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How gravity works


trevorjohnson32

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3 hours ago, trevorjohnson32 said:

alllllrighteyoh then

Proof is used in philosophy, and in mathematics, but not in science. It's an important and distinct term for a particular methodology.

In science, theory is supported by a preponderance of evidence, which gives us the current best explanation. Nothing is proved, and in this way theories grow stronger. Another important and distinct term, theory doesn't mean "educated guess". Theory is as strong as it gets in science.

Also, we rigorously attack ideas here, but not people. This is not a place to get personal. We discuss science, and that means pointing out what doesn't work, and what goes against what we observe in nature.

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Alright, i'll give it to you guys that you come off as maybe non offensive the way science should be.

So here's a question, If I was moving at the speed of light, and looked back on an object I was moving on a direct path away from, Would I see that object frozen in a second of time? and If I travelled faster then the light the object it emits,  I would begin to watch that object go in reverse? what does this say about time dilation and the aging effect?

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5 hours ago, trevorjohnson32 said:

So here's a question, If I was moving at the speed of light, and looked back on an object I was moving on a direct path away from, Would I see that object frozen in a second of time? and If I travelled faster then the light the object it emits,  I would begin to watch that object go in reverse? what does this say about time dilation and the aging effect?

As you can't travel faster than light, there is no answer.

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9 hours ago, Strange said:

As you can't travel faster than light, there is no answer.

That's fine that you have no imagination, I guess. Am I really supposed to learn something from this response? Why don't you just say I don't know, it would be a heck of a lot more true the WS you've posted.

And, just for fun, what is the scientific reason you can't travel faster then light speed?

Edited by trevorjohnson32
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14 hours ago, trevorjohnson32 said:

Alright, i'll give it to you guys that you come off as maybe non offensive the way science should be.

So here's a question, If I was moving at the speed of light, and looked back on an object I was moving on a direct path away from, Would I see that object frozen in a second of time? and If I travelled faster then the light the object it emits,  I would begin to watch that object go in reverse? what does this say about time dilation and the aging effect?

As pointed out, not only can you not travel at FTL speeds, you cannot attain speeds equaling c.   You can get extremely close to it, but never exactly reach it. 

So for the sake of argument, we'll put your speed at 0.999999999999999999c relative to the object your are watching.

At this speed it would take 44.8 years by your clock for you to see one sec pass for the object.

But a part of this is due to the fact that the distance between you is constantly increasing and the light traveling from the object takes longer and longer to reach you. If you factor this effect out, you will conclude that for every one sec that passes for the object, 22.4 years passes for you and this is the time dilation between you. 

If you were approaching at that same speed, you would see the object age 22.4 years for every 1 sec of your time.  Again, a good deal of this is due to the decreasing distance between the two of you, and when you factor this out, you would conclude that the object is aging at a rate of 1 sec per every 22.4 years for you, the exact same time dilation as when you were moving away.  

What you would see depends on whether whether you are moving apart or together but the time dilation does not.

So what do you see if you travel away for 22.4 years by your clock, and then turn around and come back at the same speed?  for the outbound leg you see the object age 1/2 sec, but during the return leg, you see it age 31,700,000,000 years,  and thus during after your 44.8 year trip you will return to the object with it having aged 31,700,000,000 yrs and 1/2 sec.

So how do we square this with the fact that according to time dilation, the object aged more slowly than you did during both the outbound and return legs?.   The answer is what happens to the object's age when you do the turn-around.  It will, by your reckoning advance some 31,700,000,000 years between the two legs( you will not "see" it advance this much, but this will be the "determined" time for the object due to the shift in simultaneity caused by your reversal of direction.)

The above illustrates the difference between "time dilation" which is the difference in time rate as measured between frames  according to a given frame at any given moment, and "the total accumulated time difference" which is the measure of total time accumulated by two clocks that have been separated at some velocity and brought back together again.

For the object, you were always aging slower than it was during the entire trip due to the combined time dilation during the two legs, which results in you aging less than it when you return.

For you, the object aged slower than you did during both legs of the trip, due to time dilation, but aged extremely fast during the turn-around phase of your trip, which more than makes up for the slowing during the legs and results in the object having aged more than you when you meet up again.  (As pointed out earlier, what you would "see" is the object aging slowly during the outbound leg and aging very fast on the inbound leg).   

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40 minutes ago, trevorjohnson32 said:

That's fine that you have no imagination, I guess.

Sorry, this is a science forum, not a science fiction forum.

40 minutes ago, trevorjohnson32 said:

Why don't you just say I don't know

Because it wouldn't be accurate.

40 minutes ago, trevorjohnson32 said:

And, just for fun, what is the scientific reason you can't travel faster then light speed?

Lets say you are on a spaceship travelling at 51% of the speed of light and you fire a missile ahead of you at 51% the speed of light. That missile will be going at 102% of the speed of light, no? No. It will be 81% of the speed of light.

https://en.wikipedia.org/wiki/Special_relativity#Composition_of_velocities

Edited by Strange
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25 minutes ago, trevorjohnson32 said:

That's fine that you have no imagination, I guess. Am I really supposed to learn something from this response? Why don't you just say I don't know, it would be a heck of a lot more true the WS you've posted.

And, just for fun, what is the scientific reason you can't travel faster then light speed?

Its not a lack of imagination,  its the fact that according to our present understanding, such a speed is not allowed.  If you try imagine a scenario in which it is allowed, you have to throw all the rules out.  But if you do that, what rules do you replace them with?  You can't even start to answer the question until you've determined that.   One could conceivably "imagine" a vast number of rules that might work, but  different set of rules would give a different answers to your question. So it not a lack of answers so much as too many conflicting ones.  Further, it is not enough to just say FTL speeds are possible.  You could do that by just reasserting Newtonian physics, but it has already been determined that Newtonian physics fails a high velocities. Thus you new set of rules would have to both explain this and allow for FTL velocities.

There are a number of different ways to answer this question of why FTL speed are not allowed.

One is the time dilation equation:

T = t/sqrt(1-v2/c2)

if v>c than you get a negative number under the radical sign and the square root of a negative number doesn't have an answer.

The other is considering the kinetic energy of an object as it nears c. It approaches infinity.  In other words, the amount of energy needed to get an object up to any given speed approaches being infinite as you get closer to c.

Then there is the addition of velocities approach.

w=(u+v)/(1+uv/c2)

u is the initial relative velocity of an object to some reference frame, and v the velocity added as measured by the object, then w, the final velocity with respect to the reference frame can never add up to even being c.

For example if u=0.5c and the object fires an second object forward at 0.5c relative to itself(v), then the final velocity of this fired object relative to the reference frame which the first object is moving at 0.5c relative to will be 0.8 c.   If this second object fires a third object at 0.5c relative to itself, it will be measured as moving at 0.9286c relative to the reference frame.  No matter how many times you repeat this, you never get a velocity relative to the reference frame of even c, let alone greater than c.

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On 1/11/2018 at 10:22 AM, trevorjohnson32 said:

Then here, the text from the video:

  • A quark is a particle of extremely dense space time
  • Its density puts a squeezing effect on the surrounding space time that it exists in
  • The squeezing effect creates its gravity field and is stronger the closer to the quark
  • A planet creates a gravity field of its own from the astronomical number of quarks in the planet
  • When the Edge of a quark’s gravity field and the edge of a planet’s gravity field touch the gravity field of the quark is squeezed on its edge
  • This pulls the quark in the direction of the planet’s gravity field
  • The quark is continuously pulled in as the lavers of space time are denser the closer to the planet

Every person is entitled to his or her own opinion/s, but not their own fact/s. 

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21 hours ago, Janus said:

What you would see depends on whether whether you are moving apart or together but the time dilation does not.

So is time dilation caused by an objects movement through space or what do you think causes it? Do objects create a reference frame  by  moving around each other? and GR states that you can't tell if an object is at rest or  moving only that it appears to be moving in relation to other objects, Is that right? Do you believe this stuff?

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13 minutes ago, trevorjohnson32 said:

So is time dilation caused by an objects movement through space or what do you think causes it? Do objects create a reference frame  by  moving around each other? and GR states that you can't tell if an object is at rest or  moving only that it appears to be moving in relation to other objects, Is that right? Do you believe this stuff?

Time dilation is result of the fact that clocks in relative motion with respect to each other measure time( and space) differently, but is not connected to any absolute motion with respect to space.

So no, there is no state of absolute motion or rest in the universe.

As to what I "believe", I accept that this is presently the best description of how the universe behaves that we have. It is not only logically consistent, but has passed every physical test ever thrown at it.  

And neither is this just accepting what "authority" says.  It comes from my own personal deliberations on the subject.  In other words, it does make "sense" to me.

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I believe the universe is a single object and not infinite. From a great distance outside our universe we are just another indivisible cube of super dense space that causes gravity in that universe. 

9 minutes ago, Janus said:

So no, there is no state of absolute motion or rest in the universe.

So the universe does not create a reference frame for objects in spite of the fact that two clocks travelling at two different speeds will tell time differently? If they weren't slowed down by the passing through space alone then what else causes the clocks to read differently?

 

13 minutes ago, Janus said:

As to what I "believe", I accept that this is presently the best description of how the universe behaves that we have. It is not only logically consistent, but has passed every physical test ever thrown at it.  

Yeah, I believe time dilation exists, is that what you mean time dilation has passed every test?  There are some pretty basic logical questions that general relativity doesn't pass. 

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22 minutes ago, Janus said:

 

So no, there is no state of absolute motion or rest in the universe.

Would you  be defining "state of motion" and "state of rest" as opposites or does/can a (local) "state of rest " describe a non-acceleration?

Can the distinction really be more fundamentally along the inertial and non-inertial lines ?( I have been wondering that for a long time)

 

Hope I am not too vague.

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33 minutes ago, trevorjohnson32 said:

So the universe does not create a reference frame for objects in spite of the fact that two clocks travelling at two different speeds will tell time differently? If they weren't slowed down by the passing through space alone then what else causes the clocks to read differently?

It can't really be explained by "passing through space" because the amount by which a clock changes depends on who observes it. So, while you are sat still in your chair, you are moving at a variety of different speeds relative to different observers. You are not moving relative to your neighbour so your clock is not dilated. You are moving quite fast relative to a GPS satellite so your clock is dilated a small, but measurable, amount relative to that. You are also travelling at a much higher speed relative to, say, the Andromeda galaxy and so your clock is dilated larger amount according to those observers. So it is not caused by your clock moving through space.

Quote

There are some pretty basic logical questions that general relativity doesn't pass. 

What are these?

Or by "logical" do you just mean that it doesn't make intuitive sense to you?

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13 minutes ago, Strange said:

It can't really be explained by "passing through space" because the amount by which a clock changes depends on who observes it. So, while you are sat still in your chair, you are moving at a variety of different speeds relative to different observers. You are not moving relative to your neighbour so your clock is not dilated. You are moving quite fast relative to a GPS satellite so your clock is dilated a small, but measurable, amount relative to that. You are also travelling at a much higher speed relative to, say, the Andromeda galaxy and so your clock is dilated larger amount according to those observers. So it is not caused by your clock moving through space.

Oh so what causes time dilation is....

 

13 minutes ago, Strange said:

What are these?

Or by "logical" do you just mean that it doesn't make intuitive sense to you?

I'm sure you know about thtwo clocks. Here's another one, so according to your belief in GR if one should fall to his face on earth, there is no way of telling if you fell or the earth came up and hit you in the face since objects only move relative to each other. pretty absurd logic or I guess its just my intuition questioning what I see.

Edited by trevorjohnson32
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14 minutes ago, trevorjohnson32 said:

Here's another one, so according to your belief in GR if one should fall to his face on earth, there is no way of telling if you fell or the earth came up and hit you in the face since objects only move relative to each other. pretty absurd logic or I guess its just my intuition questioning what I see.

Seems to me if you find that hard to accept you will find it impossible to accept anything  more involved.

 

"Even" Newton was comfortable with that surely.

 

Relativity predated GR by many centuries as far as I know.

 

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18 minutes ago, trevorjohnson32 said:

I'm sure you know about thtwo clocks. Here's another one, so according to your belief in GR if one should fall to his face on earth, there is no way of telling if you fell or the earth came up and hit you in the face since objects only move relative to each other. pretty absurd logic or I guess its just my intuition questioning what I see.

OK. So you do just mean that it doesn't make sense to your intuition. 

There is not (cannot be) anything illogical (as in, inconsistent in any formal or mathematical way) in GR because it is a self-consistent mathematical theory.

Things like the Twin Paradox that you refer to are just called "paradoxes" because they seem counter-intuitive, not because there is any real paradox to be resolved. It is explained within the framework of GR.

2 minutes ago, geordief said:

Relativity predated GR by many centuries as far as I know.

Indeed. The idea that speed can only be determined by reference to something else goes back to at least Galileo. 

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What causes time dilation requires years of heavy mathematics to fully understand. However here is a helpful starting point. What causes propogation delay of a signal in an electric circuit? As stated its a start point, however its applicable to other field interactions. You must first be absolutely clear on a few key definition.

mass is resistance to inertia change....

kinetic energy ability to perform work due to momentum 

potential energy ability to perform work due to position.

They may sound unrelated but believe me they are not. They are essential to understand how multiparticle fields interact and cause signal delays which is the essence of time dilation. 

 

Edited by Mordred
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2 hours ago, trevorjohnson32 said:

Oh so what causes time dilation is....

Before I attempt to answer that question, the first step that you need to accept is that time dilation is experimentally and observationally verified and has been many times. If you are unable to accept that, because it presumably offends your personal sensibilities and seems personally counter intuitive, then you have a problem. Let me add another fact...Your offended intuition, of course only applies to a very limited set of conditions. Those conditions though, with the advances in science and technology, have been extended many times, and it is consequently evident that things that were once intuitively accepted, are not valid when relativistic speeds, gravitational wells and temperatures are experienced or brought into vogue.

As simply as I am able to put it, and from one lay person to another, time dilation occurs because the proper speed of light, "c" is the same for all observers in all frames of references. Thus time dilation is evident when two different observers are moving with relation to each other, or when residing in a different gravitational well. At Earthly based speeds and pre-Einstein, this effect was not noticed due to it being very very tiny, and only becomes noticable when moving at near relativistic speeds. 

On any other questions of "why" or "how" that you have, you should realize that science is based on a preponderance of evidence supporting a particular concept. The following short video of around 7.5 minutes long may explain exactly what I'm trying to say......

https://www.youtube.com/watch?v=MO0r930Sn_8

 

Edited by beecee
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2 hours ago, trevorjohnson32 said:

Oh so what causes time dilation is....

The fact that space and time are not the separate and unrelated concepts that Newtonian Physics treat them as being, but rather parts of a larger construct known as Space-time.  As such, measurement of the space and time separation of events is frame dependent.   Reference frames in with relative motion with respect to each other will disagree as t0 the difference in time and separation in space between any two events. 

To use an analogy, Newtonian Physics treats time and space like the North-South and East-west directions, which everyone would agree upon no matter which way they are facing,  While in Relativity they behave more like Left-Right and Front-back, which each person determines individually.

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6 minutes ago, Janus said:

 

To use an analogy, Newtonian Physics treats time and space like the North-South and East-west directions, which everyone would agree upon no matter which way they are facing,  While in Relativity they behave more like Left-Right and Front-back, which each person determines individually.

Awesome analogy to explain relativity to a layman. I’m stealing this. 

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6 minutes ago, trevorjohnson32 said:

Sorry guys, I know where your coming from and I'm not buying it. I have my own theory on how time dilation is caused. No need to ask for it like I'm sure your all frantically typing to do right now, I ll eventually post it.

 

 

!

Moderator Note

You have to do better than this. We expect rigorous, scientific justification for your ideas, not, 'I'm not buying it.' Why not? What specifically do you take issue with in the replies you've received? If you can't comply with this expectation, this thread will be closed.

 
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1 minute ago, hypervalent_iodine said:

 

 

!

Moderator Note

You have to do better than this. We expect rigorous, scientific justification for your ideas, not, 'I'm not buying it.' Why not? What specifically do you take issue with in the replies you've received? If you can't comply with this expectation, this thread will be closed.

 

I didn't know that I was required to post responses to the absurd word salad of the other posters here. I can just generally say about any and all of the responses so far nothing has answered any of the questions I've asked. But to keep the thread alive for fun I'll read them again and try to pick something out. 

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