" inside the orbit of the Sun at the centre of the galaxy"
Wow! Our star is the centre of the galaxy?
Our Milky Way galaxy is INSIDE OUT. Just as we suspected, mutter boffins
New data from the European Space Agency's Gaia-ESO project has confirmed that the Milky Way galaxy grew from the inside out, backing up theories espoused in the standard model of the Big Bang. On-edge view of the Milky Way's star formation Right after the Universe exploded into existence, it was made up almost entirely of …
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Wednesday 22nd January 2014 13:28 GMT Bunbury
Just because a theory has weaknesses does not make it invalid as long as it is the best fitting theory to the facts. While I don't understand the physics involved, I can appreciate that it may be the best fit to the data at hand. I understand (from a programme on the telly, which I watched to the end emerging with a pathetic sense of smugness as if I'd worked it all out myself instead of sitting there like a gormless idiot) that a number of scientists working in the field no longer believe that the actual bang occurred. Unclear whether a successor theory will emerge it seems - we see but through a mirror darkly.
I particularly struggle with the concept that everything in the universe emerged from a very small space and yet if you tried that now you'd just have a massive black hole. Or perhaps similar things do occur now and become black holes. Presumably it's that we don't have enough data to form a theory that's correct. In the same way that 19th century scientists struggled to understand the power source of the sun "it surely can't be coal, as it would have burned out by now"
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Thursday 23rd January 2014 10:02 GMT Anonymous Coward
"everything in the universe emerged from a very small space"
That's because you are looking at it wrong. You seem (unless I have misunderstood you) to think that spacetime existed, and the Big Bang expanded into spacetime.
It didn't. Spacetime resulted from the Big Bang. The "size" of the universe at the BB is really a meaningless concept, like the tangent of 90 degrees. The present universe has lots of spacetime, and matter can fall into a small part of it and make a black hole. The BB universe had no spacetime and was at an incomprehensible temperature and pressure, so there was no Higgs field, no particles to feel one if it existed, and so no gravitational force to constrain it against the pressure for expansion.
Physicists tend not to dwell on this stuff, but the numbers are impressive. In the inflationary theory, the size of the universe at the end of inflation is about that of a marble, which is not what I imagine most casual readers think. This is also the order of magnitude of the size that just our Sun would be if it condensed into a black hole.
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Thursday 23rd January 2014 16:40 GMT Anonymous Coward
Re: "everything in the universe emerged from a very small space"
In fact, there is a theory of how the particles appear and disappear at different energies. As things cool off after the BB, particles appear due to processes called "symmetry breaking". As soon as the energy level is high enough that there isn't any spacetime, the question how much energy you can hold in your universe becomes immaterial. (pun)
This is why currently inflation is needed - somehow some handwaving has to produce an expansion faster than the speed of light to get to a size at which the universe can expand into its present form. Despite the speed of the expansion, at the end of it the universe is still conveniently pocket sized, assuming your pocket is rather rad-hard and very shortlived.
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Tuesday 21st January 2014 20:09 GMT Tinker Tailor Soldier
Of course, Polonium cannot exist!
Believe the commentard was referring to then following quasi-science:
http://www.freechristianteaching.org/modules/smartsection/item.php?itemid=92#axzz2r43pqucU
However, of course, nuclear synthesis cannot possibly happen in nature. (209Bi can capture a proton to produce 210Bi and decay to 210Po). Which can be quickly looked up here:
http://en.wikipedia.org/wiki/Polonium
But then fundamentalists were never known for their critical thinking abilities... or ability to understand math. By the same logic, He3 couldn't exist either.
Nuclear explosion 'cos this is all about nuclei...
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Thursday 23rd January 2014 09:59 GMT TRT
Centre of the galaxy...
well if it said "central part of the galaxy" in the article... but it doesn't. It says centre. To me, that's a point.
And as regards centres of orbits, they can be terribly complicated things and can move around relative to something else. For example the centre of the moon's orbit is inside the Earth, but it's not the centre of the Earth.
The point I was making with my first post in this thread is that the article could be more clearly written.
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Wednesday 22nd January 2014 11:22 GMT Ed_UK
Re: Not had Hersheys, then?
"Or Cadburys Dairy Milk made in Australia?"
Yay - it's not just me then. I tried it on a visit to Oz in the 1990s. Familiar wrapper but it was like trying to each a choc-flavoured ceramic tile. We speculated that maybe Cadbury's modified the recipe to tolerate the higher temperatures than Blighty's. However, I think I once saw a FAQ section on their website which said that they didn't tweak their recipes. Maybe I've just forgotten.
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Wednesday 22nd January 2014 11:28 GMT Anonymous Coward
Re: It's just a theory!!!
Tim Minchin gave the definitive response to this 'it's just a theory' nonsense, albeit originally in relation to religious nuts stock argument against the theory of evolution. I think the same sentiment applies;
"... which is true, it is a theory, it’s good that they say that, I think, it gives you hope, doesn’t it, that - that maybe they feel the same way about the theory of gravity… and then they might just float the f**k away."
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Tuesday 21st January 2014 14:21 GMT Khaptain
Many dimensions
I always like to imagine the universe as a torus who's centre is very small and who's outside edges are very very distant. Things evolve/revolve along it's various axes permanently, thereby giving the universe a cyclic nature.
What's here today is gone tommorrow but back again the day after ( on a universal scale that is).
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Tuesday 21st January 2014 15:24 GMT Scott Broukell
Re: Many dimensions
@Khaptain
Or what about a simultaneous miniscule spherical (oblate) surface, within, a massively larger spherical (oblate) surface and replace the euclidean topography of the torus with pathways that continue each surface infinitely, as you suggest, but via black holes, contorting and compressing the field-lines of space time endlessly along said 'conveyor belt'. The 4% of matter we can account for, which includes ourselves and all observable galaxies, being made up merely from the exhaust / pollution / remnants, call it what you will, of the sudden massive inflation which befell the quark-gluon plasma that hung around for a relatively short while after an instability / perturbation set in on the singularity, that may or may not itself, have resulted from a prior super-massively-tiny universe, having reached a (near) perfect entropic state of pure photons only to find itself ripped apart by the fact that space-time cannot tolerate a static 'conveyor belt', whichever direction it is traveling in. That's my take on it.
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Tuesday 21st January 2014 16:49 GMT Sir Sham Cad
Re: That's my take on it.
You'll be disappointed to know that your high entropy collection of pseudo-scientific jargon is just a lot of made up bollocks.
Inflationary cosmology explains why the shape of the universe we observe is flat (read: Euclidean so your toroids etc... are right out), the extremely rapid expansion caused by the collapse of the energy density of the inflaton field (no plasma of any kind as there was no matter at all prior to this point, it's all quantum fields) drove the matter density of the universe to equal the critical energy density predicted to give us a flat universe.
In terms of where the perturbation came from that set the inflaton field off on its rapid tumble towards (nearly) zero energy, simple quantum fluctuations were enough. Same as for the Higgs field that gave a meaning to a "mass" property.
In terms of where the matter came from, remember matter and energy are the same. As the inflaton field collapsed it drew energy from the negative gravity causing the inflation of space as it was shedding that energy as matter and radiation so the more space expanded the more mass/energy the inflaton field could dump into space. To the point where an original mass in the universe before inflation of 2.1601 Jub would account for all that we see in the universe including the "Dark" stuff.
So we have an original, tiny lump of spacetime containing only quantum fields at high energy. Quantum jitters go jitter and we have a amazingly rapid period of expansion creating all matter and energy in the universe. As gravity starts to have an effect this expansion slows down and astrophysical processes start making galaxies and all the good stuff. Right up until the point that space expanded so much that the negative gravity left over from the inflaton field having non-zero energy is enough to overcome the gravity that slowed the expansion and, right now, it's on the increase again.
Also, this article references "Standard Big Bang Theory" but the processes involved occur after the effects of Inflationary Theory therefore don't actually speak to Standard Theory versus Inflationary Theory.
Right, even I'm bored of this post now. To The Pub!
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Thursday 23rd January 2014 10:10 GMT Anonymous Coward
Re: That's my take on it.
There are some real physicists who publish proper peer reviewed papers who have doubts about inflation. It seems highly improbable, too much like a post hoc explanation.
Unless you believe that, just as the BB was happening, God put her sink plunger on top of the universe and then pulled it up really, really quickly.
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Tuesday 21st January 2014 14:52 GMT Alister
I must be reading this wrongly...
Gaia's evidence shows that older, metal-poor stars inside the orbit of the Sun at the centre of the galaxy are far more likely to have high levels of magnesium
So if there are stars inside the orbit of the Sun at the centre of the galaxy, how can it be "The Sun at the centre of the galaxy"?
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Tuesday 21st January 2014 15:52 GMT Tom 260
Re: Bah!
There seems to be a debate as to whether a galactic collision can result in a spiral galaxy, or it always leads to an elliptical galaxy. Give it a hundred million years or so for any of the currently observable galaxies in collision to sort themselves out and we'll have a definitive answer.
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Tuesday 21st January 2014 17:17 GMT davoid
Of course, if metals are also being produced by material closely orbiting the black hole, you might expect to see a similar distribution of any given element. Did the study only map Mg or did it map several elements? If the latter are the abundances consistent with the supernovae process, or are there divergences which get stronger as you move inwards?
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Tuesday 21st January 2014 19:00 GMT Sir Sham Cad
Re: Just a simple question.
It's not a simple question but a very profound one. Unfortunately it's founded on a notion of causality and familiar laws of nature that just didn't exist at the very earliest beginnings of the universe. What does it matter what came "before" when time itself didn't exist so the question itself has no meaning.
Big Bang theory only gives us info on what the universe was like about 10^-43 seconds (Planck time) into its life. Beyond that, physics of any kind just doesn't play.
It's reasonable to speculate that a singularity existed as infinite potential and had a quantum jitter (read: because it could rather than conventional quantum mechanical processes) which caused a spacetime to develop with a unified symmetrical force out of the infinite potential. However we have no way of probing back that far for reasons already mentioned.
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Tuesday 21st January 2014 20:48 GMT Jim Wilkinson
Re: Just a simple question.
This post is very enlightening. I'm reading a book ATM which shocked me... when the universe began, it was space-time that started. There was no time before the BB. How could time alone exist when there was nothing else? So prior to the BB, there was nothing, no matter, no space, no time, absolutely nothing at all. It makes sense but it's still hard to grasp because it's beyond our experience.
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Wednesday 22nd January 2014 13:43 GMT Tom 38
Re: Just a simple question.
I've tried to answer this a couple of times, it's best to go to an expert:
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Tuesday 21st January 2014 22:00 GMT Destroy All Monsters
Re: But here's a puzzle...
That kinda stuff is being pretty much very well indeed simulated on them supercomputers.
The Millennium-XXL Project: Simulating the Galaxy Population in Dark Energy Universes
No extra crank stuff needed except dark ingredients.
I do think we have ourselves a winner.
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This topic is closed for new posts.
Biting the hand that feeds IT
