Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 86 (8945 total)
364 online now:
AZPaul3 (1 member, 363 visitors)
Newest Member: ski zawaski
Upcoming Birthdays: ONESOlivia, perfect
Post Volume: Total: 865,616 Year: 20,652/19,786 Month: 1,049/2,023 Week: 557/392 Day: 101/72 Hour: 1/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   How did a new satellites get in the right position?
ramoss
Member
Posts: 3122
Joined: 08-11-2004


Message 31 of 35 (428746)
10-17-2007 2:44 PM
Reply to: Message 20 by techristian
10-12-2007 12:22 AM


Re: I'm trying to see this.
Well, you are incorrect. The big bang is not an explosian, it is an 'expansion'.

This message is a reply to:
 Message 20 by techristian, posted 10-12-2007 12:22 AM techristian has not yet responded

  
Rahvin
Member
Posts: 3964
Joined: 07-01-2005


Message 32 of 35 (428765)
10-17-2007 3:44 PM
Reply to: Message 25 by techristian
10-16-2007 11:57 AM


I would call this an EXPLOSION. It is a matter of semantics.

It's really not, though. The two models are very, very different from each other.

BTW I have read a few good SECULAR books on cosmology since my graduation from formal education. However I admit it has been over 10 years so I'll need to break them open again. "GRAVITY'S LENSE" is one of them.

Try readong something that's not
a) more than 10 years old. Cosmology has progressed a bit in the bast decade.
b) designed for the average joe. Many popular "science" books are dumbed down for general consumption, much like the simplified documentaries you see on TV.

If this balloon is a perfect sphere and expands evenly then the particles will indeed move out in a straight line. Right?

Wrong. As already noted, the balloon model was an oversimplification I used exclusively to draw a distinction between expansion and explosion. There are many other forces at work in the real universe beyond just the expansion of space. Gravity would be a pretty big one, and it makes sure those particles don't just move in straight lines away from each other.

Because we have RED SHIFT on many of the stars, this would indicate that the universe is still expanding at near light speed.

As has already been mentioned, the speed required for red shift is entirely dependant on your frame of reference. The entirety of space is expanding, which creates a much different model than the "zomg it blew up" version you're using.

This would also indicate that the expansion was even faster at the very beginning.

It does no such thing. Also, as has been mentioned, an evenly expanding space will make it appear that two objects actually accelerate away from each other, not merely moving at a set speed. Again, you're trying to use an "explosion" model becasue that's what the Big Bang is typically described as to the general public. That's the dumbed down version, and is only a weak analogy to the Big Bang so that you don't need a degree in astrophysics to get the basic idea.


Every time a fundy breaks the laws of thermodynamics, Schroedinger probably kills his cat.

This message is a reply to:
 Message 25 by techristian, posted 10-16-2007 11:57 AM techristian has not yet responded

  
LouieP
Junior Member (Idle past 4157 days)
Posts: 12
From: Schererville, IN
Joined: 01-02-2008


Message 33 of 35 (445668)
01-03-2008 11:18 AM


the expansion
is the expansion of space itself observable to us, via calculation of the distance from the earth to sun or maybe the sun to Uranus, or are these distances relatively too small to notice the expansion within our lifetimes. is there any kind of assumptions about the rate of expansion per 100,000 million miles?

Thanks
louie


Replies to this message:
 Message 34 by Rahvin, posted 01-03-2008 1:27 PM LouieP has responded

  
Rahvin
Member
Posts: 3964
Joined: 07-01-2005


Message 34 of 35 (445706)
01-03-2008 1:27 PM
Reply to: Message 33 by LouieP
01-03-2008 11:18 AM


Re: the expansion
is the expansion of space itself observable to us, via calculation of the distance from the earth to sun or maybe the sun to Uranus, or are these distances relatively too small to notice the expansion within our lifetimes. is there any kind of assumptions about the rate of expansion per 100,000 million miles?

Thanks
louie

From what I understand, those distances are too small, and gravity is holding the bodies in our solar system together anyway.

The expansion is observed in the redshift of very distant stars, and the fact that the further distant the star, the more intense the redshift (so the more space is between two object, the more space is seen to expand. Like the balloon example above, two dots close together on an expanding balloon will move apart more slowly than two dots farther apart, because every square inch of the surface is expanding at the same time.


Every time a fundy breaks the laws of thermodynamics, Schroedinger probably kills his cat.

This message is a reply to:
 Message 33 by LouieP, posted 01-03-2008 11:18 AM LouieP has responded

Replies to this message:
 Message 35 by LouieP, posted 01-03-2008 1:32 PM Rahvin has not yet responded

  
LouieP
Junior Member (Idle past 4157 days)
Posts: 12
From: Schererville, IN
Joined: 01-02-2008


Message 35 of 35 (445708)
01-03-2008 1:32 PM
Reply to: Message 34 by Rahvin
01-03-2008 1:27 PM


Re: the expansion
From what I understand, those distances are too small, and gravity is holding the bodies in our solar system together anyway.

The expansion is observed in the redshift of very distant stars, and the fact that the further distant the star, the more intense the redshift (so the more space is between two object, the more space is seen to expand. Like the balloon example above, two dots close together on an expanding balloon will move apart more slowly than two dots farther apart, because every square inch of the surface is expanding at the same time.

thank you for the timely response, I feel that i have a good grasp on what is occurring, or we assume is occurring, as we know an increase in knowledge can always change what we feel to be fact. i was definitely mainly wondering if there was some type of scale i could use even for my own purpose to simplify the extent of the expansion.

intriguing to me nonetheless.

thanks again


This message is a reply to:
 Message 34 by Rahvin, posted 01-03-2008 1:27 PM Rahvin has not yet responded

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2018 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2019