[Pseudoscience-is-malarkey (OP)]

Obviously, it's not necessary to recreate Earth conditions while traveling within the confines of geospace, but would travel to Mars or Titan or further out benefit from it in regards to health, sanity, and comfort?

[alancalverd]

Human physiology is obviously adapted to upright stance in 1g. Long periods of low g alter the distribution of water and internal organs, so even if you prevent bone density loss with resistive exercise you will end up taller and with a somewhat modified circulatory system that will take some time to readapt to an upright stance - blood flow to the brain being the most immediately problematic.

However since Martian gravitation is only about 0.3g there is no need to replicate Earth's gravitational acceleration throughout the trip.   It is left as an exercise to the reader to choose between powered deceleration at > 0.1g, say, during the last few months of the trip, or rotating a ship that is large enough to stand in radially. 

[Peter11]

The human body requires gravity to work right.Astronauts come back weak after a long space mission and you can even die if enough time is spent in zero gravity before coming back to earths gravity.

[alancalverd]

you can even die if enough time is spent in zero gravity before coming back to earths gravity.

Not sure this has been demonstrated.

[hamdani yusuf]

you can even die if enough time is spent in zero gravity before coming back to earths gravity.

Not sure this has been demonstrated.

Perhaps because the time wasn't enough.
But when someday it does, it would be a challenge to determine whether the death is caused by zero gravity or something else.

[alancalverd]

The longest single flight to date was 438 days, most accumulated time in orbit 878 days. So far no reported fatalities due to returning to 1g. 

[evan_au]

The best thing about being on the Moon is that I could finally go to the toilet

Apparently, digestion does not work so well in micro-gravity.

These days, there are supplements that can help with digestion, according to astronaut Mike Massimo, interviewed here:
https://www.thenakedscientists.com/podcasts/astronomy-podcasts/space-boffins/mike-massimino-and-meet-minister

[Peter11]

They pretty well know the limit the longest was around 450 days.They say without exercise they can loss up to 20% of muscle mass in two weeks not to mention bones start to weaken.A six month trip requires months of rehabilitation when they come back.It just hasn't happened yet and hopefully won't happen.

[wolfekeeper]

However since Martian gravitation is only about 0.3g there is no need to replicate Earth's gravitational acceleration throughout the trip.

One interesting factoid: nobody knows what the minimum g-force is for human being's long term survival.

All long-term experience is either at 0g or 1g, it's unknown whether humans can survive at 0.3g.

It is left as an exercise to the reader to choose between powered deceleration at > 0.1g, say, during the last few months of the trip,

That's completely beyond current propulsion technology.

[alancalverd]

Quote
It is left as an exercise to the reader to choose between powered deceleration at > 0.1g, say, during the last few months of the trip,
That's completely beyond current propulsion technology.

I smell a conspiracy theory!

When I was a lad, we were told to believe that people had made a soft landing on the moon, using powered deceleration to transition from zero-g to a 0.16 g environment. Worse still, we were told that "current propulsion technology"  could produce 4 to 6 g at takeoff - obvious nonsense!

[wolfekeeper]

There's two propulsion technologies in use today. Rockets and ion/plasma drives. Rockets generally pull a few gs for about ten minutes or a few tenths of a g for an hour or so. Ion drives can pull milligees (due to the power/weight ratio of practical power supplies- carrying the weight of the power supplies limits the acceleration).

There's nothing, other than an infeasibly big rocket, that can generate 0.1g for months. That would be a tremendous advance if anyone worked out how to do it.

As an exercise, take a one tonne capsule and calculate the work done to do that from force x distance. You'll find it's ... large.

[Petrochemicals]

If centrifugal force centipedal acceleration can be used to create artificial gravity how does the Theory of Rativity remain credible?

[wolfekeeper]

Because it's not real gravity.

[Petrochemicals]

Because it's not real gravity.

Motion is relative therefore centrifugal force et al is a fantasy.

[alancalverd]

Which is why "centrifuges" don't work and the tyres don't loosen from wheels spinning at high speed. Engineering would be so much simpler if people realised that physics is a myth.

[Petrochemicals]

Which is why "centrifuges" don't work and the tyres don't loosen from wheels spinning at high speed. Engineering would be so much simpler if people realised that physics is a myth.

That is obviously to do with the attraction to the centre of earth, stop being silly! In a weightless independant frame relativity obviously dictates there can be no acceleration to any other gravitational body.

[Petrochemicals]

Ahem.

[evan_au]

In a weightless independant frame relativity obviously dictates there can be no acceleration to any other gravitational body.

The ISS is a weightless (microgravity) environment  (except when the rockets are firing)
- The ISS is being continually gravitationally attracted to the Earth.
- The ISS is being continually accelerated towards the Earth (but it continually misses, due to its large horizontal velocity).

A spaceship to Mars is a weightless (microgravity) environment (except when the rockets are firing)
- A spaceship to Mars is being continually gravitationally attracted to the Sun.
- A spaceship to Mars is strongly gravitationally attracted to the Earth at the start of its journey.
- A spaceship to Mars is strongly gravitationally attracted to the Mars at the end of its journey.
- A spaceship to Mars is being continually accelerated towards the Earth, Sun and Mars (in different ratios and in different directions at different parts of the journey).

[Petrochemicals]

In a weightless independant frame relativity obviously dictates there can be no acceleration to any other gravitational body.

The ISS is a weightless (microgravity) environment  (except when the rockets are firing)
- The ISS is being continually gravitationally attracted to the Earth.
- The ISS is being continually accelerated towards the Earth (but it continually misses, due to its large horizontal velocity).

A spaceship to Mars is a weightless (microgravity) environment (except when the rockets are firing)
- A spaceship to Mars is being continually gravitationally attracted to the Sun.
- A spaceship to Mars is strongly gravitationally attracted to the Earth at the start of its journey.
- A spaceship to Mars is strongly gravitationally attracted to the Mars at the end of its journey.
- A spaceship to Mars is being continually accelerated towards the Earth, Sun and Mars (in different ratios and in different directions at different parts of the journey).

But

A spacecraft in deep space in its own frame fires thrusters on the outside of the craft which cause it to rotate, those inside rotate along with the craft,  the rotation giving acceleration to those inside that is countered by the walls of the craft, changing the direction of the peoples inside and leading to angular acceleration.

The craft happens upon Glibglub. Gilbglub and the craft are equally matched in motion, however Gilbglub has not undergone rotation. Upon stepping aboard at the wall of the craft, Gilbglub unaware of the crafts earlier rotation floats weightless in the craft and decides to float toward the captain in the middle of the craft. Upon reaching the captain Glibglub is informed that the craft had previously undergone rotation, at which point Glibglub comes under the influence of the newly informed centrifugal information and conforms to being plastered to the outside wall of the space craft.