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Author Topic:   Creation
Stile
Member
Posts: 3241
From: Ontario, Canada
Joined: 12-02-2004
Member Rating: 2.6


Message 676 of 1080 (832753)
05-09-2018 1:12 PM
Reply to: Message 669 by ICANT
05-04-2018 11:55 AM


Speed of Light vs. Expansion of the Universe
ICANT writes:

This expansion was faster than the speed of light.

Yes, and no.

You seem to be taking the context of when this is "yes" and applying to the context of when it's "no" as well.
I don't think you understand what's going on.

First, the correct answer:

quote:
How Fast is the Universe Expanding?

The best measurements for [the expansion of the universe] gives a value of about 68 km/s per megaparsec.


You'll notice that this doesn't have the same units as the speed of light... which can be measured in km/s... but not in "km/s per megaparsec."
The too cannot be compared in some "all encompassing" sense.

I'll try to explain with an example.

Let's imagine a rubber road that expands as Tom walks along it.

The rubber road expands at a rate of 1 yard/second per 10 yards.
This means that every second that goes by... what was 10 yards away is now 11 yards away.

Tom is a person I made up. He owns a truck.
So let's have Tom stand still. Tom's truck is also not moving.
Tom is 10 yards away from his truck.

1 second goes by.

Tom is now 11 yards away from his truck. (Above distance was 10 yards. This 10 yards expanded to 11).

1 more second goes by.

Tom is now 12.1 yards away from his truck. (Above distance was 11 yards. 10 of those yards expanded to 11 yards, the remaining 1 yard expanded to 1.1 yards: 11 + 1.1 = 12.1 yards).

1 more second goes by.

Tom is now 13.31 yards away from his truck. (Above distance was 12.1 yards. 10 of those yards expanded to 11 yards, the remaining 2.1 yards expanded to 2.31 yards: 11 + 2.31 = 13.31 yards).

Here's how it looks for 10 seconds:

Time (s) Tom (yards) Truck (yards) Distance between Tom and Truck (yards)
0 0 10.00 10.00
1 0 11.00 11.00
2 0 12.10 12.10
3 0 13.31 13.31
4 0 14.64 14.64
5 0 16.11 16.11
6 0 17.72 17.72
7 0 19.49 19.49
8 0 21.44 21.44
9 0 23.58 23.58
10 0 25.94 25.94

So, after 10s we can see that Tom is now almost 26 yards away from his truck!

Let's say Tom moves at 3 yards/second. Starting from the beginning with the truck being 10 yards away - how long until he reaches his truck?

Here's the table, updated:

Time (s) Tom (yards) Truck (yards) Distance between Tom and Truck (yards)
0 0 10.00 10.00
1 3 11.00 8.00
2 6 12.10 6.10
3 9 13.31 4.31
4 12 14.64 2.64
5 15 16.11 1.11
6 18 17.72 -0.28

And you can see from here that we don't have to go any further. Tom has reached his truck before the 6 second mark and he can go home now.

But what if Tom's truck is further away from him at the start? Let's say Tom's brother borrowed the truck. And when that dick returned it he left it 20 yards away from Tom.
Starting from the beginning with the truck being 20 yards away - how long until he reaches his truck?

Here's the table, updated:

Time (s) Tom (yards) Truck (yards) Distance between Tom and Truck (yards)
0 0 20.00 20.00
1 3 22.00 19.00
2 6 24.20 18.20
3 9 26.62 17.62
4 12 29.28 17.28
5 15 32.21 17.21
6 18 35.43 17.43
7 21 38.97 17.97
8 24 42.87 18.87
9 27 47.16 20.16
10 30 51.87 21.87
11 33 57.06 24.06
12 36 62.77 26.77
13 39 69.05 30.05
14 42 75.95 33.95
15 45 83.54 38.54
16 48 91.90 43.90
17 51 101.09 50.09
18 54 111.20 57.20
19 57 122.32 65.32
20 60 134.55 74.55

Oh no! What happened?

Everything was going great. Tom was moving along, getting closer and closer to this truck... but then something went wrong before the 6 second mark. All of a sudden Tom started getting further and further away from his truck! He'll never get to go home!

Worse than that... after 9 seconds of moving towards his truck, Tom is further away from it than when he started!

And from there, Tom just keeps getting further and further away from his truck, no matter how long he moves after it.

Notice that Tom's speed didn't change.

Tom moved at 3 y/s when the truck was 10 yards away... and caught up to it at almost 6 seconds.
Tom moved at 3 y/s when the truck was 20 yards away... and it eventually just got further and further away from him.

The expansion of the road didn't change either.
The expansion of the road was always 1 yard/second per 10 yards.

You can't say that the road expands faster than Tom moves... because Tom reaches his truck just fine when it starts out within 10 yards.
You can't say that the road expands slower than Tom moves... because Tom can't reach his truck if it starts out at 20 yards away.

The thing is... you can't compare Tom's speed vs. the expansion rate in any "all encompasing" way.
Because the units don't line up.

You're making the same mistake with the speed of light and expansion of the universe.

The expansion isn't faster or slower than the speed of the light.
The two values simply cannot be compared in that fashion.

Sometimes, if things are close enough to begin with, the speed of light will overcome the expansion of the universe just fine.
Sometimes, if things are far enough to begin with, the speed of light will never overcome the expansion of the universe.

Edited by Stile, : Corrected my original confusion with time and Tom's position


This message is a reply to:
 Message 669 by ICANT, posted 05-04-2018 11:55 AM ICANT has responded

Replies to this message:
 Message 677 by NoNukes, posted 05-09-2018 11:06 PM Stile has acknowledged this reply
 Message 680 by ICANT, posted 05-11-2018 8:14 PM Stile has responded

    
NoNukes
Inactive Member


(2)
Message 677 of 1080 (832766)
05-09-2018 11:06 PM
Reply to: Message 676 by Stile
05-09-2018 1:12 PM


Re: Speed of Light vs. Expansion of the Universe
You're making the same mistake with the speed of light and expansion of the universe.

I think your approach is okay. I would note another way to look at things. Expansion is not about things moving through space at all. So it does not involve special relativity. As your calculation shows, expansion is about minute increases of separation at any one point. There is no local motion at light speed.


Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)

"Give me your tired, your poor, your huddled masses yearning to breathe free, the wretched refuse of your teeming shore. Send these, the homeless, tempest-tossed to me, I lift my lamp beside the golden door!

We got a thousand points of light for the homeless man. We've got a kinder, gentler, machine gun hand. Neil Young, Rockin' in the Free World.

Worrying about the "browning of America" is not racism. -- Faith

I hate you all, you hate me -- Faith

No it is based on math I studied in sixth grade, just plain old addition, substraction and multiplication. -- ICANT


This message is a reply to:
 Message 676 by Stile, posted 05-09-2018 1:12 PM Stile has acknowledged this reply

Replies to this message:
 Message 678 by ICANT, posted 05-11-2018 5:10 PM NoNukes has responded

  
ICANT
Member
Posts: 5971
From: SSC
Joined: 03-12-2007


Message 678 of 1080 (832822)
05-11-2018 5:10 PM
Reply to: Message 677 by NoNukes
05-09-2018 11:06 PM


Re: Speed of Light vs. Expansion of the Universe
Hi NoNukes,

NoNukes writes:

There is no local motion at light speed.

I have often thought about local motion. The Milky Way is not expanding. Why is that?

God Bless,


"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

This message is a reply to:
 Message 677 by NoNukes, posted 05-09-2018 11:06 PM NoNukes has responded

Replies to this message:
 Message 679 by Modulous, posted 05-11-2018 5:24 PM ICANT has not yet responded
 Message 681 by NoNukes, posted 05-11-2018 8:21 PM ICANT has responded

    
Modulous
Member (Idle past 27 days)
Posts: 7789
From: Manchester, UK
Joined: 05-01-2005


Message 679 of 1080 (832824)
05-11-2018 5:24 PM
Reply to: Message 678 by ICANT
05-11-2018 5:10 PM


Re: Speed of Light vs. Expansion of the Universe
The Milky Way is not expanding. Why is that?

In order to escape the gravity of the Milky way you need to exceed its escape velocity which is around 500km/s.

Space expands at 68 km/s per megaparsec. That means that two objects 3.2 million light years apart experience space expanding between them at a rate of 68km/s. The milky way at its most distant points is around 100,000 light years. So the rate of space expanding between two ends of the Milky way is a small fraction of 68km/s.

The influence of gravity - 500km/s required to be pulled out of the Milky Way - is much greater than the rate of expansion - say about 2km/s. That's why.


This message is a reply to:
 Message 678 by ICANT, posted 05-11-2018 5:10 PM ICANT has not yet responded

  
ICANT
Member
Posts: 5971
From: SSC
Joined: 03-12-2007


Message 680 of 1080 (832825)
05-11-2018 8:14 PM
Reply to: Message 676 by Stile
05-09-2018 1:12 PM


Re: Speed of Light vs. Expansion of the Universe
Hi stile,

Stile writes:

Oh no! What happened?

I am not sure but I think you got your thought experiment a little wrong.

You have been in airports that have moving floors I will assume. If not you need to visit one. Your rubber road would be like the moving floor as you travel on the moving floor you gain just as much distance as the person in front of you. If that person stands still you will catch up to them If you are moving on the moving floor.

The rubber road would be a little different. Tom would move the 3 yards plus what the rubber road stretched every second.

But maybe I am wrong.

God Bless,


"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

This message is a reply to:
 Message 676 by Stile, posted 05-09-2018 1:12 PM Stile has responded

Replies to this message:
 Message 682 by NoNukes, posted 05-11-2018 8:23 PM ICANT has responded
 Message 693 by Stile, posted 05-15-2018 10:20 AM ICANT has responded

    
NoNukes
Inactive Member


Message 681 of 1080 (832826)
05-11-2018 8:21 PM
Reply to: Message 678 by ICANT
05-11-2018 5:10 PM


Re: Speed of Light vs. Expansion of the Universe
I have often thought about local motion. The Milky Way is not expanding. Why is that?

Good question. The milky way is not expanding because gravity within the galaxy is sufficient to hold it together despite the expansion.

Edited by NoNukes, : No reason given.


Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)

"Give me your tired, your poor, your huddled masses yearning to breathe free, the wretched refuse of your teeming shore. Send these, the homeless, tempest-tossed to me, I lift my lamp beside the golden door!

We got a thousand points of light for the homeless man. We've got a kinder, gentler, machine gun hand. Neil Young, Rockin' in the Free World.

Worrying about the "browning of America" is not racism. -- Faith

I hate you all, you hate me -- Faith

No it is based on math I studied in sixth grade, just plain old addition, substraction and multiplication. -- ICANT


This message is a reply to:
 Message 678 by ICANT, posted 05-11-2018 5:10 PM ICANT has responded

Replies to this message:
 Message 684 by ICANT, posted 05-14-2018 3:55 AM NoNukes has responded

  
NoNukes
Inactive Member


Message 682 of 1080 (832827)
05-11-2018 8:23 PM
Reply to: Message 680 by ICANT
05-11-2018 8:14 PM


Re: Speed of Light vs. Expansion of the Universe
The rubber road would be a little different. Tom would move the 3 yards plus what the rubber road stretched every second.

It may be hard to extend this analogy if you take into account that walkway stretching. I am not sure that doing so is helpful, but I am willing to be convinced.


Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)

"Give me your tired, your poor, your huddled masses yearning to breathe free, the wretched refuse of your teeming shore. Send these, the homeless, tempest-tossed to me, I lift my lamp beside the golden door!

We got a thousand points of light for the homeless man. We've got a kinder, gentler, machine gun hand. Neil Young, Rockin' in the Free World.

Worrying about the "browning of America" is not racism. -- Faith

I hate you all, you hate me -- Faith

No it is based on math I studied in sixth grade, just plain old addition, substraction and multiplication. -- ICANT


This message is a reply to:
 Message 680 by ICANT, posted 05-11-2018 8:14 PM ICANT has responded

Replies to this message:
 Message 683 by ICANT, posted 05-14-2018 2:49 AM NoNukes has responded

  
ICANT
Member
Posts: 5971
From: SSC
Joined: 03-12-2007


Message 683 of 1080 (832910)
05-14-2018 2:49 AM
Reply to: Message 682 by NoNukes
05-11-2018 8:23 PM


Re: Speed of Light vs. Expansion of the Universe
Hi NoNukes,

NoNukes writes:

It may be hard to extend this analogy if you take into account that walkway stretching. I am not sure that doing so is helpful, but I am willing to be convinced.

The rubber road would be streaching with tom on the road. So Tom would gain the amount the road stretched every time he took a step.

Toms rear foot would be on the rubber road as his front foot was traveling through the air. What ever amount the rubber road stretched the rear foot would travel as the front foot was in the air.

God Bless,


"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

This message is a reply to:
 Message 682 by NoNukes, posted 05-11-2018 8:23 PM NoNukes has responded

Replies to this message:
 Message 685 by NoNukes, posted 05-14-2018 6:16 AM ICANT has responded
 Message 686 by NoNukes, posted 05-14-2018 6:16 AM ICANT has not yet responded

    
ICANT
Member
Posts: 5971
From: SSC
Joined: 03-12-2007


Message 684 of 1080 (832911)
05-14-2018 3:55 AM
Reply to: Message 681 by NoNukes
05-11-2018 8:21 PM


Re: Speed of Light vs. Expansion of the Universe
Hi NoNukes,

NoNukes writes:

Good question. The milky way is not expanding because gravity within the galaxy is sufficient to hold it together despite the expansion.

I understand there is a lot of mass to exert gravitational force on items inside the Milky Way. But before those big masses formed what kept the space between the quarks from expanding in the early universe. There was no mass so why did anything ever form into anything but quarks?

God Bless,


"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

This message is a reply to:
 Message 681 by NoNukes, posted 05-11-2018 8:21 PM NoNukes has responded

Replies to this message:
 Message 687 by NoNukes, posted 05-14-2018 6:24 AM ICANT has responded

    
NoNukes
Inactive Member


Message 685 of 1080 (832912)
05-14-2018 6:16 AM
Reply to: Message 683 by ICANT
05-14-2018 2:49 AM


Re: Speed of Light vs. Expansion of the Universe
The rubber road would be streaching with tom on the road. So Tom would gain the amount the road stretched every time he took a step.

You are making an unwarranted assumption that the momentum is supplied by the stretching rather than being input by Tom when he tries to advance. What is the nature of the stretching of the walkway?


Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)

"Give me your tired, your poor, your huddled masses yearning to breathe free, the wretched refuse of your teeming shore. Send these, the homeless, tempest-tossed to me, I lift my lamp beside the golden door!

We got a thousand points of light for the homeless man. We've got a kinder, gentler, machine gun hand. Neil Young, Rockin' in the Free World.

Worrying about the "browning of America" is not racism. -- Faith

I hate you all, you hate me -- Faith

No it is based on math I studied in sixth grade, just plain old addition, substraction and multiplication. -- ICANT


This message is a reply to:
 Message 683 by ICANT, posted 05-14-2018 2:49 AM ICANT has responded

Replies to this message:
 Message 688 by ICANT, posted 05-14-2018 12:42 PM NoNukes has responded

  
NoNukes
Inactive Member


Message 686 of 1080 (832913)
05-14-2018 6:16 AM
Reply to: Message 683 by ICANT
05-14-2018 2:49 AM


Re: Speed of Light vs. Expansion of the Universe
duplicate.

Edited by NoNukes, : No reason given.


Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)

"Give me your tired, your poor, your huddled masses yearning to breathe free, the wretched refuse of your teeming shore. Send these, the homeless, tempest-tossed to me, I lift my lamp beside the golden door!

We got a thousand points of light for the homeless man. We've got a kinder, gentler, machine gun hand. Neil Young, Rockin' in the Free World.

Worrying about the "browning of America" is not racism. -- Faith

I hate you all, you hate me -- Faith

No it is based on math I studied in sixth grade, just plain old addition, substraction and multiplication. -- ICANT


This message is a reply to:
 Message 683 by ICANT, posted 05-14-2018 2:49 AM ICANT has not yet responded

  
NoNukes
Inactive Member


Message 687 of 1080 (832914)
05-14-2018 6:24 AM
Reply to: Message 684 by ICANT
05-14-2018 3:55 AM


Re: Speed of Light vs. Expansion of the Universe
I understand there is a lot of mass to exert gravitational force on items inside the Milky Way. But before those big masses formed what kept the space between the quarks from expanding in the early universe. There was no mass so why did anything ever form into anything but quarks?

The mass/energy was there before the stars formed. Both energy and mass generated gravity according to general relativity. But even without that, the amount of expanding within an atom is negligible. The rate of expansion is, as someone else explained, about 70 km/sec per megaparsec, where a parsec is about 4.3 light years. And of course, the strong nuclear force keeps quarks together.

Edited by NoNukes, : No reason given.

Edited by NoNukes, : No reason given.


Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)

"Give me your tired, your poor, your huddled masses yearning to breathe free, the wretched refuse of your teeming shore. Send these, the homeless, tempest-tossed to me, I lift my lamp beside the golden door!

We got a thousand points of light for the homeless man. We've got a kinder, gentler, machine gun hand. Neil Young, Rockin' in the Free World.

Worrying about the "browning of America" is not racism. -- Faith

I hate you all, you hate me -- Faith

No it is based on math I studied in sixth grade, just plain old addition, substraction and multiplication. -- ICANT


This message is a reply to:
 Message 684 by ICANT, posted 05-14-2018 3:55 AM ICANT has responded

Replies to this message:
 Message 691 by ICANT, posted 05-15-2018 2:30 AM NoNukes has responded

  
ICANT
Member
Posts: 5971
From: SSC
Joined: 03-12-2007


Message 688 of 1080 (832931)
05-14-2018 12:42 PM
Reply to: Message 685 by NoNukes
05-14-2018 6:16 AM


Re: Speed of Light vs. Expansion of the Universe
Hi NoNukes,

NoNukes writes:

You are making an unwarranted assumption that the momentum is supplied by the stretching rather than being input by Tom when he tries to advance. What is the nature of the stretching of the walkway?

The walkway is not stretching. It is moving in a forward direction that you can stand on. But when it reaches its end it returns underneath in the opposite direction and then comes up and starts it journey all over again. The surface of the walkway is moving in a forward direction to its destination where you get off.

The rubber road would be moving in like manner as it stretches
The stretching of the rubber road would provide momentum on the rear foot as the front foot was in the air. What ever the distance the rubber road stretched during the interval would move Tom's body forward the amount the road stretched. The same as walking on the moving walkway would.

I did not make an assumption.

I took a large rubber band and placed marks on it 1 inch apart. I placed it on a piece of cardboard and fastened it at one end. While the rubber band was in a relaxed position I made matching marks on the cardboard. I then stretched the rubber band to the right and the further I stretched the rubber band the farther the marks on the rubber band moved to the right of the marks on the cardboard. We are talking about Mod's rubber road. We are not talking about space.

God Bless,


"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

This message is a reply to:
 Message 685 by NoNukes, posted 05-14-2018 6:16 AM NoNukes has responded

Replies to this message:
 Message 689 by NoNukes, posted 05-14-2018 3:18 PM ICANT has responded

    
NoNukes
Inactive Member


Message 689 of 1080 (832943)
05-14-2018 3:18 PM
Reply to: Message 688 by ICANT
05-14-2018 12:42 PM


Re: Speed of Light vs. Expansion of the Universe
The walkway is not stretching. It is moving in a forward direction that you can stand on

Then it would not model the universe, would it?

Make up your mind. Are we having a discussion about the supposed faults of the big bang model, or are we discussing how to walk around the airport?

Edited by NoNukes, : No reason given.


Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)

"Give me your tired, your poor, your huddled masses yearning to breathe free, the wretched refuse of your teeming shore. Send these, the homeless, tempest-tossed to me, I lift my lamp beside the golden door!

We got a thousand points of light for the homeless man. We've got a kinder, gentler, machine gun hand. Neil Young, Rockin' in the Free World.

Worrying about the "browning of America" is not racism. -- Faith

I hate you all, you hate me -- Faith

No it is based on math I studied in sixth grade, just plain old addition, substraction and multiplication. -- ICANT


This message is a reply to:
 Message 688 by ICANT, posted 05-14-2018 12:42 PM ICANT has responded

Replies to this message:
 Message 690 by ICANT, posted 05-15-2018 1:31 AM NoNukes has responded

  
ICANT
Member
Posts: 5971
From: SSC
Joined: 03-12-2007


Message 690 of 1080 (832954)
05-15-2018 1:31 AM
Reply to: Message 689 by NoNukes
05-14-2018 3:18 PM


Re: Speed of Light vs. Expansion of the Universe
Hi NoNukes,

NoNukes writes:

Then it would not model the universe, would it?

The moving walkway was never represented to mimic the universe and space as I said in my post.

But it does model the rubber road that was stretching.

As I said the space between objects in the universe is expanding in every direction at the same time.

The rubber road and the moving walkway are moving in one direction only.

God Bless,


"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

This message is a reply to:
 Message 689 by NoNukes, posted 05-14-2018 3:18 PM NoNukes has responded

Replies to this message:
 Message 692 by NoNukes, posted 05-15-2018 4:46 AM ICANT has not yet responded

    
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