Recent comments in /f/space

Flaxinator t1_j5atlvd wrote

Normally maritime exclusion zones are put in place down range when a rocket launches so that if it fails the debris can fall safely into the sea.

I wonder how Djibouti will manage this given that there are very busy shipping lanes going through the Gulf of Aden, just off the coast of Djibouti. Even ignoring that the range of orbits it can launch to will be quite limited unless they plan to launch over Somali or Yemeni territory.

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Anonymous-USA t1_j5af6kl wrote

Hard to say since no one actually knows what gravity is! 😆 But the distinction I was making is that a photon has no mass, so light doesn’t actually change directions due to gravity so much as it travels a strait line through a warped space-time.

ie. Gravitational force F=(G × M1 × M2) / D^2

Photon M2 has mass of 0. This suggests it could escape the black hole as there’s no gravitational force between them, but obviously it cannot due to the curvature of space.

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egregiouscodswallop t1_j5a6jmt wrote

Since the explosive forces, swirling gasses, and gravitational rotations create a total force that is NOT spherical, there is likely a window of time when part of your blackhole requires an FTL escape velocity while the other hemisphere still lets loose photons and gamma rays. So a critical atom (singular)? No, probably not. There is also an accretion disc around blackholes which block and reflect light back into the central mass. So for a non-zero amount of time, the blackhole is not trapping photons but the blackhole system (the Greater Metropolitan Blackhole) does effectively trap everything.

Tl;dr there would be a window of time and mass during which your escape velocity is sub c but nothing escapes AND/OR your escape velocity reaches c but not uniformly in a sphere.

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Sykowsh t1_j5a1wnx wrote

Also relativity. Your atom with speed of just a tiny bit lower than speed of light would have such a relative mass on itself, that it could under the influence of your BH create some sort of space censure around itself,
from the perspective of an outside observer. ....or I confuse apples with pears.

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citybadger t1_j59r94t wrote

Light climbing out a gravity well loses energy. Unlike a object with mass, it doesn’t slow down as it loses energy, because it’s light - it can’t slow down. So it instead gets lower in frequency - “red-shifted”. Gamma rays become X-rays, which become ultraviolet light, which become blue visible light, which become red visible light, then infrared, microwave, and radio. Visible light climbing out of ordinary neutron star will be red shifted. Some of the red light will be invisible because it shifted into infrared.

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boundegar t1_j59n2ra wrote

Question doesn't really make sense. Verb has no subject. Who or what is "going to the very limit?"

What you might be asking is if a neutron star gradually accretes mass, will it reach a threshold and collapse into a singularity, and the answer is yes, in theory. A bunch of gravitational waves would result, and I think scientists have detected waves with the right pattern - but there's no way to directly observe this.

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