Thread: Does Size Matter? Big Or Small

1. rambo07 Guest
during a nuclear explosion what determines the yield of the blast? how much plutonium or how much energy put into it to split the atom? in relation to e=mc2 (this is why i doubt the current big bang theory).
why not go the other way in thinking,rather think small ,think big,,, how big a sun would you need to produce a universe if it went meganova,surely there must be a mathematical equation for this? if there is ,then why can&#39;t it be so?

2. StarLab Guest
rambo07,
I don&#39;t know math, but the Universe obeyed slightly different physical laws during, before and immediately after the big bang - if it occurred. Remember: the BB was not an explosion - it was an inflation - remember? After all, not all inflations were nuclear explosions. And what does the idea
split the atom
have to do with the BB; Atoms did not exist then&#33;

3. Originally posted by rambo07@May 5 2004, 07:45 PM
how big a sun would you need to produce a universe if it went meganova,surely there must be a mathematical equation for this? if there is ,then why can&#39;t it be so?
I don&#39;t think it&#39;s possible [as a simple exploding star]. If you assume that the entire mass of the universe was thrown out of one big star exploding, and that most of that matter being thrown out had extremely relativistic velocities, and that p-p reaction efficiently produced most of the underlying energy for the explosion, the initial star would have to have been about ten thousand to a few million times the mass of the entire universe as we see it.

The Schwarzchild radius for this much matter is quite large. If I&#39;ve calculated it correctly, it seems to be larger than the entire observable universe.

Granted, there could be some odd physics in that kind of environment, and there are some alternative theories that say the universe as we see it is the inside of a black hole, but that isn&#39;t what you were asking about.

4. John Guest
You also have to remember, as StarLab pointed out, that the Big Bang was not an explosion inside the universe. It was the creation of the universe. The space in which your hypothetical meganova would occur was created at the moment of the Big Bang. Asking where the Big Bang occurred or when the Big Bang occurred are both common misconceptions because the Big Bang created space and time&#33; There was no where for the Big Bang to occur because it created all the wheres that we know, and there was no before because time began at the Big Bang.

Now, there are a lot of other theories, not quite widely accepted, that differ from the Big Bang theory, but that&#39;s another story.

5. StarLab Guest
Big Bang created space and time&#33;
Now, John, let&#39;s assume that&#39;s not true: that they each existed independently in two different universe that collided to produce our universe, or that time came before the BB and space did too, but the latter was different than how we currently perceive it. Then what could we deduce?

6. John Guest
I was just dispelling some Big Bang misconceptions, StarLab.

If you want to talk about the other possibilities, then the Ekpyrotic model fits what you&#39;re talking about. That would involve a universe that existed long before our part of it came into being, inside a space that is larger that the part that we will ever be able to see. That involves the collision of branes to create the Bang that produced the energy and matter of our universe, but is independent of any times before and after.

My issue is basically with the "super/hyper/mega-nova creating the universe" ideas I&#39;ve been reading, and I&#39;m just trying to correct the misconceptions that seem to be the basis of their arguements.

7. StarLab Guest
John-
I&#39;m with you whatever you do, say, or write. I understand all your ideas and theories. I&#39;m trying to accomplish exactly what you are trying to accomplish. <_<

8. Guest_blacktearsofapril Guest
Originally posted by John@May 5 2004, 08:43 PM
the Big Bang created space and time&#33;
No, space and time existed before then. And remember, the universe is not infinite, its just really really big. Space is. For time to have been "created" is absurd. Even without the existence of matter, anywhere in our universe, or another, time will always exist. It is not a thing, and not an act. We will probably never know the complexities of time, or space.

Now, has anyone ever thought of the possibility of the big bang actually being a mega-nova, and that there were, and are other mega-novas out there, with nearly the same result? (example) We are a planet with its own gravitational feild and satelite, our "greater" is our solar system, and then our galaxy, and then our super-cluster, and then our universe. Is it possible then, that the universe has a "sucessor" or something bigger than it that it is part of, but that we just cannot detect?

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Conceptually, this is conceivable. Atleast, no more conveivable than the big bang. But then this is not my subject at all. As a layman, it is conceivable.

If this doesn&#39;t take to much from the original topic, what is it that we actaully know of the universe. Isn&#39;t it debatable as to whether or not it&#39;s even expanding? What about from what direction? Could someone offer me a bit of basic foundational knowledge to help me visualize this and better see a few of the most fundamental constraints that are in play here?

10. StarLab Guest
Sphinx-
Think of it this way: a firework explosion. All the stuff in the firework goes out in all different directions - that was what the BB was like - an "explosion" in which everything "inflated." Eventually, all the stuff disappears: that is the Big Rip scenario, in which spacetime becomes so thin it rips apart.
Now think this in your mind: our firework crashes into another firework with different colors than ours. The resulting explosion/inflation is a mix of the two; that is the product of M-theory. Again, it could have the same consequence as scenario one.

P.S. This is what I like to call a "thought experiment" B)

11. John Guest
Originally posted by Guest_blacktearsofapril+May 5 2004, 11:48 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Guest_blacktearsofapril @ May 5 2004, 11:48 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-John@May 5 2004, 08:43 PM
the Big Bang created space and time&#33;
No, space and time existed before then. And remember, the universe is not infinite, its just really really big. Space is. For time to have been "created" is absurd. Even without the existence of matter, anywhere in our universe, or another, time will always exist. It is not a thing, and not an act. We will probably never know the complexities of time, or space.

Now, has anyone ever thought of the possibility of the big bang actually being a mega-nova, and that there were, and are other mega-novas out there, with nearly the same result? (example) We are a planet with its own gravitational feild and satelite, our "greater" is our solar system, and then our galaxy, and then our super-cluster, and then our universe. Is it possible then, that the universe has a "sucessor" or something bigger than it that it is part of, but that we just cannot detect? [/b][/quote]
Some of the best minds in cosmology will disagree with you, although your ideas do touch on some of the current thinking.

I don&#39;t buy into the meganova idea at all. I don&#39;t think there is any object in our universe capable of producing the energy that would creat all of the matter and energy in our universe, and do it in a way that it would appear to be distributed the same in all directions we look at any distance we look.

There are, however, new ideas being formulated that would argue that both space and time existed long before our current universe was formed, but these are not as widely accepted. Several maturing versions of string and M theory are moving toward a more cyclical universe, unlike tha Big Bang/Big Crunch that seem to indicate something akin to what you said.

I disagree that space is not infinite. As far as we are concerned the only space we can ever know is the space from which light, energy, gravity, or any information can be seen. Based on the expansion of the universe, and the way in which it is cumulative, there is a finite limited to the amount of space we can observe and be affected by, but that does not mean that the space beyond that is still finite. If you are leaning toward the string/M theories then you must know that most of these rely on the fact that space is so huge that to all purposes relative to us, it is infinite. If there is an edge, it will forever be beyond our ability to observe, measure, or test it.

And for Sphinx, it has been confirmed that everything in the universe, except a few local galaxies gravitational bound together, is moving away from our region of space in all directions. Or, more technically accurate, that the space between our galaxy and all other locations in space is expanding. The gravitation attraction of the local galaxies is the only thing keeping them from receeding away from us, too. As for the direction, it is in all directions at an equal and cumulative rate. There are alternate theories to explain the expansion besides the Big Bang Inflationary model, but none of them have achieved the level of detail or accuracy that the currently accepted model has. Until string theory can get some definite equations with detailed predictive power, they will not supplant the Inflationary Model of Cosmology.

12. Newbie
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Before the BB there was nothing - the BB created the universe which is still expanding.

I am corrected, I called it an explosion earlier but that can&#39;t be right because in order to have an explosion you would have to have &#39;material&#39; existing already. But the BB was completely different , &#39;inflation&#39; you called it???

So then the BB began &#39;from nothing&#39;??? Is that right??? But how can that be?

:huh:

13. rambo07 Guest
galaxies evolve through time ,our own milkyway has absorded other smaller galaxies to form the one we see today, in our local cluster galaxies are not moving apart,the problem with seeing galaxies that seem to be moving apart is that you are not seeing the wood for the trees ,,,, if you group all galaxies in there own local cluster you will see the same,,, if there has to a constant with you its a shame you ignore whats really going off around you

14. StarLab Guest
galaxy2-

Let&#39;s get this strait. Before the BB there was nothing that OBEYED THE SAME PHYSICAL LAWS OUR UNIVERSE DOES. Something existed before the BB, but it was destroyed in favor of the physical laws that govern our universe today. B)

15. rambo07 Guest
before the big bang there must have been something ,,,, it went bang because it became unstable ,,,, the same laws apply then as now,,,, the universe was small compared as today,,,the reason why its so large today is because galaxies etc have moved space /time in the bubble we see today

16. Gyaos Guest
Originally posted by StarLab@May 6 2004, 07:18 PM
galaxy2-

Let&#39;s get this strait. Before the BB there was nothing that OBEYED THE SAME PHYSICAL LAWS OUR UNIVERSE DOES. Something existed before the BB, but it was destroyed in favor of the physical laws that govern our universe today. B)
So, "nothingness" equals "quantum fluctuation"?

Rubbish.

17. John Guest
Quantum Fluctuations, Virtual Particles, Vacuum Energy are all ideas related to teh creation of something out of nothing, but that&#39;s a misnomer and I don&#39;t think its applicable to the creation of the universe. All of the something out of nothing ideas come from the inherent energy pervading the entire universe, or the fact that absolute zero is unattainable and therefore everthing has a motion that should be tappable to obtain limitless energy.

The problem is that this presupposes and energy from which the universe could be created, which is inconsistent with the basic tenents of modern Big Bang cosmology that all of the energy in our universe was created at the moment of the Big Bang.

But that is the whole point of this discussion, and the one question we so far have found no way to answer observationally. Pushing back the time to before the Big Bang still leaves the same question. Supposing some method of generating the object or force that ignited the Big Bang does no better. These both still leave an origin question. If time didn&#39;t begin at the Big Bang, but before it, then when did it begin? If something existed before the Big Bang to start it, then where did that thing come from? Saying God did it is the easy answer, but we&#39;ve been very sucessful in diving how things really work so why can&#39;t we figure this one out, too?

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Greetings All,
I&#39;ve only posted to this forum a couple of times, but as I&#39;ve been watching and reading Carl Sagan&#39;s "Cosmos" series (very wonderful stuff by the way), I thought I&#39;d toss my hat in here too...

Ok...as far as the Big Bang goes, to the person who asked the original question, please remember that the "Big Bang Theory" is just that...a "theory". As far as to the "why", there could be a number of reasons, but the one that seems to make the most sense to me is the concept that matter simply exists. The matter that created the universe has always been here (perhaps in a somewhat different form). I.E. the universe at one times was -very- abundant with hydrogen molocules (even more so then today perhaps) and that somehow all this hydrogen and perhaps some helium molocules etc some how colillesed into a massive cloud and, for lack of a better term, exploded and the resulting explosion created the rest of the nessacary ingrediants to form what we know of the universe....or something along those lines. But please remember, this is just -one- theory...there are certainly others such as that of a "modulating universe" (one that folds in on itself, explodes, expands, contracts and folds in on itself again to restart the whole cycle). There is also the theory that the universe has always been and is part of a "multi-verse" or multiple co-existing universes (I saw something in regards to this in an issue of Sky & Telescope magazine, but I&#39;m not sure which issue). There are many possibilities, some more plausable then others and barring Razor&#39;s theorum, I honestly don&#39;t think we will know in our lifetimes for sure.

Now for a callateral question(s)....

I know that we measure the distance of a galaxy by it&#39;s "red shift" as explained by Einstiens theory of relativity and the "doppler effect"...i.e. as something moves away from you (at the speed of light?), the light waves sort of stretch, producing this red shift and that as something approaches you the light waves are compressed giving off "blue". Now while reading thru the other posts in this thread, the thought occured to me that barring human arrogance and an under lying belief that perhaps the Milky Way galaxy is the center of the universe (and we&#39;ve made this mistake before&#33, that its quite likely that the Milky Way galaxy is moving away from the "center" of the proposed Big Bang (or whatever) as well as other galaxies behind us....ok, let me try and explain this...say you have three similar spiral galaxies, and we&#39;ll label those galaxies A, B and C. Now lets assume that galaxy B is our Milky Way and that galaxy C is moving away from us (perhaps a Messier or NGC). We&#39;d measure that distance by galaxy C&#39;s red shift as C is moving away from us at a greater speed then we are moving. Now assuming that all three galaxies are proceding along a relatively straight line, how would we measure the distance of galaxy A? While A is moving in the same direction that we are, we as galaxy B are moving away from A and are presumably moving somewhat faster then A (as C is moving faster then us). Would galaxy A still apear as a red shift or would it appear blue and why? Also, if it would appear as a blue shift, why have we not detected such a thing?

As I recall, this all important "red shift" was what determined that the universe -is- expanding(yes/no?). I seem to remember reading something in regards to Einstien&#39;s early theory&#39;s and how he had to re-write/re-think a couple of things when this was discovered as he had believed the universe at that time to be static.

Now, with all of that said, asked and blithered out like an idiot, I would also like to add, that I&#39;ve never had any formal education in this stuff, so -please- take all of my comments with a grain of salt. I&#39;ve only been studying astronomy for about 3 months (when I bought my first telescope) and that all of this stuff is very new to me and I am, of course, having some problems getting my brain wrapped around this. In all fairness to myself though, I guess it&#39;s also understandable...kinda hard to grasp something in a period of only 3 months that some people who were/are considered to be geniouses (such as Einstien and Sagan) and who spent life times studying and persueing. From my stand point, we may all find out someday that the universe is really made up of nothing more then peanut butter and cheeze&#33; LOL&#33;

Like I said, just my &#036;.02 worth with a couple of questions attached.
Bright Blessings and Gentle Breezes all&#33;
Jim

19. StarLab Guest
Simply put, redshift is when the difference between two objects gets greater as time goes on...it does not matter who is doing the redshifting. If we&#39;re moving faster, we see a redshift from the other galaxy, and vice versa. Redshift is simply "moving away."
Einstein&#39;s Cosmological Constant, which required the universe to be static, is not used for that purpose any more. Physicists and cosmologists use it for other experiments, but it is widely accepted that Einstein&#39;s Cosmological Constant is invalid in terms of the expansion of the universe.
The matter that created the universe has always been here (perhaps in a somewhat different form).
I have been saying this in almost all my posts. I&#39;m proud of you&#33;... B)

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I don&#39;t know anything about this stuff at all so this may be copletely absurd But for hypothetical purposes, let us not focus on any major errors here.

You have a planet who&#39;s orbit around the sun is oblong like an egg. Around this first planet is a second planet similarly egg shaped but whos apex is slightly off to one side. ( For visual purposes, take two eggs, line them up and turn one of them slightly to the right. This is the line of travel that I am visualizing while assuming that planet 2, at no point, will cross the same line as planet one&#39;s.) If both planets line up at their own apex and orbit to the left, counterclockwise, taking an equal amount of time to make one revolution, then to planet 2, it would appear as though planet one were moveing away from it as they began their travel. As planet 2 reached the bottom of it&#39;s eggshaped line of travel, planet one would seem to breifly come towards it only to start moving away again at an even greater rate as planet 2 headed out to it&#39;s own apex. They of course reach their own apexes at the same time starting the cycle over again.

From this, wouldn&#39;t you be getting both red shifts and blue shifts from the same location? Assume that this little scenario is correct, let&#39;s say you do the same kind of measurement with two galaxies (galaxy A and galaxy B ) and let&#39;s assume that each galaxy travels on some as yet known line of travel due to gravity and what have you. Wouldn&#39;t this make it relatively difficult to make accurate measurements of any kind?

Just a hypothetical question. I&#39;m not even sure if planetary orbits have to be round or not. =) But again, for the sake of arguement, let&#39;s assume that they don&#39;t and after that, then tell me what&#39;s wrong with my analogy.

21. StarLab Guest
I like your attempted use of thought experiments...keep trying&#33;
Do not compare redshifts and blueshifts to planetary orbitals. <_< These go round and round one source - in our case, earth and mars go around dear Sol.
I say this because earth and mars constantly are close to each other sometimes - as had just happenned recently - or are far apart. Galaxies are diffferent - galaxies tend to go their own course unless they collide. With galaxy A, B, and C, if B is ours, A is moving toward us and C away, A=blueshift and C=reshift, and there are no fluctuations. Either they are moving towards you or away; galaxies cannot change their mind. For them, a path is set, they&#39;ve but no choice but to take it.

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