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Author Topic:   What's the Fabric of space made out of?
sidelined
Member (Idle past 5908 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 196 of 284 (194257)
03-24-2005 10:34 PM
Reply to: Message 195 by Buzsaw
03-24-2005 9:00 PM


Re: Properties Of Space
buzsaw
Of course, the parabola is the correct path
Then why does the man on the train view a straight path?

And since you know you cannot see yourself,
so well as by reflection, I, your glass,
will modestly discover to yourself,
that of yourself which you yet know not of

This message is a reply to:
 Message 195 by Buzsaw, posted 03-24-2005 9:00 PM Buzsaw has replied

Replies to this message:
 Message 198 by Buzsaw, posted 03-24-2005 11:32 PM sidelined has replied

  
Buzsaw
Inactive Member


Message 197 of 284 (194258)
03-24-2005 10:43 PM
Reply to: Message 193 by Sylas
03-24-2005 2:01 AM


Re: Properties Of Space
There are not even points in space then.
Logically, points are not something that exists apart from matter, energy, et al. They are not properties of space, but math mechanisms existing in the minds of people (people existing in space) so as to calculate geometric problems/measurements pertaining to things which exist in space.
A "point" is an abstraction, not a thing, used for convenience to talk about space. All our natural laws and mathematics and so on are abstractions, used to help give a description of how the world works.
Sensibly and logically, no. Rather, a "point" is an abstraction, not a thing, used for convenience to talk about that which exists in space.
Points are geometric mechanisms in men's minds. What expands is geometric measurements of that which is observed, existing in space. These geometric measurements exist only in the minds of men. The geometric calculations existing in the minds of men pertain to that which exists in space/area and is not a property of space.
Here is a fact of life. Anyone who measures the speed of a light in a vacuum gets the same result, no matter where the light comes from or in which direction it is going, or how fast they are moving.
Do you think this is "logical"?
This is very different to what we normally expect. For example, if am standing beside the traintracks, and I throw a baseball at the train (and perpendicular to the tracks) at 120 km/hr, then I measure the ball moving perpendicular to the track at 120 km/hr.
But if there is a train moving at 90km/hr along the track, then an observer in the train sees the ball travelling diagonally to the track at 150 km/hr.
On the other hand, if I shoot at a spaceship in a vacuum with a laser beam, then it does not matter how fast the spaceship is going, or in what direction. I and the spaceship both see the photons moving at 299,792,458 km/sec.
We express this a general law about all velocities; and velocity is an abstraction... a useful one.
This very unintuitive discovery is a basis of special relativity. Let me know if you can accept this as a fact of life. If so, we'll go on to consider a fact about general relativity.
Can we simplify the analogies pertaining to the above? let's use the same analogy for both vacuum and non-vacuum so as not to skew the results. Let's assume that the train and ball thrower are in a vacuum on earth. Everything in the analogy is the same for both, except one is in a vacuum and one is not. Will the outcome be the same as with your spaceship model?

The immeasurable present is forever consuming the eternal future and extending the infinite past. buzsaw

This message is a reply to:
 Message 193 by Sylas, posted 03-24-2005 2:01 AM Sylas has replied

Replies to this message:
 Message 200 by Funkaloyd, posted 03-24-2005 11:56 PM Buzsaw has replied
 Message 207 by Sylas, posted 03-25-2005 3:09 AM Buzsaw has replied

  
Buzsaw
Inactive Member


Message 198 of 284 (194268)
03-24-2005 11:32 PM
Reply to: Message 196 by sidelined
03-24-2005 10:34 PM


Re: Properties Of Space
Then why does the man on the train view a straight path?
Because he and the train existing and moving within in static, unbounded space, have a common velocity and the drop of the ball following the direction of that movement is viewed relative to the movement of the viewer, whereas to the bystander, the drop is viewed relative to the earth on which he stands. .

The immeasurable present is forever consuming the eternal future and extending the infinite past. buzsaw

This message is a reply to:
 Message 196 by sidelined, posted 03-24-2005 10:34 PM sidelined has replied

Replies to this message:
 Message 199 by sidelined, posted 03-24-2005 11:48 PM Buzsaw has replied

  
sidelined
Member (Idle past 5908 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 199 of 284 (194274)
03-24-2005 11:48 PM
Reply to: Message 198 by Buzsaw
03-24-2005 11:32 PM


Re: Properties Of Space
buzsaw
the drop of the ball following the direction of that movement is viewed relative to the movement of the viewer, whereas to the bystander, the drop is viewed relative to the earth on which he stands
Exactly.Now if the man on board the train witnesses a straight line between origin of release and impact with the ground while the man on the ground witnesses a curved line between those same two points {origin and impact} and a curved line by definition must cover a greater distance than a straight line what can we now say about the time it takes for each of these paths to occur?

This message is a reply to:
 Message 198 by Buzsaw, posted 03-24-2005 11:32 PM Buzsaw has replied

Replies to this message:
 Message 201 by Buzsaw, posted 03-25-2005 12:18 AM sidelined has replied

  
Funkaloyd
Inactive Member


Message 200 of 284 (194279)
03-24-2005 11:56 PM
Reply to: Message 197 by Buzsaw
03-24-2005 10:43 PM


Re: Properties Of Space
The same applies both in the vacuum of space and the atmosphere of Earth. If you throw a ball at a spaceship, the spaceship's measurement of the ball's speed will vary depending on the velocity (velocity includes direction) of the ship. For example, if the ball is thrown at 40mph, and the ship is flying towards the ball at 40mph, then the ship will measure the ball's speed as 80mph. If the ship is flying away from the ball at 30mph, then it will measure the ball's speed as 10mph.
Whereas if you shoot a laser at a train, the train will see the beam moving at the same speed regardless of the train's velocity.
Sylas set the second scene in a vacuum because air on Earth will slow the speed of light to slightly less than 299,792,458km/s. The difference is hardly anything, and it's irrelevant to what we're talking about anyway.

Please correct me if I'm wrong, I'm here to learn.

This message is a reply to:
 Message 197 by Buzsaw, posted 03-24-2005 10:43 PM Buzsaw has replied

Replies to this message:
 Message 202 by Buzsaw, posted 03-25-2005 12:22 AM Funkaloyd has not replied

  
Buzsaw
Inactive Member


Message 201 of 284 (194287)
03-25-2005 12:18 AM
Reply to: Message 199 by sidelined
03-24-2005 11:48 PM


Re: Properties Of Space
Longer time to fall.

The immeasurable present is forever consuming the eternal future and extending the infinite past. buzsaw

This message is a reply to:
 Message 199 by sidelined, posted 03-24-2005 11:48 PM sidelined has replied

Replies to this message:
 Message 203 by sidelined, posted 03-25-2005 12:33 AM Buzsaw has replied

  
Buzsaw
Inactive Member


Message 202 of 284 (194289)
03-25-2005 12:22 AM
Reply to: Message 200 by Funkaloyd
03-24-2005 11:56 PM


Re: Properties Of Space
Not what I called for, Funkaloyd. I want the exact same analogy on earth using vacuum/nonvacuum.

The immeasurable present is forever consuming the eternal future and extending the infinite past. buzsaw

This message is a reply to:
 Message 200 by Funkaloyd, posted 03-24-2005 11:56 PM Funkaloyd has not replied

  
sidelined
Member (Idle past 5908 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 203 of 284 (194295)
03-25-2005 12:33 AM
Reply to: Message 201 by Buzsaw
03-25-2005 12:18 AM


Re: Properties Of Space
buzsaw
So the passage of time is different for the two men?

This message is a reply to:
 Message 201 by Buzsaw, posted 03-25-2005 12:18 AM Buzsaw has replied

Replies to this message:
 Message 204 by Buzsaw, posted 03-25-2005 1:14 AM sidelined has replied

  
Buzsaw
Inactive Member


Message 204 of 284 (194310)
03-25-2005 1:14 AM
Reply to: Message 203 by sidelined
03-25-2005 12:33 AM


Re: Properties Of Space
As I think about it, it would seem that the dropper looking back would view a slower velocity of drop, than if the train were stopped when he viewed a drop from a standstill and that if the bystander and the moving (moving edited in) dropper both had stop watches, the time would be equal from drop to contact.
This message has been edited by buzsaw, 03-25-2005 01:16 AM

The immeasurable present is forever consuming the eternal future and extending the infinite past. buzsaw

This message is a reply to:
 Message 203 by sidelined, posted 03-25-2005 12:33 AM sidelined has replied

Replies to this message:
 Message 205 by sidelined, posted 03-25-2005 1:46 AM Buzsaw has not replied
 Message 206 by Sylas, posted 03-25-2005 3:02 AM Buzsaw has not replied

  
sidelined
Member (Idle past 5908 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 205 of 284 (194322)
03-25-2005 1:46 AM
Reply to: Message 204 by Buzsaw
03-25-2005 1:14 AM


Re: Properties Of Space
buzsaw
As I think about it, it would seem that the dropper looking back would view a slower velocity of drop,
Careful, buz,the dropper {man on the train} does not look back.He views the ball as dropping straight down from him and it makes contact with the ground directly below.
and that if the bystander and the moving (moving edited in) dropper both had stop watches, the time would be equal from drop to contact.
If the time is the same then how can the length be different?{straight line and curved line }
This message has been edited by sidelined, Thu, 2005-03-24 11:46 PM

This message is a reply to:
 Message 204 by Buzsaw, posted 03-25-2005 1:14 AM Buzsaw has not replied

  
Sylas
Member (Idle past 5260 days)
Posts: 766
From: Newcastle, Australia
Joined: 11-17-2002


Message 206 of 284 (194352)
03-25-2005 3:02 AM
Reply to: Message 204 by Buzsaw
03-25-2005 1:14 AM


Re: Properties Of Space
Apologies folks; most of you are trying to help buz with a simple Newtonian analysis. I can't resist adding a wrinkle.
buzsaw writes:
As I think about it, it would seem that the dropper looking back would view a slower velocity of drop, than if the train were stopped when he viewed a drop from a standstill and that if the bystander and the moving (moving edited in) dropper both had stop watches, the time would be equal from drop to contact.
Note that the claim about stop watches seems "logical", but it turns out to be false. They are equal in the Newtonian physics, which is a plenty good enough approximation to answer the questions being asked.
But if we get really technical, it turns out that the stop watch on the moving train will record less time from drop to contact. This effect is called time dilation, and it is measurable using very precise clocks even for the velocities of an express train. It may seem illogical; but that is a mistake of confusing the role of logic.
The earliest direct measurement of the time dilation effect was back in 1971, with atomic clocks placed on aircraft, flown around the world and returned to a common location. The times recorded on the clocks varied depending on whether they remained at the airport, or flew East-West, or flew West-East. It is a famous experiment, called the Hafele and Keating Experiment, and reported in Science magazine 177, 1972 (p 166).
You've have to be very very precise indeed to pick up a difference in the times in the trani example. It takes about 0.5 seconds to fall 1.25 meters. Suppose that the stopwatch on the train records 0.5 seconds, from drop to contact, and that the train is moving at 100 km/hr. An observer outside the train will record the time from drop to contact as being 0.500000000000002 seconds.
Is this "logical"?
Cheers -- Sylas

This message is a reply to:
 Message 204 by Buzsaw, posted 03-25-2005 1:14 AM Buzsaw has not replied

Replies to this message:
 Message 208 by sidelined, posted 03-25-2005 3:15 AM Sylas has not replied

  
Sylas
Member (Idle past 5260 days)
Posts: 766
From: Newcastle, Australia
Joined: 11-17-2002


Message 207 of 284 (194353)
03-25-2005 3:09 AM
Reply to: Message 197 by Buzsaw
03-24-2005 10:43 PM


Re: Properties Of Space
Can we simplify the analogies pertaining to the above? let's use the same analogy for both vacuum and non-vacuum so as not to skew the results. Let's assume that the train and ball thrower are in a vacuum on earth. Everything in the analogy is the same for both, except one is in a vacuum and one is not. Will the outcome be the same as with your spaceship model?
This is not an "analogy". It is a a thought experiment. It is an example of a certain situation, for which we can perform calculations to determine the results, and then check if our calculations actually match up with the real world. The reason for having a vacuum is technical, but it does not actually make a significant difference. The time dilation effect mentioned in my previous post turns out to be an aspect of the same phenomenon.
The speed of light is the same for all observers. It makes no difference how fast the source of the light is going, or how fast an observer is moving. If you move towards a photon source, you still them coming at you at the same speed as if you are moving away from the photon source. Weird! Illogical! Fact of life confirmed by many experiments and observations!
Cheers -- Sylas

This message is a reply to:
 Message 197 by Buzsaw, posted 03-24-2005 10:43 PM Buzsaw has replied

Replies to this message:
 Message 209 by Buzsaw, posted 03-25-2005 11:30 PM Sylas has replied

  
sidelined
Member (Idle past 5908 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 208 of 284 (194355)
03-25-2005 3:15 AM
Reply to: Message 206 by Sylas
03-25-2005 3:02 AM


Re: Properties Of Space
Sylas
Apologies folks; most of you are trying to help buz with a simple Newtonian analysis
Actually Sylas my aim was to show buz that common sense is not always sufficient to determine the actual state of affairs with even simple phenomena. Since it is difficult to reason a man out of the position he reasoned himself into in the first place I thought it best to allow him to meet the limitations such thinking imposes. I think that if he can see how the process of special relativity is counterintuitive then he will have a better capacity to appreciate that science is not a "he said/she said" process of one person trying to impose their version of the world on others.

And since you know you cannot see yourself,
so well as by reflection, I, your glass,
will modestly discover to yourself,
that of yourself which you yet know not of

This message is a reply to:
 Message 206 by Sylas, posted 03-25-2005 3:02 AM Sylas has not replied

Replies to this message:
 Message 210 by Buzsaw, posted 03-25-2005 11:38 PM sidelined has not replied

  
Buzsaw
Inactive Member


Message 209 of 284 (194566)
03-25-2005 11:30 PM
Reply to: Message 207 by Sylas
03-25-2005 3:09 AM


Re: Properties Of Space
This is not an "analogy". It is a a thought experiment. It is an example of a certain situation, for which we can perform calculations to determine the results, and then check if our calculations actually match up with the real world. The reason for having a vacuum is technical, but it does not actually make a significant difference. The time dilation effect mentioned in my previous post turns out to be an aspect of the same phenomenon.
The speed of light is the same for all observers. It makes no difference how fast the source of the light is going, or how fast an observer is moving. If you move towards a photon source, you still them coming at you at the same speed as if you are moving away from the photon source. Weird! Illogical! Fact of life confirmed by many experiments and observations!
Is the reason you can't use the train/vacuum train/non vacuum thought experiment is because it won't make your point. You will get different velocities as stated in the experiment both ways?
Like if you're flying in an airliner, you see an eagle flying in the opposite direction of your plane out the window. It appears he's flying at his normal speed/velocity plus the speed your plane is going. But if you could expand the size of your cabin and the eagle flew past you within your aircraft, he would be moving at his normal speed only. Is this relativity of the eagle within or without the cabin in any way analogous to your experiment? Also a fly flying in the direction your jet is moving can fly at jet speed plus his own speed inside your aircraft, but outside your aircraft, it's by by flying fly. I don't know. I'm still trying to think it through. It appears to have to do with relativity. I don't give much credence to analogous stuff/experiments which are dissimilar to the extent that yours is. It is after all, analogous. I haven't got my finger on it, but something seems to be skewing the experiments to your advantage. I'm hittin hay and will likely think myself to sleep on this fascinating stuff.

The immeasurable present is forever consuming the eternal future and extending the infinite past. buzsaw

This message is a reply to:
 Message 207 by Sylas, posted 03-25-2005 3:09 AM Sylas has replied

Replies to this message:
 Message 211 by Sylas, posted 03-26-2005 1:46 AM Buzsaw has replied

  
Buzsaw
Inactive Member


Message 210 of 284 (194569)
03-25-2005 11:38 PM
Reply to: Message 208 by sidelined
03-25-2005 3:15 AM


Re: Properties Of Space
Thanks Sidelined. You've got me thinking. Something logical's gotta come out in the 'wash' in the end though. Imo, none of this in any way expands or curves space. It's still all about stuff in space we're dealing with. Talk to you people later, Lord willing. Off to church tomorrow. Take care and go with God, Jehovah, that is.

The immeasurable present is forever consuming the eternal future and extending the infinite past. buzsaw

This message is a reply to:
 Message 208 by sidelined, posted 03-25-2005 3:15 AM sidelined has not replied

  
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