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How can I ever fall into the black hole if by any onlookers perspective I never do? Because Oppenheimer's original frozen-star description is the one that's right. Have a read of The Formation and Growth of Black Holes on mathpages, where author Kevin Brown refers to two interpretations: "Historically the two most common conceptual models for general ...


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This is paradoxical but not contradictory because yours and the onlooker's times flow differently, and once you fall under the event horizon there is no way to reconnect to compare times. The paradox only happens because of the implicit intuition about some "absolute time" that applies to both observers, and that you continue to exist under the horizon ...


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Good question. I think the event horizon has to be absolute, because as you suggested, light either gets out or it doesn't. I venture to suggest that isn't in accord with what most here would say is current teaching, but here's a couple of interesting facts: 1) Light is not redshifted when it ascends, and nor is it blueshifted when it descends. You can work ...


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The definition of the event horizon is `the boundary of the past of future null infinity', so it is the surface beyond which nothing can escape to infinity. It isn't defined with reference to any observer. A consequence of the definition is that an observer can never really determine where the event horizon is, since its location depends on all future ...


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The observer sees you travel from A to B - a distance that, in his frame of reference, is greater than one light year. He sees that you take more than a year. He concludes you are traveling at less than the speed of light. You, traveling so fast, "see" a much shorter distance (this is the concept of length contraction) $L' = L_0/\gamma$ where $\gamma = ...


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the forward land delegate IS approaching the light and the backwardland delegate IS moving away from it Are they? Or are the delegates sitting perfectly still, and the Earth spinning quickly beneath them? Of course we have a convention that the Earth is stationary and the train moves across it, but we also know that the Earth is not stationary - it ...


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Simply put, relativistic speeds cause for events previously thought of as simultaneous to no longer be simultaneous if the velocity of the reference frame of the event changes relative to the defined observer. The best way to wrap your head around this is to pictorially trace what is happening in space time. The case you describe is v>0 Think of v in ...


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Both observers see the other approaching at 99% of light but since observer 1 is the reference frame that accelerated, and changed it's behavior of motion, it is the reference frame that will have experienced less time than observer 2 during the duration of it's travel. The change in motion (acceleration/deceleration) is what changes the rate at which a ...


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Tme dilation refers to time in the accelerated frame (the rocket). So a clock in the rocket will run slowly compared to a clock on earth. It is us who would measure the rocket as moving at 0.5c. The speedometer in the rocket could actually show a speed greater than that. From the POV of the crew in the rocket, their clock is running normally. It is the ...


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As the other answers point out, there is no "right" or "absolute" frame of reference for measuring time. But that does not answer your question: Is there a way to measure the passing of time for this object? It turns out there is. Oscillations in the orbits of electrons depend only on the material, and in fact our clocks measure the passing of time by ...


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There is no reference object that transcends all inertial frames of reference. Everything in this universe has an inertial frame of reference, and none of them are privileged. If there were any object that existed independently of the relativistic effects of acceleration/gravity or of observer movement, then theoretically it could provide a reference to ...


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In relativity there is no standard-clock that tells you which time is "right". That's the point about relativity. There is no need for a absolute reference to compare with. Everything is just the way you observe it (that is, relative to you). Things may slightly differ from observer to observer but the qualitative behaviour stays the same just as classical ...


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Draw a spacetime diagram. Really, there is no better way to solve relativity problems. In the above, the nail has worldlines $1$ (back) and $2$ (front), while the hole's worldlines are $3$ (front) and $4$ (back). Let's agree that the origin $\mathcal{O}$ of the coordinates is the event of the front of the nail just entering the hole, i.e. the intersection ...


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Imagine a slightly different scenario: two pilots, Alice, and Bob, are in their spaceships. They move towards a tunnel of length $L$ at a velocity $v$, and remain a distance $l'$ apart. Alice is closest to the tunnel and thus enters first, approaching a wall at the end of the length of the tunnel. Just as Bob enters he decelerates, coming quickly to a halt ...


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This is a variation of the pole and the barn paradox, and is also known as the bug and the rivet paradox, see Rod Nave's hyperphysics: The final line of this article is "the paradox is not resolved". Some people will say the paradox is resolved via consideration of simultaneity, but I don't think it is. Another variation of the theme is when you and I are ...


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The bug lives! Since BOTH the hole and the nail will change length in the moving coordinate system and their proportions Ln/Lh will be constant, if you pick a third coordinate system that is moving at half the speed of the nail. In this system both the hole and the nail are moving at the same speed in opposite directions.


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The bug will die: What does cause the nail deceleration? it's the base of the nail hitting the outside of the hole. In the best case scenario for the bug the tip of nail stops as soon as it gets the information (the shock wave from the abrupt deceleration). This will travel across the nail no faster than the speed of light. So let's assume the best case ...


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Special relativity itself makes it clear that absolutes cannot be detected, such as being at absolute rest in space, or the inability to detect absolute motion. This therefore prevents one from having an absolute understanding of special relativity, since that which special relativity reveals does not extend to the point of absolutes. Thus the absolute ...


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Yes, there's a very famous example: muons produced in the upper atmosphere can be detected on the surface of the Earth. Moving at nearly the speed of light, it takes them over 300 microseconds to get down to the Earth's surface, but the average muon decays after 2.2 microseconds. If it were not for time dilation, only a few in every $10^{60}$ muons (so, ...



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