A Mcguffin is a plot device, and it allows for the suspension of the normal limitations of reality. Typically a story needs at least one such Mcguffin. Anything beyond that and you look cartoony. Examples might include the Star Trek Universe, or a
The Epstein Drive Edit
- there is no such thing as a fantastic increase in speed to be had because the laws of physics. nuclear rockets- of which we assume the Epstein Drive is one,
Specific Impulse range
Solid Core Nuclear Core Rocket Engine- 500-1100
Liquid Nuclear Core Rocket Engine- 1300-1600
Gas core nuclear rocket engine-3000-7000
What ships on The Expanse have- 1,000,000 (ability to do 10g burns for long periods.)
Space Juice Edit
It is not specifically named but the use of steroids and meds to counteract the effects of growing up in weightless seems impossible. how do you grow muscles when nothing weighs anything?
In contrast a drug that fights cancer sounds quite reasonable.