Is FTL actually possible?

[Janus]

22 hours ago, MJ kihara said:

Why then bother bringing us into the existence... finding ourselves asking this question.

This assumes that the universe has some purpose or plan.

And even if we assume that this is the case, what makes you so sure that we are a major part of it? We could just as well be an undesirable but unavoidable side effect.

Edited April 13, 2023 by Janus

[swansont]

4 hours ago, Moontanman said:

No, it was an instantaneous signal from a STL craft that caused a causality problem.  

I am not objecting to the example, I am objecting to your claim that "It appears that instantaneous communication doesn't cause time travel unless it's from a spacecraft going slower than light.”

Someone showing the effect from a STL craft in no way implies that a FTL craft would not experience this problem.

[MJ kihara]

47 minutes ago, Janus said:

This assumes that the universe has some purpose or plan.

And even if we assume that this is the case, what makes you so sure that we are a major part of it? We could just as well be an undesirable but unavoidable side effect.

The problem is us separating ourselves from the universe...we are not different entities...we are part of the universe...the particles that make us are part of the universe....we are also spacetime fabric.

And of course maybe not a major part of it...but an inevitable part of it because we exist.

 

 

[zapatos]

3 hours ago, MJ kihara said:

we are also spacetime fabric.

"Spacetime fabric" is not a physical thing. We are.

3 hours ago, MJ kihara said:

And of course maybe not a major part of it...but an inevitable part of it because we exist.

 

My wife and I are married. We exist as a team. Does that mean our partnership was inevitable?

Edited April 13, 2023 by zapatos

[iNow]

6 hours ago, zapatos said:

"Spacetime fabric" is not a physical thing.

I did, however, recently find some on clearance at JoAnn’s

https://www.joann.com/astrological-cotton-canvas-fabric/18321687.html?gclid=CjwKCAjw0N6hBhAUEiwAXab-TTn-mCraW03z3MTILFdCdmJlRLMRnJpL9SJ152yyI1RlYN2K1JBdfxoC5U8QAvD_BwE

[zapatos]

Well damn. That's what I get for jumping to conclusions. 🤣

[MJ kihara]

9 hours ago, zapatos said:

"Spacetime fabric" is not a physical thing. We are.

When the neutrinos are passing through the Earth,through our bodies, through our brains as we are thinking...they are just moving through the spacetime fabric.we are physical from our perspective...but I think from neutrinos perspective we're just spacetime fabric....being physical is just qualities of spacetime fabric.

9 hours ago, zapatos said:

My wife and I are married. We exist as a team. Does that mean our partnership was inevitable?

Since it has already happened it's an inevitable.

[Intoscience]

12 hours ago, zapatos said:

"Spacetime fabric" is not a physical thing

Are we so sure? One could argue that if it warps then it's physical (to some degree)

12 hours ago, zapatos said:

My wife and I are married. We exist as a team. Does that mean our partnership was inevitable?

If there are multiple timelines then one could argue that on this particular one then yes it was inevitable. A bit like one of the hypothetical solutions to the grandfather paradox. 

[MJ kihara]

7 hours ago, iNow said:

I did, however, recently find some on clearance at JoAnn’s

https://www.joann.com/astrological-cotton-canvas-fabric/18321687.html?gclid=CjwKCAjw0N6hBhAUEiwAXab-TTn-mCraW03z3MTILFdCdmJlRLMRnJpL9SJ152yyI1RlYN2K1JBdfxoC5U8QAvD_BwE

Spacetime fabric it's on the canvas fabric,it's on the cotton fibre,it's in the cotton fibre,it's on elements making up the cotton fibre,it's in the atoms,in their electrons in their proton and neutron,in their quarks... etc etc

It's the fabric that make you and me and the universe we know of...it's constituent being closed loops of space and time.

When we interprate it mathematically using geometry we get spacetime.

4 minutes ago, MJ kihara said:

...it's constituent being closed loops of space and time.

🤯..loop..encircling that's the idea... bubbles...😇

[swansont]

2 hours ago, Intoscience said:

Are we so sure? One could argue that if it warps then it's physical (to some degree)

A sphere has a curved geometry, but it’s not a physical object. 

[zapatos]

6 hours ago, Intoscience said:

Are we so sure? 

I'm only going on what Einstein said: "Space-time does not claim existence in its own right, but only as a structural quality of the [gravitational] field".

10 hours ago, MJ kihara said:

Since it has already happened it's an inevitable.

Not to be rude, but you should look up the definition of "inevitable".

[MJ kihara]

15 minutes ago, zapatos said:

I'm only going on what Einstein said: "Space-time does not claim existence in its own right, but only as a structural quality of the [gravitational] field".

Its right.

Space-time turning it into a thing on it's own right to become spacetime fabric.therefore..using space-time to explain/describe a thing called spacetime fabric... so that we can have a common point to merge GR and QM.

34 minutes ago, zapatos said:

Not to be rude, but you should look up the definition of "inevitable".

Inevitable... unavoidable...you can't avoid that which has happened...others are assumptions.

 

7 minutes ago, MJ kihara said:

Its right.

Space-time turning it into a thing on it's own right to become spacetime fabric.therefore..using space-time to explain/describe a thing called spacetime fabric... so that we can have a common point to merge GR and QM.

According to my thinking space-time emerged from spacetime fabric.

[Moontanman]

On 4/13/2023 at 10:57 AM, swansont said:

I am not objecting to the example, I am objecting to your claim that "It appears that instantaneous communication doesn't cause time travel unless it's from a spacecraft going slower than light.”

Someone showing the effect from a STL craft in no way implies that a FTL craft would not experience this problem.

There are people that disagree with you, do i need to post the video so you can ignore it? 

[Phi for All]

21 minutes ago, MJ kihara said:

Inevitable... unavoidable...you can't avoid that which has happened.

Sorry, but "avoid" can only be applied to future events, not past or present. Something inevitable WILL happen, but hasn't yet. You can't prevent something that's already happened, because you can't use the word "prevent" with regard to the past.

21 minutes ago, MJ kihara said:

According to my thinking space-time emerged from spacetime fabric.

To be clear, when you say "fabric", are you referencing the 2-dimensional "rubber sheet" analogy for spacetime?

 

[MJ kihara]

48 minutes ago, Phi for All said:

To be clear, when you say "fabric", are you referencing the 2-dimensional "rubber sheet" analogy for spacetime?

 

No.

It's  a fluidlike fabric...one large fabric called the universe...analogy in these case will be just like water molecules are to the ocean..spacetime particles,loops, bubbles( virtual particles) are to the universe.

[MigL]

3 hours ago, Moontanman said:

There are people that disagree with you, do i need to post the video so you can ignore it? 

There are people who disagree that the Earth is spherical.
Would you agree with them if I post a video of their claims ?

By all means, post this video, so we can point out its shortcomings.
ANYTHING involving FtL motion/communication implies causality violation.

 

2 hours ago, MJ kihara said:

It's  a fluidlike fabric...one large fabric called the universe...analogy in these case will be just like water molecules are to the ocean..spacetime particles,loops, bubbles( virtual particles) are to the universe.

So, you just made up your own definition for 'everything in the universe' ?

[swansont]

4 hours ago, Moontanman said:

There are people that disagree with you,

I’m sure there are, but I can only go by what you posted.

 

4 hours ago, Moontanman said:

do i need to post the video so you can ignore it? 

If you have a video that says what you claim - that causality is only violated for STL craft but not from FTL craft - from a credible source, and you tell us when they say it, I will watch it (if the video is watchable in the US) 

But you said the issue is with a diagram in the video, so if that’s the case, why can’t you post a screenshot?

 

[Joatmon]

Although it can't carry energy or information at that speed I'll mention, just for fun really, that phase velocity in a rectangular waveguide travels along the waveguide with a speed greater than light. I remember the incredulity with which the fact was met when first introduced to us when radar students.

[Moontanman]

40 minutes ago, swansont said:

I’m sure there are, but I can only go by what you posted.

 

If you have a video that says what you claim - that causality is only violated for STL craft but not from FTL craft - from a credible source, and you tell us when they say it, I will watch it (if the video is watchable in the US) 

But you said the issue is with a diagram in the video, so if that’s the case, why can’t you post a screenshot?

 

It's because I don't know how to post a screenshot but it's also because I am sure it's a misunderstanding on my part. I am well aware of the "fact" of ftl always implies causality violations. I'll post it so I won't be wrong anymore, that is always as important if not more so than being right.  

https://youtu.be/an0M-wcHw5A

The space time diagram starts at 06:52 the causality violation diagram starts at  12:52 the paradox explanation starts at 17:02. 

It seems (to me at least) to be saying that a causality violation only occurs if a FTL transmission goes from the STL ship to Earth.

He also seems to be conflating FTL transmissions with FTL travel when in fact travel maybe impossible due to hawking radiation but transmissions would not be affected so. 

Edited April 14, 2023 by Moontanman

[Phi for All]

3 hours ago, MJ kihara said:

No.

It's  a fluidlike fabric...one large fabric called the universe...analogy in these case will be just like water molecules are to the ocean..spacetime particles,loops, bubbles( virtual particles) are to the universe.

Except I can dip my cup into the ocean and have lots of water molecules. Can I borrow a cup of spacetime from you?

Fluid has a specific meaning in physics, whereas fabric isn't used at all in physics, except in pop-sci articles.

The way you're using "fabric" is more akin to "underlying structure", or "makeup" or "basic framework". But those are definitely physical things, so if you have an example of the geometry of spacetime actually being something I can hold (or borrow a cup of), I'd like to hear about it.

[MJ kihara]

2 hours ago, MigL said:

So, you just made up your own definition for 'everything in the universe' ?

Looking for away to make my thinking clearer...but I think the idea has been around.
You can't try to have different results such as if causality violation is possible using the same argument that has been there for more than a century expecting different results.
Some things needs modifications and readjustments.....and of course redefinition.

 

1 hour ago, Phi for All said:

The way you're using "fabric" is more akin to "underlying structure", or "makeup" or "basic framework".

 

Yes more a kin to basic framework...'pop' come first before formalization.

1 hour ago, Phi for All said:

But those are definitely physical things.

In a nutshell what are physical things?

1 hour ago, Phi for All said:

so if you have an example of the geometry of spacetime actually being something I can hold (or borrow a cup of), I'd like to hear about it.

U can't hold it..you are it, you are in it.
Just for the purpose of analogy...if you dive into the ocean you find your friend the Fish...then you borrow it a cup of water where will it hold to give it to you...in these case an ocean without a floor...?

 

[Genady]

2 hours ago, Joatmon said:

Although it can't carry energy or information at that speed I'll mention, just for fun really, that phase velocity in a rectangular waveguide travels along the waveguide with a speed greater than light. I remember the incredulity with which the fact was met when first introduced to us when radar students.

There are many phenomena moving with any arbitrary speed. They all can't carry energy or information. 

[swansont]

3 hours ago, Moontanman said:

It's because I don't know how to post a screenshot but it's also because I am sure it's a misunderstanding on my part. I am well aware of the "fact" of ftl always implies causality violations. I'll post it so I won't be wrong anymore, that is always as important if not more so than being right.  

https://youtu.be/an0M-wcHw5A

The space time diagram starts at 06:52 the causality violation diagram starts at  12:52 the paradox explanation starts at 17:02. 

It seems (to me at least) to be saying that a causality violation only occurs if a FTL transmission goes from the STL ship to Earth. 

You could draw the lines in his diagram for a FTL ship. Depending on the speed of the ship (it's not instantaneous in his example; that would be a horizontal line) you could have a violation or not, depending on the speed.  But you had said it was instantaneous, and if you drew the lines, you would get a causality violation for a finite speed FTL ship 

 

1 hour ago, MJ kihara said:

In a nutshell what are physical things?

If you can put it in a nutshell and hand it to me (in principle) it's a physical thing.

[Endy0816]

Could possibly use a wormhole connecting to somewhere outside the future extant of the Observable Universe. Avoid the main paradox that way. Only thing I could think of that might work given everything we know.

[MJ kihara]

6 hours ago, swansont said:

If you can put it in a nutshell and hand it to me (in principle) it's a physical thing.

Am trying to think about neutrino...it doesn't recognize a nutshell....can you hold it.is it physical?