Black Holes

[SHISHKABOB]

I have been confused for a while on how black holes work. I mean I was watching this one show and it was saying that there were thousands and thousands of them in our galaxy and that they never go away. In a while wouldn't that mean that the galaxy would be filled to the brim with black holes and nothing would be there?

[Morkeliph]

Black holes are one of those things that we know very little about, and for obvious reasons. They aren't convenient for study or experimentation. But I believe that the basic theory is that they are spots of intensely compacted mass that generate extreme gravitational force. Some speculate that when a star supernovas it may become a black hole or a white dwarf. What I've never understood is how does such intense gravity attract light enegy so inescapably. I thought gravity only worked between objects having mass and I don't think light has any mass because it's energy, not matter.

[hammocksleeper]

In short answer to your question, Mork, gravity affects all matter because it warps space time. However, only a massed object will create a gravitational pull of its own. A massless object can't pull, but it can still get pulled on.

[Morkeliph]

Yeah...space time...
I'm not going to pretend that I know anything about astronomy and the like, but I never understood the concept of space time. I guess no one ever explained it to me and I've never inquired further.

[SHISHKABOB]

But what about anti-matter or dark matter, whatever that is. If it is anti-matter then shouldnt it have no matter whatsoever and not be affected?

Edit:
I dont know if this is spacetime but a good explanation of how gravity effects space is say you have a bowl. At the center of the bowl there is an orange (the sun or a star)In this demonstration the marble is a space ship and the bowl is the effect on space that the star has on it because of its high gravity. If you take a marble and roll it down the side of the bowl the marble will roll down around the orange then come back down and spiral around it. But if you push the marble hard enough then it will roll down the bowl and fly up the other side and out of the bowl. If you were to push the marble at exactly the right speeds and at the right angle, it would continuosly spiral around the orange. So the dip caused by the star effects time as well because if you go across this area if it was flat, then just a random number, it would take 2 seconds. With the dip it adds a large distance you have to cross. That is about the best explanation I can give for space time. I probably missed some stuff so if its not complete dont yell.

[Uuugggg]

The most misunderstood thing about black holes is their size - it can vary... A fresh black hole formed from the death of a massive star would be puny, much smaller than the earth. They get bigger over time... a long time. According to observations, there is a black hole in the center of our galaxy - a very massive and a rather large one, but certainly not bigger than the size of Earth's orbit.

The thousands in our galaxy - small ones - would be far from the center. There's a long explanation to go along with this... but basically, the dark part of our galaxy 100,000 light-years from the center seems to orbit the center as if it were a giant solid, indicating lots of mass, which can only be explained by black holes... yea.
So, not only are we far enough away from these black holes, they are all around us, so their gravity in all directions cancels out and we don't get sucked into them... and the sun orbits the big one in the center.

Make sense?

[Darmago]

I dont know if this is spacetime but a good explanation of how gravity effects space is say you have a bowl. At the center of the bowl there is an orange (the sun or a star)In this demonstration the marble is a space ship and the bowl is the effect on space that the star has on it because of its high gravity. If you take a marble and roll it down the side of the bowl the marble will roll down around the orange then come back down and spiral around it. But if you push the marble hard enough then it will roll down the bowl and fly up the other side and out of the bowl. If you were to push the marble at exactly the right speeds and at the right angle, it would continuosly spiral around the orange. So the dip caused by the star effects time as well because if you go across this area if it was flat, then just a random number, it would take 2 seconds. With the dip it adds a large distance you have to cross. That is about the best explanation I can give for space time. I probably missed some stuff so if its not complete dont yell.


sounds like you stole that directly from Sphere :P

but more or less your right...

however instead of somthing fixed, like a bowl, it would probably be easier to imagine somthing like the screen of a trampoline. You put a basket ball on a trampoline it makes it bowl a little, you put a bowling ball and it will make an even larger dent. a black hole would be somthing the size of a grain of sand(or at least on our trampoline) weighing about as much as a large star, this will cause a large, almost infinitly deep, hole in which, unlike other large objects, once you enter its gravatational area(a.k.a. event horizon) there is no escape velocity. however its gravatational pull is much less outside of its event horizon(for unknown reasons). And seeing as black wholes are theoretical singularities, I think the even horizon is what you are talking about Uuugggg

[SHISHKABOB]

sounds like you stole that directly from Sphere :P

Ahhh you caught me. I forgot to say that. I just reread that part and there it says that black holes are "tears" in the spacetime thing or trampoline as you said because they weigh so much. So you would fall into them with no chance of "rolling" up the other side because there is no other side. Just lalalalal omg whats that AHHHHHHHHHHHHHHHHHHHHHHHHH then you blink out of existence or whatever happens.

[hammocksleeper]

Just lalalalal omg whats that AHHHHHHHHHHHHHHHHHHHHHHHHH then you blink out of existence or whatever happens.

Best description of a black hole I've ever heard.... ;)

[GrimTerror]

I'm not too sure about the matter but I do recall asking my Physics teacher about them way back in high school. He says that upon entering a Black hole, you would be squashed into a point smaller than the end of a pin. Has no little shuttle or anything been dileberatly sent into one to see what effects would really happen?

[Schwitzer]

Isn't there a theory that, due to relativity, if you were to get sucked into a black hole time would appear to stop? I forget which relative frame time stops for, but I remember something along those lines.

[hammocksleeper]

Isn't there a theory that, due to relativity, if you were to get sucked into a black hole time would appear to stop? I forget which relative frame time stops for, but I remember something along those lines.

well yeah, you would be accelerating indefinitely, approaching the speed of light....so in theory once you reach the speed of light time would be relatively still. but by then you would have already been obliterated into tiny pieces of energy.

[Neo]

It should be noted that we haven't actually observed a Blackhole as of yet, there are theories and things that MAY be blackholes, but when nothing can escape from one, including light, how do you think we are going to observe one? =P

It is interesting to see how they are protrayed in Sci-Fi stuff though.

-Neo

[Sgt.SlagRock]

I'm not too sure about the matter but I do recall asking my Physics teacher about them way back in high school. He says that upon entering a Black hole, you would be squashed into a point smaller than the end of a pin. Has no little shuttle or anything been dileberatly sent into one to see what effects would really happen?

thats funny, i remember reading in an astronomy book. that you would turn red from all the energy accelerating, then be ripped into spaghetti noodles. lol

[L2_1989]

I take it that it will be next to impossible to observe a black hole. Matter will break apart as it approaches the speed of light. I wonder, will it hold a gateway for interstellar travel, open a new dimension, or will it suck the life out of everything?

[GrassDragon]

well yeah, you would be accelerating indefinitely, approaching the speed of light....so in theory once you reach the speed of light time would be relatively still. but by then you would have already been obliterated into tiny pieces of energy.
Not exactly. If you were to enter a black hole you would actually see the entire life of the universe flash before your eyes in a moment, if you could withstand the forces. Infinite mass means infinite gravitational force. The effect on time is enormous, and relative to you the rest of the universe would speed up.

[GenocideAlive]

Light is a bunch of photons. Photons have mass.

[SHISHKABOB]

I just read a big article on black holes and here is a bit: If you were to zoom up to a black hole and get the Event Horizon, the point of no return, and somehow have an incredibly powerful rocket and hover at that spot then for you time would stop. Even if you were to stay there for like 5 minutes when you left (if you could) then it would be quite far into the future. Thats all I remember right now.

[FallenLord]

Minor correction: Gravity doesn't warp space-time, mass does; the warping of space-time is gravity. (Or rather replaces the concept of gravity.)

Also, black holes are not the same as wormholes; a black hole is only half of a wormhole.

[Toucan]

There is absolutely no evidence what so ever to suggest that photons have mass, photons have no rest mass and that is all we know about them in regard to mass, at this time it is not possible to determine an active photon's mass, that being said, I do actually agree with GA.

Particles do escape black holes, in the form of what has been called Hawking’s radiation, it is some what more complex than simply escaping, but at the end of the day it means black holes do bleed energy into space and do eventually shrink.

There is no evidence to suggest at all that black holes have anything to do with Worm Holes, half a worm hole or otherwise, worm holes are a completely different theory, this theory does some times get mixed up with theories relating to black holes.

The most interesting theory in regard to black holes is that they eventually become the rebirth of galaxies and perhaps even entire clusters or super clusters of galaxies. Eventually creating the largest of all super nova's that in turn releases a portion of matter and energy that has been collected over the eon's, all this matter then forms a huge accretion disk of sorts, then starts forming an entire new galaxy or cluster of galaxy's.

[Tissue]

Light is a bunch of photons. Photons have mass.


Wrong...so very wrong...
Photons do NOT have mass and light is not "a bunch of photons"
The reason why light spiralls into a black hole is because they distort space-time so even though to the light relative position the particle is moving in a straight line, to the outsider perspective it is spiralling inwards. Genocide alive must be someone who has never done any higher level physics or extra reading.

Oh yes...light acts as an electric wave and a magnetic wave out of phase of each other by pi at right angles to each other, hence an electromagnetic wave. Obviously this is not the full story but recalling a-level quantum physics usually give me a headache.

[GrassDragon]

Wrong...so very wrong...
Photons do NOT have mass and light is not "a bunch of photons"
The reason why light spiralls into a black hole is because they distort space-time so even though to the light relative position the particle is moving in a straight line, to the outsider perspective it is spiralling inwards. Genocide alive must be someone who has never done any higher level physics or extra reading.

Oh yes...light acts as an electric wave and a magnetic wave out of phase of each other by pi at right angles to each other, hence an electromagnetic wave. Obviously this is not the full story but recalling a-level quantum physics usually give me a headache.
Have you ever heard of "wave particle duality"? It's ironic that you accuse GA of never having higher level physics...

Photons have no mass though.

[SHISHKABOB]

If light-photons have no mass then how do they push things? They dont very much but some scientists that I cant remember were doing this experiment on space travel they thought about having a huge sail made of exetremely thin material that would catch the photons from the sun and they would push it. They proved that light can push it by creating a small vacuum and pointing an extremely bright light at a piece of the material in side of the tube of vacuum and when they turned on the light it flapped a bit. If the light was able to push and move the piece of material then shouldnt it have mass?

[Darmago]

Your thinking of solar wind... which is different from photons...how.. I don't know...

but the reason photons have no mass is they are moving at the speed of light silly :P

[SHISHKABOB]

Ah ok that confuses me alot of the time when talking about light physics and stuff.

[Tissue]

Light have no mass but have momentum. The theory behind this I am not sure, but sorry for not mentioning wave particle duality. It is simple...in order to explain light, people at the time had to compare it to the large scale models of waves and particles, both theories that scientists at the time of investigation knew about. Wave particle duality just states that light has both the properties of waves and particles but does not wholly encompasses either.

I was just slightly blinded with rage at genocidealive just posting a totally untrue one line statement for his post which is full of ignorance and a blantant attempt at putting his post count up.

I stated that light acts as a wave not that it is, if you read my post carefully.

[frazz]

Wait, if something goes the speed of light, and time stops, wouldn't that meant that the light reaching our eyes would be tenkajillion years old, or whatever.
Also, I feel that the whole space time idea is kind of silly. It overcomplicates a fundemental principle. All objects are attracted to other objects.
And wouldn't that mean the Galaxy is just one big sucking up vaccume cleaner type thing?
Anyway, someone explain the time freezing thing.

[Darmago]

time moves slower the faster you go... or so I've heard... I have no experiance with this...

so it just gets slower and slower untill when at light speed it would effectivly stop...

so say we have a space ship(and put you on it) and we send you at 99.9% of the speed of light 200 light years away and back, it would be 400 years for us on earth before you got back... but you might just think its a week...

[Toucan]

The effect you are referring to is called time dilation.
It doesn’t just occur at near light speeds, NASA has measured the effect of time dilation when they run an experiment using two atomic clocks. One on earth, one loaded on to a very fast orbiting satellite, when the satellite returned to earth the clock on board the satellite was behind the clock that was left on earth, illustrating how time had slightly slowed down for the clock on the space craft.
Interestingly enough the theory doesn’t just apply to an object that is moving at great speed, if an object moves past a stationary object at very high speed, then the stationary object might also experience, momentarily, the effect of time dilation.

[Darmago]

so they have measured units for time dilations

440*10^5mph per extra second?

[Weltall]

Well, only matter can influence matter. Protons influence matter, so, therefore, they MUST be matter, too. It's really pathetic that people are still struggling with that concept. It demonstrates the gullibility of human beings.

I don't know why people think black holes are "holes" anyway. Yes, light can't escape because of gravity. But so what?

You'd be surprised how little we know about these things.

I'm never going to believe that when matter gets to a certain density it just rips through space. Why the fuck would it do that? Makes no sense.

This place scares me.

[frazz]

Wait, I have a question. If the speed of light is the border for time dilation, then why doesn't light experience the same thing? Or does light not qualify as matter?
Since speed is relative, then time dilation is relative also, right?
Someone please answer my questions.

[Toucan]

If the speed of light is the border for time dilation, then why doesn't light experience the same thing?
Maybe it does, who is to say that for light time does not stand still, remember time may well come to a halt, the motion does not, with out motion at the speed of light, time does not stand still.

[frazz]

Hmm... How is time dilation measurable? Someone said about the two clocks, but couldn't that be vulnerable to other effects. And if you go faster than light, then what happens?

[SHISHKABOB]

You cannot go faster than light. You can do messed up stuff like ripping holes in space and jumping out somewhere else or going into an alternate demension. But you cannot go the speed of light or faster.

[Neo]

You cannot go faster than light. You can do messed up stuff like ripping holes in space and jumping out somewhere else or going into an alternate demension. But you cannot go the speed of light or faster.

Remember that that is only a theory, not fact.

In fact, black holes themselves are theorys, we've yet to actualyl "see" one or tis effects.

-Neo

[SHISHKABOB]

Arent we all going by theory basically here?

[Toucan]

Arent we all going by theory basically here?
Absolutely, thats what makes a debate like this so much fun.
How ever as one theory says some thing is impossible, another says it is possible.

[Weltall]

Remember that that is only a theory, not fact.
Yeah, yeah, yeah, whatever.
Evolution is a theory too.

Nasa's expieriments someone prove that light is the fastest you can go in a relative universe. If you look at some of the math, maybe I can find it, you'd see "time" goes slower as on goes faster. But it happens in a sort of predictable way that leads up to the speed of light. If you had a better grasp on this, you'd know that the universe is already expanding faster than the speed of light. The speed of light only works for things relative to each other in motion.

EDIT: Because I know I'm going to have to anyway...

http://www.wonderquest.com/ExpandingUniverse.htm

You are missing one thing: the expanding nature of the Universe. The object you mention was only 4 billion (not 13 billion) light years from us when it emitted the light we see 13 billion years later. We and the object are separating from each other (not flying together) at about 1.8 times the speed of light. Although this appears to break the speed-limit law, it doesn't.

[Toucan]

If you had a better grasp on this, you'd know that the universe is already expanding faster than the speed of light.
The universe is expanding into to nothing, not into space, before the universe expands to a point there is no space at that point, there is nothing. In space, special relativity applies.

EDIT: good site by the way.
A quote from it in refference to a distant quasar.
"'How fast is the distance between us and this quasar increasing?,'" asks Turner and answers, "about 1.8 times the velocity of light." Does this exceed the speed-of-light speed limit? No. Einstein's theory does not limit the speed of space expansion--only motion through it.

[frazz]

You cannot go faster than light. You can do messed up stuff like ripping holes in space and jumping out somewhere else or going into an alternate demension. But you cannot go the speed of light or faster.
Ok, howabout this? Since speed is relative, all you need is two objects going almost the speed of light in opposite directions, and boom! nearly double the speed of light! Then what happens? the time dilation theory has so many holes in it I really don't believe any of it.
You can do messed up stuff like ripping holes in space and jumping out somewhere else or going into an alternate demension.
Um, no you can't. That is all sci-fi. Some people take everything they see in sci-fi that has the least bit of scientific ground as fact.

[Tissue]

Speed is relative to the speed of light.
So for something to not move at all then it must be moving at negative speed of light relative to the speed of light.
When two objects are moving away from each other at near the speed of light, relatively one would be moving at positive speed of light and the other at negative speed of light.
Relative to one object, the other would be moving at double the speed but only if relatively it is staying still. However it is not. When speed is relative it is refering to small scale effects. For large scale effects it refers to speed can only be compared to the speed of light which is the only consistent value of speed which can be measured against since it does not obey the normal laws of mechanics.

[GrassDragon]

If the light was able to push and move the piece of material then shouldnt it have mass?
Relativistic mass accounts for this effect. Particles "seem" like they have more mass than they do when they are at high velocities and exhibit the same properties as if they really had that mass. Solar wind is just normal light from the sun.

Also, I feel that the whole space time idea is kind of silly. It overcomplicates a fundemental principle. All objects are attracted to other objects.
It doesn't overcomplicate anything. That's the way things are. "Objects attracts other objects" is simplifying it.

Well, only matter can influence matter. Protons influence matter, so, therefore, they MUST be matter, too. It's really pathetic that people are still struggling with that concept. It demonstrates the gullibility of human beings.
Arrogance is okay unless you're a complete idiot. Enter Weltall. What about magnetic and electric fields? There's no matter there.

The limit of the speed of light is theoretical. There have been experiments where particles are sent away from each other at nearly the speed of light so that their relative speeds are greater than the speed of light. Then scientists do something to one particle and the other particle mimics the movement. That would be faster than light communication. They don't really know how it works.

I didn't use any scientific terms in the last paragraph because I don't know them :P If anybody has more information on the experiment I described I would appreciate a link.

[hammocksleeper]

The limit of the speed of light is theoretical. There have been experiments where particles are sent away from each other at nearly the speed of light so that their relative speeds are greater than the speed of light. Then scientists do something to one particle and the other particle mimics the movement. That would be faster than light communication. They don't really know how it works.

I didn't use any scientific terms in the last paragraph because I don't know them :P If anybody has more information on the experiment I described I would appreciate a link.

What you're really talking about are some of the experiments they do in particle accelerators, where two particles collide, and produce super tiny particles that fly off in opposite directions. What they have observed is that some of these particles have counterparts, and when one particle is for example affected by an outside force, the other one does the same even though it wasnt directly affected. Hence the two particles seem to have a "supernatural" connection, or at least a connection we can't explain.

[Uuugggg]

Wait, I have a question. If the speed of light is the border for time dilation, then why doesn't light experience the same thing? Or does light not qualify as matter?
Since speed is relative, then time dilation is relative also, right?
Someone please answer my questions.

I heard (from a reliable source) that there are some subatomic particles, something like muons or something, that only live for a fraction of a second in the lab... but we can detect them hitting the Earth from distant stars... which would be explained if time stopped for them during their speed-of-light journey before they hit us.

Oooo...

Remember that that is only a theory, not fact.

In fact, black holes themselves are theorys, we've yet to actually "see" one or its effects.

-Neo

Hawking radiation (http://en.wikipedia.org/wiki/Hawking_radiation) seems to come out of black holes. And, our galaxy is orbiting a black hole. Otherwise, what do you think is keeping it together?...

"All objects are attracted to other objects."

And the scientist asks why, and they theorize about the fabric of space-time. Voilà.

[frazz]

muons or something, that only live for a fraction of a second]
So how exactly do particles 'die'?
When two objects are moving away from each other at near the speed of light, relatively one would be moving at positive speed of light and the other at negative speed of light.
Relative to one object, the other would be moving at double the speed but only if relatively it is staying still. However it is not. When speed is relative it is refering to small scale effects. For large scale effects it refers to speed can only be compared to the speed of light which is the only consistent value of speed which can be measured against since it does not obey the normal laws of mechanics.
Speed is relative: The speed of an object can only be measured assuming another object is still. No object is ever really still, it is moving when measured from another object. If you drive really fast and say your car is still, then everything else is moving.
Example: In a closed system there are two objects. Nothing else. The closed system is infinite, with only the two objects. You place a camera on one object. The other object appears to move at 100mph. Which is moving and which is still? Are they both moving? If you place a third object inbetween those two objects, and call the third one 'still'. You can then see which of the obecjts are moving, and how much. See, speed depends on which object is still.
In closing, your post makes no sense, and is only intended to confuse.

[Weltall]

Arrogance is okay unless you're a complete idiot. Enter Weltall. What about magnetic and electric fields? There's no matter there.
*ENTERS*

I disagree with magnetic and electric fields having no mass, which should be kind of obvious.

What I'm saying here is simple...

In the physical world, in order for something to exist it must have matter. If electric fields don't have matter, they don't exist. So they have matter. One also tell they have matter because matter pushes matter.

The only possible thing that can influence matter is matter. Matter pushes matter.

It's too bad that people are so slow to get that.

As for the last thing you said, just because the distance between them is increasing faster than the speed of light doesn't mean it breaks the speed of light. But I could be saying something I shouldn't since I wasn't playing much attention to what you said.


Look, I can't find an example with a table right now to prove speed of light shit. But, as I was telling Neo, because NASA proved that time dilation exists, that means the ratio is probably correct.

For the measuring relative speeds, there's a ratio. This ratio says that once someone reaches the speed of light, time will stop for them. For example, I'm moving at the speed of light and everyone else isn't. And because the ratio was correct for slower experiments, it's probably correct for the faster ones, too.

I did a bad job of explaining that, sorry. I wish I could find a relative speed table thingy.

EDIT: toy with the speed of light bar and get an understanding of the ratio
http://www.design.chalmers.se/people/joakim_linde/java/specialrelativity/specialrelativity.html

[GrassDragon]

So how exactly do particles 'die'?
Speed is relative to the speed of light.
So for something to not move at all then it must be moving at negative speed of light relative to the speed of light.
He means the particles decay into other particles or energy.

Example: In a closed system there are two objects. Nothing else. The closed system is infinite, with only the two objects. You place a camera on one object. The other object appears to move at 100mph. Which is moving and which is still? Are they both moving? If you place a third object inbetween those two objects, and call the third one 'still'. You can then see which of the obecjts are moving, and how much. See, speed depends on which object is still.
In closing, your post makes no sense, and is only intended to confuse.
That's called relativity.

I disagree with magnetic and electric fields having no mass, which should be kind of obvious.
...open a first year physics book and read it. That might help.

What I'm saying here is simple...

In the physical world, in order for something to exist it must have matter. If electric fields don't have matter, they don't exist. So they have matter. One also tell they have matter because matter pushes matter.
Clearly not as light exists and it has no mass.

[Prozerran]

Uhh, am I wrong by stating that there are two constants in the universe, Matter and Energy? Did I miss something in 6th grade science class, or didn't we learn that light, electromagnetic fields, etc... are all examples of energy, not matter? I think someone's stupidity and ignorance are confusing my fragile mind. Not to name names or anything...

[Weltall]

Clearly not as light exists and it has no mass.
It's really not clear at all.

What one sees with his eyes is the physical world. In order for something to exist in that physical world, it must have mass in order to be "physical".

All I can say is that matter pushes matter. Matter does not "move" for no reason. It has to be pushed.

Just try to think about it. The point of this is not to "WIN", but to learn.
What is your experience with life? When you push something with matter, it moves, right?

You don't see a tv flying for no reason, do you?

In order for something to move, it must be pushed by a force. That's physics. Yet modern science doesn't agree with it.
It should be obvious that a force "needs" a physical presense to exist.

You should try to think for yourself.


Uhh, am I wrong by stating that there are two constants in the universe, Matter and Energy? Did I miss something in 6th grade science class, or didn't we learn that light, electromagnetic fields, etc... are all examples of energy, not matter? I think someone's stupidity and ignorance are confusing my fragile mind. Not to name names or anything...
Look at Einstein's equation E=mc^2. In that equation, without movement of mass, there is no energy.

I know energy to be moving matter, for the reasons I stated before your quote and because energy can't exist without moving matter according to that formula.

[Fenguin]

It's really not clear at all.

What one sees with his eyes is the physical world. In order for something to exist in that physical world, it must have mass in order to be "physical".

All I can say is that matter pushes matter. Matter does not "move" for no reason. It has to be pushed.

Just try to think about it. The point of this is not to "WIN", but to learn.
What is your experience with life? When you push something with matter, it moves, right?

You don't see a tv flying for no reason, do you?

In order for something to move, it must be pushed by a force. That's physics. Yet modern science doesn't agree with it.
It should be obvious that a force "needs" a physical presense to exist.

You should try to think for yourself.
While I generally agree with what you're trying to say, I'd like to provide a counterexample to your assertion. When a tiny object, say an electron, is hit by a photon, there is a transfer of momentum and the electron is deflected even though the photon has no mass and therefore cannot be considered matter! (I'm using the generally accepted definition of matter here: anything that has mass and takes up space.) This is because photons have what is called a Compton momentum which is equal to Planck's constant divided by the wavelength of the light they carry.

Edit:
Look at Einsteins equation E=mc^2. In that equation, without movement of mass, there is no energy.
Note that the energy of a photon is E=hf=hc/lambda; photons do not have mass yet still have energy. This is one of the main notions of quantum physics: on the quantum level, everything becomes really weird. Read up on quantum barrier tunneling and such (which has been proven by the way; our scanning tunneling microscopes are based on that theory) to experience even more quantum weirdness.

[GrassDragon]

In order for something to move, it must be pushed by a force. That's physics. Yet modern science doesn't agree with it.
It should be obvious that a force "needs" a physical presense to exist.
Yes, Newton's first law dictates that in order for an object to accelerate from rest, a force must act upon it. But this force doesn't have to come from bumping into something else.

Consider this. If you run a sufficient current through a rod near the Earth's surface, the Earth's magnetic field will create a force on the rod large enough to lift it off the ground. What's pushing what there?

[Weltall]

While I generally agree with what you're trying to say, I'd like to provide a counterexample to your assertion. When a tiny object, say an electron, is hit by a photon, there is a transfer of momentum and the electron is deflected even though the photon has no mass and therefore cannot be considered matter! (I'm using the generally accepted definition of matter here: anything that has mass and takes up space.) This is because photons have what is called a Compton momentum which is equal to Planck's constant divided by the wavelength of the light they carry.
You say it as if it's a fact that protons have no mass in that example. I could say the same thing you said, yet state that protons and electrons have mass.

Look, my understanding of modern science is poor, very poor.

So I'm having a little trouble understanding you.



Note that the energy of a photon is E=hf=hc/lambda; photons do not have mass yet still have energy. This is one of the main notions of quantum physics: on the quantum level, everything becomes really weird. Read up on quantum barrier tunneling and such (which has been proven by the way; our scanning tunneling microscopes are based on that theory) to experience even more quantum weirdness.
According to that equation, without movement energy is 0. In order for something to move physicallly in space, it must take up space and, therefore, must have mass.

Yes, Newton's first law dictates that in order for an object to accelerate from rest, a force must act upon it. But this force doesn't have to come from bumping into something else.

Consider this. If you run a sufficient current through a rod near the Earth's surface, the Earth's magnetic field will create a force on the rod large enough to lift it off the ground. What's pushing what there?
A force is movement. And because it moves, it must occupy a point in space. It must have a "position".

I would say that the magnetic field probably has some sort of physical presence.

Don't use gravity as an example. It moves upward because of time dilation and speed. Yes, it's not being pushed now, but once upon a time it was.

I thank you guys for your attitudes, although they probably won't last.

I'm sorry that my arguments are too abstract.

But use your imagination. Matter moves because matter pushes it, right?

When I use my imagination, I can't see matter moving for any other reason.

[GrassDragon]

You say it as if it's a fact that protons have no mass in that example. I could say the same thing you said, yet state that protons and electrons have mass.
We are talking about photons not protons, FYI.

A force is movement. And because it moves, it must occupy a point in space. It must have a "position".
No. You can push on a heavy box and it won't move, but you are still exerting a force on it. Force doesn't necessarily mean movement. Force also does not occupy any space, and it doesn't have a position.

I would say that the magnetic field probably has some sort of physical presence.
It doesn't.

Don't use gravity as an example. It moves upward because of time dilation and speed. Yes, it's not being pushed now, but once upon a time it was.
I don't understand these sentences at all.

But use your imagination. Matter moves because matter pushes it, right?

When I use my imagination, I can't see matter moving for any other reason.
Then don't use your imagination, because things are not always as you observe them (in fact, they are never as you observe them).

[Fenguin]

You say it as if it's a fact that protons have no mass in that example. I could say the same thing you said, yet state that protons and electrons have mass.

Look, my understanding of modern science is poor, very poor.

So I'm having a little trouble understanding you.
I'm talking about photons, not protons. Photons are discrete quantized bundles of light.

According to that equation, without movement energy is 0. In order for something to move physicallly in space, it must take up space and, therefore, must have mass.

A force is movement. And because it moves, it must occupy a point in space. It must have a "position".
No, all that equation requires is a wavelength or frequency. Think of photons as waves instead of particles - you'll learn more about this when you study up on quantum physics.

[FallenLord]

Let’s get a few things straight:

General relativity: Mass bends space-time. This replaces the theory of gravitational attraction.
C is relative: The speed of light is constant in any frame of reference.
They’re related, but they are not exactly talking about the same thing. The textbook example of a “constant” speed of light is where you throw a baseball (level with the ground) and then are able to race alongside it. In your frame of reference, the ball looks like its standing still because your velocities are equal. From the reference of a stationary observe, he can see that both you and the ball are moving at the same speed.

However, Einstein said that the speed of light would be “relative” to your frame of reference. That is, no matter how fast you are moving, the speed of light will always appear to you as 3*10^8 m/s. If you were traveling in a spaceship (i.e., frame of reference) at c/2 and performed an experiment to measure the speed of light, you might expect that since you are traveling at half the speed of light, you should be able to measure light traveling half as fast. No such thing happens, of course; as far as you are concerned light still moves at c. Unlike the baseball, which you would measure as moving at half its speed.

Accordingly, space-time dilation (bending) occurs to make the math work out.

In simple terms, space-time is distorted by:

”Relativistic” velocities (i.e., velocities approaching the speed of light)
Mass
If you accelerate a clock to near the speed of light and then accelerate it back down, the clock will read an earlier time than a clock that’s been moving at “slow” speeds. If you move a clock away from a (large) mass and then move it back, it will also read an earlier time.

In order for something to move, it must be pushed by a force. That's physics. Yet modern science doesn't agree with it.
It should be obvious that a force "needs" a physical presense to exist.Electromagnetic and ‘gravitational’ forces are not contact forces, they are field forces. First year physics…

[Weltall]

It doesn't.

Saying it doesn't make it true.
A force is movement. And because it moves, it must occupy a point in space. It must have a "position".
No. You can push on a heavy box and it won't move, but you are still exerting a force on it. Force doesn't necessarily mean movement. Force also does not occupy any space, and it doesn't have a position.
The box isn't the force. I'm the force because I'm pushing against the box. Am I moving to push against the box? Yes.
The atoms in my hands are pushing agaisnt the box. The atoms on the surface of my hand are being pushed by atoms inside my hand and so on.
It's the same way with light. Light has a position. One time the light is here and another time it's there. And in order for light to have a position it must take up space to fit that position in the physical world.
I don't understand these sentences at all.
Oh, well. It's not a big deal.

Then don't use your imagination, because things are not always as you observe them (in fact, they are never as you observe them).

This is for everyone.
This is logic, but hard to understand logic. Matter is a mass. A mass that needs an amount of force behind it for it to move a certain speed, depending on the size of the mass. The mass exists in the physical world. And in order for the force to affect the mass it must be in the same physical world, or reality. Because the mass is physical, it only makes sense that another physical thing can touch it.
No, all that equation requires is a wavelength or frequency. Think of photons as waves instead of particles - you'll learn more about this when you study up on quantum physics.
I got it mixed up. I thought the M was movement. But mass still proves my point. But, as I explained above, anything that moves needs mass, too. But I would consider wavelength and frequency movement anyway. Simply because that's what it is.

This is from wiki
The theoretical physics (http://en.wikipedia.org/wiki/Theoretical_physics) equation E = mc2 states a relationship between energy (http://en.wikipedia.org/wiki/Energy) (E), in whatever form, and mass (http://en.wikipedia.org/wiki/Mass_%28physics%29) (m). In this formula, c² is only a conversion factor from kilograms (http://en.wikipedia.org/wiki/Kilograms) to joules (http://en.wikipedia.org/wiki/Joules), because joules (E) cannot be equal to grams (m).
http://en.wikipedia.org/math/e/3/9/e39b971aadbd0bdf6cd5743b14336d41.png According to the equation, the maximum amount of energy obtainable from an object is equivalent to the mass of the object multiplied by the square of the speed of light (http://en.wikipedia.org/wiki/Speed_of_light).



MOVING MATTER

http://en.wikipedia.org/wiki/E%3Dmc%5E2
Electromagnetic and ‘gravitational’ forces are not contact forces, they are field forces. First year physics…
The force that cause gravity was originally a contact force.
Same goes with electromagnetic, probably. I'm not too familiar with that.

The force of gravity wouldn't be here if it weren't for universe expansion.
That's the force that caused the gravity we have now. And it was a contact force...

Look, the only thing that causes movement is a force.
You can picture things existing in the phyical world with no mass. But if they have no mass, they have no place in the physical world anyway.

[GrassDragon]

The box isn't the force. I'm the force because I'm pushing against the box. Am I moving to push against the box? Yes.
The atoms in my hands are pushing agaisnt the box. The atoms on the surface of my hand are being pushed by atoms inside my hand and so on.
It's the same way with light. Light has a position. One time the light is here and another time it's there. And in order for light to have a position it must take up space to fit that position in the physical world.
You are not a force, you exert a force. This is a digression though.

http://en.wikipedia.org/math/e/3/9/e39b971aadbd0bdf6cd5743b14336d41.png
Read about annihilation, maybe that will help you understand what this equation implies.

The force that cause gravity was originally a contact force.
Same goes with electromagnetic, probably. I'm not too familiar with that.
It's not. You saying it is won't make it a contact force.

[FallenLord]

The force that cause gravity was originally a contact force.
Same goes with electromagnetic, probably. I'm not too familiar with that.I am familiar with it. Take my word; you're wrong. Or take a physics class.

The force of gravity wouldn't be here if it weren't for universe expansion.
That's the force that caused the gravity we have now. And it was a contact force...This is meaningless babble. The "force of gravity" is a special-case-simplification of general relativity, which states that mass bends space-time. And it was never a "contact force."

Because the mass is physical, it only makes sense that another physical thing can touch it.Buy a college physics book and read it FTW. Electrons are "physical," yet they repel each other without touching. ZOMG field force FTW.

[Weltall]

Don't you guys think it's somewhat odd how a textbook says some types of energy have mass and some don't? There's only one type of energy because of the reasoning I've already stated. It's called moving matter. Potential energy isn't even energy, at least not yet.
You are not a force, you exert a force. This is a digression though.
The force of my hands pushing is a force.


It's not. You saying it is won't make it a contact force.
What's not? Electromagnetic? You saying it isn’t a contact force, does not mean it isn’t a contact force.

Unlike you, I've provided logic, which says it does.

You guys should know that just because some text book says something doesn't mean I believe, although you guys do.


This is meaningless babble. The "force of gravity" is a special-case-simplification of general relativity, which states that mass bends space-time. And it was never a "contact force."
I take my beliefs more seriously than you or anyone on this forum, perhaps on any forum. This is my life. I believed this stuff five years ago, if not more. This is child’s play to me, if not less than child’s play. And it will never be anything more. So don't use that argument with me about how you know you're right. It doesn’t work.
Even if I do get make mistakes in some of the arguments I make with you guys. It will be arguments of your type. I'm used to abstract arguments. And through all my mistakes, my point will still be correct.

The force of gravity is a result of time dilation.
This is from a link I provided earlier on page 4:

"'How fast is the distance between us and this quasar increasing?,'" asks Turner and answers, "about 1.8 times the velocity of light." Does this exceed the speed-of-light speed limit? No. Einstein's theory does not limit the speed of space expansion--only motion through it. The theory that it's taking about is his theory of relativity.



Einstein's (http://en.wikipedia.org/wiki/Albert_Einstein) theory of gravitation answered the problems with Newton's theory noted above. In a revolutionary move, his theory of general relativity (http://en.wikipedia.org/wiki/General_relativity) (1915 (http://en.wikipedia.org/wiki/1915)) stated that the presence of mass (http://en.wikipedia.org/wiki/Mass), energy (http://en.wikipedia.org/wiki/Energy), and momentum (http://en.wikipedia.org/wiki/Momentum) causes spacetime (http://en.wikipedia.org/wiki/Spacetime) to become curved (http://en.wikipedia.org/wiki/Curvature). Because of this curvature, the paths that objects in inertial motion (http://en.wikipedia.org/wiki/Inertia) follow can "deviate" or change direction over time. This deviation appears to us as an acceleration towards massive objects, which Newton characterized as being gravity. In general relativity however, this acceleration or free-fall (http://en.wikipedia.org/wiki/Free-fall) is actually inertial motion. So in a gravitational field it is relative, a matter of relativity, whether objects are falling at the same rate due to their being in inertial motion or whether the observer is the one being accelerated. (This identification of free fall and inertia is known as the Equivalence principle (http://en.wikipedia.org/wiki/Equivalence_principle).)

The relationship between the presence of mass/energy/momentum and the curvature of spacetime is given by the Einstein field equations (http://en.wikipedia.org/wiki/Einstein_field_equations). The actual shapes of spacetime are described by solutions of the Einstein field equations (http://en.wikipedia.org/wiki/Exact_solutions_of_Einstein%27s_field_equations). In particular, the Schwarzschild solution (http://en.wikipedia.org/wiki/Schwarzschild_solution) (1916 (http://en.wikipedia.org/wiki/1916)) describes the gravitational field around a spherically symmetric massive object. The geodesics of the Schwarzschild solution describe the observed behavior of objects being acted on gravitationally, including the anomalous perihelion precession of Mercury and the bending of light as it passes the Sun.

Today General Relativity is accepted as the standard description of gravitational phenomena. (Alternative theories (http://en.wikipedia.org/wiki/Gravity#Alternative_theories) of gravitation exist but are more complicated than General Relativity.) For weak gravitational fields and bodies moving at slow speeds at small distances, Einstein's General Relativity gives almost exactly the same predictions as Newton's law of gravitation.



http://en.wikipedia.org/wiki/Gravity#Einstein.27s_theory_of_gravitation

Because relativity deals with "motion through our space expansion," but not the space expansion itself as it said in the first quote, and Einstein’s relativity theory deals with gravity as it said in the first quote, one can conclude that relativity is created by our space expansion. This is because, as I said, relativity deals with motion through our space expansion. It's because we're expanding and therefore all moving at relative speeds. And because that relativity deals with gravity, without that relative space expansion, we wouldn't have gravity. And thus the big bang is the cause of gravity.

Because you won't be able to understand the blob of shit I wrote, which you shouldn't.
In a revolutionary move, his theory of general relativity (http://en.wikipedia.org/wiki/General_relativity) (1915 (http://en.wikipedia.org/wiki/1915)) stated that the presence of mass (http://en.wikipedia.org/wiki/Mass), energy (http://en.wikipedia.org/wiki/Energy), and momentum (http://en.wikipedia.org/wiki/Momentum) causes spacetime (http://en.wikipedia.org/wiki/Spacetime) to become curved (http://en.wikipedia.org/wiki/Curvature).
See where momentum is needed? It's the momentum from the big bang that makes relativity that in turn makes gravity. And, thus, makes gravity a contact force from the big bang.

[Toucan]

The reason Einstein said it was impossible to travel the speed of light, is because it would take infinite energy to do the job.
As you accelerate to the speed of light not only does time dilate and slow down, mass becomes more massive, or heavier, to the point at the speed of light where mass becomes infinite. To continue accelerating infinite mass one would need infinite energy, nothing in this universe has infinite energy, there for it is impossible to travel at the speed of light.
The reason light can travel at its speed is because it has no mass, infinity X 0 is still 0.
If Einstein has it right, then this point alone, proves light has no mass.

[GrassDragon]

You're lacking in basic Physics knowledge. You just don't know enough to know you don't know enough. Cracking open a textbook would be a good idea to get started.

[Weltall]

I took half year of physics in high school. But it was only every other day.

[FallenLord]

What's not? Electromagnetic? You saying it isn’t a contact force, does not mean it isn’t a contact force.

Unlike you, I've provided logic, which says it does.You've provided no logic. The logic you didn't provide was wrong, anyway.

And because that relativity deals with gravity, without that relative space expansion, we wouldn't have gravity. And thus the big band is the cause of gravity.K? Did you know that the Big Bang is actually a hole-ridden out-of-date piece of crapola?

See where momentum is needed? It's the momentum from the big bang that makes relativity that in turn makes gravity. And, thus, makes gravity a contact force from the big bang.What kind of crazy non sequitor is that?

The "force of gravity" is a special-case-simplification of general relativity, which states that mass bends space-time. And it was never a "contact force."I take my beliefs more seriously than you or anyone on this forum, perhaps on any forum. This is my life. I believed this stuff five years ago, if not more. This is child’s play to me, if not less than child’s play. And it will never be anything more. So don't use that argument with me about how you know you're right. It doesn’t work.QFT.

I took half year of physics in high school. But it was only every other day.And this is supposed to make you look credible...how? I would have invoked the old, "On the internet, no one knows you're a Ph.D."

[GrassDragon]

If you can prove your theories, you are the next Einstein. So let's see the proof that light has mass and gravity is a contact force and all this mumbo jumbo.

[Weltall]

I won't be the next Einstein if I prove those pieces of shit.

Yeah, yeah my spelling can go bad sometimes. And my grammar can be bad, too.

I could've corrected the problems had I been more conscious of it, but I don't care much.


Fallen, it's not hard to find my evidence. Some of the best stuff is bolded in post 57.

What kind of crazy non sequitor is that?
It's my own style. It took a while for me to develope it.

[GrassDragon]

How do you explain Einstein Rings?

[FallenLord]

Fallen, it's not hard to find my evidence. Some of the best stuff is bolded in post 57.Evidence for general relativity. Not for gravity/electromagnet forces being contact. Which they aren't. Try pushing two magnets together.

It's my own style. It took a while for me to develope it.Logic comes in exactly one style. Non sequitor silliness comes in many.

[Weltall]

Evidence for general relativity. Not for gravity/electromagnet forces being contact. Which they aren't. Try pushing two magnets together.

The stuff on post 57 talks about how everything must be contact.


Non sequitor silliness comes in many.
I know. And, like most famous writers, I have my, own, unique, style, too.


EDIT:
How do you explain Einstein Rings?
Gravity bending light??? What do you mean??? I think gravity can bend light.

[GrassDragon]

How can light flying by a planet bend from its gravity if it's a contact force?

[Weltall]

Read what I said earlier about the stuff from wiki. Gravity is caused by a contact force, a contact force known as the big bang.

[SHISHKABOB]

Gravity is not made from the big bang you silly head. Gravity is caused by large mass. Something with alot of mass (Ex. The sun.) has alot of gravity. Something with not alot of mass (Ex. Pluto.) has alot less gravity. Also, physics isnt about what you believe and using your imagination. Physics is pure hard logic.

[Toucan]

Read what I said earlier about the stuff from wiki. Gravity is caused by a contact force, a contact force known as the big bang.

Heh, Weltall...... your funny.

[Weltall]

I'll be here all week, or until bf gets fixed...

Gravity is a result of time dilation, which, for the most part, in our universe, is a result of the big bang.

I could be wrong about the big bang thing. But time dilation causes gravity and time dilation is caused by contact forces.

[Toucan]

Gravity is a result of time dilation, which, for the most part, in our universe, is a result of the big bang.

I could be wrong about the big bang thing. But time dilation causes gravity and time dilation is caused by contact forces.

Gravity is created by mass, end of story.

Time dilation is experienced by some thing travelling at great speed, end of story.

The big bang theory is just that, a theory. Space may expand faster than the speed of light, but NOTHING moves through space faster than the speed of light



I don't even see the connection you are trying to make, how on earth you have managed to come to the belief that the big bang causes gravity. On top of that you have failed to answer Grassdragon's question, "if gravity is a contact force, how does it bend light."

Just because you don’t understand some thing does not make it wrong. You are wrong Weltall, time to accept it.

[singo]

Gravity is not a contact force. It acts over an intervening space and as such cannot be a contact force.


Although I would not call physics logical...I have found it to be VERY irrational, especially when you get down to subatomic levels :P

[GrassDragon]

Although I would not call physics logical...I have found it to be VERY irrational, especially when you get down to subatomic levels :P
I don't know about illogical, but higher Physics is definitely counterintuitive.

Weltall: You are right that time dilation and gravity are related, though one does not cause the other. They are both caused by the curvature of space time due to a massive object. However, neither of these are caused by contact forces. I have no idea where you got this idea from.

[Weltall]

The big bang theory is just that, a theory. Space may expand faster than the speed of light, but NOTHING moves through space faster than the speed of light

How do you know that space doesn't exist beyond the expansion of our universe?

I believe space is probably infinite.


Alright, maybe I shouldn't say the big bang causes it. But universe expansion causes it. I'm just assuming the big bang causes that. It's safe to assume based on what I say below that universe expansion is caused by a contact force.


They are both caused by the curvature of space time due to a massive object.
That massive object only curves space time because of universe expansion. Time dilation is not caused just by massive objects. It's caused by:
In a revolutionary move, his theory of general relativity (1915) stated that the presence of mass, energy, and momentum causes spacetime to become curved.

Time dilation is the curvature of space time due to the division of speed for a mass.

Time dilation exists because of the division of speed for matter between universe expansion and motion through our universe.

Again, this proves my point. This is my 2nd time showing you this. READ IT, PLEASE!

Einstein's (http://en.wikipedia.org/wiki/Albert_Einstein) theory of gravitation answered the problems with Newton's theory noted above. In a revolutionary move, his theory of general relativity (http://en.wikipedia.org/wiki/General_relativity) (1915 (http://en.wikipedia.org/wiki/1915)) stated that the presence of mass (http://en.wikipedia.org/wiki/Mass), energy (http://en.wikipedia.org/wiki/Energy), and momentum (http://en.wikipedia.org/wiki/Momentum) causes spacetime (http://en.wikipedia.org/wiki/Spacetime) to become curved (http://en.wikipedia.org/wiki/Curvature). Because of this curvature, the paths that objects in inertial motion follow can "deviate" or change direction over time. This deviation appears to us as an acceleration towards massive objects, which Newton characterized as being gravity. In general relativity however, this acceleration or free-fall is actually inertial motion. So in a gravitational field it is relative, a matter of relativity, whether objects are falling at the same rate due to their being in inertial motion or whether the observer is the one being accelerated. (This identification of free fall and inertia is known as the Equivalence principle.)
http://en.wikipedia.org/wiki/Gravity#Einstein.27s_theory_of_gravitation

The curvature is caused by time dilation, like it says... And that curvature causes gravity, like it says... So time dilation causes gravity.

Notice how it says it needs momentum to curve space time??? SEE!!?? It uses that momentum that creates the curvature which creates gravity, the momentum from contact forces such as space expansion. The point is, is that it needs momentum. And that momentum can't come from gravity because that momentum creates gravity.


EDIT: "if gravity is a contact force, how does it bend light."

I thought he knew the answer to that question... It's not even a good question to ask...
I already answered it anyway... I told him to read the stuff from wiki. And I'll say it again.
One could call time dilation gravity. If you want the answer to that, read what it says in the wiki quote. As I said many times before, I believe light is mass.

[SHISHKABOB]

Hey Weltall, you have no idea what your talking about. Massive objects curve space because of their large mass which cause gravity. Time dilation is caused when something goes very very fast. How is curvature caused by time dilation??? Time dilation is when time slows down by going very fast. That does not curve space. Gravity is caused by large mass. Please stop making everyone repeat themselves and this obvious fact.

[Weltall]

Just read the fricked wiki quote. Gez people, even bf would do better.

[Tissue]

What I think that weltall is trying to say is that:

As the volume of space expands, all particles are pushed apart from one another.
A particle has mass which reduces the amount of space around a particle producing the macroscopic force that we all know as gravity.

A particle pulls the fabric of space into itself and objects that exist in the fabric become closer to the massive particle. Space itself is moving toward the particle. Hence explain the theory of mass curving pace-time.

As the universe expands, all particles are pushed apart from one another. As the volume of space expands, all particles are pushed apart from one another. This acounts for the rate of universal expansion increasing.

All this assumes that time is a constant and that it is distance dialation which produces the effect more commonly known as time dilation. At a point of high gravity, it is distance which becomes longer not time.

Gravity curves space time so sub-atomic particles have a greater distance to travel at points of high gravity. (They have a greater distance to travel as their path will be curved in space.)

A particle’s probability cloud becomes distorted under time dilation. This distortion of the probability cloud causes the center of mass to shift in the direction of time dilation. In the presence of a continuous non-linear time dilation is called “gravity”.

In other words time dilation causes gravity.

I am sorry if this is complicated but the juvenile comments of some people spurred me into action. Recalling such information such as this is difficult and even more difficult to put into simple english but hopefully you can understand weltall's words better and stop this display of ignorance.

I am also sorry for not defending you earlier weltall but I dont log in every two hours like some people in this furom seems to do.

[SHISHKABOB]

Ok I kind of understand your view now. You are just reading that wrong Weltall a bit. And what is this bf thing you keep talking about?

[FallenLord]

ZOMG, momentum means contact force.Please stop the non sequitor silliness. Space-time bends vaccum; matter doesn't touch or push other matter. No contact force.

Tissue: Weltall's claiming that "gravity" is a contact force is juvenile and ignorant.

[singo]

Just read the fricked wiki quote. Gez people, even bf would do better.

No, you are talking a big load of bollocks.

Just because "wiki say so" does not automatically mean you are right. I believe you are missing the point.

Momentum is the product of mass and velocity. It is a derived concept and does not exist as a thing.

[GrassDragon]

Here's the part you are misinterpreting:

In a revolutionary move, his theory of general relativity (1915) stated that the presence of mass, energy, and momentum causes spacetime to become curved.
Note that it says mass curves spacetime. It does. The curvature of spacetime causes gravity. It also causes time dilation. Reference frames in a high gravitational field experience time slower than those in a weaker gravitational field. Time dilation doesn't cause gravity. Massive objects do cause time dilation just by themself.

Here's another thing you misquoted:
Because of this curvature, the paths that objects in inertial motion follow can "deviate" or change direction over time. This deviation appears to us as an acceleration towards massive objects, which Newton characterized as being gravity.
You are right that it says spacetime curvature causes gravity. But nowhere does it say time dilation causes spacetime curvature. Because it doesn't, it's the other way around.

Notice how it says it needs momentum to curve space time???
You clearly don't even read your own quotes. It said that the "presence of mass, energy, and momentum causes spacetime to become curved." Reading is good.

As I said many times before, I believe light is mass.
You sound like a religious zealot, unable to see the holes in your own logic and unwilling to hear out others when they know more than you.

[Tissue]

Momentum is the product of mass and velocity. It is a derived concept and does not exist as a thing.

Singo you are an idiot. Go and read a good physics book. I'll even give you the gist of it: momentum = Energy/speed of light or p=E/c

If you can actually refute this singo, go ahead. Please stop qouting and flaming weltall, Read my post as it give a much better explaination than he does.

Ok I kind of understand your view now. You are just reading that wrong Weltall a bit. And what is this bf thing you keep talking about?

I do not understand this....It is not very coherent. Please will someone translate this for me.

Grassdragon: your first two quotes are not labelled. Please tell us who you got these quotes from as I do not recognise it. Also you say that Massive objects cause time dilation by themselves. If that is true and that if time is a constant then you must agree that time dilation causes gravity.

Please will everybody stop flaming weltall and his misguided trust in wikipedia. If you actually read it, which none of you seems to have done, it doesn't actually support his claim that gravity is a contact force. Fallenlord, at no point did I support Weltall's claim that gravity is a contact force. Please read my post carefully and understand it.
Please stop qouting and flaming weltall, Read my post as it give a much better explaination than he does.

Last of all I would make it clear that I believe that light does not have mass and gravity is not a contact force. If you read posts that I have made, I was the first to discredit light having a mass. But you are free to argue that point with me if you wish.

[GrassDragon]

Singo you are an idiot. Go and read a good physics book. I'll even give you the gist of it: momentum = Energy/speed of light or p=E/c
Careful who you call idiot. Rememer that E=mc^2. Substitution in the above equation gives p=mc, or the product of mass and speed as Singo said.

Grassdragon: your first two quotes are not labelled. Please tell us who you got these quotes from as I do not recognise it. Also you say that Massive objects cause time dilation by themselves. If that is true and that if time is a constant then you must agree that time dilation causes gravity.
They were quotes from wikipedia that Weltall had in his post. And time is not constant. Here's a metaphor: After I eat stuffed jalapenos, my mouth feels like fire. Several hours later, my backside feels like fire. Saying that my mouth feeling like fire causes my backside to feel the same doesn't follow. Similarly, saying time dilation causes gravity doesn't follow, because both are the product of space time curvature.

If you actually read it, which none of you seems to have done, it doesn't actually support his claim that gravity is a contact force.
DING DING DING! I think we have a winner.

[Weltall]

Tissue I probably don't agree with what you said above, but I really don't care. I've been doing this to the point where I don't feel like posting long messages anymore, if anything at all.

Note that it says mass curves spacetime. It does.
There's a difference between matter and moving matter. It says moving matter curves spacetime, as I already said.


You are right that it says spacetime curvature causes gravity. But nowhere does it say time dilation causes spacetime curvature.
In a revolutionary move, his theory of general relativity (1915) stated that the presence of mass, energy, and momentum causes spacetime to become curved.
General relativity is time dilation...
That's what the theory is about.
If you say something like this again, I'm just not going to respond to you. This is the 3rd time...

You clearly don't even read your own quotes. It said that the "presence of mass, energy, and momentum causes spacetime to become curved." Reading is good.
Yes, in other words, it "NEEDS momentum," like the quote says.

So long...

[GrassDragon]

WTF, can't you read "presence of mass"? Do you understand relativity? You claim only moving objects curve spacetime, but as soon as you set your frame of reference to be at rest with the object's frame of reference, it is no longer moving. That's why I can sit in this chair and stay stuck to the ground. If curvature required momentum, which neither I, the chair, nor the Earth have in this frame of reference, there would be no gravity.

You continue to misread this quote from wikipedia:
In a revolutionary move, his theory of general relativity (1915) stated that the presence of mass, energy, and momentum causes spacetime to become curved.
General relativity is not time dilation. How could you possibly come to that conclusion. General relativity states (and here I am, quoting it yet again) that the presence of mass (that's mass, you know, like an object made of matter), energy (like light or heat), and momentum (here's the moving object part) cause spacetime to become curved (which in turn causes the phenomenon we call gravity and time dilation).

Seriously.

[Tissue]

The basics of general relativity:
Spacetime grips mass, telling it how to move.
Mass grips spacetime, telling it how to curve.

Grassdragon I am sure that everybody has heard of E=mc2 even if they do not truly understand it. Not as many has heard of p=E/c. Substitution does give p=mc but this will give the momentum of a massless particle such as a photon of light as zero as light has no mass. Yet you agree that light has momentum.

Be careful not to contradict yourself in your eagerness to discredit me.

The momentum of a massless particle can also be expressed:
p=planck's constant/wavelength

If you do not understand that please stop typing...all of you. you would not understand post 81.

Time can be a constant. The problem is in how we percieve time.
The newtonian theory of gravity is outdated. Einstien's theory of relativity simply explains it with geometry. However no-one is truly sure what causes this geometry or force of gravity, hence the theory of gravitons, nodal theory and string theory. However the theory outlined in post 81 is sound and serves to show how time dilation may cause gravity. If you do find a way of interconnecting mass, energy, gravity and time please inform the scientific community...they are very interested in the "Theory of Everthing" or "TOE", you may even win a nobel prize.

Seriously.

[singo]

Singo you are an idiot. Go and read a good physics book. I'll even give you the gist of it: momentum = Energy/speed of light or p=E/c


Item one, an A-level physics textbook.

http://www.pickabook.co.uk/covers/update04/04/04767320.JPG


Now then.

Momentum = Mass x Velocity

For massless things it gets a bit different, but so do most things.


E=MC^2 is a formula for defining the Rest Mass Energy of a particle. i.e, the energy it has when doing buggery squit.

That energy is the mass of the whatever-it-is, multiplied by the speed of light squared.

[Tissue]

He's actually got a book! And an good A-level one! Personally I prefer the Collins edition. Authors; Ken Dobson, David Grace, David Lovett.


For massless things it gets a bit different, but so do most things.


E=mc2 is a mass-energy relationship, for photons it describes its equivalant relativistic mass.

For massless particle please read up on:
de Broglie relationship momentum = planck's constant/wavelength
Planck-Einstein relation E=hf
and lastly Photon momentum p=E/c

I eagerly await your response.

[singo]

He's actually got a book! And an good A-level one! Personally I prefer the Collins edition. Authors; Ken Dobson, David Grace, David Lovett.

E=mc2 is a mass-energy relationship, for photons it describes its equivalant relativistic mass.

For massless particle please read up on:
de Broglie relationship momentum = planck's constant/wavelength
Planck-Einstein relation E=hf
and lastly Photon momentum p=E/c

I eagerly await your response.

Oh that is not my book, I used "Advancing Physics", that was a googled image.

I am not debating the formulae, they are all correct (as far as I remember)

I am just not entirely sure about Momentum doing the spacetime bendyness. I always though momentum was just a measure of how much force an moving object would exert upon something it hit and not a physical "thing" as such.. (hence the unit kg/ms^-1) or very small equivalents for subatomics)

And yes I think that was worded terribly, but I cant think of the proper definition, and its too late to be rooting through a load of notes.

[Tissue]

It has been theorised that momentum causes space-time to become more curved as a moving object would have more energy to "release" or distort.

Poor Shishkabob...I bet he still has no idea of how black holes work but now has a better understanding of space time physics.

[singo]

Fair enough, I thought it was only gravity that did the distortion. And the fact that spacetime is curved ANYWAY.

[Tissue]

Incidentaly, I was browsing throught the oldest posts in IR and one of the first topics ever raised was "What really goes on in black holes?" by grassdragon.

[GrassDragon]

Incidentaly, I was browsing throught the oldest posts in IR and one of the first topics ever raised was "What really goes on in black holes?" by grassdragon.
Interesting, eh? I read through it just now and it seems it was almost exactly two years ago. I know a lot more than I did then, but I have had 2 extra years of math and science.

[wa123]

I have been confused for a while on how black holes work. I mean I was watching this one show and it was saying that there were thousands and thousands of them in our galaxy and that they never go away. In a while wouldn't that mean that the galaxy would be filled to the brim with black holes and nothing would be there?

Cambridge definition:
SPECIALIZED a region in space where gravity (http://dictionary.cambridge.org/define.asp?key=34288) is so strong that nothing, not even light, can escape

From what I know Black Holes are Out of Sight. Not only do the particles and unlucky astronauts that fall into a black hole, never come out again, but also the information that they carry, is lost forever, at least from our region of the universe. You can throw television sets, diamond rings, or even your worst enemies into a black hole, and all the black hole will remember, is the total mass, and the state of rotation.

What then will happen to all the objects that fell into the hole, and all the people that either jumped in, or were pushed? They can't come out again, because there isn't enough mass or energy left in the black hole, to send them out again. They may pass into another universe, but that is not something that will make any difference, to those of us prudent enough not to jump into a black hole.

Even the information, about what fell into the hole, could not come out again when the hole finally disappears. Information can not be carried free, as those of you with phone bills will know. Information requires energy to carry it, and there won't be enough energy left when the black hole disappears.
What all this means is, that information will be lost from our region of the universe, when black holes are formed, and then evaporate.

Is therefore information is not really lost down black holes. But they have not managed to find any mechanism that would return the information.

Wait, if something goes the speed of light, and time stops, wouldn't that meant that the light reaching our eyes would be tenkajillion years old, or whatever.
Also, I feel that the whole space time idea is kind of silly. It overcomplicates a fundemental principle. All objects are attracted to other objects.
And wouldn't that mean the Galaxy is just one big sucking up vaccume cleaner type thing?
Anyway, someone explain the time freezing thing.


yes, question whether time itself has a beginning, and whether it will have an end. All the evidence seems to indicate, that the universe has not existed forever, but that it had a beginning, about 15 billion years ago. This is probably the most remarkable discovery of modern cosmology. Yet it is now taken for granted. We are not yet certain whether the universe will have an end.

As we look out at the universe, we are looking back in time, because light had to leave distant objects a long time ago, to reach us at the present time. This means that the events we observe lie on what is called our past light cone. The point of the cone is at our position, at the present time.

we will keep on getting older, and we won't return to our youth. Because time is not going to go backwards

[Ender]

Thread Necromancy.

Closed.