Entering a rotating cylinder in space and inertia gravity?

[Gawdzilla]

(16-09-2017 10:19 AM)Carlo_The_Bugsmasher_Driver Wrote:  

(15-09-2017 07:01 AM)Deesse23 Wrote:  Speed of light, c = 300.000.000 m/s
accel 1g = 10m/s/s

How long to reach c at 1g accel? -> c/1g = 300.000.000 m/s /10 /m *s *s = 300.000.00 s = 500.000min = 8333h = 347d = 1y

You need to accel for 1y constantly at 1g to reach c (ignoring your increasing mass near c).

If you go for Alpha Centauri (4ly) at 0.1 c. It will take you 40y and you need to accel/decel 0.1y (35days) each, at 1g.

Yeah except for one small detail: WHERE ARE YOU GOING TO FIND A PROPULSION SYSTEM CAPABLE OF BOTH ACCELEREATING TO, AND DECELERATING FROM, THE SPEED OF LIGHT?

E-bay.

[Deesse23]

(16-09-2017 10:19 AM)Carlo_The_Bugsmasher_Driver Wrote:  

(15-09-2017 07:01 AM)Deesse23 Wrote:  Speed of light, c = 300.000.000 m/s
accel 1g = 10m/s/s

How long to reach c at 1g accel? -> c/1g = 300.000.000 m/s /10 /m *s *s = 300.000.00 s = 500.000min = 8333h = 347d = 1y

You need to accel for 1y constantly at 1g to reach c (ignoring your increasing mass near c).

If you go for Alpha Centauri (4ly) at 0.1 c. It will take you 40y and you need to accel/decel 0.1y (35days) each, at 1g.

Yeah except for one small detail: WHERE ARE YOU GOING TO FIND A PROPULSION SYSTEM CAPABLE OF BOTH ACCELEREATING TO, AND DECELERATING FROM, THE SPEED OF LIGHT?

Yep, and an acceleration of 10m/s^2 is pretty massive, considering that the best ion drive we currently have (chemical propulsion is not an option, too inefficient) has a propellant force equal to a human trying to blow and the spaceship we need will be tons and tons and tons.

(Hydrogen) fusion has an acceptable yield and fuel could actually be collected during flight, but we need a way to convert the released energy into propulsion.

[Peebothuhul]

At work.

For 'Atomic' engins..... the earliest/most primitive proposed was the 'Atomic putt putt' or the original Orion.

From reading the 'Atomic Rockets' web site newer studies would seem to indicate that 'Pure Bussard ramjets' wont actually work.

The very interstellar medium itself will induce enough 'drag' that scoop speeds wont be maintainable.

Though the site does propose that a scoop system could be used as a way to 'stretch' the amount of fuel needed for a mission. Extra fuel is scooped into the system to suppliment that which is carried.

[Yonadav Kenyon]

(14-09-2017 12:29 PM)onlinebiker Wrote:  Read "Rendezvous with Rama" by Arthur C Clark.

I peeked into this discussion just to see if anyone had suggested that book.

[Yonadav Kenyon]

(15-09-2017 03:14 AM)OakTree500 Wrote:  Is gravity caused by "mass" ? or I am being too simple?

The gravity that we feel is caused by both the earth's mass and our distance from the center of it. An object with less overall mass but higher density could have a greater gravity at its surface. For example, if we remove the crust from the earth, we would be left with a planet that has less overall mass but higher density. We would be closer to the center of a denser planet, and would weigh more on the surface.

[onlinebiker]

I have to wonder what being in a spinning cylinder in space would be like.

Consider - there still isn't gravity...

If you were in the cylinder in orbit around earth, and were a meter from the " floor" I.E. the inner part of the cylinder BEFORE it was spun, then they imparted spin to the cylinder - you would not " get thrown to the floor" ( as many people suspect ) What would happen is as the air would over time assume the same rotation as the cylinder, while you remained suspended and then the air pressure would gradually start you moving, until you matched the rotational speed of the cylinder. We're the cylinder big enough, a vacuum would form at the axis.

The worst part would be motion sickness caused by Coriolis effect. You would feel the rotations direction each time you changed you position in relation to the cylinder.

[Erikjust]

(04-10-2017 12:09 PM)onlinebiker Wrote:  I have to wonder what being in a spinning cylinder in space would be like.

Consider - there still isn't gravity...

If you were in the cylinder in orbit around earth, and were a meter from the " floor" I.E. the inner part of the cylinder BEFORE it was spun, then they imparted spin to the cylinder - you would not " get thrown to the floor" ( as many people suspect ) What would happen is as the air would over time assume the same rotation as the cylinder, while you remained suspended and then the air pressure would gradually start you moving, until you matched the rotational speed of the cylinder. We're the cylinder big enough, a vacuum would form at the axis.

The worst part would be motion sickness caused by Coriolis effect. You would feel the rotations direction each time you changed you position in relation to the cylinder.

From what i recall as long as the cylinder is big enough, we wouldn´t feel the Coriolis Effect.
And while the cylinder won´t give true gravity, from what i understand in the vacuum of space it would be the closets thing to actual gravity we can come.
I VERY much doubt magnetic boots like shown in Tintin Destination Moon and in the show the expanse would be that useful.

But i could be mistaken.