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Is time relative or objective? If relative then can it truly be measured? If not then can we say our view of time is accurate?

I was reading an article this morning on what is concluded to be an astonishing planetary system that defies what we know about stars and orbiting planets. Two stars were found to be orbiting each other so closely that their matter was being exchanged at a constant rate which led to the theorization of orbiting planets said to be 6 to 8 times larger than Jupiter and take which take 5 and 16 years to orbit the two sons.

The article went on to say "Because of their eclipsing nature, Dr. Potter and his collaborators were quick to notice that the periodic timing wasn’t regular." My questions are those above. If these Doctors are measuring the periodic time of this system what are they measuring it's irregularity against? If what we know about time is only defined by what we see in our immediate system then wouldn't that mean that time is relative to each system, for example, the one I gave above?

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It has been known for a long time that space is not absolute. I.E We measure the spacial coordinates of events relative to no absolute reference frame. You have to declare the reference frame you are measuring the event relative to.

With the advent of Einstein's theories of relativity it becomes apparent (through theory and also through experiment) that the same is true of time. In fact it makes more sense not to consider time in the traditional more intuitive sense (whatever that is) but rather to consider it the same way we view space. Time can now be considered the fourth coordinate in a new way of mapping the universe I.E Space-time. 3 spacial dimensions, 1 time dimension. You must still state your reference point. One event may happen at different times to observers moving in different inertial (Essentially means constantly moving, though general relativity made corrections for accelerating frames of reference) reference frames. I believe we actually have the mathematics to describe how events will appear to different observers. So we can measure accurately how something appears in a different reference frame.

Not entirely sure how the questions apply to the article though? Irregularities in the period of rotation were inferred to be caused by the orbit of two large planets no?

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The questions were sparked because two suns were found to be at the center of a solar system causing abnormal orbital rates in two large planets. There's a greater gravitational pull as a result of the two suns and two large planets that take 16 and 5 years to orbit both suns which affects the measurement of time. I guess i'm just wondering if Time is relative or objective and how is it affected by gravity.

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On the planets: From the article the orbital rates of the planets and their masses were inferred from the nature of the stars themselves. You can see stars, that is easy, they're huge and emit light. Planets however are much harder to see since they're much smaller and do not emit any light therefore their existence are inferred by the effect they have on their star(s). A planet's gravitational pull will tug back on the star tugging on the planet. If you consider the 'centre of mass' of the system of the planet and the star you will find that it is not at the centre of the star, but at a point away from the stars centre (though admittedly not that far). In any case the star will orbit around this point meaning that we will observe 'wobbles' in the stars position. By observing the extent of the wobble, how it changes etc we can observe what kind of planet is orbiting it. Typically jupiter-like and sized planets are inferred because they are a) common, and B) their large size causes larger wobbles. There's presumably more to it but that's all I think I know about planet detection.

On time: Obviously whether time is objective or relative is up for debate philosophically and perhaps even physically. However I think if we could observe, from an outside perspective, the so called 'fabric' of space-time with events mapped out on it we'd find they had definite coordinates. In that sense it is objective (I think) but in terms of any observer from within the universe its a bit more complicated than that and we can only measure space and time with respect to something else. Relativity makes a point of choosing points with greater inertia as your decided inertial reference frame. In fact that is necessary to overcome some paradoxes present in special relativity such as the 'twin-paradox'... (I think I remember?) Of course the nice neat map of space-time probably doesn't exist :) A lot of things in physics on the very large scales or the very small scales are considered to be 'models'. Extremely effective ones, but the trouble is its hard to find an analogy for something that only behaves as itself.

I can think of one example off the top of my head of gravity affecting time though there are others... Proved experimentally, two extremely accurate atomic clocks were placed, one on the ground the other somewhere high in the atmosphere. They were in synch at the start of the experiment and were found to be out of synch some time later with the clock higher up (where the earths gravitational field has less effect) having been running faster.

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On the planets: From the article the orbital rates of the planets and their masses were inferred from the nature of the stars themselves. You can see stars, that is easy, they're huge and emit light. Planets however are much harder to see since they're much smaller and do not emit any light therefore their existence are inferred by the effect they have on their star(s). A planet's gravitational pull will tug back on the star tugging on the planet. If you consider the 'centre of mass' of the system of the planet and the star you will find that it is not at the centre of the star, but at a point away from the stars centre (though admittedly not that far). In any case the star will orbit around this point meaning that we will observe 'wobbles' in the stars position. By observing the extent of the wobble, how it changes etc we can observe what kind of planet is orbiting it. Typically jupiter-like and sized planets are inferred because they are a) common, and B) their large size causes larger wobbles. There's presumably more to it but that's all I think I know about planet detection.

Yeah i think I mentioned how two planets were theorized to exist.

I can think of one example off the top of my head of gravity affecting time though there are others... Proved experimentally, two extremely accurate atomic clocks were placed, one on the ground the other somewhere high in the atmosphere. They were in synch at the start of the experiment and were found to be out of synch some time later with the clock higher up (where the earths gravitational field has less effect) having been running faster.

Yeah that's precisely what I mean when I say the measurement of time is based on the gravitational pull thus being relative to where one is in relation to the sun. I'm not that bright when it comes to physics haha.

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Yeah i think I mentioned how two planets were theorized to exist.

Yeah that's precisely what I mean when I say the measurement of time is based on the gravitational pull thus being relative to where one is in relation to the sun. I'm not that bright when it comes to physics haha.

Ah I think I'm on the same page as you now! Did a quick google search to find out how much of an effect it would have. Apparently its pretty much negligible. Here. Not the best source out there but I think it addresses the problem kind of.

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I'm not going to try and be scientific, because I will fail. But I was having a conversation with someone yesterday that baffled me. He basically said that time could go backwards and we wouldn't notice. It would work as physics equations work either way, backwards or forwards. I can't remember if I argued/commented on this, but its an interesting thought.

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Ah I think I'm on the same page as you now! Did a quick google search to find out how much of an effect it would have. Apparently its pretty much negligible. Here. Not the best source out there but I think it addresses the problem kind of.

This debate is taking an interesting turn. As I look into this more I'm starting to find conversations about gravitation redshift (and blueshift) which seem to define time or make up what we know of time and the age of the universe. However there seems to be disagreement about gravitational redshift and its accuracy. We seem to use this theory to determine the age of the universe but what happens if wavelengths from other stars and light sources interfere with our measurements? Can we really say are measurements are accurate? Can we even say we know the age of the universe? Those are more rhetorical questions, but the conversations out there on this subject are nowhere close to unified.

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