1. Subscribersonhouse
    Fast and Curious
    slatington, pa, usa
    Joined
    28 Dec '04
    Moves
    52724
    17 May '14 11:271 edit
    Is it possible given unlimited propulsion? It could be ship time which would shift with relativistic time dilation but how much accel would you need to arrive there with zero velocity relative to Mars?

    I know if you accelerate at one G for about one year you are very close to c so since there are about 32 million seconds in a year, if you could accel at 32 million G you get to c in about one second.

    So the same ole same ole then, accel for half the trip, decel for the other half but how close to c do you come doing that?

    Assuming Mars is 100 million miles or 160 million kilometers away ATT.

    What would the real trip time be? That is to say, Mars time?
  2. water
    Joined
    24 Jan '14
    Moves
    3078
    20 May '14 04:32
    Kerbal space program
  3. Subscribersonhouse
    Fast and Curious
    slatington, pa, usa
    Joined
    28 Dec '04
    Moves
    52724
    20 May '14 08:25
    Originally posted by Copope
    Kerbal space program
    ?
  4. Subscribertalzamir
    Art, not a Toil
    60.13N / 25.01E
    Joined
    19 Sep '11
    Moves
    45051
    20 May '14 16:02
    Sunlight reaches earth in 8 and Mars in about 13 minutes, so we're talking relativistic here - and that's assuming a flying start. Starting and ending at zero velocity would require speed in excess of light speed. Sure, time delation could mean that the rocket crew (in addition to becoming flat tomato sauce on the walls) would think they are on time, but they'd still be late on arrival, Mars time, and that's the clock they get paid on so they'd be fired?
  5. Subscribersonhouse
    Fast and Curious
    slatington, pa, usa
    Joined
    28 Dec '04
    Moves
    52724
    20 May '14 16:552 edits
    Originally posted by talzamir
    Sunlight reaches earth in 8 and Mars in about 13 minutes, so we're talking relativistic here - and that's assuming a flying start. Starting and ending at zero velocity would require speed in excess of light speed. Sure, time delation could mean that the rocket crew (in addition to becoming flat tomato sauce on the walls) would think they are on time, but th ...[text shortened]... d still be late on arrival, Mars time, and that's the clock they get paid on so they'd be fired?
    That's why I specified ship time. 160 million Km takes about 9 minutes at c.

    So you can't do mars in 5 minutes Earth time or Mars time. I was just setting up the problem to solve given an unlimited G force acceleration, like I said, 1 G gets you close to the speed of light in one year or so, 32 million G gets you to c in about 1 second.

    So using figures like that, how close to you get to c, accelerating half way then decelerating the rest of the way, how many G's of accel for how many seconds does it take to give a ship time of 5 minutes when we know c takes about 10 so you have to average a velocity that gives an average relativistic time dilation about 2 to 1 or so. But what are the actual numbers?
  6. water
    Joined
    24 Jan '14
    Moves
    3078
    21 May '14 21:22
    Remember that you are in a vacuum, so for every meter a second you accelerate you have to decelerate.
  7. Subscribersonhouse
    Fast and Curious
    slatington, pa, usa
    Joined
    28 Dec '04
    Moves
    52724
    22 May '14 09:56
    Originally posted by Copope
    Remember that you are in a vacuum, so for every meter a second you accelerate you have to decelerate.
    That's what I specified, accel half the trip, decel the rest so you are at local zero velocity. It wouldn't help much for package delivery if you go by at .99c🙂
Back to Top