Where Does Space End? It Must End Somewhere!

[One of the Few]

Also realize this, due to the curvature of space if you had some means of doing it and left the universe, you would arrive at YOU GUESSED IT the other side of the universe.

[StringJunky]

Also realize this, due to the curvature of space if you had some means of doing it and left the universe, you would arrive at YOU GUESSED IT the other side of the universe.

 

It is not possible to leave something that is in itself everything? The term 'Universe' represents everything that exists, therefore, you can't leave it. The Universe doesn't have an outside....don't try and imagine anything beyond it because there is nothing ....does that make sense?....the idea of nothing is difficult to grasp but you'll have to accept it because that's what the physicists here will tell you.

 

Nothing, is the absence of anything.

 

Any computer-aided 3D model you see of the Universe is a representation of it in its entirety...it is not in space. it is space...all of it.

 

Leaving the Universe does not make sense now does it?

[Airbrush]

It is not possible to leave something that is in itself everything? The term 'Universe' represents everything that exists, therefore, you can't leave it. The Universe doesn't have an outside....don't try and imagine anything beyond it because there is nothing ....does that make sense?....the idea of nothing is difficult to grasp but you'll have to accept it because that's what the physicists here will tell you.

 

Nothing, is the absence of anything.

 

Any computer-aided 3D model you see of the Universe is a representation of it in its entirety...it is not in space. it is space...all of it.

 

Leaving the Universe does not make sense now does it?

 

Maybe what we call the universe is only a regional peculiarity. There could be larger scale structures, universes that exist within a "multiverse". There could be individual big bangs separated by unimaginably long distances, such as Trillions or Quadrillions of light years between them.

 

I also don't believe there would be an "outside" to such a multiverse.

 

We don't have ANY evidence for any "nothing". Something seems to permeate all visible space. There are about one hydrogen atom per cubic meter of "empty space" even in the middle of the great voids between superclusters.

 

NOWHERE is there nothing. There are also virtual particles popping in and out of existance everywhere.

[Sisyphus]

There could be individual big bangs separated by unimaginably long distances, such as Trillions or Quadrillions of light years between them.

 

No, there could not. The Big Bang is not an explosion in space. It is the beginning of an expansion of space. It does/did not have a location, from which you could be a distance away.

[Airbrush]

No, there could not. The Big Bang is not an explosion in space. It is the beginning of an expansion of space. It does/did not have a location, from which you could be a distance away.

 

Is everyone else in agreement with Sisyphus? I distinctly remember an episode of The Universe about parallel universes, the Type I parallel universe, or something like that, meant there could be an infinite number of distinct universes inside some kind of hyperspace.

 

What makes you so sure that beyond our visual horizon there is not a lot more? Just like when we used to think our galaxy was the entire universe. If universes bud off of prior universes, or Big Bangs are caused by colliding higher dimensions, then that means a location in space, or hyperspace.

[Sayonara]

I think what Sisyphus means is that if there are other universes, they are not simply 'outside the boundaries' of this one in the spatially-separated sense.

[StringJunky]

Maybe what we call the universe is only a regional peculiarity. There could be larger scale structures, universes that exist within a "multiverse". There could be individual big bangs separated by unimaginably long distances, such as Trillions or Quadrillions of light years between them.

 

I also don't believe there would be an "outside" to such a multiverse.

 

We don't have ANY evidence for any "nothing". Something seems to permeate all visible space. There are about one hydrogen atom per cubic meter of "empty space" even in the middle of the great voids between superclusters.

 

NOWHERE is there nothing. There are also virtual particles popping in and out of existance everywhere.

 

When I said ' nothing ', that's what I meant...not even empty space which you seem to think I'm suggesting...like I said, it's a difficult idea to grasp.

 

Why don't you have a gander again through the "What was there?" thread and see if you can absorb it better second time round.

 

http://www.scienceforums.net/forum/showthread.php?t=42499&page=2

 

What is the need for a Multiverse or Paralell Universe...What's wrong with one? What can't the present standard model explain that these two ideas can?

 

The idea of our Universe being in a bigger one (Multiverse) is symptomatic of the difficulty of grasping the idea of nothing beyond the limits of the Universe. We try to fill this deficiency of comprehension with things like Russian Doll Universes...like yours...I've done it myself 'til recently.

 

On the subject of whether I agree with Sysiphus, my answer is 'yes' because a) I don't know any better and b) he (and Swansont, Klaynos, Martin, Moo, Severian etc) is delivering the standard view which is what I'm interested in...I won't argue against something until I fully understand the subject first. When they tell us something, it's not 'their' personal opinion (unless they say it is) it's the current consensus of mainstream science that they are telling us about....surely that's what laypeople should come to this forum for?

 

Sayonara: to take your description, could it be there is only one Universe but possibly made up of many 'mini-verses' (a system or group of many galaxies that act independently of other groups extremelly far apart : in our case the Observable Universe is one of them?

[J.C.MacSwell]

I'm sorry, I'm having a real hard time believing that something thats impossible to see or know about exists. It sort of reminds me of God, or Santa Claus.

 

Hey, someone's been bringing those presents every year...

[One of the Few]

Yes there is nothing to leave in "OUR universe", but also one must see anothers point of view to enlighten ones self, our universe is "OUR" universe. Our universe "technically" has physical constraints, if all is known about our universes expansion, the acceleration and current velocity, then it can be measured.

 

But in a multiverse an infinite realm where infinite universes absolutely indentical in every way to ours, and those that posess only one or five or even one billion fundamental forces. Inifinity has many, many definitions. To many, many people, but there is one that cannot be denied, and that is "Endless possibilities" if you say our universe is infinite then it "is" the multiverse, but in turn the multiverse is us. We are everything and at the same time nothing in comparison to the endless multiverse. the overwhelming truth that this knowledge of everything is not within our grasp, this paradox of us being everything, yet only part of a whole is for you to contemplate.

[raen_rfm]

There are theories based on a model of an expanding universe that given an observer located anywhere within said universe they would observe the same expansion in all directions and thus postulate that they are located at the epicentre of that universe.

 

If we were able to somehow communicate with someone placed near the "edge" of our observable universe, they would most definately tell us they are no where near the edge, but would probably tell us that we look like we're on the edge, so thinking that the universe is this nice uniform bubble that is expanding doesn't make sense.

[toastywombel]

Well the Universe is expanding and actually the objects farther away from us are moving away from us faster than objects more near to our planet. We know this because the light coming from nearly all the stars in the night sky tends to be in the red section of the light spectrum. This doesn't mean they are actually red it just means they travel in elongated waves. We can use this to determine the velocity of the distant bodies.

 

Commenting on the initial question, mathematically space and time must be finite. Why? because if time has been going on for infinity then there would of been an infinite amount of time before we existed, thus making our existence impossible. And remember space and time are connected.

 

New theories in quantum physics paint the universe as having eleven dimensions, The reason we live in the third dimension? There seems to be a direct client-server relationship between conciseness and reality. And at some level our minds seem to communicate with reality to change how it shows itself to us. Since we are limited to the 3 dimensions and linear time line the Universe may seem like its infinite, but its because were limited in our dimensions. It would be like being a two dimensional object moving around a sphere. The space you would be moving in is finite but it has no boundaries. That may be what our Universe is like, finite but without boundaries. Many of these theories are based in hard fact. Quantum Mechanics is very effective at determining the probabilities of particle movements and its what nearly all computer processing is based off of.

Edited October 11, 2009 by toastywombel

[Airbrush]

Well the Universe is expanding and actually the objects farther away from us are moving away from us faster than objects more near to our planet. We know this because the light coming from nearly all the stars in the night sky tends to be in the red section of the light spectrum.

 

I think you mean galaxies outside our Local Group are red shifted, not stars we see in the night sky. Stars we see in the night sky are all in our galaxy and thus not moving away from us. Right?

[KaiduOrkhon]

The first Doppler redshift was described in 1848 by French physicist Armand-Hippolyte-Louis Fizeau, who pointed to the shift in spectral lines seen in stars as being due to the Doppler effect. The effect is sometimes called the "Doppler-Fizeau effect". In 1868, British astronomer William Huggins was the first to determine the velocity of a star moving away from the Earth by this method.[7]

 

In 1871, optical redshift was confirmed when the phenomenon was observed in Fraunhofer lines using solar rotation, about 0.1 Å in the red.[8] In 1901 Aristarkh Belopolsky verified optical redshift in the laboratory using a system of rotating mirrors

 

Source: Google, 'stars, redshift'.

[liarliarpof]

We shall never 'see', literally. As the rate of acceleration of the cosmos continues to increase, we too are moving away from some region near this hypothesized perimeter. At some point, the rate of seperation will be so large that light signals from either end will never reach the other. Not unless you believe a 'faster than light' signalling system is possible. If you do, let me know- I've got this wonderful bridge in NYC I can let you have for a song!

[toastywombel]

I think you mean galaxies outside our Local Group are red shifted, not stars we see in the night sky. Stars we see in the night sky are all in our galaxy and thus not moving away from us. Right?

 

Yes everything is moving apart, the moon moves an average of 2 cm a year away from us. The planets are moving apart as well.

---

Merged post follows:

Consecutive posts merged

We shall never 'see', literally. As the rate of acceleration of the cosmos continues to increase, we too are moving away from some region near this hypothesized perimeter. At some point, the rate of seperation will be so large that light signals from either end will never reach the other. Not unless you believe a 'faster than light' signalling system is possible. If you do, let me know- I've got this wonderful bridge in NYC I can let you have for a song!

 

A faster of light communications system is possible through "quantum twins". These are subatomic particles that have been created have strange properties, if you force one to go up, no matter how far away it is (as far as we can measure) its twin will mimic its path. This has been observed!

 

It would provide a faster-than-light communication method. But like you said it would be impossible to get something there that could communicate back to us.

 

And even if we were able to send something through a worm whole and its alive, its hard to believe it would be alive afterwards haha

 

Good Points

Edited October 14, 2009 by toastywombel
Consecutive posts merged.

[Airbrush]

Yes everything is moving apart, the moon moves an average of 2 cm a year away from us. The planets are moving apart as well.

 

No, not everything is moving apart. The moon is moving away from Earth at a miniscule rate, but where did you hear all the planets are moving away from the Sun? I don't believe that. Also ALL the stars in our galaxy are gravitationaly bound and NOT moving apart, except for minor movements of density in the spiral arms. Galaxies are tightly bound together with very few exceptions of a very few stars getting flung outward because of interaction in binary systems of several stars. Andromeda is actually speeding toward us. Our entire local group of galaxies are also bound together permanently. Even clusters of galaxies are bound together. No, not everything is moving apart, except for superclusters of galaxies.

[toastywombel]

No, not everything is moving apart. The moon is moving away from Earth at a miniscule rate, but where did you hear all the planets are moving away from the Sun? I don't believe that. Also ALL the stars in our galaxy are gravitationaly bound and NOT moving apart, except for minor movements of density in the spiral arms. Galaxies are tightly bound together with very few exceptions of a very few stars getting flung outward because of interaction in binary systems of several stars. Andromeda is actually speeding toward us. Our entire local group of galaxies are also bound together permanently. Even clusters of galaxies are bound together. No, not everything is moving apart, except for superclusters of galaxies.

 

-The moon is still moving away from the earth even if its minuscule.

-You said all stars in our galaxy are gravitationally bound. Stars release energy, this energy released causes their mass to become less and less over time. Less mass causes weaker gravitational force. This makes your statement that all the stars in our galaxy being gravitationally bound false. The force of gravity is weakening as time progresses.

 

Stephen Hawking explains this in his books Brief History of Time, and Universe in a Nutshell.

 

Another note every year the Earth and the Sun move 15 centimeters apart!

 

Check out this link.

 

http://www.newscientist.com/article/dn17228-why-is-the-earth-moving-away-from-the-sun.html

 

Furthermore, Gregory Laughlin of NASA, Fred Adams of the University of Michigan, and Don Korycansky of the University of Santa Cruz have recently released a paper in the journal, "Astrophysics and Space Science," in which they claim that modifying the Earth's orbit is not only "alarmingly feasible," but that it may eventually prove necessary in order to keep the life on our planet safe. They make this point based on the fact that the Earth is moving away from the Sun.

 

Finally have you heard of Hubble's Law? This is from Wikipedia

 

"Hubble's law describes the observation in physical cosmology that the velocity at which various galaxies are receding from the Earth is proportional to their distance from us.[1] The law was first formulated by Edwin Hubble in 1929[2] after nearly a decade of observations. The recession velocity of the objects was inferred from their redshifts, many measured much earlier by Vesto Slipher (1917) and related to velocity by him.[3] It is considered the first observational basis for the expanding space paradigm and today serves as one of the pieces of evidence most often cited in support of the Big Bang model."

 

Note: not a theory, but a law

---

Merged post follows:

Consecutive posts merged

Finally one more point if the Universe was not expanding apart, the wavelength of the light from stars in the night sky would not be stretched. This would cause the stars to appear as bright to someone on earth, as they are on the surface of one of these stars.

(Olbers' Paradox)

Edited October 14, 2009 by toastywombel
Consecutive posts merged.

[Airbrush]

Stars release energy, this energy released causes their mass to become less and less over time. Less mass causes weaker gravitational force. This makes your statement that all the stars in our galaxy being gravitationally bound false. The force of gravity is weakening as time progresses.

 

Stephen Hawking explains this in his books Brief History of Time, and Universe in a Nutshell.

 

Another note every year the Earth and the Sun move 15 centimeters apart!

 

Check out this link.

 

http://www.newscientist.com/article/dn17228-why-is-the-earth-moving-away-from-the-sun.html

 

Furthermore, Gregory Laughlin of NASA, Fred Adams of the University of Michigan, and Don Korycansky of the University of Santa Cruz have recently released a paper in the journal, "Astrophysics and Space Science," in which they claim that modifying the Earth's orbit is not only "alarmingly feasible," but that it may eventually prove necessary in order to keep the life on our planet safe. They make this point based on the fact that the Earth is moving away from the Sun.

 

Finally have you heard of Hubble's Law? This is from Wikipedia

 

"Hubble's law describes the observation in physical cosmology that the velocity at which various galaxies are receding from the Earth is proportional to their distance from us.[1] The law was first formulated by Edwin Hubble in 1929[2] after nearly a decade of observations. The recession velocity of the objects was inferred from their redshifts, many measured much earlier by Vesto Slipher (1917) and related to velocity by him.[3] It is considered the first observational basis for the expanding space paradigm and today serves as one of the pieces of evidence most often cited in support of the Big Bang model."

 

Note: not a theory, but a law

---

Merged post follows:

Consecutive posts merged

Finally one more point if the Universe was not expanding apart, the wavelength of the light from stars in the night sky would not be stretched. This would cause the stars to appear as bright to someone on earth, as they are on the surface of one of these stars.

(Olbers' Paradox)

 

Interesting about how stars lose mass over time. How much mass can a star shed before it dies by nova or supernova? Our sun will just expand into a red giant then shrink back into a white dwarf? In the process how much mass will the sun shed, both during its' lifetime, and upon death?

 

Did Hawking say that stars will eventually shed so much mass that they will drift apart, no longer bound? What about dark matter, will that also dissolve? If dark matter does not evaporate, then the galaxy will remain gravitationally bound.

 

15 cm per year? Wow. Are the other planets also spinning out?

 

How do you think we can change the Earth's orbit?

[bob000555]

The universe is defined as everything that exists; to ask what exists beyond everything that exists is meaningless. It’s like asking what lies north of(which is deferent from above) the north pole. Remember the laws of physics are under no obligation to exist in a form that is similar to our terrestrial experiences.

[Spyman]

-The moon is still moving away from the earth even if its minuscule.

But the Moon is not moving away from us due to expansion, it's because of the tidal lock with Earth.

 

"Most of the tidal effects seen on the Earth are caused by the Moon's gravitational pull, with the Sun making a somewhat smaller contribution. Tidal drag slows the Earth's rotation by about 0.002 seconds per day per century. As a result of the conservation of angular momentum, the slowing of Earth's rotation is accompanied by an increase of the mean Earth-Moon distance of about 3.8 m per century, or 3.8 cm per year.

http://en.wikipedia.org/wiki/Moon

 

-You said all stars in our galaxy are gravitationally bound. Stars release energy, this energy released causes their mass to become less and less over time. Less mass causes weaker gravitational force. This makes your statement that all the stars in our galaxy being gravitationally bound false. The force of gravity is weakening as time progresses.

Stars release energy by nuclear reactions, but when they grow old most of them becomes White dwarfs which no longer can sustain it and thus since they no longer loose mass they also keep their gravity and stay bound.

 

"White dwarfs are thought to be the final evolutionary state of all stars whose mass is not too high—over 97% of the stars in our galaxy."

"The material in a white dwarf no longer undergoes fusion reactions."

http://en.wikipedia.org/wiki/White_dwarf

 

Finally have you heard of Hubble's Law? This is from Wikipedia

 

"Hubble's law describes the observation in physical cosmology that the velocity at which various galaxies are receding from the Earth is proportional to their distance from us.[1] The law was first formulated by Edwin Hubble in 1929[2] after nearly a decade of observations. The recession velocity of the objects was inferred from their redshifts, many measured much earlier by Vesto Slipher (1917) and related to velocity by him.[3] It is considered the first observational basis for the expanding space paradigm and today serves as one of the pieces of evidence most often cited in support of the Big Bang model."

 

Note: not a theory, but a law

"various galaxies" not the Sun, the Moon, planets or other stars within the Milky Way, are mentioned in this law.

 

Finally one more point if the Universe was not expanding apart, the wavelength of the light from stars in the night sky would not be stretched. This would cause the stars to appear as bright to someone on earth, as they are on the surface of one of these stars.

(Olbers' Paradox)

Fine, then explain why the light from stars in the Milky Way doesn't appear to be redshifted due to expansion.

 

 

Space is expanding but objects that are gravitationally bound does NOT increase the distances between them due to the expansion.

 

"The metric expansion of space is the averaged increase of metric (i.e. measured) distance between distant objects in the universe with time."

At smaller scales matter has clumped together under the influence of gravitational attraction and these clumps do not individually expand, though they continue to recede from one another.

http://en.wikipedia.org/wiki/Metric_expansion_of_space

[Airbrush]

Interesting info Mr. Spyman. So the ultimate fate of 97% of the stars in our galaxy, or perhaps all galaxies, is the white dwarf stage, to slowly cool into a black dwarf over trillions of years, the other 3% collapse into neutron stars or black holes?

[toastywombel]

Wow, I see how I misunderstood the expansion of the Universe.

 

However I still have a question. If the whole Universe was expanding down to the molecular level, because the cosmological constant does effect objects down to the molecular level, how would we know?

[Airbrush]

The cosmo constant does not affect objects down to the molecular level. It doesn't even affect stars within a galaxy. If the gravity within a galaxy is enough to overcome the cosmo constant, then certainly electromagnetic forces would overcome the cosmo constant a Trillion Trillion Trillion times over. And the nuclear forces are WAY more powerful.

[Mr Skeptic]

No, I think he is right. From my calculations, every meter will gain an additional length of about one 10,000,000th the size of an atom every second. How would we notice?

[tar]

Question.

 

 

What is the canvas upon which we paint our model of the universe?

 

Or what are the characterists of the nothing that the big bang occurred in?

 

Or if you take away space and time, matter and energy, what is left?

 

From a 13 year old point of view, which I unfortuneatly still have, even though I am 55, the Russian Doll model seems to have some evidence behind it. Every entity seems to be made of a complex of sub-entities, and in turn, is a sub-entity in a greater whole, a larger or more longlived entity. Infinity seems plausible in all four directions, out, in, back and forward.

 

If back is cut off, at 13.73billion years ago, and there is no before. And in is cutoff at the quantum level of each concept, and there is no further in, and forward will come to an end in a big freeze, or a big crunch, then out must be finite as well, and there is an edge.

 

Regards, TAR