Question about the big bang.

WOW! You are some very smart people no doubt!
Thank you so much for taking the time to school me a little!
Although I will not pretend that I understand everything discussed here, I will say it has expanded my imagination.
Thanks also for the great links!
I couldn't sleep last night and had this thought in my head.
I did some searches but did not quite know how to word it, to get the results I was looking for.
So the answer is we don't know. Cool!
You guys rock!
Thanks Again!
 
rockoon said:
This doesnt sound right.

Our observation horizon is expanding at C and nothing should be able to overtake that, regardless of its acceleration.
Click to expand...

True. What I meant was that our descendants will be in a 'smaller' universe (well, it'll be the same diameter, but there will be less stuff in it). The real horizon, for all intents and purposes for myself, is objects whose light will strike earth within my lifetime.

One forecast is that intelligent creatures 8Billion years from now in our galaxy will not see any other galaxies. There's an exception regarding Andromeda, on account of it'll be smooshed with Milky Way by then.

Phil Plait covers this a bit in the most recent SGU, and Dr. Singh talks about it a bit in the last chapter of Big Bang.

Incidentally, on the topic of Big Bang, I strongly recommend this book for a layperson who is interested in the scientific argument for the theory. It also covers a decent amount of the history of cosmology and astronomy, which makes it a very dog-eared book in my collection.
 
strathmeyer said:
RecoveringYuppy, things aren't moving away from us and "disappearing over the horizon". The expansion of the universe is caused by more space forming between objects, like two dots on an inflated balloon moving apart. Does this make sense?
Click to expand...
I think it's both. A point in space that is near our current horizon is inevitably going to cross over the edge (assuming the expansion is accelerating). But a civilization at that point could choose to send some objects out in various directions. Some of those objects would disappear over our horizon faster and some slower.

An objects acceleration is the sum of what it experiences due to forces and the acceleration of the expansion (or contraction) of the universe. It's the former that can't exceed c.
 
Brattus said:
I couldn't sleep last night and had this thought in my head.
Click to expand...

I like the sound of that. I think a sign of a dyed-in-the-wool skeptic is somebody with three attributes: the desire to have something actually make sense, right down to the last detail, and secondly, not being afraid to turn to others for clarification.

The third is the ability to distinguish a crap answer from a good one. That comes with time. For many, it never happens at all.
 
Jarom said:
I'm sure you meant "subset of the real numbers that are also infinite. Just wanted to avoid any confusion for others reading this thread.
Click to expand...


Sorry, I should have said integers are an infinite set that is a subset of rational numbers also an infinite set.
 
RecoveringYuppy said:
I think it's both. A point in space that is near our current horizon is inevitably going to cross over the edge (assuming the expansion is accelerating). But a civilization at that point could choose to send some objects out in various directions. Some of those objects would disappear over our horizon faster and some slower.

An objects acceleration is the sum of what it experiences due to forces and the acceleration of the expansion (or contraction) of the universe. It's the former that can't exceed c.
Click to expand...

It is my understanding that smaller independent masses are not as affected by this spacial hyperinflation, so a spaceship will not be 'carried along' with spacial inflation. I have never understood this part of the equations, and I don't think the model explains it well either. That's a component of the model that confuses me: why is, say the solar system, not experiencing this expanding force proportionally? (knowing that it would be counteracted by gravity, of course - I'm not saying that I expect the solar system to fly apart in this model.)

My suspicion is that the travelling object will not have had enough time exposed to this expansion to be properly accelerated. I'll defer to list members with the appropriate background for this.

The example is that these small pseudogalaxies / min-galaxies that orbit majors like the Milky Way are so more affected by the gravity of their parent galaxy than they are by inflation that the galactic gravity is completely adequate to explain their position. The exception being the need for dark matter or dark energy to explain their inertia.
 
blutoski said:
I like the sound of that. I think a sign of a dyed-in-the-wool skeptic is somebody with three attributes: the desire to have something actually make sense, right down to the last detail, and secondly, not being afraid to turn to others for clarification.

The third is the ability to distinguish a crap answer from a good one. That comes with time. For many, it never happens at all.
Click to expand...

Well Thanks!
I am reading what you guys are posting. I am trying but not understanding most of it.
Dark matter? Is that like anti-matter? How can something be a non thing?
I do however understand the vastly larger universe thing I said though.
There can't be anything outside of space itself. Larger than time and space just can't be.
I really need to find another source to feed my brain than my collection of Silver Surfer comics.:wackywideeyed:
 
Brattus said:
Dark matter? Is that like anti-matter? How can something be a non thing?
Click to expand...

Dark Matter is the term used for the matter in the universe we cannot see directly. Ie, the stuff does not emit observable radiation within the limits of our technology.

But we can see its effects on things we CAN directly see, such as its effects on the motions of stars within galaxies, so we know it must be there (and there must be a hell of a lot of it, more dark matter than anything else)

http://en.wikipedia.org/wiki/Image:DarkMatterPie.jpg
 
Last edited:
rockoon said:
Dark Matter is the term used for the matter in the universe we cannot see directly. Ie, the stuff does not emit observable radiation within the limits of our technology.

But we can see its effects on things we CAN directly see, such as its effects on the motions of stars within galaxies, so we know it must be there (and there must be a hell of a lot of it, more dark matter than anything else)

http://en.wikipedia.org/wiki/Image:DarkMatterPie.jpg
Click to expand...

I like how the \image:DarkMatter take the :D smilie....very cheery :D
 
rockoon said:
Dark Matter is the term used for the matter in the universe we cannot see directly. Ie, the stuff does not emit observable radiation within the limits of our technology.

But we can see its effects on things we CAN directly see, such as its effects on the motions of stars within galaxies, so we know it must be there (and there must be a hell of a lot of it, more dark matter than anything else)

http://en.wikipedia.org/wiki/Image:DarkMatterPie.jpg
Click to expand...

Wow! Very cool! Thanks Rock! The links in this thread have been awesome!
 
You must log in or register to reply here.

Back
Top Bottom