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ArtificialHalo t1_isjwqqu wrote

yea and it's fkin' absurd right.

You are having the same pull on the M87 black hole as it is having on you.

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Grombrindal18 t1_isjxzkn wrote

I'm pretty sure the black hole is pulling me towards it more than I'm pulling it to me.

But it's still wild to think that I am pulling every black hole in existence towards me, just a little bit.

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ExtonGuy t1_isjzraz wrote

M87 is pulling on you exactly as much as you pull on M87. The forces are equal and opposite, at about 1 x 10^(-24) N. Which is super small.

EDIT: if there were no other forces involved (like Earth's gravity), that much force would move you about 0.1 micrometers in 100 years. For comparison, a red blood cell is 7 micrometers diameter.

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wanted_to_upvote t1_iskc92s wrote

I think what he means is that he will move towards the black hole as opposed to the other way around (in relation to other objects) as the orbit decays.

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FatiTankEris t1_iskgas5 wrote

The force then is still equal. People forget that acceleration depends on mass too, and that's why people fall towards Earth more than Earth falls towards people.

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GarunixReborn t1_isl6dvp wrote

>M87 is pulling on you exactly as much as you pull on M87. The forces are equal and opposite

no, M87's gravity is much much stronger than that of a single human. They are anything but equal.

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ExtonGuy t1_islave3 wrote

The forces are equal. The responses to the forces are unequal.

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GarunixReborn t1_islz49p wrote

So why do you fall faster on earth than you would on the moon or mars? Do they themselves accelerate at 6m/s towards you?

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ExtonGuy t1_isnzn9h wrote

You fall faster on Earth because the force is 6 times more than on the Moon. They don't accelerate at 6 m/s^(2), because even thought they feel the same force you do, they are many billion of times more massive.

Acceleration = Force / Mass

On Earth, your acceleration is 9.81 m/s^(2). Earth's acceleration toward you is 8.21 x 10^(-23) m/s^(2).

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GarunixReborn t1_ispnp90 wrote

>You fall faster on Earth because the force is 6 times more than on the Moon.

So the forces are not equal then

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ExtonGuy t1_ispy79c wrote

The force of the MOON on you is not equal to the force of the EARTH on you, that much is true. But the force of the moon on you is equal to the force of you on the moon. For any two bodies X and Y, the gravitation force of X on Y is equal to the force of Y on X.

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Miserable_Site_850 t1_iskk6fm wrote

All we need from a black hole is a lil bit, get the pulling and tugging a lil bit, go shake that thing I want to touch that thing keep it pulling us round and round

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Courcy6185 OP t1_isjxnic wrote

Well, different amounts since theres more mass in 1 right?

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LaunchTransient t1_isjzlqr wrote

No, Newton's 3rd law - every action has an equal and opposite reaction.
The force acting on one object is equal to the force acting on ther other - now the relative motion of each object will be different, as a lighter mass will accelerate more than the larger mass, but the product of an objects mass and acceleration will be equal to the other's.

In short: Small mass has big acceleration, Huge mass has tiny acceleration. Both have same force acting on them.

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[deleted] t1_isjvp36 wrote

[deleted]

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autoposting_system t1_isk1a57 wrote

So there's a point when two objects stop pulling on each other if they're moving apart at greater than light speed due to the expansion of space?

Does this account for the increasing rate of expansion? The decreasing effect of gravity?

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Ape_Togetha_Strong t1_isk9xkm wrote

The rate of expansion is not increasing. It increases with distance, so individual objects have an increasing rate of expansion over time but "the rate of expansion of the universe" is not increasing.

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autoposting_system t1_iskeush wrote

I'm sorry, I'm not following you. What's the difference? The rate at which objects at opposite edges of the visible universe move apart is increasing, yes?

I am a layman, sorry

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Ape_Togetha_Strong t1_iskio0k wrote

Well, they're different because they are entirely different things. The fact that the rate increases for specific objects moving away from us is a consequence of the fact that the rate of expansion increases with distance. That's just not the same as the rate of expansion, 73ish km/s/mpc, increasing over time.

>The rate at which objects at opposite edges of the visible universe move apart is increasing, yes?

This is a weird way to think about the expansion. It's only true because the size of the observable universe is also increasing, since it's limited by the age of the universe, not distance. If instead of "at opposite edges of the visible universe" you just say "at the same specified distance apart", then that does not increase.

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Usedtodrum t1_isjx78p wrote

If this were true wouldn't this contradict the final parsec problem with black holes?

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[deleted] t1_isjyly2 wrote

[deleted]

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Usedtodrum t1_iskrvb2 wrote

Hmm, I thought the issue was that there wasn't enough material left between them to 'eat up' thus making it impossible for them to attract each other and merge.

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brknsoul t1_isjuu2d wrote

Imagine a completely empty universe, in which you place two stationary objects. Given enough time, these two objects will meet, no matter how far apart they are.

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Morbos1000 t1_isjx59g wrote

That is not the universe we are in however. The universe is expanding at such a rate that objects outside the visible part of the universe are expanding away from us faster than causality, meaning their gravitational influence never reaches us.

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[deleted] t1_isjy2ky wrote

[removed]

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UAPDATASEEKER t1_isjy768 wrote

I know dark energy is the expanding source but just pointing out how the current model is going to fail eventually if we don't find dark matter.

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ski233 t1_isk1bb0 wrote

We don’t know this for certain that there are any parts of the universe expanding faster than the speed of light. That is just a theory.

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BridgeOnColours t1_isk9dz3 wrote

However there's a force that makes light or electromagnetic wavelengths stretch which can't be explained by any other means but space expanding at a rate faster than light

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ski233 t1_isk9jq8 wrote

Space is expanding. But not faster than light in any way/place we have observed.

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BridgeOnColours t1_iskbwn9 wrote

The reason we need JWST instead of Hubble telescope to see extremely far objects is the reason why your statement is wrong

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ski233 t1_iskc265 wrote

If the distant objects were expanding away from us faster than the speed of light then we wouldnt be able to observe them.

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BridgeOnColours t1_iskcrcu wrote

But we are able to observe them, because JWST is able to picture objects which wavelengths have been stretched into the infrared wavelengths, making it unobservable to Hubble, which can mostly detect visible light and some UV light.

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Ape_Togetha_Strong t1_islj6l3 wrote

We cannot observe things that are expanding away from us faster than the speed of light.

We can only observe the past of objects that are currently expanding away from us faster than light, because the evidence of that past was emitted before the object was expanding away faster than light.

That is the light that is highly red-shifted.

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MisterET t1_islgwk5 wrote

That's exactly true! That's called the observable universe, which is smaller than the actual universe. Our observable universe is expanding at the speed of light, but objects already outside of that bubble will NEVER be inside that bubble. They are forever outside our observable universe.

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MisterET t1_islgnlf wrote

Think about the implications of what you just said though. If space is expanding, and space is also very, very large, then there exists two points so far apart that they are expanding away from each other faster than the speed of light.

You don't even need to observe it specifically. If space is in fact expanding, that expansion is cumulative, and it necessarily exceeds c once you get enough space between points.

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Ape_Togetha_Strong t1_iska6mb wrote

The majority of the observable universe is expanding away from us faster than C. The distance at which the expansion is faster than C is only around 14.5 billion lightyears, and the radius of the observable universe is ~46billion.

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Jamandi_Aldori t1_iskmhhy wrote

>We don’t know this for certain that there are any parts of the universe expanding faster than the speed of light.

The statement he made does not require the universe to be expanding faster than light. Just expanding faster than the rate of acceleration that the gravitational influence of distant objects would have.

We know this it to be true, objectively, because we can measure and observe the relativistic red-shift of distance galaxies as they move away from us at various fractions of the speed of light.

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ski233 t1_isksz60 wrote

What he said was “faster then causality” ie the speed of light.

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panzuulor t1_isk794f wrote

No, there is no pull. Nothing pulls anything. Space is warped and that’s why there’s an effect.

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BridgeOnColours t1_iskb10e wrote

The actual answer. Mass warps space, that warp creates a movement. Two massive objects far enough of eachother warp space too little in regard to eachother to overcome other forces that are unto them, eg the expansion of space

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FatiTankEris t1_iskh1ut wrote

Which then aren't really forces but same geometric effects as gravity? I thought that gravity is caused by motion through time combined with spacetime geometry. Kind of like a treadmill on which we roll, and if it curves forces appear. It doesn't make much intuitive sense so far to me, so the only way to understand is to go to math, and the wrong trampoline analogy only makes it worse.

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BridgeOnColours t1_iskpw6m wrote

Exactly, they aren't really forces but features/effects of how mass and spacetime interact with eachother. Spacetime is a field, with which mass interacts with, being a mass of collection of forces if it's own.

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panzuulor t1_isl3wwz wrote

I conclude that every atom warps spacetime and that’s why it can have a combined effect over Lightyears in galaxy clusters. But then I don’t understand why it’s so hard to combine gravity with quantum mechanics?

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[deleted] t1_iskn916 wrote

Not on opposite ends of the universe, simply because two objects on opposite sides of Earth's observable universe would not be in each other's observable universe. For example we've got A, then Earth, then B. For simplicity I'll just say "left" and "right" even though it's technically inaccurate. Earth would be on the edge of A's observable universe, on A's right, and Earth would be on the edge of B's observable universe on B's left, but A and B would be 2x the observable universe from each other, and thus not mutually observable.

But going with the spirit of the question yes gravity has essentially infinite range, and propagates at the speed of light. So if you can see an object, you are also within range of it's gravitational influence. So even a galaxy billions of light years away will be having some incredibly tiny gravitational effect on you, just the same as it's light would have an incredibly tiny effect on you, but it does reach you.

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panzuulor t1_isl3irt wrote

Gravity does not propagate. Changes in gravity propagate at the speed of light.

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Jamandi_Aldori t1_iskm454 wrote

Yes. Gravity's range is infinite.

Past a certain distance, of course, the degree of gravitational influence becomes so small that the rate of universal expansion is greater than it.

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CharlesJHV t1_isl7b9z wrote

Not to digress from the original question but I’ve always been interested by the idea of what the overall “shape” and “barrier” of the universe might actually be, after reading Cosmos by Carl Sagan he shed some light on that question, which at the time of publication there was some speculation that the universe is actually a 4 Dimension hypersphere, which could also be called a glome

An article I had found which I’ll try to find later on my desktop bookmarks insinuated one of the implications of this is that if you attempted to travel in a straight line, away from your point of origin, you would eventually wind up back where you started (I probably butchered that idea, but I hope it’s at least partially right in a broad sense)

I just bring that up since it’d be hard to define what two “ends” of the universe are

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mangalore-x_x t1_islhl1d wrote

I am pretty sure gravitational waves are propagating with light speed as the maximum limit to the spread of information as well.

Hence two objects beyond each other's oberservational horizon would not affect each other in terms of gravity and current assumptions about our universe is that it is alot larger than the observable part we can see.

This fact is also critical in the early creation of the universe where the pattern within the background radiation was analyzed based on the fact the "clumping" of hot and cold areas would be limited by the propagation of gravitational waves and hence allow interpretation from it to the geometry of the universe.

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SpartanJack17 t1_islv01r wrote

Hello u/Courcy6185, your submission "Do 2 objects on opposite "ends" of the universe pull on each other to some extremely minute degree?" has been removed from r/space because:

  • Such questions should be asked in the "All space questions" thread stickied at the top of the sub.

Please read the rules in the sidebar and check r/space for duplicate submissions before posting. If you have any questions about this removal please message the r/space moderators. Thank you.

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Redpanda248 t1_isjucdh wrote

yes and thats why there will be a big colapse also in our universe and we will become a singularity once more as the universe ends.

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Morbos1000 t1_isjxans wrote

That is only true if our current understanding of the universe is wrong.

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