universes center

[moonstarsquazars]

ill start by saying im a noob poster as you can tell but i often come here and read all the cool and exciteing things all of you have to say about the most intresting subjects i have ever known (space).i was at work today and started thinking bout how we have telescopes that can see to just about the known edge of the universe( like 12 billion light years or such). If we arent located in the center of the universe than shouldnt it be alot shorter in one direction yet alot longer in another? and if thats the case how is it we know we arent looking in the short direction and the universe is actually alot bigger? wouldnt it be safe to think that those stars that are severley the most) red shifted are the ones that were blasted in the opposite direction away from us during the big bang? and if thats the case than how is it are able to see past the massive black hole thats supposed to be in the middle? also would we even know we were looking at the black hole in the middle? isnt it supposed to be very packed with stars there? sorry for all the questions ill cut em short here and ask more later. thanx for your time.

 

[nimbus]

There's no center <img src="/images/icons/smile.gif" /><br />If the universe is in fact finite in volume, you'd eventualy track right back to where you started, if you set off for the "edge of the universe". The same way a satellite in earth orbit could fly around the planet and return to it's "starting point", the universe's apparently flat space is "curved" like that satellite's path.<br /><br />http://www.atlasoftheuniverse.com/bigbang.html <br /><br />Try to imagine a "center" point in that satellite's path, or anywhere on the sphere of all possible orbits of a same altitude above the earth.. <div class="Discussion_UserSignature"> </div>

 

[pyoko]

Search for similar threads.<br />The basic answer is : if the Universe were a balloon with an extra dimension, that would be an approximate idea of an expanding Universe. Just make sure you don't think of it as an actual expanding sphere (like a balloon is). <div class="Discussion_UserSignature"> <p> </p><p> </p><p><span style="color:#ff9900" class="Apple-style-span">-pyoko</span> <span style="color:#333333" class="Apple-style-span">the</span> <span style="color:#339966" class="Apple-style-span">duck </span></p><p><span style="color:#339966" class="Apple-style-span"><span style="color:#808080;font-style:italic" class="Apple-style-span">It is by will alone I set my mind in motion.</span></span></p> </div>

 

[qso1]

At just the most basic level, when we observe an object 12 BLY away...were looking at one object and using it as a marker. We would not expect to see objects at exactly the same distance no matter which direction we point our scope in. The objects we see at such distances are usually quasars or galaxys...whole collections of stars.<br /><br />What we cannot see or measure is the void these objects occupy. The void of space, the absence of light and color that make it black. The largest objects we know of are galaxie's. But galaxies occupy small portions of the void.<br /><br />In effect, we have no way to actually know if were at the center of the Universe without knowing where the outer boundries lie...boundries that we designate such as the most distant object. That remains the boundry until we are able to see further but it by no means tells us if we are centered in the Universe. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[origin]

<font color="yellow">wouldnt it be safe to think that those stars that are severley the most) red shifted are the ones that were blasted in the opposite direction away from us during the big bang? and if thats the case than how is it are able to see past the massive black hole thats supposed to be in the middle?</font><br /><br />It is a bit confusing. The big bang is not like an explosion that has a center, the expansion of the universe is happening everywhere. <br /><br />You mention a massive black hole. There is no massive black hole in the center of the universe, there IS a massive black hole in the center of the galaxy. I think you may have mixed up universe and galaxy.<br /><br /> <div class="Discussion_UserSignature"> </div>

 

[moonstarsquazars]

ok i can understand that it clears up alot for me as far as what quasars are and why we see them at a certain distance out. is it safe to assume that anything beyond that we wont see anything because the light hasnt reached us yet even though theres plenty still out there? also yes i was getting galaxies and universe confused with the whole blackhole thing and on a side note as for the speed of light if what ive always seen and heard are correct the way i interpet it is if you go faster than the speed of light you can go back in time but i dont see it that way. wouldnt it be more like for an example if you were traveling away from earth at the speed of light towards an object it would seem like time had stopped because your traveling at the same speed as that little bit of light that left earth , but it would also seem like you were traveling forward towards the object your approaching because your approaching it faster than it takes for light to have reached you ( im not explaining it real well i know hopefully someone understands) when the the whole while time is traveling at the same constant pace regardless? so youd actually reached the point exactly at the time its supposed to be at and youll have aged at exactly the pace you would had regardless?

 

[SpeedFreek]

According to special relativity, the faster you accelerate to, the slower time passes for you. According to general relativity, the more gravity you are experiencing the slower time will pass for you also.<br /><br />It is impossible to accelerate anything with mass to the speed of light - infinite energy is required to do so. As you accelerate faster and faster, you experience time passing slower and slower until at speeds just below the speed of light time almost stops for you. Theoretically, if you were able to accelerate to the speed of light (which you cannot), time would stop passing completely for you, so any journey at the speed of light would seem instantaneous to you.<br /><br />But, if no time passes for you at the speed of light, then there is no way for you to stop! It would be like your spaceship and its contents were frozen in time so you (or your ships computer) would be unable to change anything within that ship.<br /><br />At a speed of around 86.6% of the speed of light, time would pass for you at half the rate that it was passing for you before you started.<br /><br />So if you were on Earth with your twin brother and you decided to leave and travel on a long "relativistic" journey at 86.6% of lightspeed, when you returned you would have aged half as much as your twin brother aged while you were away.<br /><br />If you went on a journey of 5 light years at 86.6% of light-speed and then turned round and came back again at that speed, you would only age 5.77 years during the whole journey, but back home 11.54 years would have passed. <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[alokmohan]

Only point I know is that Univers is finite and unbounded.

 

[moonstarsquazars]

that just blows my mind. i dont see why speed has anything to do with time. useing that theory if you could somehow break the speed of light and go faster than time would really go forward in reverse .. my head hurts now thanx for the replys everyone. (i never even thought of the whole time stopping so itd be impossible to do anything before, just crazy, lots to think about now.)

 

[alokmohan]

Universe has no center.It expnads like a balloon.

 

[nova_explored]

well time wouldn't really stop, time would simply cease to exist. a photon traveling at C does not exhibit any reference towards time simply because the photon does not exhibit any change. no change equals no reference point to measure any change. this is precisely what einstein and physicists refer to as time standing still.<br /><br />so in relativity anything that could theoretically achieve C would no longer exhibit any change. Its not that we the universe would age that much more as we travel at C, its that we would remain the exact same and the universe would change, unawares to us. <br /> <div class="Discussion_UserSignature"> </div>

 

[dryson]

There is no center to the Universe and there are not any boundries. What happens if we come to the edge of space? What do we do fall off into? What more space?<br /><br />Space is infinite.

 

[qso1]

Thats a good way to look at it. Reminds me of what used to be thought in the days of Columbus. Only today, the Universe is a preconcieved theoretical notion backed by some data in both onservational (CMB) and mathematical. But not enough data to conclude wheter the Universe is flat...or endless. I tend to see it as endless but I have no data to back that.<br /><br />Maybe some future Columus or Columbi will settle the question. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[schmack]

<font color="yellow">Maybe, but he'd have to have a very fast ship..</font><br /><br />hmmm, some big sails. or maybe a "hyper" drive would get him there..... has anyone here invented that yet? the hyper drive? what are ya's doing for goodness sake... ya'all know we need one! <div class="Discussion_UserSignature"> <p><font size="4" color="#ff0000"><font size="2">Assumption is the mother of all stuff ups</font> </font></p><p><font size="4" color="#ff0000">Gimme some Schmack Schmack!</font></p> </div>

 

[qso1]

Oh yeh. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[alokmohan]

If the universe is expanding ballon it has center at all points,am I wrong?

 

[SpeedFreek]

<font color="yellow">If the universe is expanding ballon it has center at all points,am I wrong?</font><br /><br />Yes, I think you are trying to describe the infamous "balloon model" of space, which is a model that can illustrate how something can expand and have no centre of expansion.<br /><br />It is important to remember that with the "balloon model", we are only concerned with the <b>surface</b> of the balloon. That surface represents a 2 dimensional universe, where there is no up or down (the 2 dimensional inhabitants of that 2 dimensional surface have no way of knowing that their 2 dimensional universe is wrapped onto a 3 dimensional sphere, as they can only see in 2 dimensions!).<br /><br />We can stick small dots on the surface of the balloon, to represent 2 dimensional galaxies, and then we inflate the balloon! The inflation of the balloon (the change in its 3rd dimension) represents <b>time</b>. When the balloon was smallest, all the dots were closest together, and as time passes and the balloon inflates, the dots get further apart.<br /><br />As the balloon inflates, the dots on the the surface all move apart from each other, but as the dots are separate objects that have been stuck onto that surface, they stay the same size. So a dot representing a galaxy will see its nearest neighbour moving away slowly, and the further they look, the faster a galaxy will be moving away from them. If they could see far enough, they could see all the way around their universe.<br /><br />Nobody living on that surface in that 2 dimensional universe can claim they are at the centre of the universe. If light moves across that surface at a constant speed, then <i>wherever</i> anybody is, they will see themselves as sitting at the centre of their universe, with all the other galaxies moving away from them. (The dots actually represent clusters of galaxies, where galaxies can move towards each other within that cluster, but all clusters outside are moving away).<br /><br />If <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[nova_explored]

"There is no center to the Universe and there are not any boundries. What happens if we come to the edge of space? What do we do fall off into? What more space?"<br /><br />Who knows.<br /><br />The only construct we have towards wrapping our thoughts around infinity is a mathematical one. Nothing of science gives us a yes or no answer yet- study of photons and electrons, redshifts, etc.<br /><br />so its impossible to say outside of what your imagination comes up with. <div class="Discussion_UserSignature"> </div>

 

[alokmohan]

Infamous ballon model.It is accepted by scientists.At least I know like that.

 

[SpeedFreek]

Yes it is well accepted, and a good model. I only use the term "infamous" because it can cause so many misconceptions and is often misinterpreted, and that is why I posted my more detailed description of it.<br /><br />I was answering your post where you stated "If the universe is expanding ballon it has center at all points". That statement alone is not enough to help anybody understand the concept. It might have been better to say "If the universe were represented by the <b>surface</b> of an expanding balloon, anywhere on that surface can be considered the centre of expansion" or something similar. <img src="/images/icons/smile.gif" /><br /><br />The problem with the balloon model is that it is too easy to misinterpret it and think the volume inside represents space, when it only represents the passage of time. <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[bearack]

"Only point I know is that Univers is finite and unbounded."<br /><br />But, if you also recall, we also "knew" that the Earth was flat. <div class="Discussion_UserSignature"> <p><br /><img id="06322a8d-f18d-4ab1-8ea7-150275a4cb53" src="http://sitelife.space.com/ver1.0/Content/images/store/6/14/06322a8d-f18d-4ab1-8ea7-150275a4cb53.Large.jpg" alt="blog post photo" /></p> </div>

 

[SpeedFreek]

True, we don't <i>know</i> that the universe is finite but unbounded, but we think it <i>might</i> be. It is one of the possibilities, one that Einstein considered and we still consider today.<br /><br />"Unbounded", in this context, doesn't necessarily mean it might go on forever, rather that it might be unbounded in the same way as the surface of a balloon. If you travel across the surface, you will never find an "edge". <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[robnissen]

<font color="yellow">unbounded in the same way as the surface of a balloon. If you travel across the surface, you will never find an "edge". </font><br /><br />I don't think your analogy works. Eventually if you travel across the surface of a balloon you will get to your starting point. If eventually you travel across the universe and you get back to your starting point, the universe would not be unbounded.

 

[SpeedFreek]

Okay, perhaps if I phrase it a little differently.<br /><br />The universe may have no boundary. But that doesn't necessarily mean it goes on forever, it might just loop back on itself! <img src="/images/icons/wink.gif" /><br /><br />If there is no edge or boundary, that doesn't necessarily make it infinite, in other words.<br /><br />We don't yet know if space is totally flat or not, but we have studies that put space within 2% of being flat, which means that the universe might be curved, but the radius of that curve is larger than the observable universe. (Paraphrased from Shapiro, Cornish, Key et al, "Extending the WMAP Bound on the size of the universe")<br /><br />This allows us the possibility that a straight line is actually part of an absolutely massive arc, with a radius larger than our observable universe. <br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[mindmute]

...Indeed speedfreek,<br />as you pointed out on another thread, the observable universe is only the part we can observe.<br />The universe on it's whole is much larger.<br />Question to you:<br />Could the 3 dimensional aspect be finite and the fourth infinite?<br /><br />