Who thinks Faster Than Light travel is possible?

[Mon0Zer0]

Ah but what does my omniscient observer see?

If they're all knowing, does their vision matter? They know it all anyway. Maybe they just see clouds and harps and stuff, whilst the knowledge just pops in there at the moment it happens.

Or are we talking about seeing like... observing, in the physics sense? Like... their brains are entangled with every particle in the universe, with an observer that causes all probabilities to collapse, man?

*inhales*
*passes one reefer*
*blows smoke*

 

[Mon0Zer0]

Apparently the universe is expanding, but also there (apprently) is no 'edge' to it. How can that be? If there was no edge, we would either be going around in circles or the universe would be (somehow) expanding into itself. We are faced with so many anomalies and contradictions that almost anything is both possible and impossible at the same time. The more we are told, the more I think that Douglas Adams had a better understanding of the meaning and workings of the universe than all of the astronomers and scientists combined.

Aren't those only contradictions because we lack the imaginative faculties to be able to picture them as they are? The meaning of the words is so beyond our realm of experience it's like trying to imagine a new colour.

 

[Mon0Zer0]

As for FTL? I think probably not. Putting aside the physics, the engineering and power challenges of the Alcubierre drive are unsurmountable. If we move beyond our world, it'll be at a snail's pace and over many centuries.

Pessimistically, I'm not sure we'll last long enough to make the leap to an interplanetary civilisation. I hope I'm wrong.

 

[Astro Pen]

At the end of the day it is very simple, and yet it makes our heads hurt.
The speed of light IS the speed of time
So there goes the "now" winging away at lightspeed. But every point in the universe has a 'now' romping out from it at the same time. Other nows arrive at a single observer at origin dependent times.
The omniscient veiwpoint is a way to model that. Forget your single viewpoint and your clock, look instead at the cats cradle of motion. The continuous dynamic of nows on the temporal axis, and the things moving on the velocity curve with various balances between time and space.
If inflation theory is true then Lots of stuff was lobbed 'outside' of our space time. WE can never ever access it from our single viewpoint but that doesn't mean it doesn't exist in the 'big picture'.

 

[paranoid marvin]

Aren't those only contradictions because we lack the imaginative faculties to be able to picture them as they are? The meaning of the words is so beyond our realm of experience it's like trying to imagine a new colour.

I think that most scientific advances are based around mathematics and numbers. Because the 'numbers' involved in calculating anything in our universe are so mind-bogglingly huge, you get to the point where they become redundant. What are the odds of me and you and everyone on this forum discussing this topic? From the 'big bang' to the creation of planets, to the evolution of life and then technology to a state where we can be sat in front of keyboards/on mobile phones. The odds/numbers are so staggeringly large as to be a mathematical impossibility. Numbers just are sufficient.

 

[Astro Pen]

Yes @paranoid marvin The Ford Mustang is a product of nature.
It is a shame so many take the view that nature is a walk in the spring woodland rather that everything that biology and geology, working together, makes.

 

[psikeyhackr]

In thought gravity operated at the speed of light. If so the ‘moon would hang around’. Not sure how long for.

Less than 2 seconds.

Which way it would go would depend on time of month. At new moon it would drop into an orbit closer to the Sun. At full moon farther out.

In between gets more complicated. Maybe more elliptical orbits around the Sun.

 

[msstice]

Ah but the concept of an omniscient observer is meaningless. There is no such thing as a snapshot of the universe that shows the balls in my example two light years apart at a moment in time one year later. Because that particular moment only exists at the location where I threw the balls. Space and time are not separate parameters.

Scenario: Two objects A, B, each giving off little flashes of light, are accelerated to slightly less than c and released in opposite directions from a station C.

In one year station C will observe A (and B) to be each 0.5 LY from the station (a separation of 1 LY). Computed speed will be 0.5c (though redshift will tell a different story). Rate of increase of separation will be c.

In two years station C will observe A (and B) to be 1 LY from the station. Computed speed will be 0.5c for each object and rate of increase of the distance between them will be c.

Now consider an observer D who is far from C, and perpendicular to the line A C B. Say the observer D is 10000 LY from C.

D sees A and B shoot out from C at some time. 1Y later D sees A at a distance of ~1 LY from C and ~2LY from B. Inferred speed will be ~c for each object and ~2c for the lengthening of the gap.

From geometry it seems that D will see A and B slowing down the further they go because of the larger angles.

But I vaguely recall Euclidean geometry doesn't apply so I'm likely wrong, but don't know how I'm wrong.

 

[Swank]

In case you're not joking:

C doesn't apply to relative speed as each is independently travelling at light speed. Both particles are moving in opposite directions at the speed of light. Each particle has its own inertial reference frame.

"You can ask how fast the distance between them is increasing in a particular inertial reference frame, and the answer will indeed be that it's increasing at 2c, but the light-speed limit only applies to things like particles and information, it doesn't apply to concepts like "the distance between two objects"."

Reference: Light in opposite directions

Edit: Christine and Alai beat me to it

Your gaze is moving between photons arriving at your eyes, not between the galaxies.

I love the idea of your eye actually moving from one object to another as you look at them - as if you were touching them with your eyeball.

Your post sounds like you disagree with me and agree with Alia and Chistine, but you are making the same point I was: Relative speed is a concept.

My example of moving my eyes was to demonstrate other types of conceptual speed rather than actual velocity.

 

[Christine Wheelwright]

From geometry it seems that D will see A and B slowing down the further they go because of the larger angles.

Yes, that does all seem correct.

 

[Swank]

Yes, that does all seem correct.

Like the opposite of ground rush?

 

[TheEndIsNigh]

In case you're not joking:

C doesn't apply to relative speed as each is independently travelling at light speed. Both particles are moving in opposite directions at the speed of light. Each particle has its own inertial reference frame.

"You can ask how fast the distance between them is increasing in a particular inertial reference frame, and the answer will indeed be that it's increasing at 2c, but the light-speed limit only applies to things like particles and information, it doesn't apply to concepts like "the distance between two objects"."

Reference: Light in opposite directions

Edit: Christine and Alai beat me to it

Your gaze is moving between photons arriving at your eyes, not between the galaxies.

I love the idea of your eye actually moving from one object to another as you look at them - as if you were touching them with your eyeball.

Of course technically if I was sat on a photon observing another bloke on a photon travelling in the opposite direction I wouldn't be able to observe him at all. Likewise if we were travelling toward each other the first observation would be when his head impinged on my personal space. (all visible light having been squashed into the ultra violet)

I've mentioned it before but here we go again.

Humans are so self centred. It used to be the sun revolves around the Earth.

The it was we are the only planet.

Then it was we are the only planet with intelligent life (well any life at all).

Now it's the universe is big- so big it contains all matter.

Yet since no one has or ever will understand how all this stuff around came into being and how it all works my I suggest the following.

There was/is/willbe/can be/ many such events. Maybe our big bang is just that. A localised event in a vastness of other places that bangs have and will occur. If it can happen once why not many times.

If there are other localised dollops of matter all around us it would also explain why our bit is expanding because the gravitational pull of, oh I don't know lets say 10,000,000,000,000 such dollops, would be pulling us this way and that. Obviously space is not at a premium so why limit it.

AND I'm not talking parallel universes here - God forbid

 

[Mon0Zer0]

Relevant:

A Slower Speed of Light is a first-person game in which players navigate a 3D space while picking up orbs that reduce the speed of light in increments. A custom-built, open-source relativistic graphics engine allows the speed of light in the game to approach the player's own maximum walking speed. Visual effects of special relativity gradually become apparent to the player, increasing the challenge of gameplay. These effects, rendered in realtime to vertex accuracy, include the Doppler effect; the searchlight effect; time dilation; Lorentz transformation; and the runtime effect.

 

[Mon0Zer0]

Your post sounds like you disagree with me and agree with Alia and Chistine, but you are making the same point I was: Relative speed is a concept.

I was making the point that "conceptual speed" is not speed. In the example you gave the "relative speed" is not speed but a ratio of two objects moving at speed. Speed is a physical process, comparisons or relations of objects at speed are not.

 

[Astro Pen]

As the condemned man, and his whole world, rushed toward the stationary bullet.

 

[Swank]

I was making the point that "conceptual speed" is not speed. In the example you gave the "relative speed" is not speed but a ratio of two objects moving at speed. Speed is a physical process, comparisons or relations of objects at speed are not.

Correct. That was exactly what I was demonstrating when it was suggested that after 1 year two opposite beams of light are only 1 light year apart. They are 2 light years apart, and that isn't a conflict with the max speed of light because the two aren't connected except in our minds.

 

[Wayne Mack]

Scenario: Two objects A, B, each giving off little flashes of light, are accelerated to slightly less than c and released in opposite directions from a station C.

In one year station C will observe A (and B) to be each 0.5 LY from the station (a separation of 1 LY). Computed speed will be 0.5c (though redshift will tell a different story). Rate of increase of separation will be c.

In two years station C will observe A (and B) to be 1 LY from the station. Computed speed will be 0.5c for each object and rate of increase of the distance between them will be c.

Now consider an observer D who is far from C, and perpendicular to the line A C B. Say the observer D is 10000 LY from C.

D sees A and B shoot out from C at some time. 1Y later D sees A at a distance of ~1 LY from C and ~2LY from B. Inferred speed will be ~c for each object and ~2c for the lengthening of the gap.

From geometry it seems that D will see A and B slowing down the further they go because of the larger angles.

But I vaguely recall Euclidean geometry doesn't apply so I'm likely wrong, but don't know how I'm wrong.

My understanding is slight different. To repeat the scenario (at least my understanding), there is a central point C. At time 0, light beams A and B are released in opposite directions. Assuming some magic form of observation, an observer at point C will see A and B being 1 lightyear distant from C. There have been no relativistic alterations at C. At C, an observer would see a 2 lightyear separation between A and B without requiring either to travel faster than the speed of light.

An alternate way to view this scenario would be to have point C1 with points A1 and B1 each 1 lightyear distant along a straight line and not moving relative to each other. A1 and B1 simultaneously release a beam of light towards C1. Each beam, travelling at the speed of light will take 1 year to reach C1. This is the basic definition of velocity. Furthermore, each beam will take 2 years to reach an opposite point at A1 and B1.

Where things get really bizarre (and where I am moving beyond my knowledge of physics) is when one uses an observation point at A in the original scenario. In my understanding, A would observe C moving away at the speed of light. However, A would also observe B moving away at the speed of light, yet there would also be an expanding gap between B and C. I do wish to reiterate that the latter is only my (mis)understanding of relativistic physics and I would appreciate someone more knowledgeable stepping in and setting me straight.

 

[Christine Wheelwright]

Correct. That was exactly what I was demonstrating when it was suggested that after 1 year two opposite beams of light are only 1 light year apart. They are 2 light years apart, and that isn't a conflict with the max speed of light because the two aren't connected except in our minds.

But doesn't this depend on the concept of the omniscient observer who can look at both objects at a single moment in time and say; "yes, they are now two light years apart having travelled at 1C for one year in opposite directions." The problem I have with this is that there is no single point in time that exists across multiple frames of reference. Time is inseparable from space. You have to pick a frame of reference and observe from that. And there is no frame of reference in which the two objects are two light years apart after one year.

 

[SilentRoamer]

There was/is/willbe/can be/ many such events. Maybe our big bang is just that. A localised event in a vastness of other places that bangs have and will occur. If it can happen once why not many times.

If there are other localised dollops of matter all around us it would also explain why our bit is expanding because the gravitational pull of, oh I don't know lets say 10,000,000,000,000 such dollops, would be pulling us this way and that. Obviously space is not at a premium so why limit it.

AND I'm not talking parallel universes here - God forbid

There seems to be a logical disconnect here. The Big Bang wasn't an explosion of matter in an existing space - in fact the terminology of "Big Bang" is not a great descriptor.

The "Big Bang" is the metric scale expansion of spacetime, it is not expanding "into" anything because spacetime itself is part of the expansion.

Any other such "dollops" are actually parallel universes, because they are not part of our spacetime. The Big Bang was not an explosion in a pre-existing space, it was the expansion of all spacetime.

Now it is possible there are infinite "dollops" but they cannot operate in the same "space" because "space" is not nothingness, there are properties to spacetime - it is not the nothingness that existed before the Universe came into being (where even the term "before" has little value because there was no before, spacetime began at the Big Bang.) It would be like standing at the North Pole and asking which way is further North.

I hope that makes some sense.

 

[Mon0Zer0]

Where things get really bizarre (and where I am moving beyond my knowledge of physics) is when one uses an observation point at A in the original scenario. In my understanding, A would observe C moving away at the speed of light. However, A would also observe B moving away at the speed of light, yet there would also be an expanding gap between B and C. I do wish to reiterate that the latter is only my (mis)understanding of relativistic physics and I would appreciate someone more knowledgeable stepping in and setting me straight.

From A's perspective, C would remain in place as the photons from C moving in the opposite direction would not be able to catch up with A, travelling at the speed of light.

See the video above too, you also get some freaky visual effects travelling at the speed of light. Looking forwards the entirety of your field of vision changes to encompass the entire field of view. Looking backwards everything goes black. Navigating at the speed of light is a nightmare.