Post AoTdDQgpw7J77psNaC by [email protected] | |
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Post #AoPZPlhWSzwnJez9l2 by [email protected] | |
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A hundred starship captains, bored with life in the Federation, decide to form … | |
Post #AoPZXhcDXa2cxgHrnM by [email protected] | |
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@johncarlosbaez trick question, time stops at the horizon, they never actually … | |
Post #AoPZhc0vDodAU6ZGXw by [email protected] | |
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I believe that as the 50th captain crosses the horizon, they'll see 49 star… | |
Post #AoPa6gUlhHrfcgU2oi by [email protected] | |
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@johncarlosbaez I don't understand the physics involved, at all, but from a… | |
Post #AoPbjfXPI59Ttws3fs by [email protected] | |
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@johncarlosbaez So when the captain is 1m in front of the horizon do they see t… | |
Post #AoPbymtoCgov4lYgBE by [email protected] | |
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If the event horizon were like a black veil, this would be paradoxical. How ca… | |
Post #AoPcs4Mgy3BhAkQdUG by [email protected] | |
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The 50th captain never sees the ships in front of him hit the singularity! In… | |
Post #AoPd41Jo7WAZCNmIMq by [email protected] | |
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@Corax42 - you're right! You win the prize! And the prize is a smiling k… | |
Post #AoPdWVxZn1J6L7xzXM by [email protected] | |
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@johncarlosbaez Yay! Best prize ever!!! | |
Post #AoPe5SXGVsr1r3K4si by [email protected] | |
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@OscarCunningham - I don't know what "one meter in front of the horizo… | |
Post #AoPeJMwa6FI2ZBnT16 by [email protected] | |
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@johncarlosbaez Given that I read your four postings in reverse order on Mastod… | |
Post #AoPeUhZrizpVkJZki8 by [email protected] | |
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@starwall @johncarlosbaez I don't think time "stops" at the horiz… | |
Post #AoPeUhj5AjCcCtt74q by [email protected] | |
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@FelisCatus @starwall - someone orbiting the black hole will never see the 100 … | |
Post #AoPee2XPAEtRMLsSlE by [email protected] | |
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@dadakopf - I've always wondered what it's like to take a cruise. | |
Post #AoPepAtwPQuEU3jCgS by [email protected] | |
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@johncarlosbaez From what I’ve seen and heard, boredom dealt with alcohol… | |
Post #AoPeyTjbkyU3V6KbBY by [email protected] | |
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@johncarlosbaez Unless they lay down a trajectory that does not "follow on… | |
Post #AoPfauYKUoOngCNjwu by [email protected] | |
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@johncarlosbaez @FelisCatus surely they would see the starships ahead of them t… | |
Post #AoPhDya5YIxBQBOcd6 by [email protected] | |
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@johncarlosbaez @BartoszMilewski I think it is not that easy. Light travels at … | |
Post #AoPhLKJX9Eesqt9q8O by [email protected] | |
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@johncarlosbaez @starwall as long as the 50th ship has not crossed the horizon … | |
Post #AoPhjTldeVdB7YovHE by [email protected] | |
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@johncarlosbaez @BartoszMilewski I guess you have to be very careful when think… | |
Post #AoPlZjspHKe01ZnFLc by [email protected] | |
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As the 50th captain falls toward the horizon, he always sees 49 ships in front … | |
Post #AoPmVYDenqrCe36UOu by [email protected] | |
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@jaztrophysicist - thanks! I'm dreaming of a video series on YouTube, so I&… | |
Post #AoPnO9TIW3fxonSHEe by [email protected] | |
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@johncarlosbaez @3blue1brown @gregeganSF Alessandro Roussel, aka ScienceClic, a… | |
Post #AoPr6xCPI6useLbqdM by [email protected] | |
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@johncarlosbaez @3blue1brown @gregeganSF Low tech by todays standards but still… | |
Post #AoPsYaaf2lBoamhBRY by [email protected] | |
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@johncarlosbaez @3blue1brown @johncarlosbaez @gregeganSF I think I learned a lo… | |
Post #AoPvpQe1ZgJqX0zRfk by [email protected] | |
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@gregeganSF @johncarlosbaez how dare you tease this dream collaboration only to… | |
Post #AoPxdaHS7eD0qlubwm by [email protected] | |
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@BartoszMilewski @johncarlosbaez The first ship does actually "wait for yo… | |
Post #AoPxdaSnRTHbPxDfd2 by [email protected] | |
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@glocq @johncarlosbaez Doesn't that contradict our earlier discussion? @joh… | |
Post #AoPxdaaEznEnn2hcES by [email protected] | |
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@BartoszMilewski - you see nothing special happening to you as you cross the ho… | |
Post #AoPy4BR2bYgZc253Ka by [email protected] | |
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@johncarlosbaez In toot (2/n) you are using the phrase "at that very momen… | |
Post #AoPzRiH8lsiS4zEWdk by [email protected] | |
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@SvenGeier - I tried to clarify what I meant:"I believe that as the 50th c… | |
Post #AoQ6Hr8Xfa3ULUSTg0 by [email protected] | |
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@gclef - I answered my question so you can compare your answer with that! | |
Post #AoQAdw8ABOL21O47NI by [email protected] | |
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@gclef - according to general relativity, after the 50th captain crosses the ev… | |
Post #AoR1hnDgYBkp76N8kq by [email protected] | |
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@johncarlosbaez @glocq Surely their navigators should be able to calculate thei… | |
Post #AoRECPSo7k3jrWoM0O by [email protected] | |
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@johncarlosbaez @gregeganSF There is no lightlike trajectory that goes radially… | |
Post #AoRECPeVQFPuRoHhEu by [email protected] | |
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@johncarlosbaez @gregeganSF ok this reasoning is flawed because you can see the… | |
Post #AoRECPkt2WWMlbGnBY by [email protected] | |
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@trebor - if you don't use Schwarzschild coordinates, and instead use a Pen… | |
Post #AoTdDQADtNDfUgcKkS by [email protected] | |
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@glocq @johncarlosbaez @gregeganSF You're right. I just figured out what I … | |
Post #AoTdDQJnJmsLyN5yfR by [email protected] | |
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@BartoszMilewski Your first paragraph is correct *as long as you're looking… | |
Post #AoTdDQSempxsPrF3Tt by [email protected] | |
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@glocq @johncarlosbaez @gregeganSF Consider what it would look like from the po… | |
Post #AoTdDQa6L9v4mwj05I by [email protected] | |
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@BartoszMilewski No, the bacterium is also flattened (from the point of view of… | |
Post #AoTdDQgpw7J77psNaC by [email protected] | |
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@glocq is doing fine, but just to chime in here:"Right before you hit the … | |
Post #AoTmLfmib4ydqTdIK8 by [email protected] | |
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@johncarlosbaez @glocq @gregeganSF The equivalence principle is valid only appr… | |
Post #AoU10ljilx59XFilw8 by [email protected] | |
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@glocq @johncarlosbaez @gregeganSF Notice that I'm not saying that your nos… | |
Post #AoU10lswDgSFzq28Iq by [email protected] | |
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@BartoszMilewski What experiment do you suggest I do, once near the horizon, to… | |
Post #AoU10m0jkgh2O1gMSW by [email protected] | |
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@glocq @johncarlosbaez @gregeganSF The standard way to measure distance is to c… | |
Post #AoU10m8BJ0eEl7AJ3w by [email protected] | |
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@BartoszMilewski Just so we're clear: you're suggesting that the bacter… | |
Post #AoU10mEuty2H60JgYq by [email protected] | |
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@glocq @johncarlosbaez @gregeganSF When you're learning special relativity,… | |
Post #AoU10mLIWF8jPnImVU by [email protected] | |
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@BartoszMilewski - if you're falling through the event horizon of a very la… | |
Post #AoU8hL26d96AqaZAFE by [email protected] | |
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@johncarlosbaez @glocq @gregeganSF Frankly, I don't know. Is the answer obv… | |
Post #AoUAFDbkqJR1cQxZ2m by [email protected] | |
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@BartoszMilewski - yes, it's obvious! I explained the basic idea in a rec… | |
Post #AoUX3ii5g4iLYFPS5o by [email protected] | |
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@johncarlosbaez 'imho, It's a lot easier to visualize if you use the Kr… | |
Post #AoUXsdCLvkA3E1qBQO by [email protected] | |
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@johncarlosbaez well okay, there has to be curvature (read: tidal forces) becau… | |
Post #AoUiVdAcxztDyTGjFQ by [email protected] | |
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@johncarlosbaez and this also answers the red-shift question pretty quickly, i.… | |
Post #AoUj0m6TnswEenBBNA by [email protected] | |
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@wrog - if the first ships pass the horizon long before the 50th, the captain o… | |
Post #AoUlLkYawrwLqlSY2i by [email protected] | |
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@johncarlosbaez a distant observer sees them all redshifted. But that says not… | |
Post #AoUmCBRwCvIoJYLdWC by [email protected] | |
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@wrog - I'm imagining all 100 ships falling in from different starting posi… | |
Post #AoUpll2QBLlqgi4F3g by [email protected] | |
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@johncarlosbaez except that if ship #50 is on a trajectory parallel to ship #1 … | |
Post #AoUqkWYadYmvRL5cgq by [email protected] | |
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@johncarlosbaez Though not precisely your scenario, the calculations here might… | |
Post #AoV1HAk1lawCsVe7KS by [email protected] | |
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@johncarlosbaez I'm trying to reconcile our points of view, and the only wa… | |
Post #AoVUaAbfODHkdI98am by [email protected] | |
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@BartoszMilewski wrote: " I'm trying to reconcile our points of view, … | |
Post #AoVWKCv5DmeR58kDlw by [email protected] | |
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@gregeganSF - thanks, that's very helpful! I very dimly remembered it fro… | |
Post #AoVdG7DRBafnucKEsq by [email protected] | |
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@johncarlosbaez @BartoszMilewski We see the image flattened on the horizon from… | |
Post #AoVdo85uQSmYU01VS4 by [email protected] | |
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@johncarlosbaezThe stationary observer only gets to see the first falling astro… | |
Post #AoVnpNdL8UeQVYtZYm by [email protected] | |
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@johncarlosbaez I'm not trying to be difficult. The reason I'm jumping … | |
Post #AoVnvyaIfMEwqZcQ6a by [email protected] | |
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@gregeganSF - thanks, that's extremely helpful. I was surprised that peopl… | |
Post #AoVt44IpmyjifZ7wyu by [email protected] | |
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@BartoszMilewski - I'm glad you're not *trying* to be difficult.Let'… | |
Post #AoW12ihhPJ0z1ccqWW by [email protected] | |
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@johncarlosbaez Yeah, the whole mix of gravitational and Doppler redshifts/blue… | |
Post #AoWFSJrDo57oqwBFjM by [email protected] | |
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@gregeganSF - thanks! Do you think I'm right about this?If you and a frien… | |
Post #AoWjsKurUSZyI4CmH2 by [email protected] | |
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@johncarlosbaez Better than what I think, this is an exact calculation. Note th… | |
Post #AoWuax3S3JKmrH8TUO by [email protected] | |
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@gregeganSF - great, thanks! It's interesting how the decrease in Alice… | |
Post #AoX8g8WiE4zxFCBlhI by [email protected] | |
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@johncarlosbaez @gregeganSF The reason I'm struggling is that I'm despe… | |
Post #AoXkC5l5kXxsEJ10q0 by [email protected] | |
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@BartoszMilewski wrote: "I'm desperately trying to reconcile the large… | |
Post #AoXpo6swVbv8UzdSDI by [email protected] | |
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@johncarlosbaez @gregeganSF You keep saying that my questions make no sense, bu… | |
Post #AoYCQQWS90XBOlnA0m by [email protected] | |
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@BartoszMilewski @johncarlosbaez @gregeganSF Right, there's no frame-indepe… | |
Post #AoYCQQhRU9KBwqvw8m by [email protected] | |
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@OscarCunningham - yes, true! The angle subtended can get very large or small … | |
Post #AoYDXqhFKOWsYbwYNc by [email protected] | |
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@BartoszMilewski wrote: "You keep saying that my questions make no sense, … | |
Post #AoYFtFyIkbj8w6Fy3k by [email protected] | |
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@johncarlosbaez @gregeganSF That's what I mean:"an outside observer wi… | |
Post #AoZpLqUUG40LrOdfIO by [email protected] | |
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@BartoszMilewski I think you need to make it clear if the observer is going int… | |
Post #AoZpLqgBYZMWRg70Wu by [email protected] | |
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@glocq @johncarlosbaez @gregeganSF We're in agreement. But let's go slo… | |
Post #AoZpLqqSwLaMxYvDYO by [email protected] | |
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@BartoszMilewski Correct@johncarlosbaez @gregeganSF | |
Post #AoZpLqxYVzFzJYEsbY by [email protected] | |
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@glocq @johncarlosbaez @gregeganSF You answered yes to question (1) and no to q… | |
Post #AoZpLr4I6we1eROG6S by [email protected] | |
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@BartoszMilewski @johncarlosbaez @gregeganSF I assume "question 2" re… | |
Post #AoZpLrC5dwso2d2UG8 by [email protected] | |
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@glocq @johncarlosbaez @gregeganSF Even if Bob follows Alice from a long distan… | |
Post #AoZpLrKF9dPARuqzy4 by [email protected] | |
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@BartoszMilewski @johncarlosbaez @gregeganSF > Bob will eventually see her a… | |
Post #AoZpLrRghxMMp0KwZU by [email protected] | |
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@glocq @johncarlosbaez @gregeganSF Yes, he can "say" (this is why I s… | |
Post #AoZpLrZUExb9DBzAjA by [email protected] | |
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@BartoszMilewski @johncarlosbaez @gregeganSF Ok but I still don't get why h… | |
Post #AoZpLrhHlxpvbNdOsq by [email protected] | |
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@glocq @johncarlosbaez @gregeganSF Because he sees her in front of the horizon,… | |
Post #AoZpLrojKHn7yT7LUG by [email protected] | |
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@glocq @johncarlosbaez @gregeganSF Moreover, the photons emitted from an object… | |
Post #AoZpLrukxsc0H9w9se by [email protected] | |
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@BartoszMilewski - "Ok but I still don't get why he should "see h… | |
Post #AoZz7S4XFRbtcBH7oW by [email protected] | |
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@johncarlosbaez @glocq @gregeganSF This is exactly why I drew a pair of eyes--w… |