Time appears to be fixed to space and this gives rise to some surprising effects. A gravitational field is the result of a mass displacing time. An inertial field is the modification of a masses’ gravitational field so that the mass remains in motion.

The inertial field represents the kinetic energy of a mass. This energy is conserved in all rates of time.

In weaker gravitational space the energy required to displace time decreases. The kinetic energy of a mass is conserved (as energy) not as the displacement of a certain amount of time. The mass must speed up (in faster space) so that that it will displace more time equaling the same amount of energy. A mass speeding up would not seem to be a problem for space travel. The devil is in the details.

(Ship Time, ST) One of the observers (and their clock) will be on a small mass spacecraft traversing faster time rate space. The mass of the ship is too small to allow it to shield itself from the increased rate of space time.

(Fixed Time, FT) The other observer (and clock) will remain in the Sun’s deep gravity well.

The duration of the voyage (using normal physics) would be calculated by dividing the distance by the spaceship’s velocity. The problem is that velocity is time dependent. How much distance do you travel in one second of your local time? If time speeds up by a factor of 2X but your velocity does not increase by at least that same amount then as a practical matter you have slowed down.

Fixed Observer Near Sol Fixed Time (FT)

To the FT observer the spacecraft’s journey to a nearby star would be noticeably shorter than calculated from the starting velocity (cool). The clock signal received from the spacecraft would show the increasing rate of time. The time rate would peak when the spacecraft is the farthest from both stellar masses. (The Pioneer’s internal oscillator signal was processed to erase this effect). But if the FT observer calculated the velocity of the spacecraft using the clock speed received from the spacecraft then the journey took a lot longer.

Observer and Clock on Spaceship (ST)

The observer on the spacecraft (ST) will watch their velocity drop versus the rate of accelerated time (direct observation and by comparing to FT’s clock). Velocity increasing by the square root of the time rate (rough possible calculation) means that time is passing quicker but the spacecraft is moving slower (not cool).

Kinetic energy is constant but velocity (using your local time) is not.

The time period for an interstellar journey already looks bad in linear time. If these speculative properties of Space-Time of interstellar space are real then the problems of interstellar travel are a lot worse.

Because of the shielding effects of the Sun’s mass we never experience these effects as we travel around the galaxy through various rates of time.

David Brin wrote a story called the “Crystal Spheres” where inhabited systems were protected by a bubble which could only be broken from the inside. The universe was protecting inhabited systems from invasion by more advanced forms.

If my crude analysis of Space-Time is correct then crossing interstellar space in a small spacecraft can take a lot longer than calculated using constant linear time. The difficulty factor for interstellar travel goes from difficult to nearly impossible.

If I give this physics an anthropomorphic interpretation it would also suggest that Warp Fields and FTL are also impossible. Any galactic civilization would be both patient and stable over giga years. Davis Brin’s “Library Institute, the repository of all knowledge” might exist in some form.

The Fermi Paradox seems to have a hidden term directly written into the physics of spacetime. We are in a cage but on the other hand nothing can easily get to us either.