Posted on 05/18/2021 12:11:52 PM PDT by Red Badger
“The three dimensions of length are altered by gravity...”
This is just a nonsense statement. Gravity isn’t “altering” anything. Einstein actually proposed that gravity isn’t even a true force at all, but just an emergent phenomenon created by warping of spacetime. It is mass and energy that warps spacetime (never space) to create the appearance of gravity, NOT the other way around.
It’s analogous to surfing. A wave is moving 40 mph. The actual water is not moving 40 mph, only the wave. But the surfer can ride the wave and be effectively moving at 40 mph, although he appears to be just standing still on top of the moving wave.
The three dimensions of length are altered by MASS-ENERGY just as surely as the fourth dimension of time; in special and general relativity, the only difference between length and time is their opposite signs in the distance metric.
It may be that God created much of the universe to make a special location (Earth) able to sustain life. I'm speaking as an old-earth creationist who on the one hand believes God had a direct hand in creating all things (including breathing life into man -- I'm not a theistic evolutionist who believes God created a system of natural selection and sat back and let nature do all the rest). But at the same time, I also believe God could have put a lot into the design of the Earth so that the Earth itself can have a universe custom made for it to "inhabit" just like the Earth is custom made for life to inhabit.
Here are some possible reasons:
1. God just likes to create stuff. Asking why God created the universe is kind of like asking why God made flowers pretty. Maybe He's just into creating cool stuff.
2. There is a theory that God likes to re-use things He already made. My take on why organisms often seem a lot alike is not because of natural selection, but because they were made by the same Designer. Can't God do the same thing with other stuff? It may be that the cosmic radiation from other galaxies provided the substance -- at just the right mass and energy and timeline -- for our galaxy to form. For our sun to form. For the planets around our sun to form.
3. There are all kinds of things to show that our milky way galaxy was specially made so that one planet within it can support life. For example, most stars in the milky way galaxy have orbits that are highly elliptical. Just by observing our nearest most stars we can see how special our star's circular orbit is (much less volatility wreaked onto the planets that orbit it).
Yes. If you are considering travel as “pushing” yourself to that limit.
The concept of “warp” drives means moving within a pocket of “space time.” The traveler never exceeds light speed—but the bubble bends the space around it.
All very theoretical. I know the back of the envelope description. But they say it might work in theory. Practically? Not in our lives.
For example, in the Schwarzschild metric (the solution to the Einstein field equations outside a spherically symmetric mass distribution) the coefficients of both radial distance and time are different than in the absence of mass: https://en.m.wikipedia.org/wiki/Schwarzschild_metric
You aren’t accelerating the mass, you’re compressing and stretching the warp bubble (like reference frame). Relativity theory does not put limits on the speed the bubble can be manipulated. The occupants of the spacecraft would feel no acceleration, AT ALL.
I don’t doubt a big reveal is coming but Miguel Alcubierre’s theory was published in 1994.
Lentz’ paper was published just this March.
130 years ago, people were saying that about heavier-than-air flight.
Its likely that this technology has been around for 70 years or more but held back from the public domain.
First of all, it’s spacetime; not space. And in either case, second: it is *not* shorthand for “nothing”!
If it were nothing, there’d be total chaos. There’d be no infrastructure there to determine which trajectories are inertial, which paths are trajectories in time, versus curves in space, which directions are temporal versus which ones are spatial, to determine what is congruent to what, which angles are right angles, which points are near which other points, which regions are contiguous to which regions, how many dimensions there are, which paths & motions are smooth versus jagged, the lengths of paths, the durations of trajectories, which speeds are light speed, etc.
That all counts as something. And all that infrastructure is what spacetime is and contains. In fact, everything else can be reduced to it (via Einstein’s field equation). Even the law of inertia is, itself, a consequence of Einstein’s field equation.
So, it’s not only not nothing, it’s everything.
Of course length is altered. But length is different than space. Which is why Einstein always spoke of “length contraction” rather than “space contraction”.
When Einstein talks about length being altered, he is speaking about the apparent change in length, of measuring rods and such, to the observer in a moving inertial frame. He never talks about the actual 3 spatial dimensions in the universe in reality being “warped” as some modern day interpreters of Einstein do. Only the measurements, or our perceptions of length are being altered by motion, that is what Einstein talks about.
Your measurements of length are certainly altered but space itself is not altered. For example, if you travel from here to Alpha Centauri at a relativistic velocity, the length between Earth and Alpha Centauri, to YOU, appears to shorten. However, the space between Alpha Centauri and Earth is not actually changing, as anyone who measures it from either Earth or Alpha Centauri, or any other point in the universe can confirm. Only YOUR measurement is changing.
I’m not disputing that when you do the math that time and the spatial dimensions are interchangeable. However, these are just mathematical conventions. In reality, time and space are clearly different things, even if we can conceptually represent them as interchangeable axes in a coordinate system for our own convenience. Einstein’s entire focus in relativity was solving the problem of SIMULTANEITY in moving systems, which is a temporal problem, not a spatial one. His use of Minkowski space to unify the mathematics of space and time to solve the problem works, but it has the unfortunate side effect of creating this confusion that time and the spatial dimensions are interchangeable IN REALITY, when they are really only interchangeable in this limited mathematical framework.
Otherwise science fiction as we know it would collapse.
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