The Bridge, Ship Size, and Hull Size

[whulorigan]

This has nothing to do with elastic collision, that is about the material of the colliding bodies?

https://en.wikipedia.org/wiki/Elastic_collision

If there were no inertia, then one object could not "crash into" another; it would bounce back by the angle of incidence = angle of reflection principle. No inertia = "massless" (effectively). And in Classical Physics it would by extension mean no momentum, regardless of velocity.

(Yes, E=mc^2 kicks in here with Quantum Mechanics and Relativity - meaning there would be energy, and hence some (small) inertia-mass from Kinetic Energy).

 

[AnotherDilbert]

If there were no inertia, then one object could not "crash into" another; it would bounce back by the angle of incidence = angle of reflection principle. No inertia = "massless" (effectively).

Yes and no, no inertia would mean that even a tiny force would accelerate any object to lightspeed. That collision would not conserve energy or momentum, so not be elastic.

That is theoretically different from no mass.


No inertia breaks physics completely.

 

[mike wightman]

It doesn't change or affect inertia (= resistance to accel) in any way, it just accelerates you with the ship, in strict accordance with F=m×a. It manipulates F, not m.

Exactly in the same way as artificial gravity (=acceleration), but in another direction.

No.
The inertial compensator acts on the inertial mass of an object the same way a gravitic plate acts on gravitational mass.

Your example is actually incorrect, you can't have gravitics being an acceleration on the one hand while claiming inertial compensation is a force, they are either both forces or they are both accelerations.

Now since 'gravity' is an acceleration that produces a pseudo 'force' an inertial compensator must be the same but acting on inertial mass rather than gravitic mass, but since there has never been an experiment to show anything but inertial mass and gravitic mass are the same...

 

[mike wightman]

I am arguing that Traveller inertial compensators affect inertial mass, not inertia. Thus Traveller does have technologies that affect inertial mass, since they have technologies that affect gravitic mass.

F = m x a where m is resistance to the force, not the force.

Anti-gravity is the second major breakthrough. The postulated technology
produces both neutralization of weight and lateral thrust

underscore - gravitational mass
bold - inertial mass

which is why you don't need a separate inertial compensation system in Striker.

 

[AnotherDilbert]

The inertial compensator acts on the inertial mass of an object the same way a gravitic plate acts on gravitational mass.

There is no inertial mass vs gravitational mass, there is only mass.

Your example is actually incorrect, you can't have gravitics being an acceleration on the one hand while claiming inertial compensation is a force, they are either both forces or they are both accelerations.

They are both accelerations, and through F = m × a both forces.


https://en.wikipedia.org/wiki/Equivalence_principle

It's exactly the same. Without looking out the window you can't notice the difference.

 

[AnotherDilbert]

Anti-gravity is the second major breakthrough. The postulated technology
produces both neutralization of weight and lateral thrust

Exactly like a helicopter. It can hover and can move laterally.

Describe it as thrust (force) or acceleration, it's the same thing seen from different perspectives.

CT Striker, B3, p8:
K. Grav Generators: A grav vehicle requires grav generators installed in its chassis. Each .02 m³ of grav generators produces 1 ton of thrust and requires .1 megawatts of power from the power plant. They weigh 2 tons and cost Cr100,000 per m³.

A grav generator produces thrust, just like a helicopter rotor. It is not weightless and inertia is unchanged.


Anti-grav tech can of course not declare itself immune to the geometry of curved space-time. If it did it would no longer be connected to the local planet or star system and would careen away into space as the planet accelerated away from it...

 

[kilemall]

Equal countering would mean you are pushed and pulled in different directions - could be messy

I assume repulsion plates pointing in the exact opposite direction of the M-drive 'thrust'.

 

[Grav_Moped]

Yes and no, no inertia would mean that even a tiny force would accelerate any object to lightspeed. That collision would not conserve energy or momentum, so not be elastic.

Looked at through the right lens, man, that could make for a really nifty spaceship drive!

 

[AnotherDilbert]

Looked at through the right lens, man, that could make for a really nifty spaceship drive!

As used by e.g. the Outsiders in Niven's Known Space.

Unfortunately it would mean that our understanding of physics is completely wrong. But then if jump works...

 

[Condottiere]

It's quite possible there are more than one way to manipulate gravity.

Or create it.

In Traveller.

 

[robject]

There's also the fabled Inertialess Drive. Shades of Triplanetary.

 

[Straybow]

Mr. Meticulous says, "To damp is to reduce vibration or flow magnitude. To dampen is to make wet."

 

[robject]

A: "What's this? This thing says it's a Nuclear Dampener."

B: "Yes".

A: "Doesn't it mean Nuclear Damper?"

B: "No, this machine here actually stops gamma particles with water molecules."

A: "But water can't stop gamma radiation!"

B: "Magic!"

 

[Condottiere]

Also referred to as the wet blanket effect.

 

[kilemall]

Mr. Meticulous says, "To damp is to reduce vibration or flow magnitude. To dampen is to make wet."

Meticulous saves lives in critical engineering situations but does not get invited to parties.

 

[Grav_Moped]

Looked at through the right lens, man, that could make for a really nifty spaceship drive!

As used by e.g. the Outsiders in Niven's Known Space.

Unfortunately it would mean that our understanding of physics is completely wrong. But then if jump works...

There's also the fabled Inertialess Drive. Shades of Triplanetary.

... and E. E. "Doc" Smith's entire Lensman series, of which Triplanetary was the first book, as you figured out.

Yes, I'm explaining the joke months later. Ran across this post looking for something else and thought I should close the loop.

Classically-trained SF reader* here, all credit to my father's book collection. (Thanks, Dad, wherever your spirit is.)


Those books may seem jam-packed with cliche's, but they're where the cliche's started from! (They're also written within the cultural context of 3/4 of a century ago, so keep that in mind as well if you check out Smith's works.)

______________________________
*hat tip to MWM for the phrase, though I expect I mangled it slightly.

 

[Silverhawk]

I remember reading the Lensmen Series in high school. Always a favorite to come back to. The other is the Spindizzy from Blish's Cities in Flight stores.