I've been taken an interest in learning about black holes operate and if it's ever possible to study them.
We can only study them from powerful telescope. The reality is it would take thousands or tens of thousands of years to get close enough to one. Because of that it's just not possible to obtain any physical data.
With the technology we currently use it's not remotely possible to expect spacecraft to get close enough to the speed of light.
What do you think about wormholes? Do they exist?

You'd need a lot, and some more, and then some more, and then a s#itload more, and probably about 8 more booster stages to get anywhere near a quarter of the speed of light. Eventually I believe we can, but not with today's technology. And even at light speed it would take 4 light years to reach the closest goldilocks planet in orbit around Proxima Centauri.

You'd have to go he Halo: Combat Evolved route and make what is essentially a wormhole generator to do long distance space travel in a timely manner.

Mike89406 wrote:

Because of that it's just not possible to obtain any physical data.

Considering they are so massive (whether physically large or small) that not even electromagnetic waves such as light and radiation can escape them, if we could hypothetically reach and maintain a position just beyond the event horizon of one, at best the only data we could probably gather (that which is beyond the event horizon) would be "unaffiliated" with the black hole itself and instead had emanated from other places "behind" it (stars, quasars, pulsars, etc). But taking that data, comparing it to synonymous data obtained from a different location relative to the black hole, and then calculating the difference in gravitational-lensing distortion caused by the black hole between data sets, you could, in effect, calculate the mass and size of the black hole itself. But that's probably all we could determine about it...and we already seem to have (an albeit-small grasp) of being able to calculate that already from our existing instruments gathering "indirect" data. Even "gravity waves" associated with the collisions of black holes, as now being detected by LIGO, are simply based on indirect observations of the "ripple" effects such collisions have on spacetime.

That said, discounting the high probability that it would be well beyond our present or even long-term capability to remotely consider such a mission or feat, the almost-infinite time-warp effect from the black hole's gravity placed on an observing spacecraft "parked" just outside its event horizon, relative to Earth, would almost certainly ensure that human life on Earth had become extinct (relatively) long before the spacecraft has a chance to begin to transmit back...even if we somehow had developed a way "to do long distance space travel in a timely manner" as TWA772LR describes with "what is essentially a wormhole generator" or some other mechanism.

Jebediah Kerman just vanished in a black hole

TWA772LR wrote:

And even at light speed it would take 4 light years to reach the closest goldilocks planet in orbit around Proxima Centauri.

#Pedant - No, it'd take 4 Julian years (4x 365.25 days). "Light year" is a unit of distance.

ChrisKen wrote:

TWA772LR wrote:

And even at light speed it would take 4 light years to reach the closest goldilocks planet in orbit around Proxima Centauri.

#Pedant - No, it'd take 4 Julian years (4x 365.25 days). "Light year" is a unit of distance.

I totally know that but for some reason I typed what I did! I feel stupid now.

How did I get an A in astronomy? Lol

TWA772LR wrote:

How did I get an A in astronomy?

Per aspera ad astra?


David

KFLLCFII wrote:

Mike89406 wrote:

Because of that it's just not possible to obtain any physical data.

Considering they are so massive (whether physically large or small) that not even electromagnetic waves such as light and radiation can escape them, if we could hypothetically reach and maintain a position just beyond the event horizon of one, at best the only data we could probably gather (that which is beyond the event horizon) would be "unaffiliated" with the black hole itself and instead had emanated from other places "behind" it (stars, quasars, pulsars, etc).

*Cough* Hawking Radiation *Cough*

moo wrote:

KFLLCFII wrote:

Mike89406 wrote:

Because of that it's just not possible to obtain any physical data.

Considering they are so massive (whether physically large or small) that not even electromagnetic waves such as light and radiation can escape them, if we could hypothetically reach and maintain a position just beyond the event horizon of one, at best the only data we could probably gather (that which is beyond the event horizon) would be "unaffiliated" with the black hole itself and instead had emanated from other places "behind" it (stars, quasars, pulsars, etc).

*Cough* Hawking Radiation *Cough*

Hawking Radiation, in theory, is simply the emission of a byproduct of the black hole's effect upon another event taking place near its event horizon but not inside it (the creation/annihilation of particle-antiparticle pairs) which supposedly normally takes place not only there, but everywhere else: If, before the created pair self-annihilates, one-half of the pair happens to fall into the black hole while the other half escapes, then that other half can be "seen" in the form of radiation and gathered as data. But it is still the case that such data was not coming directly from the black hole, but from points beyond its event horizon. (Albeit yes, not necessarily from "behind" the black hole as some other observations seen through gravitational-lensing.)

There is a theory that supermassive black holes might be at the center of almost all currently known galaxies, but currently astronomers don't have real proof of it. I read at http://solarstory.net/objects/ that each galaxy consists of several solar systems and is differentiated by their primary star. Not so long ago, scientistsm also have found evidence that there’s a black hole at the center of the Milky Way. As for me, I'm inclined that black holes really exist.

Mathematically, something that fits the modern discription of a black hole MUST exist. We have evidence of such objects causing gravitational effects on other objects in their vicinity in a way that matches the mathematical models. However, we have no direct observations of such a body as it is quite impossible according to theory. If we look at them through the lens of information theory, then we realize that we can never directly observe them as they are theoretical constructs that release no information, only draw it in.

That all being said, the logical conclusion to be drawn is that black holes do exist as theory predicts. What we can't ever fully understand is what is really going on inside of the event horizon. In theory, there should be some horribly contorted area of space/time between the event horizon and what we would consider the "surface" of the matter that makes up the black hole. That matter is thought to be a hyper-compacted 100% solid object composed of the most elementary of the subatomic particles heated up to an immeasurable temperature. Everything is broken down molecules to atoms to neutrons to quarks to the theoretical sub particles that make them up, then mashed together so hard that they are all physically touching, filling all possible voids. Some theories indicate that the compaction force is so great that the contents of the ball is in some sort of halfway state between matter and energy due to the intense heating that comes from all the force required to crush everything so much, and then the gravity not letting the thermal radiation leave the object.

The problem that we have as humans is that the math that we use to make sense of the universe breaks down past the event horizon. Things go to infinity that should be bound and things go to 0 that should always be nonzero. Thusly, everything that we think we know about black holes is conjecture based on what we think happens. However, since modern physics breaks down there, we just can't know.

LightingZ71, great post!

I wonder if, inside the event horizon the strings unzip or are further compressed....assuming they even exist.

Threadstarter, great topic. Anet at its best!

A 16-year study has determined to within about 1 part in 100 the mass of Sagittarius A*, the supermassive black hole at the center of our galaxy - it's equivalent to about 4 million of our sun.

The study imaged the orbits of a number of stars around the black hole, including one full orbit of a star which approaches within one light day (about 5 times the distance between our sun and Neptune).

https://youtu.be/KD2MgpiGAPE

As far as travel, significant speed will never be accomplished with chemical rockets. Our best-developed option is ion thrusters. Next best experimental option is solar (or laser) sails.

kellyon wrote:

There is a theory that supermassive black holes might be at the center of almost all currently known galaxies, but currently astronomers don't have real proof of it. I read at http://solarstory.net/objects/ that each galaxy consists of several solar systems and is differentiated by their primary star. Not so long ago, scientistsm also have found evidence that there’s a black hole at the center of the Milky Way. As for me, I'm inclined that black holes really exist.

There's actually very little real doubt about this. Observing the motion of stars near the center of the Milky Way, for example, no explanation fits other than the presence of an object about 4 million times the mass of our sun that they orbit around. There's also radio source in the same location that seems to match the emissions expected from dust and gas heating up as it falls towards the black hole.

We currently have no viable way of traveling significantly closer to the center of the Milky Way, and no pending ideas how to develop a way that is known to be physically possible.

Black Holes exist in that scientific realm of "known" but not directly proveable items. We can infer their existence through many indirect means and can even mathematically model the effects that they have on their surrounding region, but we get absolutely nothing from them in the form of direct emissions (this includes hawking radiation) as almost anything we're seeing that appears to come from them is actually coming from the edge of their event horizons. Even Quasars are modeled to be powered by the intense forces acting upon matter as its actively consumed by the black holes at the center of their galaxies and not by direct emissions from the black hole itself. This is not to cast doubt upon their existence, but to just expand on the terms used when discussing them. I have no problem with believing their existence and behavior as modeled by current astrophysics techniques.

LightningZ71 wrote:

That all being said, the logical conclusion to be drawn is that black holes do exist as theory predicts. What we can't ever fully understand is what is really going on inside of the event horizon. In theory, there should be some horribly contorted area of space/time between the event horizon and what we would consider the "surface" of the matter that makes up the black hole. That matter is thought to be a hyper-compacted 100% solid object composed of the most elementary of the subatomic particles heated up to an immeasurable temperature. Everything is broken down molecules to atoms to neutrons to quarks to the theoretical sub particles that make them up, then mashed together so hard that they are all physically touching, filling all possible voids. Some theories indicate that the compaction force is so great that the contents of the ball is in some sort of halfway state between matter and energy due to the intense heating that comes from all the force required to crush everything so much, and then the gravity not letting the thermal radiation leave the object.

We have mathematics to describe the space between the event horizon and the singularity. On crossing the event horizon, an unfortunate astronaut would see an infinitely bright flash of light caused by the photons stuck in a 1c orbital shell exactly at the surface of the event horizon. That event would probably kill our hero, but if we assume he brought an extra-expensive pair of Ray Bans and survived the flash, once he crossed he would see something very strange. He would appear to have an event horizon above him (in the direction from which he came) and another one below him. Light would still be streaming in from the outside universe, so the stars outside would be mostly unchanged. However, no matter where he looks, he cannot see the singularity because all light is streaming towards this object and none of it is streaming away. When you sit at dinner across from your date, you see your date in the past, as s/he was a nanosecond ago when the light from the candle on the table reflected off his/her face and then into your eye. We see *everything* in the universe in the past. But the singularity of a black hole is always in the future, so we can never see it. As our unfortunate hero approaches the singularity the tidal forces begin to grow and just a few seconds before he becomes part of the singularity, he is ripped into spaghetti-like strands as his feet (assuming he's falling feet-first) begin to accelerate much more rapidly than his head.

But at the singularity itself, the math breaks down. It isn't made of any particles, because we do know that it is a point (for a non-rotating black hole) or a small one-dimensional ring (for a rotating black hole, which likely describes all real black holes). Either way, the singularity has no volume and so not even a single elementary particle can fit in there. Physics breaks down at this point because no two particles of the same kind can occupy the exact same quantum state, and yet this must be the case for a singularity. In the end, it appears that a singularity is just made of pure mass, and it might as well be made of quarks or unicorns. It just doesn't matter. As physicists turn to the study of quantum gravity, we may be able to get a better picture of the mass at the center of the singularity but for now, a singularity is just that: a singularity.

It would logically follow then that if the center of a singularity basically crushes all matter into energy? It would have to be a technical impossibility that all the matter crushed into a black hole occupies one infinitely small point if it remained matter. However, as our current understanding of the universe allows matter and energy to be converted back and forth (though not trivially), it would follow that energy, being massless, could be reduced to a single point. However, that breaks another "rule" in that energy doesn't generate a gravitational field (to simplify the term) and black holes very definitely have a significant gravitational field. Where does this leave things? Where does the gravitational field come from? If energy is massless, how does the black hole contain it? If it doesn't turn into energy, how do you physically pack an arbitrary amount of matter into an infinitely small space?

I heard a theory once that as the photons crossed the event horizon, they accelerated beyond "c" and that the flow of time changed drastically, bas I call resulting that everything effectively takes an infinite amount of time to reach the actual singularity itself. The net result is that each black hole has an infinite distance from the event horizon to the singularity and that the gravitational field was the net result of the total gravitational pull of all the consumed matter. I don't know how much of that I can believe, but it would fit the observed behavior.

LightningZ71 wrote:

However, that breaks another "rule" in that energy doesn't generate a gravitational field (to simplify the term) and black holes very definitely have a significant gravitational field. Where does this leave things? Where does the gravitational field come from? If energy is massless, how does the black hole contain it? .

what makes you think energy doesn´t have gravity? E=mc2 after all.

It would logically follow then that if the center of a singularity basically crushes all matter into energy?

We don´t know what a singularity is made of, we pretty much just know it has gravity. Maybe at some point gravity just becomes large enough to fold up dimensions and matter in the singularity exists in a pretty conventional way, only the space it is in is folded in to below plank length in any dimension.

best regards
Thomas

KFLLCFII wrote:

moo wrote:

KFLLCFII wrote:

Considering they are so massive (whether physically large or small) that not even electromagnetic waves such as light and radiation can escape them, if we could hypothetically reach and maintain a position just beyond the event horizon of one, at best the only data we could probably gather (that which is beyond the event horizon) would be "unaffiliated" with the black hole itself and instead had emanated from other places "behind" it (stars, quasars, pulsars, etc).

*Cough* Hawking Radiation *Cough*

Hawking Radiation, in theory, is simply the emission of a byproduct of the black hole's effect upon another event taking place near its event horizon but not inside it (the creation/annihilation of particle-antiparticle pairs) which supposedly normally takes place not only there, but everywhere else: If, before the created pair self-annihilates, one-half of the pair happens to fall into the black hole while the other half escapes, then that other half can be "seen" in the form of radiation and gathered as data. But it is still the case that such data was not coming directly from the black hole, but from points beyond its event horizon. (Albeit yes, not necessarily from "behind" the black hole as some other observations seen through gravitational-lensing.)

My understanding of hawking radition is that positive charged sub atomic particles don't get sucked in to the black hole and negative particles fall in. The positive ones emit out with a gravitational lensing effect along with other matter and radiation.

There is a pretty good video of what could happen should a probe approach the black hole from 16:00-19:00.
https://video.search.yahoo.com/video/pl ... cafee&tt=b

As mentioned before the nearest super massive black hole to us is Sagittarius "A" star in the middle of the milky way, however the V616 Monocerotis, and Cygnus X-1 are closer but still light years away.

While there are theories of whats in the singularity we simply don't know and you may not even see. The only images of black holes that I've found are from infrared telescopes.

Mike, that is about what I've read, (according to theory mind you) that "virtual particles" are created near the event horizon (always in pairs, with one having negative energy and the other having positive energy). The pair is torn apart before they can rejoin and self annihilate, with the negative partner falling into the black hole (and thus lowering it's energy/mass) and the positive partner accelerating away from the singularity. This is the heart of what is known as black hole evaporation and behind the premise that a black hole that isn't actively feeding will begin to "evaporate" away. Again, the math on a lot of this is thought to be predictive as long as certain laws hold true in the region that is inside of the event horizon. The math predicts that as a black hole evaporates away, it gets extraordinarily hot and should end its life in a giant burst of gamma rays.

I haven't dug too deep into it, but black holes are unusual in another way: they destroy information. I believe there is something like a law of conservation of information which black holes violate.

Anyway, it's my understanding that the rendering of the black hole in Interstellar was quite accurate based on our understanding. The distortion is related to gravitational lensing and possibly something else as well.

How's THAT for a vague post about stuff I read once?

treetreeseven wrote:

I haven't dug too deep into it, but black holes are unusual in another way: they destroy information.?

they may destroy information

if the Einstein–Cartan theory shows to be correct one day, that problem is solved.

best regards
Thomas

DocLightning wrote:

In the end, it appears that a singularity is just made of pure mass, and it might as well be made of quarks or unicorns. It just doesn't matter.

Possibly the best explanation of singularities ever.

V/F