# QuestionTime and Gravity

#### J@i

Time and Gravity seems to work in tandem!!!

Are they just one and the same or if they are just connected somehow?

#### Catastrophe

##### "Science begets knowledge, opinion ignorance.
You would need to incorporate 'the arrow of time'.

Cat

sam85geo

#### J@i

Do we today know for sure what is gravity?

Catastrophe

#### Catastrophe

##### "Science begets knowledge, opinion ignorance.
Answer: We don't really know. We can define what it is as a field of influence, because we know how it operates in the universe. And some scientists think that it is made up of particles called gravitons which travel at the speed of light.

What is gravity? - Starchild (NASA)

Cat

sam85geo

#### SIDexplorer

Time and Gravity seems to work in tandem!!!

Are they just one and the same or if they are just connected somehow?

Time is baseless, it all is movement, so we are left with just movement and space, so gravity is a property of space conjoined with movement. Time is but movement given a nickname, besides movement, memorisation of movement is time.

#### Catastrophe

##### "Science begets knowledge, opinion ignorance.
You can represent time on a 4 (space) dimensional graph as ct. How are you going to represent gravity in a way which conforms to dimensional analysis?

Cat

sam85geo

#### J@i

How about Einstein theory that massive objects cause a distortion in space-time, which is felt as gravity.

#### Catastrophe

##### "Science begets knowledge, opinion ignorance.
J@i,
That is fine. My question was somewhat rhetorical, in that I cannot see an equivalent way of representing an acceleration due to gravity. You can toy with the acceleration part (ct divided by length per time ^2, ct), but I don't find it possible to ignore the "due to gravity" bit.

To harmonise gravity with time, you need to have some dimensional analysis agreement, as in expressing time as ct as a length.

Cat

sam85geo

#### J@i

J@i,
That is fine. My question was somewhat rhetorical, in that I cannot see an equivalent way of representing an acceleration due to gravity. You can toy with the acceleration part (ct divided by length per time ^2, ct), but I don't find it possible to ignore the "due to gravity" bit.

To harmonise gravity with time, you need to have some dimensional analysis agreement, as in expressing time as ct as a length.

Cat

Hi Cat, I was only referring to your reply #7... If I understand it right, we have three possible known ways that allows Gravity to exist:

1. Spinning Objects simulate gravity effects, this theory should allow us to create artificial gravity in space
2. Einstein theory that massive objects cause a distortion in space-time, which is felt as gravity
3. Theory around existence of Graviton - yet to be proved or rejected

Even if #2 or #3 are proved to be true at some point of time, can we safely assume that #1 will always hold true or will it be otherwise?

#### Catastrophe

##### "Science begets knowledge, opinion ignorance.
Hi J@i, let me put it another way.

Starting from the Force of Gravity, according to NLs,
Force = Mass x Acceleration, therefore I am having difficulty with squaring the Dimensional Analysis. Incorporating Time into the x, y, z length graph (whatever other opinion one might have) is no problem if you multiply by c, since c x t is dimensionally (length / time) x time = length.

To incorporate gravity, we need to introduce mass. This does not fit.

Cat

#### DrRaviSharma

Gravity is felt through matter, certainly matter as we know it, but it is also felt through Dark Matter (DE is not yet understood by me?).

It can today be understood as influencing spacetime fabric as distortion proportional to how that fabric goes near massive and very massive objects. As we expect colliding neutron stars create gravity ripples!

#### Catastrophe

##### "Science begets knowledge, opinion ignorance.
proportional to how that fabric goes near massive and very massive objects

That is an interesting thought. I had always thought of the smaller body orbiting the more massive body and causing the distortion, like a ship creating a bow wave.

Your quote, to me, brings to mind spacetime, like the discredited aether, 'sinking' into a hollow or pit as it approaches a stationary massive object.

Of course, relativity can invert anything, so it is just another way of looking at the question, but it did 'smile at me from the aether'

Cat

#### DrRaviSharma

I did not say "aether". Implied that spacetime could be thought of as a quantum field as we interpret QFT in QED and QCD!

#### Catastrophe

##### "Science begets knowledge, opinion ignorance.
1.
2. (uncountable, physics, historical) Often as aether and more fully as luminiferous aether: a substance once thought to fill all unoccupied space that allowed electromagnetic waves to pass through it and interact with matter, without exerting any resistance to matter or energy
My underlining, not my bold.
Source: Wiktionary.

As a chemist, I prefer aether to ether, to distinguish it from (CH2CH2OH)2O

2.
I did not say "aether". Implied that spacetime could be thought of as a quantum field as we interpret QFT in QED and QCD!

Neither did I. I said
Your quote, to me, brings to mind spacetime, like the discredited aether, 'sinking' into a hollow or pit as it approaches a stationary massive object.
to me, brings to mind
means that "it brings to my mind that" , , , . . . that is purely my subjective thought. It is not implying anything external whatsoever.

Cat

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#### Jzz

Time is a manmade construct, while gravity is a natural phenomenon, it would be wrong to confuse the two or to equate them on the same terms. Repeated experiments have confirmed the effect of gravity on clocks and the results seem to agree with this reasoning, namely that in a stronger gravitational field things, including atoms, are more restricted than in a weaker gravitational field. As expected, time would move faster on a space ship far from any gravitational fields than it would on earth. Therefore, it would appear that time as measured by clocks is solely dependent on gravity or (with reference to the equivalence principle) on the rate of acceleration of the vehicle in which the clock is situated. This being so, (time being a manmade construct) and since the exact deviations due to the influence of gravity (or acceleration are known. It is possible to adjust clocks in order to compensate for the distortion due to gravity or rate of acceleration, this would result in a Universal time. Time for everyone would be the same, since everyone would have the same frame of reference. Since everyone occupies the same frame of reference, time dilation and length contraction are not present. While physical effects due to traveling under great acceleration might result in funny effects akin to the twin paradox, surely this could be written down as an effect of travelling at high rates of acceleration rather than to time dilation?

This raises the question of whether humans will be able to survive under the G- forces necessary for such changes in time to take place. A pilot can experience up to 9 G’s in a modern jet fighter, this equates to 317 km/h/s (kilometres per hour per second). So it’s increasing its speed by almost 317 kmph every second! While a speed of 320 Kmph might be very fast on earth, it is not very fast when it comes to space. For instance the space station has an orbital speed of about 25,000 kmph! Yet, the astronauts inside the space station experience near zero G forces but that is because the space station is in free fall and the effect is the same on astronauts as may be experienced by objects in a free falling lift. What is clear is that under forces of very rapid acceleration, as would be needed to reach near light speeds, survival would be problematical.

As for gravity changing with pure velocity where the effects of acceleration are not present, this is very much a moot point. For instance in the space station, theoretically an acceleration is taking place since the orbit of the space station requires constant directional changes, yet this is not reflected, either in the clocks or in the astronauts. Because the space station is still under the influence of the earth's gravity. Similarly, on the Apollo missions, even though the space ship was considerable distances from earth, the astronauts still experienced weightlessness for the same reason.

#### Jzz

That is an interesting thought. I had always thought of the smaller body orbiting the more massive body and causing the distortion, like a ship creating a bow wave.

Your quote, to me, brings to mind spacetime, like the discredited aether, 'sinking' into a hollow or pit as it approaches a stationary massive object.

Of course, relativity can invert anything, so it is just another way of looking at the question, but it did 'smile at me from the aether'

Cat
Do you also smile at Dark Matter ?

#### Catastrophe

##### "Science begets knowledge, opinion ignorance.
Just to ask a polite question . . . . . .

Would you not think that there is a difference suggested between
it did 'smile at me
and
did you . . . smile at
?

Cat

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