy and particles. Post 370 K was when temperatures cooled enough to allow photons to penetrate the fog.

Given that the distance in space are so vast that such uniformity implies that the speed of light has been breached. The trick here is that nothing can travel through space faster than C, but space can expand faster than C.

The Big Bang initial expansion is supposed to be so quick as to exceed the speed of light. However, it would not be possible for the cosmic background radiation to reach an equilibrium state if that was true. So, the rate of expansion initially for the Big Bang was relatively slow, giving time for equilibrium before there was a burst of expansion speed (inflationary expansion).

Jorrie, perhaps you could explain this better, but my understanding was there was a surge of expansion driven by "negative" gravity after about 370 K years. I think that Einstein stated that gravity is a function of both mass and "energy pressure". I think the early universe was was expanding slowly until the critical point where the close proximity of the universe with itself could no longer override or slow down the effect of this negative gravity pressure and thus a surge caused a period of hyper-expansion until the energy density fell below another critical level and negative gravity subsided.

The theory for the hyper-inflationary period is that the whole hyper-inflation took place in a tiny, tiny fraction of a second while space expanded explosively by many, many orders of magnitude and the contained matter within was separated much faster than the speed of light.

Hi AH: "The uniformity by which the the cosmic radiation speaks says that at some point about 370 K years after the Big Bang that the universe has to be of a size where every other particle and photon could "interact" with each other so that each area in the universe would be of uniform temperature."

You have just got your 'date' wrong.

It is thought to have happened around 10^-34 seconds after the BB and lasted for 10^-32 seconds. Roughly at your 370 K years, recombination of electrons and nuclei into atoms happened, making the whole lot transparent.

-J

Okay, the hyperinflation takes place before the fog lifts. Thanks. I guess I was a little foggy, too.

There being no "universal time" it must be our solar time..

The only way of us knowing anything about the age of the universe is by observing light, the oldest of which we 'know' to have originated some 13.3 billion years ago (thanks BBC), measured in 'light-years', which I believe is estimated based on Earth's Solar orbit/ year.

Lightyears is a unit of distance, not time - the distance light travels in one solar year. It is a universal yardstick by which we measure our playground called the universe and, as you noted, is based on the speed of light.

We based our time system on our Earth - Sun relationship. There is not really anything special with regard to our time system in that a day is a day and a year is a year or even a second is a second. It is just convenient for us given how long seasons last and the apparent rotation of the Earth.

As society became more advanced we had to make corrections to our system to keep it synchronized with the seasons, such as leap years and even leap seconds.

For another civilization the term lightyear is meaningless if they have no idea of the time it takes for our planet to circle our sun.

Lightyear is a unit of measurement of light travelling over time. As such it can and is used to measure both. As we observe a phenomenon in space, we know how far away it is, and how long ago it happened simply by knowing how many lightyears away from us it is.

Well, if you want to talk about the details, Wikipedia defines it as a unit of length.

Since the units are the speed of light, C, divided by time it is (d/t)/t.

Mathematically the 't' cancels out and you are left with 'd' or distance.

But you are right that anything we observe electromagnetically happened in the past based on the units of time chosen. Nature's visual time machine. :-)

"Lightyear is a unit of measurement of light travelling over time. As such it can and is used to measure both."

This is OK, as long as we accept that due to cosmic expansion, this type of light-year has little meaning at cosmological distances. As an example, light from the farthest observed GRB is calculated to have traveled for 13.2 billion years. When that light left the GRB, it was a mere 3 billion light-years "from us". Today its host galaxy is at a calculated 31 billion light-years from the real us (because we are here today).

It is true that somewhere in-between those two times, long ago, it must have been at 13.2 billion light years from us...

-J

t= sd, so no argument there AH, but I only answered the original question:

According to whose time? (since there is no universal time according to Special and General Relativity).

I write under correction, but our estimates of the age of the universe seem to coincide very nicely with our estimate of the oldest observable light ?

You wrote, "but our estimates of the age of the universe seem to coincide very nicely with our estimate of the oldest observable light ?"

I think Jorrie answered why that is in post number #4. The difference in clock rates is not that great on cosmological scales.

I think of time as though I were lost at sea, floating on the ocean.

Time changes... we measure that by comparison, when we have the tools to differentiate. (We can see waves, and they are different than the one we are in)

We don't know much about the composition of time, or how it might vary (ie, salt water/fresh water, color, temperature, density, etc.) Travelling faster than light would be like flying in the air, rather than swimming under water.

I think that all the potentials of matter and life are dissolved in the water (time) and arise from it at those instants (ie big bang) when matter comes forth.

but this is just a mental model, and not any kind of reality.

chris

The wave of time we are in started before the time we can see. because that we see the universe expanding because the time is getting short and the space still the same size. The only noticeable is the reddish of the light. The far away the older the light is and the reddish the light is because the time before was more slow and the light have a little variation on it. and that make the look like we are watching our universe no only speeding faster away but every time faster and faster. in a very long future the time is going to start the reverse process and then the universe is going to contract over the next wave.

Did you heard of "String Theory" ? It has a different explanation.

Yes, but to the best of my understanding String Theory, M-Theory, Supersymmetry, etc., really don't have a different explanation for time (space-time) than what Einstein presented.

If anything, these theories are more of an extension of the work done by Einstein on space-time and focus on trying to unite what we observe with the macrocosm with observations in the quantum physics realm.

Time is distance. What is a year, the distance the earth orbits the Sun from one point in its orbit back to its starting point. What is a day, the distance a point on its surface makes one complete revolution back to this same point. What is a second even, so many oscillations of a cesium atom. What is oscillation, Merriam-Webster dictionary: "The action or state of oscillating." What is oscillating: "a) To swing backward and forward like a pendulum, b) to move or travel back and forth between two points." Time is but another measure of distance, whether it is the earth around the Sun, the same point on the earth around itself, so many swings of a pendulum or the distance a cesium atom moves from point to point. Instead of miles or feet we choose to call them years, days and seconds to differentiate them from other distances. One can not divide two unrelated things. They must be related in some way for any equation to relate them together.

A stunning question with apparently no sound/statistically 100% accurate verbal definition available..It seems we constructed a 24 hour clock to measure our diurnal rotation on the earths axis and then correlated that to our planets rotation around our sun because we are lost without order...So all measurements of time originate with this human construct and at the end of the day time is perhaps meaningless to the whole functioning of the cosmos anyway as it evolves and collapses everywhere we humans can see...the cosmos ie...There is a dynamism in the universe that we as a race try to capture in a box only to find that the box doen't hold up forever as we continue to peer into the very large(where we measure time in big quantities)to the very small (molecular interactions where we measure time at the very smal splitting seconds into pico seconds or smaller fractions of a second.)..So time is merely a measuring tool made up by we humans looking for orderly expression of our surroundings because we like that...

No, but if you let that egg sit there it will rot and the atoms that make up the egg will eventually break down into their component parts to once again re-enter the system to be used again to make anything from an egg to a steel bar, to a human being. An round and round it goes.

Actually, my dog will recycle it long before then and about 12 hours later to be redeposited outside.

"to be redeposited outside."

hopefully... or else

There's the nub of the matter...

Time is an abstract which is only of consequence to concious carbon-based life as we know it, and derives from primeval urges eg time to sleep, time to eat, etc...

With expanding intellect, we have developed such abstract into virtual construct in order to assist our ability to rationalise our situation vis a vis our perceived natural order of things....much like our construct of zero, it is convenient and brilliant, but does it actually exist outside of mathematics ?

Observable ageing is merely a rate-of-decay, which infers time, and for which we have 'invented' a convenient unit standard, based on observations of decay and movement within our own ambit.

Well, without getting into the metaphysical aspect of life and the universe, we have observed the after effect of things that happened long before we were a species.

I think that the premiss of cause and effect is a powerful demonstration of time. One always precedes the other, which proves time. I would stipulate that the absence of time would be all things happing at once (or not at all).

The construct of zero may not be so abstract. When you have eaten the last fruit on the tree you are down to zero. I can't see zero as being any more abstract than one or two is.

It wasn't until the genesis of the loan shark did we enter the realm of negative numbers. ;-)

When you have eaten the last fruit on the tree you are down to zero.

Let's strip this down ...

1. Especially in American English, 'zero' denotes the symbol '0' in a numbering system, describing a value of naught/ nil / none or multiplied by ten. I term this abstract zero.

2. True Zero, means 'absolutely nothing' . From your excerpt above, if I picked all the fruit, they do not cease to exist. ...there are just none/ nil left on the tree. If I ate all the fruit, they simply change state...and in either case, the tree remains (the friut is merely a function of the tree) ie the remainder cannot be 'absolutely nothing'.

3. Universally accepted BB theory postulates a singularity as the start point, so our physical laws thus based, cannot entertain true Zero, or absolutely nothing. eg limits in calculus only tend to zero..

cause and effect is a powerful demonstration of time.

This is more an advocation , rather than a demonstration.....if a court had to decide it, the 'evidence' would be considered circumstantial, not empirical, so a ruling would be based on 'balance of probability', rather than hard evidence. Verdict would begin with "In merciful consideration toward the sanity of ordinary men.."

Therefore,.... time clearly cannot exist independently, since it is merely a function of a conglomerate of inter-acting extraneous physics (no motion, no time?).

So time is either a phenomenon, concept, perception or similar (ghost comes to mind), rather than tangible fact ...we sense it and rationalise it to our convenience.

Interesting that you would postulate that time is tied to motion. Time runs as we normally observe it, but slow things down to a point near absolute zero (sorry for the use of that term ;-) ) and time still runs as it did before.

Reach absolute zero and time stops. Which means that time operates as a Boolean function (on or off only).

Okay, how do you substantiate that theory? More importantly, what theory can you put forward that mathematically describes that?

Perhaps that premise is further flawed (if not fatally) as there is always motion, whether it is on a macro scape or a quantum scale.

I think your court case should be thrown out, but let's just retry it. Clearly we have a long list of empirical evidence of the Earth changing states long before we arrived. There is so much evidence for past cause and effect, that even if you still contend the evidence is not absolute in its nature (because we were not there personally to witness it), the preponderance of it is so overwhelming as to win on an appeals case. Many, many murder cases were convicted on exactly that kind of evidence without an actual witness as an observer at the scene.

In other words, there is far more evidence for the existence of time as a series of continuous states of change before our existence than there is evidence that it is not or a simple construct of our imagination.

Also, we do not sense time. We can't even measure it, smell it, touch it, or capture it in a test tube. We can use clocks to mark the passage of time, but time can not be measured. That doesn't prove it does not exist any more than darkness can't be disproven. We can determine the absence of light, but you can't measure darkness either.

In the end we can agree that we do not understand time. However, just because we don't understand something does not prove that something as non-existant.

Well we agree :) as if time is tied to velocity then time is slowing even as you read this as the universe expands at an accelerating rate. Measurements of past or future then have no meaning, ages based upon time irrelevant and meaningless, all consistency is gone, only the here and now matters. A second today not the same as a second one year ago. To estimate the past would require speeding time up by the same rate it has slowed, to estimate the future by slowing it down.

If I accelerate a spacecraft in the opposite direction of the solar systems orbit around the galaxy and therefore slow my orbital velocity around the galaxy would time therefore speed up? What, we have a contradiction don't we.

Bunk.

Wait. I have a question...

How do you know time is slowing down?

I don't claim it is, the ones that say velocity slows time have no choice but to admit that time slows as the universe expands faster. I think velocity has nothing to do with time, you misinterpret my reasoning as support of velocity slowing time. You want to disagree so bad you cant even see I was supporting your argument, not arguing against it.

I don't think you have any understanding of inertial frames of reference.

As far as what you think about the relationship of time and velocity, that relationship has been proven true ad nausium. So, you are absolutely wrong on that accord.

For that matter, you are wrong on so many other aspects of cosmology it is stunning. I also note that when Jorrie provides scholarly evidence to debunk what you claim you simply fail to respond. However, I wish you would, but I suspect you recognize you are outmatched.

"If I accelerate a spacecraft in the opposite direction of the solar systems orbit around the galaxy and therefore slow my orbital velocity around the galaxy would time therefore speed up? What, we have a contradiction don't we."

Interesting point, but no, we don't have a contradiction.

Let the two spacecraft go all the way around the galaxy, so that after perhaps millions of years, they approach Earth from opposite sides. If our ancestors compare them directly with Earth clocks, they would find the same effect as the Hafele-Keating test and its follow-ups.

There is no difference in the principle, as stated in reply #48. Since that principle has been demonstrated beyond the shadow of a doubt, why would we doubt the outcome a galactic test?

-J

That's not based on logic. If I apply enough thrust to come to a complete halt in space, and I do not mean just an orbit around our Sun, but all movement with respect to our galaxy, then according to that theory time must speed up considerably for me since speeding up makes time run slower, slowing down must make time run faster.Did you once stop to think it may have nothing to do with your velocity but may be instead the direction you are traveling with or against the magnetic field of the earth? An interesting article by one of the premier authorities on GPS, you might want to read it.

http://www.worldnpa.org/pdf/abstracts/abstracts_1843.pdf

SJW, from your reply, you are apparently stuck at absolute motion. Your brand of logic seems to be a misconception of relativity - the spaceship that you speak about will eventually circumnavigate the Galaxy, arriving from the other direction and it will record less elapsed time than Earth clocks, not more. Same type of test as Hafele-Keating. Also the same type of time dilation effect as in particle accelerators. Proven by experiment.

The "paper" that you referred to shoots itself in the foot right from the abstract already. Not even worth a further read. I quote from abstract:

1. "The Special Relativity Theory (SRT) and the General Relativity Theory (GRT) sometimes exhibit clock effects of equal magnitude which cancel and sometimes exhibit clock effects of equal magnitude which are additive."

This is perfectly natural in orbital motion, depending on orbital radius - standard general relativity.

2. "This cannot be coincidence, yet there is nothing within the two disjoint relativity theories to suggest an underlying mechanism."

SR is just a special case of GR, when gravity is insignificant. They are part of the same theory, not "disjoint relativity theories". The different effects of gravity and velocity are quite clear from the theory. Even the simplest solution to GR (Schwarzschild) shows it.

The article is a total misrepresentation of what general relativity theory says. No wonder the author seems to find it difficult to publish relativity in reputable places - not even on arXiv, from the looks of it. If you know about refereed or arXiv relativity papers by this author, please let me know and I will read them.

I presume that you know the article and the theory well, so let's cut right down to the bone. Did Hatch make any predictions in his MLET theory that differ from standard relativity predictions, either with or without gravity? If so, are there published observational results that favor MLET above relativity?

Let's not beat around the bush - experiment is the only decider.

-J

Not disjointed? You better go read them again, gravity in SR is non-existent, it is simply bodies in motion in free-fall, a curvature of space-time caused by mass and then that curvature tells mass how to move, it has nothing to do with attraction in any way shape or form. Yet in GR gravity works by the same principles as Newtonian gravity, the attraction of bodies of mass depending on distance between them. Tell it to the school children that might be fooled by such tricks of words.

Not true, if I stop a spaceship dead in space relative to the galaxy it will "NOT" circumnavigate the galaxy, the galaxy will move on without it. Do you have any concept as to how cesium clocks work? What is used to make them work? Let me help you out, magnetism. So not only are you traveling away from a source of magnetism when gaining altitude, but depending on your orbital direction you are also going with or against the magnetic flow of the earth and Sun combined. Yet you want me to believe that the very thing that allows atomic clocks to work has no affects on atomic clocks??? You would have me believe that it is the weakest force known to man (gravity) that affects these clocks and not one of the strongest (electromagnetism)??? Even when an atomic clock would not work without electromagnetism? And then that changing distance from the source of this electromagnetic field would not affect it, even though it is abundantly clear that force does just that by the very principles that make them work?

When you are able to shield them from the electromagnetic force then we will discuss velocity, until then you have less of an argument for velocity than I do for simply movement within an electromagnetic field. The very force these clocks are traveling through makes them operate, so it is no wonder that distance or direction through the earths electromagnetic field affects them. Instead you would have me believe that the weakest force known to man affects them instead of one of the strongest. Gravity cant even hold an electron to a nucleus, but oh you attribute so many things to it against all rational thought. Magnetism causes all things to spin and orbit perpendicular to the electric force, and its just coincidence that all things spin and orbit I guess. A small child with a magnet can pick up a steel ball off of a table against the entire gravitational pull of the earth, but it is this same weak force that holds the galaxy together? Wake up to reality and stop living in the 1900's.

SJW, I will proceed with this discussion only if you stop beating around the bush. Come up with what can settle the matter (or at least make for useful discussion). I quite reasonably requested:

"Did Hatch make any predictions in his MLET theory that differ from standard relativity predictions, either with or without gravity? If so, are there published observational results that favor MLET above relativity?

My attempt to put to bed your rhetorical statements on "disjointedness" (at least): The Schwarzschild metric (a rigorous solution of GR) joins SR and GR in this simple manner:

where dtau/dt is the ratio of a the time on a clock moving inertially in a gravitational field to a distant clock in free space. The third term 2m/r is obviously the gravitational component and the next term a mix of radial velocity and gravity and the final term the angular velocity alone. Velocities are measured in the mass centered frame. Make m zero and you have pure velocity time dilation. Make both dr and dψ zero and you have pure static gravitational time dilation at distance r from mass m. All coming from within GR.

Disjointed? Not in a billion years.

The correspondence with Newton's gravity for weak fields and low speed also follows from this equation (with conservation of orbital energy and momentum). The relativistic radial acceleration caused by gravity can be simply written as follows in the mass-centered frame:

Do you spot the correspondence? Outside the bracket it is just Newton gravity and inside the bracket are the relativistic parameters: g_tt=1-2m/r, g_rr=1/g_tt; v_r is radial velocity and v_t is tangential velocity in Schwarzschild coordinates. If you do not follow these statements, let's talk about them in detail, but in another thread.

My recommendation: first understand Einstein's theories before you attempt to criticize them.

-J

Corrections (below 1st equation): "where dtau/dt is the ratio of the rate of time on a clock moving inertially in a gravitational field to a distant clock in free space. The second term 2m/r is obviously the gravitational component and the next term a mix of radial velocity and gravity and the final term the angular velocity alone."

-J

"Do you have any concept as to how cesium clocks work? What is used to make them work? Let me help you out, magnetism. So not only are you traveling away from a source of magnetism when gaining altitude, .."

Psst, have you heard that cesium clocks are actually shielded from external magnetic fields? And that by using lasers as phase detectors, they are now trying to cut it out internally as well.

Maybe you should join the school children that you referred to in their physics classes. :))

Pssst, have you heard that the only clocks shielded from magnetic fields are the main ones used for comparing clocks, the ones in vaults that are kept at constant temperatures, constant humidity and shielded from magnetism because all these things affect cesium clocks? Not one single portable cesium clock is shielded from any of these things. So maybe you should join those school children before you tell someone else they need to. Do your research before you make claims you have no idea about. You hear of shielding of atomic clocks so automatically assume all such clocks are shielded, this is entirely a false premise and like most other false premises leads to false information being presented. The only atomic clocks shielded and kept in humidity controlled environments are those the traveling clocks are compared to. Traveling atomic clocks are notorious for being unreliable. They place these clocks in shielded places, find those that are the most reliable, then remove them from these vaults and expect them to maintain that same reliability while traveling. Most do not even keep reliable time while sitting still once removed from these vaults. Just why do you think they constructed these vaults for the clocks inn the first place?

Magnetic shielding and temperature control is relatively trivial and is routinely done in military system - even in missiles.

I'm no expert on this, but surely there are some members here that are?

To calibrate clocks they do so according to a master clock, but this master clock is steered in its time as a average of 17 other clocks. So the master clock is adjusted by the average of 17 other clocks which are adjusted by the master clock. Circular reasoning. If the master clock or the 17 other clocks are so accurate, why would each need adjusted according to the other? If atmospheric and magnetic affects had so little affect they would not need to be kept in vaults to prevent its interference. Cesium reacts violently with water and must be kept in sealed glass containers. Cesium clocks also vary timekeeping with the seasons, even in sealed vaults. They may be the most accurate clocks we have, but it is based on movement of an isotope and many things affect movement. I do not doubt they are accurate when kept in ideal conditions. I just think it more likely that one of the strongest forces known to man affects it more than the weakest. Atoms are held together by the electromagnetic force, even dust does not bond together from gravity, but from the electromagnetic force.

http://iopscience.iop.org/1367-2630/11/6/063030/pdf/1367-2630_11_6_063030.pdf

Since you haven't yet come up with predictions of the MLET theory, I've found a reference to one (I could not open the paper that is mentioned, though), so I quote from Physics Forums:

"Originally Posted in RELATIVITY AND GPS, by Ronald Hatch Another Prediction

Incidentally, I have already predicted [23] that Gravity Probe B will detect a different amount of geodetic precession than that predicted by the general theory. I used a rather long argument to conclude that the predicted spin-orbit component (2.3 arc seconds per year) was only half the size it should be. The rest of the geodetic precession was due to space curvature and contributed 4.6 arc seconds per year. A simple method of arriving at my new prediction is to note that, if one measures time with a clock external to the gravitational field (local clock rate is immaterial), the "space curvature" (gradient of ether density) is twice what the general theory predicts. This leads directly to my prediction that the total geodetic precession measured by GPB will be 9.2 arc seconds per year rather than the general theory prediction of 6.9 arc seconds per year. - source"

The GPB results have since been published and it disagrees significantly with MLET. Quote:

"GP-B STATUS UPDATE - May 4, 2011
After 31 years of research and development, 10 years of flight preparation, a 1.5 year flight mission and 5 years of data analysis, our GP-B team has arrived at the final experimental results for this landmark test of Einstein's 1916 general theory of relativity. Here is the abstract from our PRL paper (see next section) summarizing the experimental results.

Gravity Probe B, launched 20 April 2004, is a space experiment testing two fundamental predictions of Einstein's theory of General Relativity (GR), the geodetic and frame-dragging effects, by means of cryogenic gyroscopes in Earth orbit. Data collection started 28 August 2004 and ended 14 August 2005. Analysis of the data from all four gyroscopes results in a geodetic drift rate of -6,601.8±18.3 mas/yr and a frame-dragging drift rate of -37:2±7.2 mas/yr, to be compared with the GR predictions of -6,606.1 mas/yr and -39.2 mas/yr, respectively ('mas' is milliarc-second; 1 mas= 4.848 X10-9 radians or
2.778 X10-7 degrees).

The table and diagram below show the individual gyroscope results, the weighted average results for all four gyroscopes combined, and the theoretical predictions for both effects from Einstein's general theory of relativity, as calculated by Stanford physicist, Leonard Schiff.

Note: The individual and combined statistical uncertainties are corrected for the "over" and "under" dispersion using the Χ2 of the individual estimates in the N-S and W-E directions. Please see our PRL paper (next section below) for more detailed information about these results and their derivation.

Gravity Probe B - Final Experimental Results

rN-S (Geodetic Measurement) rW-E (Frame-Dragging Measurement)

Gyroscope #1 -6,588.6±31.7 mas/yr -41.3±24.6 mas/yr
Gyroscope #2 -6,707.0±64.1 mas/ yr -16.1±29.7 mas/yr
Gyroscope #3 -6,610.5±43.2 mas/yr -25.0±12.1 mas/yr
Gyroscope #4 -6,588.7±33.2 mas/yr -49.3±11.4 mas/yr

Weighted-Average Results for All Four Gyroscopes
All Gyroscopes -6,601.8±18.3 mas/yr -37.2±7.2 mas/yr

Schiff-Einstein Predicted Theoretical Values

Theoretical Gyroscope -6,606.1 mas/yr -39.2 mas/yr"

The worst-case measurement error for the geodetic effect is ±0.064 as/yr, while MLET differs from the mean by 2.6 as/yr. MLET apparently did not predict the frame dragging effect.

-J

A quote from his paper:

[quote]Ashby, in the opening paragraph of his abstract, states:
Important relativistic effects arise from relative motions of GPS satellites and users, ...
And Ashby also states, at the start of a section on time dilation:
First, clocks in relative motion suffer (relativistic) time dilation,...
But these statements are patently untrue of GPS. It may appear to be a subtle
difference, but it is very important to note that the GPS satellites' clock rate and the
receiver's clock rate are not adjusted as a function of their velocity relative to one
another. Instead, they are adjusted as a function of their velocity with respect to the

GPS and Relativity chosen frame of reference-in this case the earth-centered, non- rotating, (quasi) inertial frame.[/quote]

Even two satellites in opposite orbits are not adjusted with respect to one another, and yet their clocks agree. According to your theory by traveling in different directions around the earth they should not agree with one another if one is chosen as the reference frame instead of the earth. Yet no adjustments need be made besides the prior adjustments of the original reference frame of the earth. Switch reference frames and all other clocks should run slow, yet no adjustments will need to be made.

Your own theory is why dating the universe is useless. If the universe is expanding at an accelerating rate then time "IS" slowing down which also means time was faster in the past. Your estimate of 13 billion years must be off by orders of magnitude. So if you believe that velocity affects clocks then you agree that time is not constant and any estimates of the age of the universe that do not take this time shifting into consideration (none of them) then those estimates can not even be anywhere near correct. I expect you will now argue that it is correct in direct opposition to your belief that time runs slower with velocity, which then would contradict that theory. So which theory is correct, velocity changes time or the universe is 13 billion years old?

I will answer Ron Hatch's relativistic misconceptions in the Blog post that I referred to in my previous post.

If you then still disagree, you are welcome to post comments there. I'm done here...

-J

Please post the link, and I'll be sure to ask that same question about determination of the age of the universe.

Jorrie's Blogs are at:

Jorrie's Blog

Reach absolute zero and time stops.
I did not mention temperature...but in the premise, I tend to agree with you. Reduce the universe to absolute zero, and this may well extinguish stars by rendering all matter still at quantum level, and also create absolute darkness. However, since mass and gravity remain present, orbits of stellar bodies, and expansion of space will endure and so motion (and therefore time) remain.
What I did state (hypothetically) was that in the absence of all motion, there is no time. This requires no proof, just simple logic derived from t=sd. Let s = zero: then t = zero. (zero speed= zero motion).
Which means that time operates as a Boolean function (on or off only).Indeed so, in terms of zero motion. BB must have been the beginning of what we refer to as time (there's your 'on'). Alternatively, we must accept two further hypotheses, (i) that prior to BB, the Singularity was in motion (irrespective of mass and density) and, (ii) that therefore, space preceded BB, so BB only populated space and, (iii) that therefore time also precedes our universe.
In any case, my original contribution to the thread stands, and is agreed by a number of other contributors. Further development of the subject seems pointless.

Or does time reach infinity at absolute zero? If the faster an object moves the slower time goes, then the slower an object moves the faster time goes. Therefore would absolute zero velocity imply no time or all of time passing in but a blink of an eye? Could the universe therefore be eternal prior to the BB and but a few billion years old at the same time?

Then what happens next?

Well, probably, you guys will get to "if a bear breaks wind in a forest in orbit, will the trees super conduct?"

Thanks!

would absolute zero velocity imply no time or all of time passing in but a blink of an eye?

Since it appears that our version of time renders it to be a latent function/ property of motion, when all motion stops, time reverts to being a latent function (becomes dormant).

Could the universe therefore be eternal prior to the BB and but a few billion years old at the same time?

1. I assume you mean the sum of two time frames (pre & post BB) ?

2. You discount that before BB there was no universe…

That depends on whether the Singularity hypothesis is factually correct, bearing in mind that motion is dependent on space to occur at all ie did space exist before BB or not? If it did exist, then motion (and thus time) were possible for the Singularity.

Rationality will have it that motion occurs between two points, and there was only one point....the Singularity. Therefore, it must have been spinning, and since the hypothesis states it to have been infinitesimally small, then : where t=sd, and where 'd' (circumference) →zero, then t →zero.

That is the extent that the my left brain can field your question today.

My right brain says of course the Singularity must have been ancient measured against our concept of time (you don't whip up one of those overnight). Just a different yardstick needs to be applied….

Well I for one have no doubts space existsed prior to the BB if of course that is how it happened at all. For the BB to have happened it had to have someplace to happen into and had to exist someplace prior. The idea that space was created with the BB smacks just a bit too much of mysticism. Space filled with matter may not have existed prior, but space (vacuum) certainly did.

Yet theory also says if you reach the speed of c all time stops, and c certainly cannot be considered as no motion. So time stops if you reach c or zero? Another problem is that all other clocks appear slower, so how would any other clock at the speed of c appear slower if yours has stopped? Yet theory insists this is true.

It takes about 8.3 minutes for light to arrive at Earth from the Sun

Why wouldn't a clock making that trip, at that speed, show the same 'trip time' as the observers clock on Earth?

2¢

This blog by Jorrie might help.

Twin Paradox

Because people have decided they need time to slow as speed increases to uphold a theory that has no basis in reality. if I am traveling at 1/2 of c and you are traveling at 1/4 of c, my clock is slow by yours and your clock is slow by mine? makes sense to me, how about you? Wait what?

Like I said in #2:

"We just worked backwards from the time it takes for the sun to orbit the earth."

I dont think im qualified enough to give that a GA, but if i was, then I would, because I like your answer (yeh i know, personal opinion doesnt play a role in applied science), and you obviously think a little outside the normal box. Humans are always trying to justify and quantify things they may never understand. Whats to say time even exists? It seems to me, as you stated Martin, that its just a tool we created to assist our futile brains in dealing with life, and a means of attempting to controll what little we can. I honestly dont think the human brain is capable of understanding how the intricacies of the universe work, and even if we were, and some higher being explained them to us, what would we do with that info anyway?; jump through a wormhole to another dimension, and populate and destroy that habitat to? Either way, this Earth would still spin the same way, and the sun would keep coming up every morning, just like it has for the last whatever ammount of "time" we nominated. It seems like the more technology and knowledge we acqruire, the further away we get from attaining a plausible answer to anything. Im an aetheist, so I therefore have a great deal of faith in science, but its almost as if science and enlightenment have an inverse relationship.

Fish dont know they're underwater: think.

(Nonsensical rant over)

Time is a Man created Earth centric comparator.

The meter is defined against a number of cycles of light.

So if you took a meter long thing to a place where gravity is influencing the speed of light (differently) you could in turn 'compare' the the speed/time with Earths.

As this has not yet been done, Special and General Relativity remain theories.

Well,

Very interesting.

Back to the OP's very insightful question. "My question is : According to whose time?"

It seems that it is according to "our" time.

We have all added to the group definition in some way (OK, except for the sun orbits the earth, maybe) that helps us to understand it and come to grips with the fact that we "know what we know". And not much more.

Me, I know that when I see the light coming through the window:

1. I'm still alive.

2. It must be time to get up.

Well since we do tell time by the oscillation of the cesium atom there can never be a universal time for us as the cesium atom changes due to nearness to a gravity source or acceleration. So unless we can figure out how to place a clock somewhere were there is no gravity or acceleration we are stuck with our local time.

Maybe you, "tell time by the oscillation of the cesium atom", but I tell time by looking at my watch.

This is like trying to fix a Chevy Caviler, there's just too many variables to ponder.

Ok, so you tell time by the oscillation of a crystal :)

No, I tell time by the rotation of a balance wheel.

Or by the position of the sun.

That's all the precision I need.

If you know the clock rate and you know the environment you measure it in (i.e., relative velocity and gravity) you can normalize the clock to whatever standard you want.

We do this now with the GPS satellites. We calculate the temporal shift from microgravity (near zero G), which yields an increase in clock speed for the satellite over clocks on the surface of Earth and we also compensate for the orbital velocity of the satellite (which slows the onboard clock down).

Even though the atomic clocks on the GPS satellite operate in a different environment, their clocks are carefully compensated so that they match ground based clocks. We use Einstein's General Relativity to calculate the amount of adjustment we need.

So, we really have no problem calculating the effect of a clock in pure zero G and compensating for it.

Of course there is no 'zero g'

So tell me, since according to theory we are on earth in its gravitational influence, within the Sun's gravitational influence within the galaxies gravitational influence, or is not our Sun held in orbit around the galaxy by its gravitational influence? So even if you calculate zero G as compared to earth's gravity you still have not gotten to zero G as you have the Sun's influence and every star in our galaxy. Then you want the Andromoda galaxy to be attracting to us so you have its gravity. Then since you have no stationary point in space to measure the velocity of our galaxy relative to any other you can only throw in a best guess. Sort of Like the Hafele and Keating test of 1972 with clocks on airplanes, this relativity is what you mean?

It is not the acceleration vector ('g')

that influences clocks, but the Newton potential scalar

with a essentially the negative gradient of the potential.

Satellites are in zero g, but not at zero potential.

Velocity influences time, but through a different mechanism. Satellites and the Hafele and Keating experiment of 1972 tested both.

-J

Jorrie, my friend, you are genius! And I, now feel quite inferior. (as that stuff is way over my head).

Good day to you all!

Note "your" frame of reference of the question -- "whose." There is an instinctive understanding that time is something perceived within "us." Or more generally, within "consciousness." Without us there is no time. You may or may not agree. How would you suggest we prove it?