[SOLVED] Hypothetical question about gravity

[trytip]

Yeah, and Einstein?
https://www.youtube.com/watch?v=6zWy6_Mog70

i did not understand a word in that video, but i'm glad someone is actually taking Einsteins theory apart and proving special relativity is science fiction.

if you can affect decent and ascent with wings and engines, that has everything to do with gravity. we can focus a beam of light into a laser that can travel to the moon and back which means light is a tool just as gravity.

we can escape light and gravity, but never time. if you buy 1000 digital and analogue clocks of all sizes and mechanisms and put them in a row synchronize them to the second then let them run for a year, i do not believe they will stay synchronized which means time can't be measured. if you drop 1000 objects from earth's orbit or any other celestial object with a gravity field (let's say they don't burn up) they will all reach the ground at the same time and at the same speed. we can measure gravity

[Portreve]

There is no gravity, only Zuul duct tape.

A universe without duct tape scarcely bears thinking about.

[1.618]

The planet would actually wander slightly from a straight line, the radiation from it's star would still be bombarding it and this would cause a deviation in it's trajectory, and also the spin of the planet itself could cause the trajectory to wander slightly too, think of a pool ball being curled around a table with some side spin, except it's a planet with no gravity to draw it toward the star, this effect is more noticable in an atmosphere but space is full of plasma and gas so would still allow for slight variations. Although small these effects would be seen over longer periods of time.

[otacon14112]

i believe time is the one true phenomenon in the universe that is absolute constant and does not need a source. gravity and light are only bi-products therefore we can use them to our advantage but we can not and will never manipulate time.

gravity does not manipulate time

Gravity distorts time. Stephen Hawking gave an example in his book, The Universe in a Nutshell, in which a clock was put at the top of a tower, and one was put at the bottom of the tower. The two clocks were identical, and were set to the same time. As time went on, the clock at the top experienced time faster because gravity is weaker than it is closer to the planet.

[trytip]

Gravity distorts time.

maybe gravity distorted the clock's ability to report time.

[MrEen]

Gravity distorts time.

maybe gravity distorted the clock's ability to report time.

The satellites your GPS use account for the gravitational time dilation because it's much less affected by gravity then us here on the planets surface. But I think your reasoning will hold true (for you, at least) in that case as well. See http://thescienceexplorer.com/universe/ ... e-dilation.

I think the best way to settle the argument is just send someone to a Black Hole for a few days and have them return. At least it will be proven for your grand children.

[trytip]

time is a man made measurement value. do you not think it's the same "universe time" here in our solar system (away from any mass) as it is 1 billion googolplex light years away? yes, i do. who came up with the measurement for an hour? or a day? man did looking up at the sun. once you leave earth's orbit you are in space time and the clock you bring with you is only relevant beneath earth's atmosphere

another perspective of time Is Time Travel Possible? | Sadhguru

What is Time ? | Bending Space Time | Gravity and Time || Sadhguru | Adiyogi

[Fred Barclay]

I was talking about the difference in time between when gravity was turned off, and the exact moment when the planet stopped orbiting the star and began continuing on its velocity...

There is no need to wait until light reached the observer, since there is no observer involved (there doesn't need to be a scientist hypothetically watching from an observatory in this scenario for us to know the unfolding event); this is a hypothetical situation in which you would instantly know, as if you were outside the universe watching the simulation (or whatever you want to call this hypothetical scenario).

Ay, but there's the rub. You're assuming that time is absolutely constant, and that just isn't so. Unless I've badly misunderstood you (which is certainly possible!).

(adding a tangent line reference is redundant, since velocity is a vector).

Habit from uni, where you really have to be specific about what's what. That said, it's not a bad idea to be specific here. Vectors aren't necessarily tangent to something.

I thank everyone for their input, but what does the acceleration rate near Earth (9.8 m/s/s) have to do with this situation? That unnecessarily adds more complexity to this scenario.

True -- I just got caught up with the other chaps' explanation of g = 9.8 m/s^2 and ended up typing a long and mostly useless blurb. I was so busy seeing if I could, I didn't stop to think if I should.
I'd like to blame being so excited to talk physics for my going off on tangents. (pun completely intended).

time is a man made measurement value

Not really, no more than mass or length. Sure, we came up with techniques and units for measuring them (seconds, kilograms, meters). But if humans weren't around, wouldn't you still think that massive objects would exist, or that London would still be very far away from Sydney? The universal constants don't owe their existence to humanity. Why should time be any different?

The satellites your GPS use account for the gravitational time dilation because it's much less affected by gravity then us here on the planets surface.

This + 1000!
Relativity may not be easy to think about -- and for sure it's not a perfect or complete theory -- but it does a rather good job of explaining observations that would otherwise be unexplainable with our current knowledge. The precession of Mercury and other planets, our ability to see stars "behind" the Sun during an eclipse or "Einstein's cross" where massive objects can be directly observed to bend light, time dilation -- these are all unexplainable to the very best of my knowledge without relativity.
https://en.wikipedia.org/wiki/Tests_of_ ... relativity

we can escape light and gravity, but never time.

I'm afraid we can't escape light (or rather, electromagnetic radiation) or gravity. There's no perfect insulator that can shield you from either.
The only exception would be a thought experiment where you imagine you're in a remote corner of the galaxy so far away from any object that neither light nor gravity have had time to reach you. If such a corner even exists, there's no known way for us to reach it -- by the time we travel there, even if we could travel at light speed, light and gravity would have already beaten us there!

if you buy 1000 digital and analogue clocks of all sizes and mechanisms and put them in a row synchronize them to the second then let them run for a year, i do not believe they will stay synchronized which means time can't be measured

Isn't that rather a flaw with your measuring device rather than with time itself?
If I buy 1000 wooden metersticks and leave them out in the rain for a year, they won't all be the same length (or "synchronised") either!

If I buy 1000 palladium metersticks and place them in a carefully controlled environment, they'll probably all be identical even a hundred years from now. As it turns out, we have a pretty good "palladium meterstick" for time too. By measuring oscillations of caesium-133 atoms in a carefully controlled environment, we can get an extremely accurate device for measuring time.
https://www.timeanddate.com/time/how-do ... -work.html

don't know what terminal velocity is on mars or jupiter but i'm sure it's much greater than here on earth

Less on Mars, greater on Jupiter -- if you ignore the effects of atmospheric resistance as you fall.

if you can affect decent and ascent with wings and engines, that has everything to do with gravity.

It has everything to do with forces . The force due to gravity acts "down", the forces of atmospheric resistance or engine thrust act up. Take the (vector) sum of the two and you get the net force acting on you (and acceleration if you know your own mass). You're not manipulating gravity, you're just adding forces.

who came up with the measurement for an hour? or a day? man did looking up at the sun. once you leave earth's orbit you are in space time and the clock you bring with you is only relevant beneath earth's atmosphere

Ah, but you're only thinking about how time measurement can be conveniently defined. Sure, it was far easier for our ancestors to define a day as sunset to sunset instead of measuring ~3.309x10^13 Cs-133 oscillations. But that doesn't mean that 24 hours can't be measured both ways.

Time is not a slave of however we chose to measure its passing, just like the Great Pyramid has the same mass no matter if a tourist prefers to use kilograms or pounds.

I just remembered -- we have more evidence that time dilation occurs for objects approaching light speed. IIRC muons (or "mu mesons") from the Sun can be consistently detected here on Earth. But muons only live for about 0.2 seconds before they decay, while it takes light ~8 minutes to reach us from the Sun. Since nothing can travel faster than light, what's going on?
As it turns out, solar muons are traveling at close to light speed. Relative to them, they do only live ~0.2 seconds before decaying. But relative to us on Earth, they have survived 8 minutes. The only way both of these are possible is if they experience time dilation so that 0,2 seconds for them is 8 minutes for us -- and it appears that's exactly what's happening.
Therefore, time cannot be truly constant for all observers in all reference frames.

Cheers!
Fred

[Pippin]

Also related:
https://www.youtube.com/watch?v=8TbrGaQ ... Q3_a4s_GoC

[trytip]

I'm afraid we can't escape light (or rather, electromagnetic radiation) or gravity. There's no perfect insulator that can shield you from either.
The only exception would be a thought experiment where you imagine you're in a remote corner of the galaxy so far away from any object that neither light nor gravity have had time to reach you. If such a corner even exists, there's no known way for us to reach it -- by the time we travel there, even if we could travel at light speed, light and gravity would have already beaten us there!

[Fred Barclay]

Haha, maybe so, but darkness isn't actually a "thing".

[trytip]

Haha, maybe so, but darkness isn't actually a "thing".

darkness is time or the constant or the denominator, the thing we can't explain with math and science. the thing that exists between light particles.

we put too much emphasis on light being such a great energy, that it travels the fastest and we build models and formulas upon that equation. but isn't the one thing that doesn't have to travel at all and be everywhere at once ultimately stronger?

[Fred Barclay]

Haha, maybe so, but darkness isn't actually a "thing".

darkness is time or the constant or the denominator, the thing we can't explain with math and science. the thing that exists between light particles.

we put too much emphasis on light being such a great energy, that it travels the fastest and we build models and formulas upon that equation. but isn't the one thing that doesn't have to travel at all and be everywhere at once ultimately stronger?

Not really IMHO. If that were the case, wouldn't an empty bank account be "stronger" than one with thousands in deposits?

On a serious note, we can explain darkness with science. It's just the absence of something else -- visible light in this case. But no model of the universe says that real darkness actually exists that I'm aware of -- darkness isn't really a thing in our physical universe. Everything is influenced by some form of radiation, up until the point where the boundaries between space and time break down.

Just remember -- it's not as if all the world's scientists woke up on a sunny morning and all simultaneously decided, "Hey, let's make light the cornerstone of all our theories and build everything up from here." It's that centuries of research have all pointed to there being certain rules that govern our universe. Why those rules are in place is another discussion, but they do exist.

EDIT: as further potential evidence that darkness doesn't exist, the devices we use to measure how dark something is don't measure how much dark is there, they measure how much light isn't.

[trytip]

i use darkness for lack of better description and i associate time with it. you must admit that if we were able to remove all mass and radiation and particles and atoms at a quantum level we would still not be able to remove the thing that's in between them all. comparing it to an empty bank account is not quite the same

[Fred Barclay]

you must admit that if we were able to remove all mass and radiation and particles and atoms at a quantum level we would still not be able to remove the thing that's in between them all...

But there is nothing in between! You can't remove nothing from nothing.

[MrEen]

You can't remove nothing from nothing.

Nothin' from nothin' leaves nothin'

https://www.youtube.com/watch?v=8HqyEHqEYho

[slipstick]

I just stumbled across this thread - timely as I've been reading some physics books lately - lots of stuff I haven't delved deeply into since university 50-odd years ago. I recently read the first 8 of Andrew Thomas' books "Hidden in Plain Sight" on my Kindle - interesting, though a lot of it is his own speculation, but cheap at the price - each volume available from Amazon on Kindle for USD 0.99. He has an interesting way of explaining things; since everything moves through spacetime at the speed of light, light does not experience the passage of time and nearly stationary objects in space (such as us) are moving through time at the speed of light. Another one is the concept of negative potential energy - if every bit of mass in the universe was an infinite distance away from every other bit of mass, then there would be no force between the masses and their potential energy would be zero. Because it requires work to move the mass out to infinity, the potential energy when they are not an infinite distance away must be negative. Supposedly this negative energy is exactly enough to counteract the positive mass-energy of the universe so the universe as a whole has zero energy.
Link to the books on Amazon: https://www.amazon.com/Hidden-Plain-Sig ... 154&sr=8-2

After reading those, I decided to get a bit more serious and tackle Leonard Susskind's "Theoretical Minimum" series - presently about 2/3 of the way through the first book which is on classical mechanics. There are currently two other books in the series, on quantum mechanics and on special relativity & field theory. Warning - some mathematical competence needed for these books, though he does give a brief review of the math needed, so if you've seen it before, but are a bit rusty (like me), you'll be OK.
Link to the books on Amazon: https://www.amazon.com/s?k=theoretical+ ... ss_sc_3_20

[trytip]

you must admit that if we were able to remove all mass and radiation and particles and atoms at a quantum level we would still not be able to remove the thing that's in between them all...

But there is nothing in between! You can't remove nothing from nothing.

ah, but there is something. when i look into the darkness i do not see nothing. staring into nothingness is an oxymoron term, a paradox. if you stare at nothing this means you exist outside of the laws of physics, since you can't stare at something that is not in existence. for this we need to learn the real meaning of nothing. that nothing you say doesn't exist is in fact there but it's called something because it has length and width and height and i'm sure time also progresses. if i hold out my hand empty and say am i holding nothing? no i'm holding length and width and height and i'm sure time also progresses, but i'm holding nothing.

2013 Isaac Asimov Memorial Debate: The Existence of Nothing <<< i post the url at the time i found of use to this discussion. the panel is quite uneventful but hard to imagine a group of scientist can't agree on what nothing really is.

[stormryder]

If I buy 1000 palladium metersticks and place them in a carefully controlled environment, they'll probably all be identical even a hundred years from now. As it turns out, we have a pretty good "palladium meterstick" for time too. By measuring oscillations of caesium-133 atoms in a carefully controlled environment, we can get an extremely accurate device for measuring time

How would you know the difference if they changed? If you send 500 of your palladium metersticks off at the speed of light would they still be the same length as the ones at rest? How could you even compare them with each other to find out if there was a difference?
I am quite certain I couldn't afford even one palladium meterstick anyway.

Clearly gravity has an effect on the vibrational frequency of the particles we use to measure time and one could even make the case that the variation of the frequency (quantum metabolism?) of particles that make up a conscious being could change the experience of the passage of time for that being.

Acceleration could similarly affect oscillation frequency and once velocitized any effects may remain unchanged. The problem is that if the relativity of time is dictated by speed distance must also be relative in order for observable movement to exist. When one follows this to the finite end the observation is, that at the speed of light, time stops and distance collapses to a single point.
The size of an object is certainly relative to temperature, but we perceive the vacuum as the absence of matter, so binding distance to the expansion and contraction of matter doesn't seem to make much sense in this case.

This logic seems to suggest the moment the first atom sprang into existence gravitational radiation propagated from it at the speed of light stopping time and causing all distance to collapse to a single point.

The only way out of that seems to be down the rabbithole of philosophy.

I know the math helps us understand a lot of things we have no other explanation for just seems quite a paradox to claim a speed of something is constant while both components required to compute speed vary.

[trytip]

math can be manipulated to look nice and is impressive