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The Universe expanding rests on the observation that everything is moving away from us.
The Cosmic Microwave Background supports the Big Bang.
...the fact that the Universe is expanding.
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Originally Posted by Mike555
There are actually two major reasons pointing to a so called 'big bang' origin of the Universe. One is the expansion of the Universe, and the other is the cosmic microwave background radiation (CMB) which can be detected throughout the Universe in every direction. The CMB is a relic of the 'big bang' and is the first light of the Universe. The wavelength of that first light is now stretched out so that it is in the microwave range of the light spectrum.
For a period of perhaps 380,000 years after the big bang the Universe was too hot to allow photons to travel freely because the photons were contained within a dense and opaque plasma of energy. Once the Universe cooled sufficiently the photons could travel freely in straight lines instead of bouncing around inside a thick soup of plasma. That is the first light that we now detect as the CMB.
When we look at a map of the CMB we are looking back in time to 380,000 years after the birth of the universe.
This is a map of the CMB.
...an expanding Universe does when you run it in reverse point to a smaller Universe in the past whether that ultimately points to a singularity or to a very small area such as planck length. According to string theory, the Universe at the beginning was at planck scale size.
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Originally Posted by jacqueg
We're right out here on the edge of what is explainable within our ordinary frame of reference.
Can you accept that the evidence we have indicates an expanding universe?
There is physical, measurable evidence for which an expanding universe is currently the best explanation we have. That's about all you can say for sure.
As we speak, physicists are working steadily at answering your questions. They will find new evidence. They will find new explanations. But I know of no way to predict what that new evidence will be, nor what that new explanation might be.
Y'all seem to be making a bit of an error here, in that you seem to be assuming that what we [currently] can see of 'the Universe' is all that there is to the Universe.
The Universe is not expanding, it is already as big as it can be. Consider the concept of 'infinity'- that is the true size of the Universe. The Universe is infinite, there is no beginning, and there is no end, just as Time is infinite, with no beginning and no end.
We can see only a small portion of the Universe- the matter and energy that comprises our small corner of it, and while it may be true that what we can see is apparently expanding, it does not mean that what we can see is all that there is, nor does it mean that it has only happened once.
It is quite possible, perhaps even likely, that there are an infinite number of matter/energy groups such as we can currently see, in all stages of birth and death; and that these events have occurred an infinite number of times before as they will continue to occur an infinite number of times in the future.
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Originally Posted by rstevens62
Personally I am starting to believe Panspermia is the reason we are all here.
Off-topic thread hijack.
Quote:
Originally Posted by bobspez
My theory is the big bang was not the start but the restart. At some point all matter should be sucked into black holes until all matter gets smaller and smaller. At some point it all gets so compressed it just explodes, which I think is a big bang. It makes sense that the big bang would just be part of an endless cycle, like everything else in nature.
If you and Mr5150 keep bringing the Bible and theology into it the moderator is going to close this thread. And that would be a shame because the topic is a good one.
I am not going to close, but I am issuing a warning that might follow with infractions:
This is a SCIENCE FORUM.
If anyone wants to discuss religion, please post in Religion Forum.
Preaching and other religion related stuff will be deleted.
Y'all seem to be making a bit of an error here, in that you seem to be assuming that what we [currently] can see of 'the Universe' is all that there is to the Universe.
I don't think that anyone on this thread has made the claim that all we can see of the Universe is all that there is of the Universe. The radius of the observable Universe is estimated to be approximately 46.5 billion light-years. How big the Universe is beyond what we can observe is unknown. It is further unknown whether the Universe is infinite or if there are other Universes beyond our own finite but expanding Universe.
Quote:
The Universe is not expanding, it is already as big as it can be. Consider the concept of 'infinity'- that is the true size of the Universe. The Universe is infinite, there is no beginning, and there is no end, just as Time is infinite, with no beginning and no end.
Actually, cosmologists have measured the rate of expansion of the Universe.
''The most precise measurement ever made of the speed of the universe's expansion is in, thanks to NASA's Spitzer Space Telescope, and it's a doozy. Space itself is pulling apart at the seams, expanding at a rate of 74.3 plus or minus 2.1 kilometers (46.2 plus or minus 1.3 miles) per second per megaparsec (a megaparsec is roughly 3 million light-years).''
We can see only a small portion of the Universe- the matter and energy that comprises our small corner of it, and while it may be true that what we can see is apparently expanding, it does not mean that what we can see is all that there is, nor does it mean that it has only happened once.
Again, the size of the observable Universe has been measured. Cosmologists and physicists have speculated on what lies beyond what we can see. The Universe could be infinite. On the other hand, our Universe, while expanding may be of finite size with other Universes beyond our own, whether they be bubble Universes, or perhaps branes. We don't know.
Quote:
It is quite possible, perhaps even likely, that there are an infinite number of matter/energy groups such as we can currently see, in all stages of birth and death; and that these events have occurred an infinite number of times before as they will continue to occur an infinite number of times in the future.
The eternal inflation model, if true, and which arises out of the big bang theory, predicts an endless succession of 'big bangs' occurring.
Eternal Inflation and Colliding Universes
On 21 January, 2014, in Outreach, Papers, Science, by admin
''In modern cosmological models, the very, very early Universe was dominated by a period of exponential growth, known as inflation. As inflation stretched and smoothed the expanding space, particles that were once right next to each other would soon find themselves at the edges of each other’s cosmological horizons, and after that they wouldn’t be able to see each other at all. It was a time of little matter and radiation — an almost complete void except for the immense vacuum energy that drove the expansion.
Luckily, at some point inflation stopped. The vacuum energy decayed into a hot dense plasma soup, which would later cool into particles and, by gravitation, conglomerate into all of the complicated cosmic structure that we see today.
The theory of eternal inflation is quite similar: the very early Universe was dominated by exponential growth, and at some point the growth needed to stop and the energy needed to be converted into matter and radiation. The difference is that in eternal inflation, the growth need not have stopped all at once. Instead, little bubbles of space could have randomly stopped inflating, or fallen onto trajectories which would lead to inflation’s end. The bubbles’ interiors would be in a lower energy state (less vacuum energy means slower inflation), and since they’re in an energetically favorable state they would expand into the inflating exterior. This is much the same as little bubbles of steam growing and expanding in a pot of boiling water: a steam bubble nucleates randomly, and then grows by converting water into more steam. If the Universe weren’t expanding, or if it were expanding slowly, each bubble would eventually run into another bubble and the entire Universe would be converted to the lower vacuum energy. But, in a rapidly expanding universe, the space between bubbles is growing even as the bubbles are themselves growing into that space. If the expansion is fast enough, the growth of inflating space will be faster than its conversion into lower-energy bubbles — inflation will never end.''
Y'all seem to be making a bit of an error here, in that you seem to be assuming that what we [currently] can see of 'the Universe' is all that there is to the Universe.
And I find it interesting that you felt the need to react the way you did to my post. If you felt my professor was wrong, just say so , but don’t claim I have some sort of mental illness. As for your opinion about the Bible it is just that; your opinion and nothing more.
So tell me, since the primary stuff during the early time of the Big Bang was photons where did the or how did the larger subatomic come from or form?
My post responding to this was too religion related (anti-bad-theology) and is now gone. Basically, I don't think you have a mental illness, nor would I ever suggest such a thing of you given your posts that I have read. Memory reconsolidation is a common topic in psychological and neurological sciences.
It wasn't an opinion on your particular bibliolatry but on a specific theology. [gone now, don't worry]
The idea I am under the impression of is quoted below [carefully this time]. You can look it up further, I guess.
Quote:
Originally Posted by LuminousTruth
Restructuring memories is not a mental illness. If I recall the evidence-based psychology correctly, it's basically what every person seems to do (especially in their sleep) in order to remember parts of them, forget others, combine others, etc.
I just found it interesting that you would remember an astrophysics class that way, given that they would have had no reason back then to believe that [i.e. that light came first and became matter] (other than some version of a Christian Bible saying that light came first, [expansion snipped out]).
[... good non-science-related logic snipped out here...]
Isn't the primary stuff during the early time of the Big Bang postulated to be all elementary particles?
(i.e. electrons, photons, quarks, gluons, neutrinos, etc. and the "anti" of these)
the quarks and gluons make protons and neutrons, and protons get a boson added to become neutrons).
the boson in question is a composite of an electron and an "electron anti-neutrino."
Neutrons are thus always slightly heavier than Protons.
N&P make Atomic Nuclei, and then further electrons revolve around them to balance the charge and create a Periodic Element such as Hydrogen or Helium or any Element's atom really.
Photons thus don't make Periodic Element atoms by being cooled
Last edited by LuminousTruth; 03-17-2018 at 08:25 PM..
Y'all seem to be making a bit of an error here, in that you seem to be assuming that what we [currently] can see of 'the Universe' is all that there is to the Universe.
I don't assume that at all.
You don't have to see the universe out to its boundary to note that everywhere you look, as far as you can see, everything you can see is moving away from everything else you can see.
So even if only a part of the universe is expanding, it's still true that the part of it we can see is definitely expanding.
And thinking that part of the universe is fixed in size while other part(s) of it are expanding introduces a completely unnecessary complication. If some other thing we observed called for that condition, well and good. So far, though, nothing seems to call out for it.
I love to listen to Krauss tell his fairy tale. The universe arose from a quantum fluctuation, OK, great, and you sold some books. Now Dr. Krauss, can you explain where the laws of quantum mechanics came from since they had to predate your initial state? And the arm waving begins...
Physicist John Wheeler once warned his young grad students about things they should avoid. He said never chase women, busses, or theories of cosmology, another will come along in a few minutes.
In honor of Stephen Hawking - I am wondering how could everything form in one big bang?
My understanding is this theory primarily rests on the observation that everything is moving away from us. Isn't this logic a bit too simplistic and "linear"? It's like looking at prices keep rising and predict it must be 0 at some point.
And how can everything fit into one "singularity"? We know even an atom has a certain width.
I am atheist, by the way.
I guess you should have asked him while you still had the chance. It's a bit late now.
I am somewhat confident that humans may someday laugh at the certainty we currently display about our current theories regarding the universe. One would have to study these theories constantly in order to avoid ridicule for espousing a theory that was popular a couple years ago.
If any forum should be lenient regarding alternate theories, one would certainly hope that science and technology would strive for open mindedness.
Absolutely. The idea that we are sure that something like the elongation of electromagnetic wavelengths can ONLY be the result of increasing distance is pure hubris. Who is to say that it is impossible for EM radiation to be stretched due to interaction with an incredibly thin concentration of dark matter, or something inherent in the structure of space itself that we simply haven't discovered yet? Yet the vast majority of researchers just accept that you can scale the Doppler Effect to the entire universe, and that's that.
Quantum physics and all sorts of advanced maths are amazing tools, but that is all they are, man-made tools. We CREATED math, we didn't discover it. For a long time it helped us model the universe, but at some point there is more than we can understand with the tools at hand.
When all you have is a hammer, everything looks like a nail.
Last edited by rugrats2001; 03-18-2018 at 09:21 AM..
I love to listen to Krauss tell his fairy tale. The universe arose from a quantum fluctuation, OK, great, and you sold some books. Now Dr. Krauss, can you explain where the laws of quantum mechanics came from since they had to predate your initial state? And the arm waving begins...
Physicist John Wheeler once warned his young grad students about things they should avoid. He said never chase women, busses, or theories of cosmology, another will come along in a few minutes.
That's true. Please tell me which cosmologist thinks it is all nailed down.
I'm quite sure that Krauss, in particular, thinks no such thing.
Don't make the mistake of thinking that because we don't yet know everything, that must mean that we know nothing.
We can only learn something if we set up a hypothesis, discuss it every way we can imagine discussing it, and then do our best to disprove it. That's all any of these folks are doing. They don't add this disclaimer to everything they say, because they take for granted that the people they are talking to are educated enough to understand this.
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