(Demo) Black Holes

[UK_Eliter]

There are some amazing planet textures shown within that thread.

That black hole - sucking in stuff, yes? - has an amazing appearance!

[Switeck]

A Black Hole would be on the edges of a regular Oolite solar system? Or in Interstellar Space?

Hmm. I'd expect a black hole to be the center of a galaxy. Which means it starts as a collapsed star and as that in the center of a solar system, then aggregates mass such that it influences all star systems in a growing range.

If we leave out the time ranges, the black hole would be found as the center of a star system or considered in intergalactic space. But never on the edge.

A "small" black hole of 3-10 solar masses might seem to be at the edge of a star system, but only because everything else either orbits it or they orbit the other star/s in the same system. Getting near a black hole may seem unhealthy, but what created the black hole (typically a supernova) tends to ruin the whole stellar neighborhood!

It's easier to "fall" into a regular star than a black hole. Much larger target!

[hiran]

It's easier to "fall" into a regular star than a black hole. Much larger target!

No matter the size of a black hole - it's gravity is big enough to prevent even light from escaping. However stars emit light, which means their gravity is too small to prevent it.

So even if the black hole might be small, it's gravitational effect is bigger than that of stars. So it can attract matter in a wider range. I wonder why you state hitting a star would be easier.

[Switeck]

If a star's diameter is 1 million km and a black hole's event horizon is 100 km then getting within 1/2 million km of the center-of-mass of the star is crashing into it while the same is not even close to hitting the black hole.

A "near miss" of a star by 1 million km means either an elliptical orbit or parabolic (leaving the system) orbit.
The same is true for a black hole.

It's why throwing Earth's nuclear waste into the Sun is so difficult!

[hiran]

A "near miss" of a star by 1 million km means either an elliptical orbit or parabolic (leaving the system) orbit.
The same is true for a black hole.

Hmm. Seems I was not looking at inertia. Good point.
But then, does it matter for Ooniverse?

[Switeck]

Really close to a black hole, even Oolite's ships should have trouble overcoming both Newtonian and relativistic forces.
And the event horizon is death!

RooTers News Public Service Announcement:

Don't go flying into the Pulsar at Tianve near top right of Galaxy Chart 1.

It isn't a wormhole, you'll just die.

3 ships have tried in the last 100 days.

Is it suicide, stupidity, or the 'Entrance to Heaven' cult?
(Assistant editor here: those last 2 are repeats.)

Truth is, we don't know!

[UK_Eliter]

Re the Rooters ('Tooters') PSA: hah!

[Wildeblood]

And the event horizon is death!

Only for small black holes, where one gets the spectacular spaghettification and all that jazz. For supermassive black holes, the event of crossing the horizon would pass unremarkably. (Just as a ship sailing away from a coast on earth experiences nothing special when it crosses the horizon as viewed from a fareweller on the shore.) You'd only know you'd crossed the horizon when you tried to look back and discovered you couldn't, because every direction is forward, and backward no longer exists as a spatial dimension.

[Cholly, in my gut I feel this sentence, "Just as a ship sailing away from a coast on earth experiences nothing special when it crosses the horizon as viewed from a fareweller on the shore," requires two commas, but where?]

[Cholmondely]

[Cholly, in my gut I feel this sentence, "Just as a ship sailing away from a coast on earth experiences nothing special when it crosses the horizon as viewed from a fareweller on the shore," requires two commas, but where?]

Does it? Really? The punctuation is to help people parse it - and I could see no issues - unlike much other prose I've recently read.

[Switeck]

Only for small black holes, where one gets the spectacular spaghettification and all that jazz. For supermassive black holes, the event of crossing the horizon would pass unremarkably.

Jury's still out on whether the Killing Horizon would actually kill you for supermassive black holes, but it could be that dimensions are folded flat/curled up and/or time itself stops.

Oppenheimer and his co-authors interpreted the singularity at the boundary of the Schwarzschild radius as indicating that this was the boundary of a bubble in which time stopped. This is a valid point of view for external observers, but not for infalling observers. John Wheeler later described black holes viewed from an external reference frame as "frozen stars" because an outside observer would see the surface of the star frozen in time due to gravitational time dilation, never to fully collapse.

On the assumption that an Oolite-class ship (with physics-breaking shielding from gravitational influences) could overcome all but the worst spaghettification, it might be possible for such a ship to cross a supermassive black hole's event horizon estimate by a huge margin and then hyperspace out of it. The ship might exit such a wormhole with a much higher exit velocity than normal due to its relativistic speeds on entry.

[hiran]

On the assumption that an Oolite-class ship (with physics-breaking shielding from gravitational influences) could overcome all but the worst spaghettification, it might be possible for such a ship to cross a supermassive black hole's event horizon estimate by a huge margin and then hyperspace out of it. The ship might exit such a wormhole with a much higher exit velocity than normal due to its relativistic speeds on entry.

Hyperspace with big masses around? Although being close to a big mass is different from being inside a big mass. And then being inside the Schwarzschild radius is not being inside the mass. I am confused.

[Wildeblood]

Wilhelm Killing had the most German-sounding name ever.

Since you've linked the Wikipedia article, allow me to have a whinge about that dreadful excuse for a reference source.

At first, it was suspected that the strange mathematical singularities found in each of the black hole solutions only appeared due to the assumption that a black hole would be perfectly spherically symmetric, and therefore the singularities would not appear in generic situations where black holes would not necessarily be symmetric. This view was held in particular by Vladimir Belinski, Isaak Khalatnikov, and Evgeny Lifshitz, who tried to prove that no singularities appear in generic solutions, although they would later reverse their positions.[56] However, in 1965, Roger Penrose proved that general relativity without quantum mechanics requires that singularities appear in all black holes.[57][58] Shortly afterwards, Hawking generalized Penrose's solution to find that in all but a few physically infeasible scenarios, a cosmological Big Bang singularity is inevitable unless quantum gravity intervenes.[59] For his work, Penrose received half of the 2020 Nobel Prize in Physics, Hawking having died in 2018.[60]

Tell me with a straight face that that passage is not attempting (deceitfully) to imply that Hawking would have received the other half, had he still been alive.

The Nobel Prize in Physics 2020 was divided, one half awarded to Roger Penrose "for the discovery that black hole formation is a robust prediction of the general theory of relativity", the other half jointly to Reinhard Genzel and Andrea Ghez "for the discovery of a supermassive compact object at the centre of our galaxy"

[Wildeblood]

On the assumption that an Oolite-class ship (with physics-breaking shielding from gravitational influences) could overcome all but the worst spaghettification, it might be possible for such a ship to cross a supermassive black hole's event horizon estimate by a huge margin and then hyperspace out of it. The ship might exit such a wormhole with a much higher exit velocity than normal due to its relativistic speeds on entry.

Hyperspace with big masses around? Although being close to a big mass is different from being inside a big mass. And then being inside the Schwarzschild radius is not being inside the mass. I am confused.

You're correct, hiran, Oolite-style FTL* is ruled out, because of the mass-locking (in-game) phenomenon. The only plausible escape from a black hole, here in our universe and in the ooniverse, is via time-travel. In an environment where spatial dimensions have become time-like, the only way to back out is to go back in time.

* I consider the Oolite FTL process - use a magic technology to generate a "wormhole" then jump in - to be implausible, but that's what the rules of the ooniverse have.

[Cholmondely]

You're correct, hiran, Oolite-style FTL* is ruled out, because of the mass-locking (in-game) phenomenon. The only plausible escape from a black hole, here in our universe and in the ooniverse, is via time-travel. In an environment where spatial dimensions have become time-like, the only way to back out is to go back in time.

Ahem! Of the three "engines" which your ship may possess -Torus, Injector-adumbrated engine, & regular engine, only Torus is affected by Mass-lock

[Switeck]

Tell me with a straight face that that passage is not attempting (deceitfully) to imply that Hawking would have received the other half, had he still been alive.

There may have been an intentional cruel act of waiting till Hawking died to award the Nobel Prize...

You're correct, hiran, Oolite-style FTL* is ruled out, because of the mass-locking (in-game) phenomenon.

I had a bug with Oolite a few years ago where I hyperspaced out from inside the main planet's atmosphere...on arrival in another system (or interstellar space), any movement was treated as though I was still trying to fly through that planet's atmosphere, so my ship heated up and exploded.