## Spacetime

So what's really going on?

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MJA
Posts: 136
Joined: Wed Oct 26, 2011 6:35 am

### Spacetime

Space is measureless and time is measure, therefore spacetime is a contradiction.

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Resha Caner
Posts: 122
Joined: Tue May 08, 2012 4:44 pm
Location: U.S.

### Re: Spacetime

Why is space measureless?
Impenitent
Posts: 3192
Joined: Wed Feb 10, 2010 2:04 pm

### Re: Spacetime

space and time share similar beginnings and endings...

measure?

-Imp
ForgedinHell
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Joined: Sun Mar 04, 2012 8:26 am
Location: Pueblo West, CO

### Re: Spacetime

Space can be measured, it is just that people from different reference frames will get different measurements. Time also may be measured, and again, people in different reference frames will get different measurements. That is why physicists use "spacetime," because it is an invariant quantity. People in different reference frames will still meaure spacetime as having the same value. The only exception is when the value does not matter because the events are so far apart in spacetime that there is no causal link between the events. So, where is the contradiction?
RIW
Posts: 11
Joined: Tue Aug 21, 2012 10:46 pm
Location: Portsmouth RI
Contact:

### Re: Spacetime

Hi hope this helps

It's important to understand Einstein's work on the space-time continuum and how it relates to the Enterprise traveling through space. In his Special Theory of Relativity, Einstein states two postulates:

The speed of light (about 300,000,000 meters per second) is the same for all observers, whether or not they're moving.
Anyone moving at a constant speed should observe the same physical laws.
Putting these two ideas together, Einstein realized that space and time are relative -- an object in motion actually experiences time at a slower rate than one at rest. Although this may seem absurd to us, we travel incredibly slow when compared to the speed of light, so we don't notice the hands on our watches ticking slower when we're running or traveling on an airplane. Scientists have actually proved this phenomenon by sending atomic clocks up with high-speed rocket ships. They returned to Earth slightly behind the clocks on the ground.
MJA
Posts: 136
Joined: Wed Oct 26, 2011 6:35 am

### Re: Spacetime

Resha Caner wrote:Why is space measureless?
Because space is nature and nature is measureless too.

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Last edited by MJA on Thu Sep 06, 2012 8:32 am, edited 1 time in total.
MJA
Posts: 136
Joined: Wed Oct 26, 2011 6:35 am

### Re: Spacetime

RIW wrote:Hi hope this helps

It's important to understand Einstein's work on the space-time continuum and how it relates to the Enterprise traveling through space. In his Special Theory of Relativity, Einstein states two postulates:

The speed of light (about 300,000,000 meters per second) is the same for all observers, whether or not they're moving.
Anyone moving at a constant speed should observe the same physical laws.
Putting these two ideas together, Einstein realized that space and time are relative -- an object in motion actually experiences time at a slower rate than one at rest. Although this may seem absurd to us, we travel incredibly slow when compared to the speed of light, so we don't notice the hands on our watches ticking slower when we're running or traveling on an airplane. Scientists have actually proved this phenomenon by sending atomic clocks up with high-speed rocket ships. They returned to Earth slightly behind the clocks on the ground.
An object at rest, what is that? Is there such a thing?
And the speed of light is constant, in a vacuum I suppose?
Is there such a thing as a vacuum in the universe?
And if not then what is the speed of light outside a vacuum, in reality?
Quantum mechanics, probability or uncertainty at best?

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Last edited by MJA on Thu Sep 06, 2012 8:30 am, edited 1 time in total.
MJA
Posts: 136
Joined: Wed Oct 26, 2011 6:35 am

### Re: Spacetime

ForgedinHell wrote:Space can be measured, it is just that people from different reference frames will get different measurements. Time also may be measured, and again, people in different reference frames will get different measurements. That is why physicists use "spacetime," because it is an invariant quantity. People in different reference frames will still meaure spacetime as having the same value. The only exception is when the value does not matter because the events are so far apart in spacetime that there is no causal link between the events. So, where is the contradiction?
From my reference frame I find space measureless.
From your reference frame you find it measurable. How then do you measure space?
Oh and thanks all for your input!

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Resha Caner
Posts: 122
Joined: Tue May 08, 2012 4:44 pm
Location: U.S.

### Re: Spacetime

MJA wrote:Because space is nature and nature is measureless too.
That's called "kicking the can down the road."
MJA
Posts: 136
Joined: Wed Oct 26, 2011 6:35 am

### Re: Spacetime

Resha Caner wrote:
MJA wrote:Because space is nature and nature is measureless too.
That's called "kicking the can down the road."
I call it the truth!

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ForgedinHell
Posts: 762
Joined: Sun Mar 04, 2012 8:26 am
Location: Pueblo West, CO

### Re: Spacetime

MJA wrote:
ForgedinHell wrote:Space can be measured, it is just that people from different reference frames will get different measurements. Time also may be measured, and again, people in different reference frames will get different measurements. That is why physicists use "spacetime," because it is an invariant quantity. People in different reference frames will still meaure spacetime as having the same value. The only exception is when the value does not matter because the events are so far apart in spacetime that there is no causal link between the events. So, where is the contradiction?
From my reference frame I find space measureless.
From your reference frame you find it measurable. How then do you measure space?
Oh and thanks all for your input!

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It would only be "measureless" from your reference frame if you are insane.
MJA
Posts: 136
Joined: Wed Oct 26, 2011 6:35 am

### Re: Spacetime

ForgedinHell wrote:
MJA wrote:
ForgedinHell wrote:Space can be measured, it is just that people from different reference frames will get different measurements. Time also may be measured, and again, people in different reference frames will get different measurements. That is why physicists use "spacetime," because it is an invariant quantity. People in different reference frames will still meaure spacetime as having the same value. The only exception is when the value does not matter because the events are so far apart in spacetime that there is no causal link between the events. So, where is the contradiction?
From my reference frame I find space measureless.
From your reference frame you find it measurable. How then do you measure space?
Oh and thanks all for your input!

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It would only be "measureless" from your reference frame if you are insane.
I only asked you a simple question: how do you measure space as you claim you can do?
Would you please try again and if all you can answer is to call me names then I would ask that you not respond at all.
Thanks,
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ForgedinHell
Posts: 762
Joined: Sun Mar 04, 2012 8:26 am
Location: Pueblo West, CO

### Re: Spacetime

MJA wrote:
I only asked you a simple question: how do you measure space as you claim you can do?
Would you please try again and if all you can answer is to call me names then I would ask that you not respond at all.
Thanks,
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My statement was perfectly correct. If you cannot measure length, like by taking out a damn ruler and using it, and measure something in your reference frame, then it could only be because you are insane and deluded into thinking measurement is not possible. You are speaking of an act that small kids learn how to do. Your measurement is correct for your reference frame. The fact is that if you measure the volume of a can of coke, and you get a number, it is perfectly correct for your reference frame. It is reality. Relativity just states that you cannot state that your measurement is the absolute correct one, since it will differ for people in other frames of reference, who may measure the volume of your can of coke as half the value you did. They would also be correct, for their reference frame. You are stating that you can't make any measurement at all? Seriously? You can't take a friggin ruler and measure your foot size and at least figure out that it is less than a meter? If you are unable to make such determinations about the world around you, then you would have to be insane.
thedoc
Posts: 6473
Joined: Thu Aug 30, 2012 4:18 pm

### Re: Spacetime

Space, (The Universe) is described as finite but unbounded. If it is finite it is of a fixed size at any one instant in time, that humans do not have the means to measure it is irrevelant. I, myself, do not have the means to measure the speed of light, but I do not question the accuracy of those who have.
MJA
Posts: 136
Joined: Wed Oct 26, 2011 6:35 am

### Re: Spacetime

ForgedinHell wrote:
MJA wrote:
I only asked you a simple question: how do you measure space as you claim you can do?
Would you please try again and if all you can answer is to call me names then I would ask that you not respond at all.
Thanks,
=
My statement was perfectly correct. If you cannot measure length, like by taking out a damn ruler and using it, and measure something in your reference frame, then it could only be because you are insane and deluded into thinking measurement is not possible. You are speaking of an act that small kids learn how to do. Your measurement is correct for your reference frame. The fact is that if you measure the volume of a can of coke, and you get a number, it is perfectly correct for your reference frame. It is reality. Relativity just states that you cannot state that your measurement is the absolute correct one, since it will differ for people in other frames of reference, who may measure the volume of your can of coke as half the value you did. They would also be correct, for their reference frame. You are stating that you can't make any measurement at all? Seriously? You can't take a friggin ruler and measure your foot size and at least figure out that it is less than a meter? If you are unable to make such determinations about the world around you, then you would have to be insane.
So get your ruler out and tell us the measure of space.

Thanks,

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