Gravity bends space?

If gravity bends space (and therefore elliptic trajectories of celestial objects), then why do comets breakup due to tidal forces? Shouldn't they glide (stretching and shrinking) through the space as it is (bent or not)?

What does it mean for space to be bent? What does it mean for objects that exist and travel through that space.

Wtf, guize, I'm confused with relativity theory and all this gravity bends space thing.

nb4 troll. please, discuss.

The fuck. Comets don't break due to "tidal" forces, they burn up because of friction. Also, everything "stretches and shrinks", but this is a negligible property of gravitation except in black holes, and for light being pulled towards a mass of sufficient size.

tidal forces = stretch/shrink

It's usually the stretching that tears things apart.

Basically, all things have finite size; the part closer to the sun is pulled harder than the part further from the sun -> in reference frame of center of mass, there is stretch.  This is also true of Newtonian gravity, and is not a special feature of relativity.

space being bent = non zero Riemann curvature tensor at that point

what it means for something to exist = ontology shitstorm

Read the book by Wheeler, Misner, and Thorne.

>>2

Comets do breakup due to tidal forces (lookup "Roche limit").

>>3

If bending of space tears things apart then we could say that the object is torn apart by being stretched between the curved space itself and some ideal flat space. Otherwise, the object should follow the curvature of the space with no resistance (which does not happen).

In my opinion bending of the space does not occur. Only objects acting upon each other by gravity.

I also have a question regarding space-bend-mind-fucking stuff.
If gravity bends space,then why do objects with enough velocity can escape the gravitational field of,say, a planet?shouldn't they just hit the planet at higher speed?

>>4
In my opinion
Lol wut? By all means, feel free not to think of it as a rubber sheet or whatever, but if the resulting effect is exactly similar to the effect of space being bent, right down to non-Euclidean geometry, why would you go through pains to not think of it as such?

>>6
>exactly similar

Lol wut? If something looks similar to X, why not pretend that it is X?

Corner cases. They tend to invalidate theories.

>>4
"between the curved space itself and some ideal flat space"
Sorry, I have no idea what you're trying to say here.

Objects follow geodesics (which minimize the 4-distance between any 2 points it passes through).

>>5
Not a GR question.  The answer depends on direction.  If you're at escape velocity, and pointed at the center of the earth, you're going to hit the earth.  If you're aimed in the opposite direction, you'll escape (ignoring moon, sun, etc).

>>7
Sure, do you have some actual corner cases where it's not working? Or are you just rejecting the theory that best fits the experimental evidence based on personal preference and wishful thinking?

>>9

can you read?

>>10
Sure. Can you write? If so, excellent, we have established the possibility of (one-way) communication. Don't worry about me, you can use as long and difficult words as you want. So go ahead and write up an example.

Space bends are an illusion produced by gravity, much like seeing a fish in water. The difference between space skews and water is mass, the skews are what we see, not what is actually effected.

Ever heard of a black hole? The explanation of POV when someone is falling into a black hole.
Person1 falling into black hole would perceive the falling into and would be unharmed.

Person 2 watching from the event horizon would see the person being ripped apart atom by atom very slowly.

It's perception! It's all about questioning perception! :P

Curved space is a Jewish lie

>>12
You, sir, are a fucking retard.

>>14
What do you expect? It's Jesus.

Space is flat.  Spacetime can get bent.

>>16
We're actually not certain about that, though it seems flat.

I like >>12, he seems to have his head on straight, though his way of describing the effect of gravitational space bends is pretty rediculous. I would guess that this guy, Jesus, needs to understand that everyone here is a student, not a teacher. You can't teach a teacher anything, but you can learn from everyone here. Just like I have. That's how I learned that I'm no scholar, I just make-believe I am to get ratings. :P

>>11

Ok. If indeed gravity bends space my assumption is: the objects "follow" the space curvature. They, do not escape it (as it becomes curved).

If gravity acts upon space and not objects directly then we would not experience tide (in all forms, including fragmentation of objects gone past Roche limit) because objects would retain their integrity within that space however curved it is.
Why would objects tend to escape space's curvature (favoring flat one)?

If however bent space results in objects being ripped or under tension then there is no space bending. There is only objects influencing other objects with gravity.

Is my understanding wrong or what?

Also: The fact that I don't understand something doesn't automatically make me a retard (unlike the fact that I'm discussing this on 4chan).

Thanks.

Here are some very valid questions to ask when performing any science experiment.

Is what I'm seeing actually happening?
What is the distance that event occurred relative to my position?

Often no questions are asked about the observer's relation to the event, so basically the observer doesn't exist in relation to the experiment at all. If we only know of an event, than everything about that event is skewed as there is only one point to base any general direction off of. <I don't care if it's a preposition|
My science teacher always said to include your personal observations with your perspective questions included, how many scientists do this? :|
Well, if I'm saying I believe in god, does god have to exist outside of my body for it to be true or false to me? NO, what exists inside of a person's head and what exist outside are two completely different things entirely and will remain so for eternity!!!

It would look something like this:
- {+} - {+} - <see? everything outside of a mind "{ }" is "-" and everything inside of a mind is "+". Therefore, you can't trust perception due to it being a conduit for confusion, and therefore must question it's integrity everytime. To not do so puts the entire scientific process, findings, and evidence retrieved into question. Who here has anything to add?

ETHEREAL

Swift shimmering shadow steps silently; saddened, still softly severing serenities, slicing sympathy staggering sturdily; suffering sarcastic solace. Never noticing naïve naiads nor narrows nor necrotic nethers nestled nearby; naughty neutral nocturnal nexus nevertheless normally nostalgic notions; noteworthy nemesis neo neurotic neuralgia. Exceptional effervescing elemental ephemeral entity experiencing euphoria everlasting eternally eschew evermore, Ethereal

>>20

Thank you, RedCream, for destroying this thread.

>>19
Very well. Let's first simplify your objection; it amounts to "How can curved space make two objects physically move in relation to another", right? If the sun can accelerate an object that initially was at a relative stand-still towards it, then it follows that it can accelerate each individual atom of a comet, and that it can do so slightly differently, leading to the destructive forces you mention, etc.

So how does gravity accelerate objects? Let's take two appropriately-sized objects, like two planets, and place them next to each other. They'll start moving towards one another. How, you say? They're not moving, so why would the shape of the space matter? Wrong! They're actually moving as fast as they can, timewards (the direction of which is relative, of course, but let's use the starting speed of our planets as a FOR.) So our planets, both continuing in a straight line at constant speed, shift course towards another (and thus go slightly slower timewards, but hardly noticable). Thus, motion.

So back to the Roche limit. The comet is moving through space, but very slowly. It's mostly moving timewards. It is held together by its own gravity, which means space curves around it so its particles, traveling in a straight line, tend to move closer to another (other forces stop the particles, keeping them in place (and making their path non-straight?))
Enter the sun. The sun also curves space. At a point, the space-time the comet inhabits will begin to curve the other way, dispersing rather than collecting the travel lines of the comet's particles. When this tendency becomes stronger than other forces holding the comet together, the particles separate, disintegrating your comet.

tl;dr 1: It is not the curvature of the space-time itself that give the effects you describe, but the effect of previously parallel direction lines passing through and becoming non-parallel.

tl;dr 2: Relativistic gravity normally is very close to Newtonian gravity. Thus of course these phenomena will happen very similarly to in Newtonian theory. If you accept that both theories predict that apples will fall to the ground etc., tidal forces follow trivially.

yup, I have no idea what you said, but it sounds right, so let's roll with it.

>>20

So if internal ideas and external reality are two different things, you're agreeing that God does not exist.

Gravity does not bend spacetime; mass bends spacetime.  Gravity is  just what we call that bending.

>>26
Mass used to bend spacetime where I live, but then I told those damn catholics to pray a little less intensely.

>>23

This was enlightening. Thanks.

Also, bricks were shat.

M'ass used to bend space, but then I went on a diet!

>>29
Your humor must have been lost in the transition.

Ma SS used to bend space, but then they shot jews instead.

You're mom's so fat that light bends around her equator. XD

Your mom's asshole is so expansive, even light can't escape its pull.

...""equate expansive to expensive""...

Your mom's mouth is so expensive, even money can't escape its vacuum.