The Nature of the Universe, Time Travel and More...

[Asbo Zaprudder]

Define "exist", but first define "define". In the end, it's probably easiest to just kick the stone and say "I refute it thus."

“I refute him thus!”: Misunderstanding Berkeley – Irish Philosophy

 

[Will The Serious]

it is essential to it that it must be possible to perceive it. Thus, all sensible objects are necessarily dependant on minds.
-Berkeley

Precisely.
What of the "real" Universe without the question? If there was no mind to perceive the solid, there is no solid, from any practical position.

Since this is a Trek forum, consider the original episode, The Cage, where the Enterprise has destroyed the gate to the subterranean complex, but unable to perceive that distruction, the gate remained to lock out the crew, just as real as if it had actually been solid.

-Will

 

[StarCruiser]

Actually - time itself does not exist as an actual 'thing'. As a measurement of change (entropy's effects) yes...

 

[Asbo Zaprudder]

One model of the universal wave function*, the Wheeler-DeWitt equation, is timeless. Within it, time can be constructed using various mathematical techniques. In General Relativity, the general covariance principle implies that time is a label assigned to one of the coordinate axes. In one interpretation, the time evolution of any physical system is similar to the U(1) local gauge transformation of quantum electrodynamics (QED) and the phase of the gravitational field plays the role of local time. Prior to the electroweak phase transition in the early Universe, there was effectively no local time as all particles were massless and travelled at the speed of light (c). After the electroweak symmetry was broken at about t = 10^-12 seconds, matter particles such as quarks acquired mass by interaction with the Higgs Field and could no longer travel at c. That was when space-time and therefore time, as we experience it, effectively began.

* All of the following is somewhat of a simplified description.

 

[Will The Serious]

https://www.vice.com/en/article/dy3g5j/dark-big-bang-dark-matter
Apparently, the quest for Dark Matter has led to a theory of a second Big Bang, within about a month of the first Big Bang, more of a Dark Bang. The evidence of Dark Matter is inductive. The evidence of a second Big Bang is based on the fact that we guess Dark Matter exists and haven't yet found it, so there is possibly a different origin of Dark Matter.

Not having the math or science background to fully appreciate the science behind the whole Big Bang theory regarding the time frame, scope, energy levels, etc. I have even more difficulty imagining how any reasonable theory can propose a second Big Bang with a time frame of less than a month of the first Big Bang.

As has been pointed out in previous posts, all this theorizing seems to be based on premises that are not much more than guess work, but taken as facts. We need to start somewhere, but the traditional Scientific Method of hypothesis - test, approach can often lead people to commit too strongly to their ideas. The machinations we sometimes go to in order to cling to our concepts can hold science back hundreds of years. However, these new observations of our Universe that are proving inconsistent with current theories may help to shake us loose from our grip on a false reality.

-Will

 

[Will The Serious]

In General Relativity, the general covariance principle implies that time is a label assigned to one of the coordinate axes.

A dimension, mathematically, is simply a different identifying attribute. We could easily decide color or frequency or furiness was a dimension in a coordinate system. What is important is the uniqueness of the axis. Any number of such axis can be calculated with the right definitions and perspectives. Time is not an unreasonable 4th dimension, but perhaps there are others, as well. What we haven't yet seen is a 3 dimensional object that occupied the same space twice over the same time period. If we do find that, we will definitely need a fifth dimension. The question then becomes, have we seen the same object occupy the same 3D position more than once over a dimensionless time axis? That is, without time or change. Time may be unnecessary for a coordinate system, unless time travel is possible.

-Will

 

[Asbo Zaprudder]

A lot of standard cosmology is taken way too seriously and that includes the Big Bang. We infer the distant past based on observations that even now are very patchy samples of the night sky. Even the cosmic microwave background data can be questioned as large parts have to be interpolated because of obscuration by signals from our own galaxy. We invent dark matter and dark energy and we don't have a clue as to whether they really exist and, even if they do exist, what they are. They could equally well be phantasms due to inadequate or over-simplistic theories or systematic observational bias. We should be prepared to throw most of what we think we know should better theories and observations become available. JWST is throwing up a lot of questions about the validity of our models and that's a good thing. It appears that electromagnetic forces might well be more important on a cosmic scale than was though, and while I don't subscribe to theories such as Alfvén–Klein cosmology or Electric Universe, that's also not a surprise, to me at least.

 

[Will The Serious]

while I don't subscribe to theories such as Alfvén–Klein cosmology or Electric Universe, that's also not a surprise, to me at least.

Electricity is common throughout the universe, generated by all cosmic plasma as it moves through magnetic fields. Peer reviewed papers describe electricity in the Sun, and associated with the interplanetary medium (solar wind), planets and their satellites, comets, in interstellar space, other stars, and intergalactic space.
https://www.electricuniverse.info/

Tesla came up with the Dynamic Theory of Gravity. Apparently, he had his whole theory developed and written down. But, it disappeared along with most of the contents of Wardenclyffe, after his death.
Tesla equated gravity with electromagnetism. One of his claims, from his research into ultra-high frequency electromagnetism, was that he actually felt a gravitational pull coming from a generating electrical device through his protective screen.

Obviously, if he felt such a pull, it is an assumption, at that point, to attribute the force to gravity. However, whether or not gravity is a result of warped spacetime or some other as yet unidentified phenomenon, it is not an outrageous notion that electricity could be involved.

If gravity is warped spacetime, what warps that spacetime? Answering, "mass" only leads to the question of, what is mass that it warps spacetime? How does physical existence cause spacetime to warp?

On another forum, I was involved in a discussion in which numerous people pointed out that gravity is not a force, but rather an acceleration. However, an acceleration without a force would seem counter to the classical mechanics we all learned in school.

So, by what "force" is space curved? If we were to apply the concept of 'least effort' to space, the straight line would seem to make the most sence, if lines at all were involved. Therefore, curving space would have to take energy for it to be refracted from the classic "shortest distance" model.

As for electromagnetic energy at a cosmic scale, what we may measure as a zero force may not really be zero, and like the guy clapping in the top row of the Super Dome, you can't hear him from the parking lot, but add a thousand more fans, and it becomes a roar two blocks away.

-Will

 

[Asbo Zaprudder]

Force = mass x acceleration but we assume (as does General Relativity) that inertial mass is equal to gravitational mass (or at least, always in direct proportion to it, hiding the constant of proportionality in the gravitational constant, G). From what experiments that have been done, this appears to be true, but the reason why is uncertain. One explanation is that it is due to the effect of the rest of the mass of the Universe on an accelerated body. As to why mass-energy curves space-time, that is suggested by the mathematics of General Relativity, which appears to explain observational anomalies that Newtonian gravitation doesn't. Einstein's original idea was that mass affects the speed of light and that space-time does not curve. It might be that one can interpret the equations in both ways, but it's not something that I've ever given much consideration, given that I'm not a professional physicist. I do not feel that considering such things is a useful way to spend my time. I'm just not good enough at mathematics.

 

[publiusr]

I wish Ramanujan was still with us.

In terms of force---I heard that researchers "at the University of Illinois Urbana-Champaign have detected the existence of a charge density wave of electrons that acquires mass as it interacts with the background lattice ions of the material over long distances."
Fahad Mahmood, Observation of a massive phason in a charge-density-wave insulator, Nature Materials (2023)

Something to do with tantalum selenium iodide...

There is till part of me that hopes for quantized inertia---maybe a variation on this is a way to go about it?

The speed of nothing
https://bigthink.com/hard-science/photons-light-time/

More
https://phys.org/news/2023-04-evidence-gravity-earth.html

 

[Asbo Zaprudder]

Ringing an electronic wave: Elusive massive phason observed in a charge density wave (phys.org)

Yes, it always seems remarkable (although perhaps, on reflection, it shouldn't) how excitations in condensed phases of matter are often analogues of processes in particle physics and the early universe.

 

[Will The Serious]

Traveling faster than light.

Imagine what it would look like if a physical object could travel faster than light.

If a space craft, for instance, wasn't limited to sub-light speed, it would look really odd to an observer towards whom the craft was heading.

If we were to take a spacecraft that started, say 2 ly away and flew at 2 ly/y of speed towards Earth to land on a space port landing pad, with something like instant acceleration to zero, to set down at the destination, (don't want to complicate things), what would an observer see as the observer watched the flight?

1. First, it would take the light 2 years from the launch planet to arrive at the terminating (observing) space port.
2. The spacecraft does it in 1 year.

So,
the observer wouldn't have to start watching until a year after the spacecraft arrived, if the observer wanted to watch the craft take off.

let's say, the observer knew the launch was exactly two years earlier at 12 noon, the observer's time. The observer would go out to the telescope and, maybe look into it a couple of minutes in advance. Just to be sure the observer didn't miss anything. What the observer would see, instantly, was that the timing was wrong, the spacecraft had already launched and was two minutes into its flight.

Instead of giving up and calling it a missed opportunity, the observer decides to continue watching, following the spacecraft's progress to Earth. Remember, the craft has already been sitting on the landing pad for a year.

Maybe not so surprising, the observer saw no progress towards Earth, but instead spent the next two minutes watching what would appear to be a space craft traveling at 2 ly/y backwards and land at its point of origin. The strange of part is that at that point, the craft would disappear and life would go on as normal two years prior on that distant launch pad. The observer would see the spacecraft land then dissappear while the ground crew stared up, trying to see that faster than light ship travel to its landing pad two light years away. They might even see that craft, like a ghost, reflecting only half the light that it normally would and it would never look, to them, like it would make it, in less than two years.

The observer, back at the destination, if it wanted to see the entire flight of this faster than light craft, would have to start watching once the craft landed. Then, the observer would watch the craft fly backwards at 2ly/y back to its destination, which it would reach a year later. Two years after it launched.

Now this is just me using my imagination and what I take to be sound logic, but something similar works with sound in the shift of wave lengths as a super sonic jet or something else passes. As it flies towards you at Mach 2, you hear nothing, but then, boom, the jet and its noise is there and past, only to be followed by its soundwave that was generated well before it got to you. You wouldn't hear that wavelength shift until the jet had traveled well past your position. Then, all the noise left is what can reach your ears from miles away in the direction it was heading.

How fascinating would it be to have a spacecraft land at a spaceport, only to watch its ghost, travel backwards at hyper-light speed, all the way back to its point of origin, while the craft was still sitting right there in front of you, on the landing pad?

-Will

If the observer checked

 

[Asbo Zaprudder]

How will a faster than light spaceship look like to an outside observer? Are there any Scientific paper about this? (I recall reading something like that on a science communication site sciencealert but can't find it again) - Quora

The first response seems to come to a similar conclusion to you. I'm not entirely sure myself as it's not the sort of thing that either practising or lapsed physicists consider. I suspect an Alcubierre driven ship might look relatively normal apart from appearing to travel faster than light speed as it is deforming the local space-time metric. In its own warp bubble, it is actually in free fall I believe apart from extreme tidal effects near the edge of the bubble. However, my understanding is that no-one is really sure how to create such a bubble nor how to get it in motion.

 

[StarCruiser]

And no one's sure how much energy would be needed even if we did know how create/move one (hint - it's a lot).

 

[Will The Serious]

And no one's sure how much energy would be needed even if we did know how create/move one (hint - it's a lot).

Maybe, maybe not.

Maybe you let the cosmos provide the energy.

-Will

 

[XCV330]

Maybe, maybe not.

Maybe you let the cosmos provide the energy.

-Will

that doesn't make any sense to me. anyway, this is naval gazing.

 

[Will The Serious]

I spend most of my online time on a sailing forum. Did you know there are sailboats that can sail faster than the wind? Most sailboats can, in fact, sail upwind. They do it by a sort of incline plane, like the way a surfboard can traverse the face of a wave at a velocity faster than the wave is traveling. Wind and water combine to create a sheering force that squeezes the boat at a velocity faster than the closing speed of the water and wind. Like pinching your fingers together causing a slippery watermelon seed to shoot out perpendicular to the forces and get out of the way of your closing fingers much faster than the pinch. If we can figure out how to "surf" a wave traveling at light speed, but "fall" at an angle to that velocity, maybe the energy is already there, we just have to harness it with finesse.

-Will

 

[XCV330]

true+apparent wind is not a an indicator of some kind of trick around the laws of physics. You can sail in space, magsails, solar sails, for instance, and gravity slingshots, and you might even manage to get close enough to c to get relativistic effects, but you still won't violate causation and go faster than light.

 

[Asbo Zaprudder]

The Lorentz factor effect on inertial mass ensures that you can never attain light speed. There is a proposal* for a light-hugger kind of drive based around a particle accelerator. Wave surfing is a possible mechanism for constructing compact accelerators. Depending on your target, the time dilation effect would mean that you should probably never go home again as everyone you knew might well be long dead.

*Enzmann Echolance - not something I've expended any effort on researching though. Such a drive would have to obey the rocket equation and inertial mass increase of special relativity, and although the drives gather some fuel using a Bussard-type mechanism, I suspect that would limit the velocity as would the extra weight required for the cooling circuits of the nuclear reactors and particle accelerator.

 

[Will The Serious]

the time dilation effect would mean that you should probably never go home again as everyone you knew might well be long dead.

Half the solution to time travel, right there. Time dilation for the jump ahead in time. Next we just need to work on that going back-in-time half.

Is there any part of the time compression in general relativity that sends the traveled towards total time stop? This would allow for instantaneous jumps to any distant future. The traveler would then need to figure out how to go back in time to return to the original time.

That does leave me wondering. Which frame of reference would have to control the time traveled in order to stop at any given future time? If the traveler was controlling it, how would that work? The traveler would not experience the passage of time in order to create a time based method for stopping. That would also imply an inexhaustible energy supply. If you had enough energy to reach light speed and all time stopped, you would maintain that speed forever. No more energy would or could be spent because there was no movement of time to expend the energy across.

If the outside frame was in control, the mechanism would have to be able to exist across the whole time period, outside the traveling object and be able to affect the object from without; stop the traveler going light speed.

You know, in time travel movies, the time capsule disappears from the present time when it jumps to the future, but maybe it wouldn't. Maybe it would appear to exist in all time from the present, up to the future when the time traveler steps back out of the time capsule. It would only disappear when moving back to the original present. Then, it's presence might be erased from all that time in between.

I can picture the humor in a movie scene, where the lab was testing their new time traveling invention for the first time. The lab guysigive the pilot/time traveler the thumbs up before they hit the switch to send it into the future. First test, just a day ahead. The pilot raises a hand to return the gesture as the lab guys hit the switch and nothing happens. The capsule doesn't move.

"What's wrong?" one scientist might ask. Then they turn to look at the capsule and through the window is the pilot, frozen in the thumbs-up gesture. The lab can't effect the capsule. It has to stay, anchored in the middle of their lab for 24 hours before the time traveler can step out, convinced of success. Good thing they didn't try to jump ahead a century or more, that capsule would then have become a permanent centerpiece in their lab for a hundred years. Awkward

-Will