|
On April 07 2009 08:16 Gnojfatelob wrote:
The answer to your question is very simple: an explosion propelles matter away with a certain acceleration a, if there is no resistance force (like in the vacuum of space), the acceleration a will remain constant and the speed of the expanding matter will increase.
does the force of gravity no longer matter after a certain distance?
|
On April 07 2009 09:47 travis wrote:Show nested quote +On April 07 2009 08:16 Gnojfatelob wrote:
The answer to your question is very simple: an explosion propelles matter away with a certain acceleration a, if there is no resistance force (like in the vacuum of space), the acceleration a will remain constant and the speed of the expanding matter will increase.
does the force of gravity no longer matter after a certain distance?
the bigger distance=the lesser power
|
On April 07 2009 09:47 travis wrote:Show nested quote +On April 07 2009 08:16 Gnojfatelob wrote:
The answer to your question is very simple: an explosion propelles matter away with a certain acceleration a, if there is no resistance force (like in the vacuum of space), the acceleration a will remain constant and the speed of the expanding matter will increase.
does the force of gravity no longer matter after a certain distance?
The strength of gravity relates inversely with the square of distance. So it gets weaker pretty quickly. It's actually the weakest force.
|
On April 07 2009 07:59 travis wrote:Show nested quote +On April 07 2009 07:47 Swarmy wrote:
The problem with the way you describe the phenomenon is the fact that you appear to consider matter to be flying outwards from a central point. According to inflationary cosmology, space itself is expanding like a loaf of raisin bread (the raisins representing galaxies, the bread space-time etc.). This means that all galaxies are moving away from every other galaxy. Space is expanding in every direction. There is no central point away from which matter is moving. ok, I have heard this and I do understand it. But the actual matter must be moving away from a central point - or else it should be coming together. Right?
No, that's the point of the bread example. The space in between every raisin is increasing, the raisins are essentially stationary.
|
On April 07 2009 10:30 Swarmy wrote:Show nested quote +On April 07 2009 07:59 travis wrote:On April 07 2009 07:47 Swarmy wrote:
The problem with the way you describe the phenomenon is the fact that you appear to consider matter to be flying outwards from a central point. According to inflationary cosmology, space itself is expanding like a loaf of raisin bread (the raisins representing galaxies, the bread space-time etc.). This means that all galaxies are moving away from every other galaxy. Space is expanding in every direction. There is no central point away from which matter is moving. ok, I have heard this and I do understand it. But the actual matter must be moving away from a central point - or else it should be coming together. Right? No, that's the point of the bread example. The space in between every raisin is increasing, the raisins are essentially stationary.
well.. you could ad an origin.. but any place is just as possible as the last... it would merely be used as a point of reference or place helpful to visualize....
edit: nvmd... i missed the point... if the origin was placed anywhere it wouldnt be for the origin of where the big bang banged 
|
iNcontroL
USA29055 Posts
On April 07 2009 09:39 Artosis wrote:
from what i understand, the universe expanding forever is just 1 theory. i've also heard the theory that it will eventually hit some point and turn around and compact into a point again (pulsating hypersphere), and also that eventually it will just stop and remain at one size.
^ wiki ftw
^_^
+ Show Spoiler +
|
On April 07 2009 10:30 Swarmy wrote:Show nested quote +On April 07 2009 07:59 travis wrote:On April 07 2009 07:47 Swarmy wrote:
The problem with the way you describe the phenomenon is the fact that you appear to consider matter to be flying outwards from a central point. According to inflationary cosmology, space itself is expanding like a loaf of raisin bread (the raisins representing galaxies, the bread space-time etc.). This means that all galaxies are moving away from every other galaxy. Space is expanding in every direction. There is no central point away from which matter is moving. ok, I have heard this and I do understand it. But the actual matter must be moving away from a central point - or else it should be coming together. Right? No, that's the point of the bread example. The space in between every raisin is increasing, the raisins are essentially stationary.
ok but then a couple followup questions
1.) why are the raisins essentially stationary? shouldn't they either be moving away from the origin of the big bang, or moving towards the "gravitonical center" of the universe? or have the raisins been stationary since the big bang started? because if that's the case then I have more questions.
2.) what leads anyone to believe that space itself is expanding rather than the "raisins" just moving farther apart? I've looked but can't find any actual explanation of this.
|
i hope u pass the mods recognize ur name test
anyhow it doesn't stop expanding due to the laws of entropy, diffusion, and inertia (newton's first law i believe?)
though the last of the three may be invalid in that galaxies might affect the trajectory of other galaxies, i think most galaxies are relatively the same size and/or mass which means that gravitational attraction b/w galaxies will have as muhc of an effect on them as 2 soccer balls attract each other...
also no1 really noes exactly wtf happened w/ the big bang and some ppl say it wasn't a big bang but a little bang and then there was a big bang afterward, etc. u get my point.
"infinitely small spinning point, that suddenly explodes in mass, spinning out matter/energy in all directions outward from it's center point?"
nvr heard of that one b4... y was it spinning again?
On April 07 2009 04:43 travis wrote:
Like, if the milky way was somewhat near the center, it would have shot out slowly and "quickly" began deceleration. Whereas a galaxy much farther away from us could be likely to still be accelerating, but eventually slowing down, no? Just like if you put some paint in the middle of a paper plate and spun it at an extremely high rate. What is flung out closest to the center decelerates the fastest, and what is flung out the farthest continues to accelerate longer.
Is my understanding of this incorrect anywhere?
it only decelerates cus the paper does... ...
...
like i said newton's 1st law, the one about inertia (object in motion will try to stay in motion)
|
more questions:
1.) is light bound by gravity? if so, then how does light have a constant speed?
2.) can't the redshift we observe be because something is happening to the light rather than that space is expanding?
3.) since light moves faster than the universe's expansion - where does light go when it reaches the edge of the universe?
|
On April 07 2009 11:43 R3condite wrote:
i hope u pass the mods recognize ur name test
what?
anyhow it doesn't stop expanding due to the laws of entropy, diffusion, and inertia (newton's first law i believe?)
though the last of the three may be invalid in that galaxies might affect the trajectory of other galaxies, i think most galaxies are relatively the same size and/or mass which means that gravitational attraction b/w galaxies will have as muhc of an effect on them as 2 soccer balls attract each other...
also no1 really noes exactly wtf happened w/ the big bang and some ppl say it wasn't a big bang but a little bang and then there was a big bang afterward, etc. u get my point.
"infinitely small spinning point, that suddenly explodes in mass, spinning out matter/energy in all directions outward from it's center point?"
nvr heard of that one b4... y was it spinning again?
well if u examine the universe, everything is spinning. on every scale. so I guess that's just what I like to imagine. obviously I am no physicist but inferring from what I have learned of nature it would make sense that it started from spinning.
I guess that would change what the "big bang" was, in that it wouldn't be so much of a "bang" but rather just a spinning point of stuff that was spinning so fast that everything spun outward
Show nested quote +On April 07 2009 04:43 travis wrote:
Like, if the milky way was somewhat near the center, it would have shot out slowly and "quickly" began deceleration. Whereas a galaxy much farther away from us could be likely to still be accelerating, but eventually slowing down, no? Just like if you put some paint in the middle of a paper plate and spun it at an extremely high rate. What is flung out closest to the center decelerates the fastest, and what is flung out the farthest continues to accelerate longer.
Is my understanding of this incorrect anywhere? it only decelerates cus the paper does... ... ... like i said newton's 1st law, the one about inertia (object in motion will try to stay in motion)
well I can't describe a better model than that lol. try forgetting that the paper plate is there. the ball of paint spins on it's own.
or maybe imagine a spinning egg, and then the shell shatters.
|
Korea (South)17174 Posts
travis when u realize theres no answer to your questions, don't big bang your head
and if theres any good place for looking for good answers, tl.net certainly isn't it
|
United States24745 Posts
On April 07 2009 11:44 travis wrote:
more questions:
1.) is light bound by gravity? if so, then how does light have a constant speed?
2.) can't the redshift we observe be because something is happening to the light rather than that space is expanding?
3.) since light moves faster than the universe's expansion - where does light go when it reaches the edge of the universe?
1: light is affected by gravity, but only when the gravity is strong; in most cases light is virtually unaffected. The way Einstein's general relativity was partially confirmed was... they looked along the edge of a large object in space to see if they could see the stars behind it.... according to the geometry, the stars should have been visible along the edge of the large object, but they couldn't see the stars. This was because the light coming from the distant stars which was slated to pass by the large object was pulled towards it like a meteor.
2: Frequency of light (color) very rarely changes aside from a doppler shift.
|
On April 07 2009 12:09 Rekrul wrote:
travis when u realize theres no answer to your questions, don't big bang your head
and if theres any good place for looking for good answers, tl.net certainly isn't it
I am not here for answers I am hear to expand my mind
and I think this is a great place to do what I am trying to do
|
On April 07 2009 12:12 micronesia wrote:
2: Frequency of light (color) very rarely changes aside from a doppler shift.
but how do we know this when we have no way to test the affects of traveling over such a long distance on light?
also micronesia do you know why red shift led to the theory of expanding space? rather than just galaxies moving at different velocities?
|
Korea (South)17174 Posts
what is outside of the edge of expanding space?
|
On April 07 2009 12:21 Rekrul wrote:
what is outside of the edge of expanding space?
If you get there, more space!
|
Korea (South)17174 Posts
so space is infinite and the universe is merely all the matter galaxies etc that came from the big bang?
|
well it's just a guess based on what seems most logical to me.
but it's also misleading, because what I really think is that it takes a "being" there for the universe to exist. something has to observe it.
|
and if I had to wager a guess to the nature of the physical universe, it is that it operates on laws of cause and effect and maybe is cyclic.
geesh im high i just edited this like 1000 times
|
On April 07 2009 12:21 Rekrul wrote:
what is outside of the edge of expanding space?
what?... no doughnuts?...
this place sucks.. or perhaps it just wraps around
|
|
|
|
|
|
EPT
