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| whiskeypriest |
 Posted: Mon Mar 17, 2014 1:34 pm |
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Joined: 20 May 2004
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Location: "It's a Dry Heat."
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| Brothers. |
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I ask you, Velvel, as a rational man, which of us is possessed? |
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| gromit |
| Posted: Mon Mar 17, 2014 2:21 pm |
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Joined: 31 Aug 2004
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Location: Shanghai
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I was just trying to read up a little on dark matter and dark energy last week.
Seems that physical matter is believed to be only about 17% of the mass of the universe. Which is pretty crazy. That 83% of the mass of the universe is believed to be something that can't be seen and hasn't been observed. And might not exist. Cause once you start making things up -- such as interstellar space being filled with ether or whatnot -- there's a good chance your model is wrong and that's why you have to posit something bizarre and unobservable. Unless of course it happens to be right.
Veering somewhat, since there are some sciencey people here, let me toss out the theory I came up with in the shower the other day:
How did the universe come into existence?
Obviously positing a God just defers the question back a stage.
As does the Big Bang, as per Gary's tagline.
My idea is maybe we are asking the wrong question.
We assume that matter doesn't come from nothing, so wonder how matter got started. But maybe the fundamental nature of the universe is that matter and antimatter pop in and out of existence all the time, furiously. Not trees, but subatomic particles, on a scale we don't see.
And maybe that's what dark matter is, just an insanely enormous amount of subatomic particles coming into being and bopping back out everywhere throughout the universe. Or maybe that's just one component of dark matter. And when subatomic particles collide and coalesce, things start to get interesting and observable matter commences and other properties develop and we get the universe and here we are ...
Okay, not really sure that answers the question of why there is something instead of nothing. But it would explain to some degree why there is a universe and why there is undetected dark matter. Maybe on a quantum level matter and antimatter are ... well, I don't have to spell it all out for you guys, do I? |
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Killing your enemies, if it's done badly, increases their number. |
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| bartist |
| Posted: Mon Mar 17, 2014 5:46 pm |
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Quote: And maybe that's what dark matter is, just an insanely enormous amount of subatomic particles coming into being and bopping back out everywhere throughout the universe.
There is one view of dark energy (distinct from dark matter, which could include invisible but conventional fermionic matter - dust, brown dwarfs, misc. particle debris) very much like that.
The two main forms of dark energy being bandied about are the cosmological constant, which has a constant energy density (it fills all space homogeneously) and scalar fields like "quintessence" or "moduli" whose energy density can vary in time and space.
The cosmological constant has been formulated in recent times to be equivalent to vacuum energy, a kind of quantum percolating of fleeting particles - sort of like what you describe, Gromit. Vacuum energy is also the basis for the Casimir Effect - you can get a negative energy density between two metal plates that are very close together (basically the vacuum energy is partially suppressed by the plates) - the greater density outside the plates exerts a pressure on the plates pushing them together. It's really cool stuff.
And that also connects with your speculation about the big bang - it might have been a quantum fluctuation (giving the universe a net energy of....zero!) in a vacuum that is giving rise to some unthinkable numbers of universes. The philosophic issues are many, but one that intrigues me is the possibility that physical "laws" may be set differently, and evolve differently (read Lee Smolin's "Time Reborn" on this), in each such resulting universe. In the ones where the physical constants can support matter (i.e. with symmetry-breaking, which I won't get into right now unless someone asks) and the self-organizing of long chain molecules, consciousness can arise and wonder just how those physical constants "happened" to be just right for life....further mindbending fun may be found in a search of "anthropic principle." It's interesting to contemplate universes that do not give rise to life, or cannot quantumly "compute" the self-organizing algorithms that ours does. They are empty in a way we can scarcely imagine.
Have I mentioned how much I love physics and cosmology? |
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He was wise beyond his years, but only by a few days. |
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| jeremy |
| Posted: Mon Mar 17, 2014 5:48 pm |
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Joined: 21 May 2004
Posts: 6794
Location: Derby, England and Hamilton, New Zealand (yes they are about 12,000 miles apart)
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| About bloody time...and space. |
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I am angry, I am ill, and I'm as ugly as sin.
My irritability keeps me alive and kicking.
I know the meaning of life, it doesn't help me a bit.
I know beauty and I know a good thing when I see it. |
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| gromit |
| Posted: Tue Mar 18, 2014 12:32 am |
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Joined: 31 Aug 2004
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Location: Shanghai
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So according to Bart I was right and Syd was wrong!
Okay, so we haven't actually gotten to the latter part of that yet, but it would make my victory cigar taste sweeter. I mean, have you tasted a cigar lately, they really need all the help they can get in the taste department ...
In a nice bit of symmetry, people do the same as my subatomic particles -- we pop in and out of existence, coming from almost nothing. Also, we are stardust, and we are golden ... |
Last edited by gromit on Tue Mar 18, 2014 2:42 am; edited 1 time in total
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Killing your enemies, if it's done badly, increases their number. |
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| jeremy |
| Posted: Tue Mar 18, 2014 2:08 am |
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Joined: 21 May 2004
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Location: Derby, England and Hamilton, New Zealand (yes they are about 12,000 miles apart)
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Gromit,
To respond to your observation about Gary's tagline; the scientific consensus is that time didn't exist before the big bang...which makes everything clear. |
_________________
I am angry, I am ill, and I'm as ugly as sin.
My irritability keeps me alive and kicking.
I know the meaning of life, it doesn't help me a bit.
I know beauty and I know a good thing when I see it. |
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| gromit |
| Posted: Tue Mar 18, 2014 3:38 am |
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Joined: 31 Aug 2004
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Location: Shanghai
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Quote: Big bang, shmig bang; still doesn't explain how anything starts.
Obviously it explains: time and space in our observable universe, cosmological background radiation, gravity waves, the movement of galaxies/red-shifting, and other phenomena, most of which we work back through to discover the Big Bang to begin with.
It doesn't explain why there was an exploding singularity which could expel an immense amount of material vast distances. But you have to figure things out before you can figure out what you still don't know.
I like how we live on one fairly middling planet among a number of varying planets and moons and inner and outer debris, all circling around a very ordinary star, one of billions in a rather commonplace spiral galaxy, just tucked into one unremarkable part of the universe. And there are billions of us. Yet we're sure were unique ...
I remember reading somewhere that this could be described as the Age of Bacteria and that bacteria make up some sizable percent of the organic mass on Earth, etc. Yet, of course, we don't perceive things that way, even though our bodies and environment are loaded with bacteria. I wonder if subatomic particles are similar. While atoms and molecules are sexy and visible, maybe it's really a Universe of Unattached Sub-Atomic Particles, but were just to big and busy to notice. |
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Killing your enemies, if it's done badly, increases their number. |
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| bartist |
| Posted: Tue Mar 18, 2014 8:39 am |
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Time may not exist now. Check out Julian Barbour's "The End of Time."
Age of Bacteria - yeah, the power plant of our cells, the mitochondria, were originally separate bacteria that invaded early one-celled organisms and entered into a symbiotic relationship with them. And they contain ONLY your mother's (and her mother's, and on back to the dawn of life...) DNA. Basically, the mitochondrial unit in your mother's egg is replicated as the zygote begins to divide. The nuclear DNA has no role in the mitochondria. Mitochondrial DNA is a powerful tool for studying the genetic past - and often is intact in fossil remains where the nuclear DNA has mostly fallen apart. OK, I need a small JPEG of Poindexter.... |
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He was wise beyond his years, but only by a few days. |
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| bartist |
| Posted: Tue Mar 18, 2014 8:42 am |
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Oh dear.
Honey, I thought it would shrink the kid! |
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He was wise beyond his years, but only by a few days. |
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| jeremy |
| Posted: Tue Mar 18, 2014 8:42 am |
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Joined: 21 May 2004
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Location: Derby, England and Hamilton, New Zealand (yes they are about 12,000 miles apart)
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| I can't express it very well, but I like the analogy that we're like the people living in a two dimensional world who try to make sense of the sections of the 3D world that move through their dimension. They might glimpse various manifestations of an elephant or parts of an elephant, say, and give them different names. They suspect they are connected in someway, but have no real comprehension of what an elephant is. |
_________________
I am angry, I am ill, and I'm as ugly as sin.
My irritability keeps me alive and kicking.
I know the meaning of life, it doesn't help me a bit.
I know beauty and I know a good thing when I see it. |
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| carrobin |
| Posted: Tue Mar 18, 2014 9:33 am |
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Joined: 21 May 2004
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Location: NYC
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| The main thing to remember is: Don't Panic. |
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| gromit |
| Posted: Tue Mar 18, 2014 9:41 am |
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Joined: 31 Aug 2004
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Location: Shanghai
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Jeremy is right -- he can't express it well.
I think you combined two different metaphors/thought experiments.
One is a person living in a two-dimensional world trying to understand what a 3-D world would be like.
The other one is two blind men investigating an elephant, one at the front and the other at the back -- each with access to only half the animal. Something like that.
Or like Jeremy trying to describe a two-dimensional elephant ... |
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Killing your enemies, if it's done badly, increases their number. |
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| Syd |
| Posted: Tue Mar 18, 2014 9:49 am |
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bartist wrote: Time may not exist now. Check out Julian Barbour's "The End of Time."
Age of Bacteria - yeah, the power plant of our cells, the mitochondria, were originally separate bacteria that invaded early one-celled organisms and entered into a symbiotic relationship with them. And they contain ONLY your mother's (and her mother's, and on back to the dawn of life...) DNA. Basically, the mitochondrial unit in your mother's egg is replicated as the zygote begins to divide. The nuclear DNA has no role in the mitochondria. Mitochondrial DNA is a powerful tool for studying the genetic past - and often is intact in fossil remains where the nuclear DNA has mostly fallen apart. OK, I need a small JPEG of Poindexter....
Not only that, but chloroplasts in plants were originally cyanobacteria (what are also called blue-green algae although they're not really algae). |
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I had a love and my love was true but I lost my love to the yabba dabba doo, --The Flintstone Lament |
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| marantzo |
| Posted: Tue Mar 18, 2014 10:14 am |
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A human's brain is not able to figure how something can come from nothing. Maybe when one dies, he/she figures it out and yells, "Eureka! So that's the way it is created from nothing!"
Having a fine time in Tampa right now. |
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| bartist |
| Posted: Tue Mar 18, 2014 10:15 am |
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jeremy wrote: I can't express it very well, but I like the analogy that we're like the people living in a two dimensional world who try to make sense of the sections of the 3D world that move through their dimension. They might glimpse various manifestations of an elephant or parts of an elephant, say, and give them different names. They suspect they are connected in someway, but have no real comprehension of what an elephant is.
As it happens, there is an aspect of LQG (Loop Quantum Gravity) which deals with the universe in the context of information theory. Basically, it says that we we can treat all physical events as presented on a 2D surface, on which all the information about a 3D manifold manifests as pixel-like areas, which contain 1 bit of information on an area of the surface that is 2 Planck Lengths (a verrrry tiny unit) on each side. Sometimes called a "screen theory." This theory came from the study of the thermodynamics of black holes, which basically deals with how much information a black hole contains. A guy named Beckenstein came up with a definition of a surface, called the Beckenstein Bound, which is the horizon of the black hole - and its surface represents, with these Planck squares, the information (in a thermodynamic sense) inside the BH. I imagine Stephen Hawking could make this clearer than I can...
I sort of liked your mixing of metaphor and famous elephant parable. What I describe would sort of like just feeling the skin of the elephant and figuring out its 3D bulk. |
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