In the world of Newtonian gravity the torpedo would indeed get there in less than an hour of your (and its) time. In GR there is gravitational time dilation that makes things more interesting. According to GR in your frame of reference the torpedo will first indeed accelerate but then closer to the BH it will slow down, basically halting near the horizon. In GR, by your clock, the torpedo will never reach the horizon. Not in a day, not in a year. Literally never in the simple model of a static BH. And because time ticks differently depending on where you are and how you move, it's not so obvious how to define the set of events simultaneous to you now. A common approach is to say an event N light seconds away is simultaneous to you now if light from that event will reach you in N seconds. Because of time dilation near massive bodies, coming from some places will take more time than from others of the same distance, so if you carefully trace such set of simultaneous events it won't be a plane, it will be a non-flat hypersurface that goes around the BH never touching it. No wonder since light cannot leave the BH horizon.
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timeasmymeasure
Re: Can't say anything about black hole?
Date: 2020-08-10 10:11 pm (UTC)In GR there is gravitational time dilation that makes things more interesting. According to GR in your frame of reference the torpedo will first indeed accelerate but then closer to the BH it will slow down, basically halting near the horizon. In GR, by your clock, the torpedo will never reach the horizon. Not in a day, not in a year. Literally never in the simple model of a static BH.
And because time ticks differently depending on where you are and how you move, it's not so obvious how to define the set of events simultaneous to you now. A common approach is to say an event N light seconds away is simultaneous to you now if light from that event will reach you in N seconds. Because of time dilation near massive bodies, coming from some places will take more time than from others of the same distance, so if you carefully trace such set of simultaneous events it won't be a plane, it will be a non-flat hypersurface that goes around the BH never touching it. No wonder since light cannot leave the BH horizon.