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Re: The Dark Universe

Posted: Mon Jun 27, 2011 11:30 am
by Slammr (imported)
BossTamsin (imported) wrote: Mon Jun 27, 2011 6:25 am I'd be most appreciative if you could provide any information about the story. I've looked through the most obvious choices, and have come up blank so far.

This may be the story: http://www.enotes.com/all-myriad-qn, All the Myriad Ways, a short story by Larry Niven.

Re: The Dark Universe

Posted: Mon Jun 27, 2011 12:09 pm
by Slammr (imported)
Arab Nights (imported) wrote: Mon Jun 27, 2011 10:03 am I originally could accept the concept of the Big Bang. But then I ran into a real conceptual problem. I still visuallized it as the universe explosively forming from a point of infinite density. That means that it is from a point source and moving outward in all directions from the point. When I asked astronomy types where that point was, I got mumbo jumbo answers like 'it was everywhere.' That makes no sense to me in terms of the Big Bang and an expanding universe.

The problem is that you're thinking in three dimensions - we all do - while space is four dimensional. For instance, from our perspective, it looks like other galaxies, except for the ones in our local cluster, which are bound to us by gravity, are receding from us, and it seems we are at the center, but if you were in one of the other galaxies, the Milky Way would be one of the other galaxies receding from you, and you would seem to be at the center. In four dimensional space-time there is no center.

Take a balloon, paint spots on it, call those spots galaxies, and blow it up. As you blow it up, the spots get farther and farther apart, and the farther one spot is from another, the faster it recedes from the other spot. Yet, considering only the surface of the balloon, there is no center. Space, the surface of the balloon, is expanding everywhere at once.

We look at distant galaxies and see that they are receding from us, but they aren't moving through space. Space is expanding in every direction at once. Space has no center.

Imagine the balloon again. Suppose that it starts out infinitesimally small with the spots already painted on it. Say it's a self inflating balloon. No one has to blow it up, and it has no spout in which to blow air. Consider only the surface of the balloon, which we will call space. As the balloon inflates, the spots - galaxies - spread apart, but there is no spot on the surface of the balloon you could call the center.

Re: The Dark Universe

Posted: Mon Jun 27, 2011 12:46 pm
by Arab Nights (imported)
Slammr (imported) wrote: Mon Jun 27, 2011 12:09 pm The problem is that you're thinking
- while space is four dimensional. [/I]

Proof positive that all the people who have called me a one-dimensional asshole are wrong, wrong, so wrong.

Re: The Dark Universe

Posted: Mon Jun 27, 2011 3:04 pm
by Dave (imported)
..
Arab Nights (imported) wrote: Mon Jun 27, 2011 10:03 am . The thing is that it is a collision along the entire area of the two 'towels' or universes, hence not from a single point and it then follows that the starting point was everywhere and not just a single point...

But remember, the two towels do not have to stay flat and parallel to each other. They could bend and wave and flap around. So they could just touch at one point (one dimension) or they could touch on a line (two dimensions). They don't have to touch all three dimensions.

The reason that these multiple membranes (what you call the towels, good simile, good image) are postulated or theorized was to explain the weakness of gravity. The graviton (the particle that creates gravity like the electron creates electricity and magnetism) is thought to exist between the membranes or towels. Gravity is an amazingly weak force compared to all the others existing in nature.

And from what I understand, the universe right after the big bang did exhibit 11 dimensions. Those dimensions require lots of energy and as the universe expands, the energy density decreases and closes off the other dimensions. Right now, we have four dimensions. (up/down, left/right, front/back and time)...

Re: The Dark Universe

Posted: Mon Jun 27, 2011 10:43 pm
by Riverwind (imported)
All I know is that the universe is fascinating in its wonder.

River

Re: The Dark Universe

Posted: Tue Jun 28, 2011 3:01 am
by erikboy (imported)
BossTamsin (imported) wrote: Sun Jun 26, 2011 9:30 pm It's a sad state in some ways. First we weren't the centre of the universe, our sun was. Then our sun was just one in an astronomical number in our galaxy, and in an unfashionable end of an arm, too. From there, our place was reduced still further, as just one minor galaxy in our Local Group, which is a small part of the Virgo Supercluster.

We are lucky to live far from galaxy centers, which is unstable environment for such a tiny planet we live on. It is more probable to die in the center of galaxy due to deadly gamma bursts, close by supernovas, passing blackholes, etc.

I think we live in the quiet corner of galaxy for reason. In the center we couldn't evolve that far.

Re: The Dark Universe

Posted: Tue Jun 28, 2011 4:32 am
by Riverwind (imported)
The conditions for our planet must be just right as they say, I wonder how many other planets fall into the same category as us? Not only in our galaxy but in the billion or so others? The odds suggest that life on other planets are very good, we may never know for sure and that is part of the wonder.

River

Re: The Dark Universe

Posted: Tue Jun 28, 2011 5:45 am
by BossTamsin (imported)
erikboy (imported) wrote: Tue Jun 28, 2011 3:01 am We are lucky to live far from galaxy centers, which is unstable environment for such a tiny planet we live on. It is more probable to die in the center of galaxy due to deadly gamma bursts, close by supernovas, passing blackholes, etc.

I think we live in the quiet corner of galaxy for reason. In the center we couldn't evolve that far.

Oh, I absolutely agree with that. While the night sky at galactic centre might be far more exotic, there is no way I'd want to live anywhere near there. It's just humbling how far we've moved from our original position at the centre of creation. (Personally, I'm still not willing to rule out our running into Puppeteers fleeing a core explosion.)

Slammr: Thank you, that is indeed the short story I was thinking of, and for once it actually was in the book I first thought of (and discounted, not recognizing the title in the table of contents of N-Space.) If only I had the space to take my book collection out of storage....

Re: The Dark Universe

Posted: Tue Jun 28, 2011 6:11 am
by erikboy (imported)
Riverwind (imported) wrote: Tue Jun 28, 2011 4:32 am The conditions for our planet must be just right as they say, I wonder how many other planets fall into the same category as us? Not only in our galaxy but in the billion or so others? The odds suggest that life on other planets are very good, we may never know for sure and that is part of the wonder.

River

There might be hundreds or even hundreds of thousands such planets like our own. Only it seems to me that we and other civilisations are separated not only by vast space but with time difference too. Civilisation existence time is like short flash of light in the night. For two such a flashes to coincide is not so likely. Not speaking about space between them and us.

Another phenomena we do experience is that we are the most advanced in time. So for other signals to reach us must have invented radio at the same time we did minus signal travelling time. There is nothing parallel in universe. Time is travelling at the speed of light! And that speed is quite limited.

Re: The Dark Universe

Posted: Tue Jun 28, 2011 3:52 pm
by moi621 (imported)
Drifting (thread) amongst billions and billions (think Sagan) of planets looking for one or some that have a molten core as creates a magnetosphere to protect large cumbersome organic molecules from disintegration by cosmic rays and a companion as to be a binary planet system to moderate the effects of gravity from a sun or two.

Currently astronauts/cosmonauts are not protected from cosmic rays and do seem to get cancer. Also some astronauts report when they sleep they see "flashes" as are caused by cosmic rays hitting a retina cell, just right.

Now more on topic, would my teachers as convinced me "undiscovered matter" exists, address the concept of Dark or undiscovered Energy.

🙏

ISS needs a magnetic field! 📢

Maybe we could wrap it in copper wire and run a small current through it. 💡