Did you guys ever see the movie Moon? I thought Sam Rockwell was great in it and the ending blew my mind.....
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I liked it.
Moon base will be for science, mining and hotel for rich, but it is necessary before any real colonization.
Quick question for everyone.
How far would one have to dig under the surface of say, the Moon, to get to the point where gravity can be at the same level of the earth?
(My simple understanding is that the closer one gets to the core of a planet/moon, etc... gravity increases...I can most definitely be wrong)
Could this be another reason for the boring company?
Note the problems with lower gravity situations with the human body as per NASA.
The Human Body in Space
How far would one have to dig under the surface of say, the Moon, to get to the point where gravity can be at the same level of the earth?
(My simple understanding is that the closer one gets to the core of a planet/moon, etc... gravity increases...I can most definitely be wrong)
Could this be another reason for the boring company?
Note the problems with lower gravity situations with the human body as per NASA.
The Human Body in Space
That was one of the most fascinating lessons I remember from calculus
The answer is that no, the deeper you dig the more gravity doesn't go up. It turns out that as you dig, the effective gravity is that of a sphere of the radius of the distance you are from the center.. Everything above you cancels out, so the deeper you dig, the less gravity you feel.
Very informative. Reminds me of my astronomy teacher's question of what would happen if our Sun became a black hole?
The class said they thought everything would get sucked in including Earth.
His answer was: no. Everything would remain right where they were because the mass of the Sun wouldn't change.
Skotty
2014 S P85 | 2023 F-150L
A fun followup to this would be to graph or chart the radius of the event horizon as compared to the mass of the black hole.
Also, if you are at the center of the singularity, does the gravity cancel out? It's a nonsense question, yet a totally intriguing question at the same time.
It's called a singularity, not because they don't come in pairs, but rather that we have no idea what the physics is there.
The radius is directly proportional to the mass. However, measuring space in the vicinity of a black hole is tricky since your ruler isn't the same length.
Another oddity about black holes is that for a small black hole, flying by close to the event horizon would likely be fatal due to "spaghettification" since the gravity gradient is so steep. Your feet are much more strongly attracted than your head.
However, that's not the case for a big black hole. The event horizon is so far from the center of mass that the gravity field is pretty uniform, so you could fly by (very fast) and enjoy the view, very strong radiation, near light speed collisions, etc.
Well... it's hard to say exactly what happens when you fly close to a blackhole, as that's one of the areas of physics that there's still a huge amount of debate about. There's been a big controversy for years for example over whether the event horizon is "no drama" or a firewall. Because with our current models, both should occur, and both are mutually contradictory. Some of the more recent work has been leaning toward eliminating the physical event horizon entirely, with there only existing an apparent horizon. Everything that falls in is released eventually as the black hole evaporates (effectively "frozen in time"), but due to the exponentially-growing mass/energy densities experienced by infalling objects, it's all effectively irrecoverably scrambled, like a firewall. But technically, the information is not lost. Hawking seemed convinced by this concept late in his life, although it lacks a rigorous backing at this point in time.
Some of my favourite work I've seen has been towards introducing a space-dilatory inflation force, with effects only over very short-distances (similar to the strong force). So we don't see this force in "normal" situations; it only becomes apparent in extreme conditions, like those at black holes. When such a model is implemented properly, both the singularity and event horizon disappear; infalling matter converges to a surface that from an infinite-distance observer position appears 2d, with there being no "inside". The neat part about it is that it also explains inflation; the Big Bang can just be modeled as an extremely large evaporating black hole, and each evaporating black hole as its own new universe. There's still a lot of work to do, however; I haven't seen any new papers on this recently (although I admittedly haven't been following the topic very well of late).
If I am correct in my understanding, in any of the "no true event horizon" models, it would seem to you like you were part of the infalling matter that formed the black hole itself - that you were part of the formation event. From your perspective, you fall into an ever-more distorted region of spacetime and evaporate in the ever-increasingly intense conditions, which to an infinite-distance observer's point of view is actually the black hole's evaporation innumerable eons later. From the infaller's perspective, it all happened quickly. From the infinite observer's perspective, the universe has all but died of heat death by the time your information is released. The mass-energy is released into what's otherwise a void, and effectively its own mini-universe.
Of course, that's some pretty heavy extrapolation when you're talking about things that far in the future, given the fact that we don't know have a good model on dark energy, either! Conceptually, I would so love it if dark energy would in some way or another end up inflating black hole masses, at least some to "big bang"-sizes - each yielding not a mini-universe from its evaporation, but a full-fledged universe. Of course, what I would conceptually "like" to be real has no bearing on whether it actually is!
Some of my favourite work I've seen has been towards introducing a space-dilatory inflation force, with effects only over very short-distances (similar to the strong force). So we don't see this force in "normal" situations; it only becomes apparent in extreme conditions, like those at black holes. When such a model is implemented properly, both the singularity and event horizon disappear; infalling matter converges to a surface that from an infinite-distance observer position appears 2d, with there being no "inside". The neat part about it is that it also explains inflation; the Big Bang can just be modeled as an extremely large evaporating black hole, and each evaporating black hole as its own new universe. There's still a lot of work to do, however; I haven't seen any new papers on this recently (although I admittedly haven't been following the topic very well of late).
If I am correct in my understanding, in any of the "no true event horizon" models, it would seem to you like you were part of the infalling matter that formed the black hole itself - that you were part of the formation event. From your perspective, you fall into an ever-more distorted region of spacetime and evaporate in the ever-increasingly intense conditions, which to an infinite-distance observer's point of view is actually the black hole's evaporation innumerable eons later. From the infaller's perspective, it all happened quickly. From the infinite observer's perspective, the universe has all but died of heat death by the time your information is released. The mass-energy is released into what's otherwise a void, and effectively its own mini-universe.
Of course, that's some pretty heavy extrapolation when you're talking about things that far in the future, given the fact that we don't know have a good model on dark energy, either! Conceptually, I would so love it if dark energy would in some way or another end up inflating black hole masses, at least some to "big bang"-sizes - each yielding not a mini-universe from its evaporation, but a full-fledged universe. Of course, what I would conceptually "like" to be real has no bearing on whether it actually is!
Skotty
2014 S P85 | 2023 F-150L
Well... it's hard to say exactly what happens when you fly close to a blackhole, as that's one of the areas of physics that there's still a huge amount of debate about. There's been a big controversy for years for example over whether the event horizon is "no drama" or a firewall. Because with our current models, both should occur, and both are mutually contradictory. Some of the more recent work has been leaning toward eliminating the physical event horizon entirely, with there only existing an apparent horizon. Everything that falls in is released eventually as the black hole evaporates (effectively "frozen in time"), but due to the exponentially-growing mass/energy densities experienced by infalling objects, it's all effectively irrecoverably scrambled, like a firewall. But technically, the information is not lost. Hawking seemed convinced by this concept late in his life, although it lacks a rigorous backing at this point in time.
Some of my favourite work I've seen has been towards introducing a space-dilatory inflation force, with effects only over very short-distances (similar to the strong force). So we don't see this force in "normal" situations; it only becomes apparent in extreme conditions, like those at black holes. When such a model is implemented properly, both the singularity and event horizon disappear; infalling matter converges to a surface that from an infinite-distance observer position appears 2d, with there being no "inside". The neat part about it is that it also explains inflation; the Big Bang can just be modeled as an extremely large evaporating black hole, and each evaporating black hole as its own new universe. There's still a lot of work to do, however; I haven't seen any new papers on this recently (although I admittedly haven't been following the topic very well of late).
If I am correct in my understanding, in any of the "no true event horizon" models, it would seem to you like you were part of the infalling matter that formed the black hole itself - that you were part of the formation event. From your perspective, you fall into an ever-more distorted region of spacetime and evaporate in the ever-increasingly intense conditions, which to an infinite-distance observer's point of view is actually the black hole's evaporation innumerable eons later. From the infaller's perspective, it all happened quickly. From the infinite observer's perspective, the universe has all but died of heat death by the time your information is released. The mass-energy is released into what's otherwise a void, and effectively its own mini-universe.
Of course, that's some pretty heavy extrapolation when you're talking about things that far in the future, given the fact that we don't know have a good model on dark energy, either! Conceptually, I would so love it if dark energy would in some way or another end up inflating black hole masses, at least some to "big bang"-sizes - each yielding not a mini-universe from its evaporation, but a full-fledged universe. Of course, what I would conceptually "like" to be real has no bearing on whether it actually is!
So....no clue what you are saying....but let me pose a fairytale....maybe we are all in a black hole right now. Our known universe is just another black hole. Some eons ago our black hole had nothing left to suck up, and began to lose more from evaporation than it gained from new incoming mass. This was the big bang. Ever since, the expansion and heat death of our universe has really just been the evaporation of our black hole. From a distance, powers that may or may not be would certainly be amused by life forms bemused on the physics of something they were living in all along.
ccutrer
Active Member
Well... I’m gonna be busy for a while. I haven’t seen this channel before, and as I scroll through the list, I want to watch ALL of them! Thanks for the pointer.
This is as good a thread as any to post the following:
Have been musing ever since Mr Musk mentioned creating his "Lego Blocks" from the detritus created with the Boring operations.
If ever we needed more corroboration that such drilling is practice for Martian colonization - here is one more clue. Such blocks jibe perfectly with the need for construction materials on Mars.
Have been musing ever since Mr Musk mentioned creating his "Lego Blocks" from the detritus created with the Boring operations.
If ever we needed more corroboration that such drilling is practice for Martian colonization - here is one more clue. Such blocks jibe perfectly with the need for construction materials on Mars.
This article includes some incredible photos taken by the ESA Mars Express orbiter.
https://arstechnica.com/science/201...revealed-the-red-planet-in-stunning-new-ways/
https://arstechnica.com/science/201...revealed-the-red-planet-in-stunning-new-ways/
NASA doesn’t have the funds to get to Mars alone, Ted Cruz says
The chairman of the Senate committee that oversees NASA had this to say recently about the government working with private space companies to get to Mars, quote:
“The innovation that we're seeing from SpaceX and from private companies across the board is much of the reason for the optimism we see concerning space," Cruz said. "We need competition and entrepreneurs inventing and innovating. You know, just a few years ago the concept of reusable rockets, rockets that could land and be used again, would have seemed like science fiction. Now we're seeing that done. That's the kind of innovation it's going to take to get to Mars and beyond, and it is only through robust competition in the private sector that we'll see that happen.”
That aligns with this recent comment by the new NASA administrator Jim Bridenstine, quote:
"We know how reusability of rockets has changed the game for access to space and how it's just driven down the cost, and it will continue to drive down the cost," Bridenstine said. "So at NASA, we need to be looking at things differently. We need to be a customer when we can be a customer.”
My prediction is that when SpaceX is flying successful commercial crew missions to the ISS and has made the first successful test flight of the BFR, the pressure to cancel the SLS and award SpaceX a contract to fly NASA astronauts to Mars will be unstoppable. It’s all about cost.
The chairman of the Senate committee that oversees NASA had this to say recently about the government working with private space companies to get to Mars, quote:
“The innovation that we're seeing from SpaceX and from private companies across the board is much of the reason for the optimism we see concerning space," Cruz said. "We need competition and entrepreneurs inventing and innovating. You know, just a few years ago the concept of reusable rockets, rockets that could land and be used again, would have seemed like science fiction. Now we're seeing that done. That's the kind of innovation it's going to take to get to Mars and beyond, and it is only through robust competition in the private sector that we'll see that happen.”
That aligns with this recent comment by the new NASA administrator Jim Bridenstine, quote:
"We know how reusability of rockets has changed the game for access to space and how it's just driven down the cost, and it will continue to drive down the cost," Bridenstine said. "So at NASA, we need to be looking at things differently. We need to be a customer when we can be a customer.”
My prediction is that when SpaceX is flying successful commercial crew missions to the ISS and has made the first successful test flight of the BFR, the pressure to cancel the SLS and award SpaceX a contract to fly NASA astronauts to Mars will be unstoppable. It’s all about cost.
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