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Can we determine the physical structure of a black hole by observing its gravitational effect on objects in orbit? There are three possibilities that I see, and would like to test:
Singularity at the center - The traditional view that there is a singularity at the center (e.g. all mass is concentrated in the center).
A structure where the black hole is filled throughout with matter inside the event horizon - My proposal, due to gravitational time dilation slowing / stopping time (e.g. a singularity will not form until an infinite amount of time has passed). If the answer to my question on this subject here is correct, we should observe either possibility 2 or 3: Does matter accumulate just outside the event horizon of a black hole?
A hollow shell, with matter only on / near the outside edge of the event horizon - My proposal, combined with the "vapor bubble" behavior, as hinted at in some of the answers to the linked question.
Would these three possibilities differ gravitationally in ways that could be observed (e.g. by observing orbiting stars), or would they be identical from the outside? If they would produce different results, I would love to see what result it is that we actually observe! We have observed stars orbiting the super massive black hole at the center of the galaxy. http://scitechdaily.com/astronomers-discover-star-orbiting-the-black-hole-at-center-of-the-milky-way/
The comments from @userLTK, and @Lacklub are correct.
Lets assume there is an object of radius $R$ and mass $M$, from a Newtonian point of view, if you are at another radius $r$, such that $r > R$, then there is no difference in the gravitational field experience by an object at $r$ if the mass spread across a shell of radius $R$ or if its concentrated anywhere between $r=0$ and $r=R$. GR doesn't do much to change this, and in fact if $r >>R$, then the result is of course exactly the same.
Now to black holes, all taken from from Wiki https://en.wikipedia.org/wiki/Black_hole
Physical Properties "The simplest static black holes have mass but neither electric charge nor angular momentum… This means that there is no observable difference between the gravitational field of such a black hole and that of any other spherical object of the same mass."
So basically if you're outside the event horizon (not that'd you know where it was) you're experience with the black hole is the same as with a planet or star of that mass.
Again from same wiki article:
Singularity "At the center of a black hole, as described by general relativity, lies a gravitational singularity, a region where the spacetime curvature becomes infinite… It can also be shown that the singular region contains all the mass of the black hole solution".
The "it can be shown" references page 204 of Carroll, Sean M. (2004). Spacetime and Geometry. I don't have my copy with me right now so I can't look it up, but I would say I remember reading at in Carroll back in the day.
Finally, let me just add that, once something passes into the event horizon of a black hole, there's no getting back. So we really have to ask ourselves how any information about the "stuff" inside the event horizon would come to us? I like your idea of getting some indirect evidence and perhaps gravitational waves will shed some light on this topic but I don't suppose there is any known way to getting direct access to anything beyond the event horizon.
How an Advanced Civilization Could Exploit a Black Hole for Nearly Limitless Energy
We know black holes as powerful singularities, regions in space time where gravity is so overwhelming that nothing—not even light itself—can escape.
About 50 years ago, British physicist Roger Penrose proposed that black holes could be a source of energy. Now, researchers at the University of Glasgow in Scotland have demonstrated that it may be possible.
Marion Cromb is the lead author of this new study. They’re a PhD student at the University of Glasgow’s School of Physics and Astronomy. The paper is titled “Amplification of waves from a rotating body.” It’s published in the journal Nature Physics.
“We’re thrilled to have been able to experimentally verify some extremely odd physics a half-century after the theory was first proposed.”Professor Daniele Faccio, Co-Author, University of Glasgow
Space-interested and science-interested people know that black holes have a singularity at the very center, and an event horizon, the boundary over which nothing can return once it passes. But black holes have other elements to their complex structure. This new research revolves around the black hole’s ergosphere.
The ergosphere is the outer region of the event horizon. In 1969, Penrose theorized that if you lowered an object into the ergosphere, it could generate energy.
In the ergosphere, it is impossible for an object to stand still, due to frame-dragging. General relativity predicts that a rotating mass, like the black hole, will drag adjacent space-time along with it. So any object put into the ergosphere will start to move, and there’s no way to stop it.
The ergosphere is a region outside of the event horizon, where objects cannot remain stationary. Image Credit: By Yukterez (Simon Tyran, Vienna) – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=50352912
Penrose said that if an object were dropped into the ergosphere, it would gain negative energy. If an object were dropped in and then split in two, one half would be swallowed up by the black hole, and one half wouldn’t. If that half were recovered from the ergosphere, recoil action means that the recovered half would lose negative energy. Since a minus of a minus makes a plus, that object would gain some energy from the black hole’s rotation.
Clearly, this is not something that human civilization will be attempting any time soon. Penrose said that only a highly advanced civilization would even come close to something like that. And even then…
But after Penrose floated the idea, another physicist thought about it some more. Yakov Zel’dovich proposed that the idea could be tested by sending twisted light waves towards the surface of a rotating metal cylinder. If sent at the right speed, these waves would bounce off the cylinder after acquiring additional energy from the cylinder’s rotation. It’s all due to a strange property of the Doppler effect.
An artist’s illustration of a star being ripped apart by a black hole. There was no way to prove that Penrose and Zel’dovich were right about energy from black holes, until now. Credit: Mark Garlick
When people talk of the Doppler effect, they’re usually referring to the linear Doppler effect. The often-used example is an ambulance siren. As an ambulance approaches the listener, the sound waves are compressed to a higher frequence in front of the ambulance, and the listener hears that as an increase in pitch. Conversely, after the ambulance passes the listener, the sound waves are not compressed by the forward motion of the ambulance anymore, and the listener hears the lowered frequency as lower pitch.
But this idea involves the rotational Doppler effect.
“What we heard during our experiment was extraordinary.”Marion Cromb, Lead Author, University of Glasgow
Lead author Cromb describes it like this in a press release: “The rotational doppler effect is similar, but the effect is confined to a circular space. The twisted sound waves change their pitch when measured from the point of view of the rotating surface. If the surface rotates fast enough then the sound frequency can do something very strange – it can go from a positive frequency to a negative one, and in doing so steal some energy from the rotation of the surface.”
This figure from the study illustrates how the sound from the speakers is given a twist before being sent into the rotating disc, with microphones labelled with “M”. The four inset pictures show different configurations used in the experiment: left inset, the supporting disk with microphones and absorber are co-rotating centre left inset, the absorber is detached and remains static, while microphones rotate centre right inset, the absorber is placed in front of only one of the two microphones right inset, the absorber is completely removed, and microphones rotate. Image Credit: Cromb et al, 2020.
In any case, Zel’dovich’s idea was never tested. The problem is that the cylinder would have to be rotating at an unattainable rate of billions of times per second, because light itself travels so fast. That’s well out of reach for our technology.
The team at the University of Glasgow came up with a way of testing this. They reasoned that the whole thing could be tested with sound waves, which travel much slower than light. That means that the cylinder would only need to rotate at a much slower, attainable rate too.
In their study, the authors wrote, “Although amplification of waves due to a rotating absorber is very hard to verify with optical or electromagnetic waves, direct measurements of it are possible using acoustic waves.”
In their lab, the team built a ring of speakers that could create a twist in the sound waves, similar to the twist required in the light in Zel’dovich’s proposal.
The device in the team’s lab. Image Credit: Cromb/University of Glasgow.
The device begins with a ring of speakers to produce the twisted sound waves. Those waves are directed toward a rotating foam disc that absorbs the sound. Behind the foam disc is a microphone to measure the sound. When the experiment starts, the rotational speed of the foam disc rises.
The team was looking for a distinct change in both the frequency and the amplitude of the sound as the sound waves passed through the foam disc. At first, as the speed of the rotating disc increased, the pitch of the sound became so low that it’s inaudible to human ears. Then the pitch, or frequency, rose again. It reached its original pitch again, but this time the amplitude, or loudness, was increased to 30% louder than the original. The sound waves had acquired energy from the rotating disc.
This figure from the study shows the rise in amplitude created by a rotating disc, versus a static disc. Image Credit: Cromb et al, 2020.
“What we heard during our experiment was extraordinary,” Cromb said. “What’s happening is that the frequency of the sound waves is being doppler-shifted to zero as the spin speed increases. When the sound starts back up again, it’s because the waves have been shifted from a positive frequency to a negative frequency. Those negative-frequency waves are capable of taking some of the energy from the spinning foam disc, becoming louder in the process – just as Zel’dovich proposed in 1971.”
It just goes to show us that some ideas can seem outlandish and untestable at one point in time. But as time goes on, they can be tested. Just like relativity, for example, and the bending of light by gravitational lensing.
Professor Daniele Faccio is a co-author on the paper, and is also from the University of Glasgow’s School of Physics and Astronomy. In the press release, Faccio said “We’re thrilled to have been able to experimentally verify some extremely odd physics a half-century after the theory was first proposed. It’s strange to think that we’ve been able to confirm a half-century-old theory with cosmic origins here in our lab in the west of Scotland, but we think it will open up a lot of new avenues of scientific exploration. We’re keen to see how we can investigate the effect on different sources such as electromagnetic waves in the near future.”
How do we study black holes if everything that gets close to it, even photons, gets sucked in and crushed? What methods are used to verify what we are looking at is a black hole?
Someone will offer a million times better answer, and so this may be in vain but most observations in space happen by seeing how the observed item is in relation to other things. Things like black holes and dark matter may not be directly observable, but their affect on their surroundings are very observable phenomenon.
You should check out the Event Horizon Telescope, a project to use a radio telescope (effectively) the size of the Earth (a technique called Very Long Baseline Interferometry) to image Sagitarius A* (the supermassive black hole at the centre of the Galaxy). They have some amazing results coming out where they can show that their measurements are consistent with the crescent shape we expect due to frame dragging. They promise to have actual images (and even movies!) soon. In the future this will push our understanding of black holes and General Relativity.
As you said, black holes are black. They can still be detected, though.
One - they are massive objects and exert a gravitational force. When you see an object, such as neutron star, orbiting nothing at all, you've got yourself a black hole. A great example of this is the Sagittarius A* radio source at the centre of our galaxy. This thing has a whole swarm of stars orbiting it, and the orbits allow us to calculate the mass of the central object. It's estimated to be around 4 million solar masses - given that it cannot be seen, it's pretty much got to be a black hole.
The other method, I'm not sure if it's been done in practice yet, would be gravitational lensing. Massive objects like black holes bend light that comes near them (because they deform the spacetime around them). It would be like sliding a lens across the stars.
Oh - I forgot. Black holes have been observed with gravitational waves in the LiGo observatory. That's the newest and coolest way to study these things (along with neutron star mergers).
The most common was to detect a black hole is by observing the light coming from the galaxy which is far behind the black hole. Some of the photons coming from the galaxy orbits (far away from the event horizon) around the black hole and escape towards the direction of the observer.
One more way is to observing the gravitational field as there will be huge depression in the fabric of space time resulting in objects orbiting around the black hole. So we can observe that these objects are orbiting around nothing (as we can’t see black holes).
Its actually based around fairly rudimentary math. Mass=stuff. More stuff in smaller spaces has more gravity. but certain gravitational pulls from select "objects" dont have any visible stuff. So what gives? Something like sag A* is 4 million solar masses based around the orbit trajectories and other properties but isnt a crazy huge ball of mass that we see in a telescope. In fact, its seemingly nothing at all.
It turns out that as you accumulate mass and push gravity further, it changes the nature of matter. Example being neutron stars- objects massive and compact enough to cause electrons to "fall into" protons which merge to form neutrons creating a ball of neutrons.
Black holes are seemingly what happens when you have so much gravity you actually overwhelm neutrons ability to stay dispersed. That much mass in such a small volume creates a pocket of space that is cut off from the rest of the universe and events in that pocket have no causal link to our universe. Hence the "event horizon" title.
Black hole-star pair orbiting at dizzying speed (w/ video)
(Phys.org) —ESA's XMM-Newton space telescope has helped to identify a star and a black hole that orbit each other at the dizzying rate of once every 2.4 hours, smashing the previous record by nearly an hour.
The black hole in this compact pairing, known as MAXI J1659-152, is at least three times more massive than the Sun, while its red dwarf companion star has a mass only 20% that of the Sun. The pair is separated by roughly a million kilometres.
The duo were discovered on 25 September 2010 by NASA's Swift space telescope and were initially thought to be a gamma-ray burst. Later that day, Japan's MAXI telescope on the International Space Station found a bright X-ray source at the same place.
MAXI J1659–152 is a rapidly spinning binary system comprising a black hole more than three times more massive than the Sun and a red dwarf companion star only 20% the mass of the Sun. The pair are separated by only 1.3 solar radii, or just under one million kilometres. Thanks to a 14.5 hour observing campaign by ESA’s XMM-Newton, scientists were able to measure a record-breaking orbital period of just 2.4 hours – the fastest spinning binary system with a black hole. The black hole orbits around the system’s common centre of mass at 150 000 km/h, while the companion travels at two million kilometres per hour, making it the fastest-moving star ever seen in a binary system. The centre of mass is so close to the black hole due to its vast mass that it appears as if it is not orbiting. In this animation the focus is on the periodic absorption dips detected by XMM-Newton as the stream of material from the companion impacts on the black hole’s accretion disc. The system was first found on 25 September 2010 by NASA’s Swift space telescope, with follow-up observations by the Japanese MAXI instrument on the International Space Station, NASA’s Rossi X-ray Timing Explorer, ESA’s XMM-Newton and ESO’s ground-based Very Large Telescope. Credit: ESA
More observations from ground and space telescopes, including XMM-Newton, revealed that the X-rays come from a black hole feeding off material ripped from a tiny companion.
Several regularly-spaced dips in the emission were seen in an uninterrupted 14.5 hour observation with XMM-Newton, caused by the uneven rim of the black hole's accretion disc briefly obscuring the X-rays as the system rotates, its disc almost edge-on along XMM-Newton's line of sight.
From these dips, an orbital period of just 2.4 hours was measured, setting a new record for black hole X-ray binary systems. The previous record-holder, Swift J1753.5–0127, has a period of 3.2 hours.
The black hole and the star orbit their common centre of mass. Because the star is the lighter object, it lies further from this point and has to travel around its larger orbit at a breakneck speed of two million kilometres per hour – it is the fastest moving star ever seen in an X-ray binary system. On the other hand, the black hole orbits at 'only' 150 000 km/h.
"The companion star revolves around the common centre of mass at a dizzying rate, almost 20 times faster than Earth orbits the Sun. You really wouldn't like to be on such a merry-go-round in this Galactic fair!" says lead author Erik Kuulkers of ESA's European Space Astronomy Centre in Spain.
His team also saw that they lie high above the Galactic plane, out of the main disc of our spiral Galaxy, an unusual characteristic shared only by two other black-hole binary systems, including Swift J1753.5–0127.
"These high galactic latitude locations and short orbital periods are signatures of a potential new class of binary system, objects that may have been kicked out of the Galactic plane during the explosive formation of the black hole itself," says Dr Kuulkers.
Returning to MAXI J1659−152, the quick response of XMM-Newton was key in being able to measure the remarkably short orbital period of the system.
"Observations started at tea-time, just five hours after we received the request to begin taking measurements, and continued until breakfast the next day. Without this rapid response it would not have been possible to discover the fastest rotation yet known for any binary system with a black hole," adds Norbert Schartel, ESA's XMM-Newton project scientist.
Physics professors talk about recent black hole breakthrough
Black holes can be identified by looking at the bodies, such as gas or stars, orbiting around them.
This past week, evidence of a new, intermediate mass black hole was found in the Milky Way.
If the evidence points in the direction of being an intermediate mass black hole, this could serve as an important window into how supermassive black holes are formed and how they get so big.
Stefan Ballmer, associate professor of physics at Syracuse University, and Duncan Brown, professor of physics at SU explain why this discovery was so significant, and what it means for future space research.
The Daily Orange: To start, what are black holes and how are they formed?
Stefan Ballmer: We know that small black holes are formed at the end of stellar evolutions. If a heavy star burns out its nuclear fuel, there is essentially nothing left to support the star’s structure and it just collapses into a black hole. The question becomes how do you form heavier black holes?
One tantalizing hint to this story comes from the likely discovery. We’ve observed that the black holes of several solar masses can actually merge and form heavier black holes, and so that’s one possible path. In fact, we’ve known now for a while that at the center of every galaxy there is a supermassive black hole. The mass of that black hole seems to track the number of stars of the galaxy, the size of the galaxy essentially.
Nobody really knows how they form, so that’s a strong hint that there might be sort of a small to big merging cycle — that smaller black holes form first, then intermediate black holes, then as the galaxies of all those smaller galaxies surround it, that they end up merging and forming a bigger black hole in the center.
If this really is a missing link, the way to prove this is to look for gravitational waves, which is the only thing these things send out as they start forming heavier and heavier black holes.
The D.O.: Why was this particular recent discovery considered so important to space research?
Duncan Brown: It’s the first observation of a black hole that lives in this so-called intermediate mass regime. You can infer the existence of a black hole by observing the behavior of the objects moving around it.
In the latest observation, what they’ve seen is a cloud of gas moving around in a way that suggests that there is a 100,000 solar mass black hole in that cloud of gas. This is certainly the strongest evidence we have so far, but it’s not the same as seeing two black holes collide into each other and the gravitational waves they emit.
S.B.: People have speculated about the existence of these intermediate black holes and until now, only a few of these were known. The fact that we can now locate them in our Milky Way is important.
The D.O.: What equipment is used to find these black holes and how are they identified?
S.B.: With a black hole you can somehow infer its gravitational pull by observing gas or stars that are orbiting it. If you conclude that there must be a certain mass because you see something orbiting that area, and you can observe that gas moving relatively close in, you can estimate how big this area of heavy mass can be.
Once you convince yourself there’s lots of mass in a tiny area, that’s sort of the smoking gun that there’s a black hole, if you do it with optical astronomy. Gravitational waves have a unique feature in that you can only observe mergers of two black holes, but you see the signal when they literally ram into each other, so there’s no doubt what you’re observing.
The D.O.: What does this discovery mean for future space research?
S.B.: The LISA (Laser Interferometer Space Antenna, a gravitational wave detector consisting of three separate spacecrafts which each operate millions of miles from each other), which is supposed to fly in about 10 years, will be sensitive to anything that would involve intermediate black holes merging. If this really is a missing link, we will know for sure when LISA flies.
The D.O.: What are the chances that a black hole would occur close enough to our solar system to see any effects?
D.B.: The chances of there being a black hole close enough to our solar system to cause any effect that we would notice in our everyday lives are vanishingly small. There’s a lot of empty space between our solar system and objects in the Milky Way.
And a popular misconception about black holes is that they suck things into them. They are basically manifestations of pure gravity. A black hole has basically the same effect as a real object of the same mass. You can fall into a black hole like you can fall down to the surface of the earth, but you can’t get sucked into it.
Even if there was a 10 solar mass black hole just outside our solar system, you would perceive it because it would change the orbits of the planets because there would be this other massive object, but we wouldn’t get sucked into the black hole or anything.
Could we verify the structure of a black hole by observing an orbiting object? - Astronomy
“Astronomical fads have always involved miracle working to some degree, and their discussion in so-called workshops and in the streams of papers that pour into the journals have affinities to the incantations of Macbeth’s witches on the blasted heath.”
—Fred Hoyle, Home is where the wind blows.
The so-called “queen” of the sciences, cosmology, is founded upon the myth that the weakest force in the universe—gravity—is responsible for forming and shaping galaxies, stars and planets. But even if this were true, gravity remains unexplained. How it works is a mystery.
Newton gave us a mathematical description of what gravity does. Einstein invoked an unreal geometry to do the same thing. Newton had the sense to “frame no hypotheses” about how gravity worked. Einstein made it impossible to relate cause and effect—which means that the theory of general relativity is not physics! How, precisely, does matter warp empty space? The language is meaningless. But this hasn’t stopped scientists declaring a law of gravitation with a ‘universal’ physical constant—‘G.’
For many years now, astronomers have been reporting that supermassive black holes — several million times the mass of the Sun — exist in nearly every galaxy.
This image, taken by the Very Large Array of ground based telescopes at radio wavelengths, shows a bright source at the centre of the Milky Way that is thought to surround a black hole. From observations of stars in orbit around the Galactic Center it is concluded that there is indeed a supermassive black hole in this region, approximately 4,000,000 times the mass of the Sun. The structure known as the Galactic Centre Radio Arc (upper left) is described as “hot plasma flowing along lines of magnetic field.”
The thoughtless followers of Einstein have fashioned God in their own image as a mathematician but “He” is much smarter and avoids high school howlers like the gravitational “black hole.” Yes, a theoretical “black hole” exists—and it sucks the very heart out of astronomy and astrophysics. The astronomer Halton Arp articulated the math howler of dividing by zero to give a near infinite concentration of mass in a hypothetical black hole:
“Since the force of gravity varies as the square of the inverse distance between objects why not make the ultimate extrapolation and let the distance go to zero? You get a LOT of density. Maybe it goes BOOM! But wait a minute, maybe it goes in the opposite direction and goes MOOB! Whatever. Most astronomers decided anyway that this was the only source that could explain the observed jets and explosions in galaxies.”
Precisely! And when the gravitational force is as close to zero as doesn’t matter, in comparison to the electric force, you must be very careful (as any high school student knows) to not divide by zero, otherwise you introduce infinities. What does it mean for the radius of a physical object to tend to zero?
In the face of discordant data, a scientist is required to check the original works and assumptions that lead to the theory under test. But there are very few such scientists in this modern age. As Sir Fred Hoyle put it, today the pressure is on to “do what aging gurus tell them to do, which is nothing” and simply build on the consensus those gurus have established. A fellow Australian, Stephen Crothers, has shown mathematical theorists to be remarkably unintelligent and sloppy in the application of their talent to physical problems. It seems that most of them don’t really follow the mathematical arguments anyway (which is not surprising) but are happy to extol the results of others, based on reputation, regardless of the principles of physics or commonsense. Crothers has done his historical and mathematical homework and delivered a paper, The Schwarzschild solution and its implications for gravitational waves, at the Conference of the German Physical Society, Munich, March 9-13, 2009. He concludes, inter alia, that:
• “Schwarzschild’s solution” is not Schwarzschild’s solution. Schwarzschild’s actual solution does not predict black holes. The quantity ‘r’ appearing in the so-called “Schwarzschild solution” is not a distance of any kind. This simple fact completely subverts all claims for black holes.
• Despite claims for discovery of black holes, nobody has ever found a black hole no infinitely dense point-mass singularity and no event horizon have ever been found. There is no physical evidence for the existence of infinitely dense point-masses.
• It takes an infinite amount of observer time to verify the presence of an event horizon, but nobody has been and nobody will be around for an infinite amount of time. No observer, no observing instruments, no photons, no matter can be present in a spacetime that by construction contains no matter.
• The black hole is fictitious and so there are no black hole generated gravitational waves. The international search for black holes and their gravitational waves is ill-fated.
• The Michell-Laplace dark body is not a black hole. Newton’s theory of gravitation does not predict black holes. General Relativity does not predict black holes. Black holes were spawned by (incorrect) theory, not by observation. The search for black holes is destined to find none.
• No celestial body has ever been observed to undergo irresistible gravitational collapse. There is no laboratory evidence for irresistible gravitational collapse. Infinitely dense point-mass singularities howsoever formed cannot be reconciled with Special Relativity, i.e. they violate Special Relativity, and therefore violate General Relativity.
• General Relativity cannot account for the simple experimental fact that two fixed bodies will approach one another upon release. There are no known solutions to Einstein’s field equations for two or more masses and there is no existence theorem by which it can even be asserted that his field equations contain latent solutions for such configurations of matter. All claims for black hole interactions are invalid.
• Einstein’s gravitational waves are fictitious Einstein’s gravitational energy cannot be localised so the international search for Einstein’s gravitational waves is destined to detect nothing. No gravitational waves have been detected.
• Einstein’s field equations violate the experimentally well-established usual conservation of energy and momentum, and therefore violate the experimental evidence.
In an audience of theoretical physicists there was stunned silence—and not a single question.
A final official word on black holes from the Astronomer Royal who follows an unenviable tradition of holders of that office being completely wrong and retarding progress:
“Black holes, the most remarkable consequences of Einstein’s theory, are not just theoretical constructs. There are huge numbers of them in our Galaxy and in every other galaxy, each being the remnant of a star and weighing several times as much as the Sun. There are much larger ones, too, in the centers of galaxies. Near our own galactic center, stars are orbiting ten times faster than their normal speeds within a galaxy.”
—Martin Rees, Our Cosmic Habitat (2001).
Electric Galaxies have Electromagnetic Hearts
The question for the ELECTRIC UNIVERSE® is therefore: If black holes don’t exist, how do we explain recent observations at the center of our own Milky Way?
The well-established study of plasma cosmology shows that galaxies are an electrical phenomenon. It has been found that filaments, arcs, and shells characterize the small-scale structure of molecular gas in the Galactic Center. They are all well-documented electrodynamic plasma configurations. A single charged particle in 10,000 neutral gas molecules is sufficient to have the gas behave as plasma, where electromagnetic forces dominate. Conventional theorists admit to “no plausible explanations either for the origin of the complex kinematics or for most of the peculiar features.” In May last year I described the plasma focus phenomenon generated at the Galactic Center by filamentary helical “Birkeland” currents flowing in along the spiral arms and out along the galactic spin axis.
This image shows the form of the plasmoid at the center of the galaxy (and the particle jets created when the magnetic field begins to collapse). Image credit: E. Lerner.
A letter to Nature provides supporting evidence for that model in the form of the infrared “double helix” nebula. The nebula is located about 100 parsecs from the Galactic Center. Its axis is oriented perpendicular to the Galactic plane and is apparently connected to the circum-nuclear disk (CND), which is conventionally thought to be an accretion disk harboring a “supermassive” black hole.
The 80 light-year long Double Helix Nebula (DHN) observed in infrared with the MIPS camera on the Spitzer Space Telescope. The spatial resolution is 6 arcsec. On the right we see the context of the DHN with respect to the Galactic plane taken with the MSX satellite. The spatial resolution is 20 arcsec. The relative locations and sizes of the nebula, the circumnuclear disk (CND), and the proposed channel linking them, are all shown. Credit: M. Morris et al., UCLA.
The double helix is the characteristic form of a Birkeland current filament. Like the filaments in the Galactic Center Radio Arc in the first image, it is a glowing section of the electric circuit connecting the central plasmoid to the galaxy and beyond. The CND is typical of a dusty plasma ring current circulating around a magnetized celestial object. There is no gravitational or dynamical explanation for the twin helical filaments. It has no place in black hole theory. The metaphors and language used in the scientific report are wrong and misleading. The title of the report alone highlights the problem— “A magnetic torsional wave near the Galactic Centre traced by a ‘double helix’ nebula.” As usual, there is no explanation for the presence of the magnetic field (which requires an electric current and circuit) or the source of the imagined “torsional wave.” The authors admit: “The absence of a negative-latitude counterpart is another potential weakness of the torsional wave hypothesis, inasmuch as such waves should propagate equally in both directions away from the driving disk, if that disk is symmetric about its midplane” and “One question that our hypothesis leaves unanswered is why the helical structure has two strands.”
Researchers also report that “the magnetic field in the central few hundred parsecs of the Milky Way has a dipolar geometry and is substantially stronger than elsewhere in the Galaxy.” Birkeland filaments align with the ambient magnetic field which is, in turn, generated by electric currents flowing into the central plasmoid.
The energy of the jets seen issuing from active galactic nuclei (AGNs) is attributed to conversion of gravitational energy of accreting matter into radiation. But that does not explain the character of the jets, or the puzzling “quietness” of our own hypothetical black hole. As recently as 26 March in Nature it was admitted “the mechanisms that trigger and suppress jet formation in [black holes] remain a mystery.” Meanwhile, the plasmoid is well known in the plasma laboratory as a high-density energy storage phenomenon that produces well-collimated jets after a time that depends upon particle collisions within the plasmoid.
X-ray emission is a signature of electrical activity. There is a persistent high-energy flux from the heart of the Milky Way. The spectral characteristics of the X-ray emission from this region suggests that the source is most likely not point-like but, rather, that it is a compact, yet diffuse, non-thermal emission region, which we should expect from an electromagnetic plasmoid. There is an overabundance of X-ray transients in the inner parsec of the Galactic Center compared to the overall distribution of X-ray sources. Recent observations show that X-ray flares fire roughly every 20 minutes – a regularity that is hard to explain in terms of erratic infall of matter into a black hole. But clockwork regularity of plasma discharges already explains the pulsations from other bodies in deep space. Scientists were also startled when they discovered in 2004 that the center of our galaxy is emitting gamma rays with energies in the tens of trillions of electron volts. The plasma focus is the most copious source of high-energy particles and radiation known to plasma experimenters.
The orbits of stars in the center of the Milky Way. Credit: S. Gillesen et al., Max-Planck-Institute for Extraterrestrial Physics.
The confidence of astrophysicists in their diagnosis of a “supermassive black hole” at the center of the galaxy has been boosted greatly by some brilliant observational work that has allowed the orbits of stars close to galactic center to be determined. Their motion has been used to better estimate the size and massiveness of the assumed “black hole” dwelling there. However, this brings us back to the question of what astrophysicists understand about gravity and mass.
In Electric Gravity in an ELECTRIC UNIVERSE® I argue for the origin of mass and gravity in the electrical nature of matter. Mass is not a measure of the quantity of matter. The ‘universal constant of gravitation,’ G, is neither universal nor constant since it includes the mathematical dimension of mass, which is an electromagnetic variable. In the powerful magnetic field of a plasmoid, charged particles are constrained to accelerate continuously in the complex pattern of the plasmoid. Like electrons and protons in particle accelerators on Earth, the apparent masses of those particles become enormous as they approach the speed of light. So to report that the object at the center of the galaxy has the mass of 4 million Suns is meaningless in terms of the amount of matter trapped there electromagnetically. The matter there is not constrained by gravity, nor is it there as a result of gravitational accretion. Maxwell’s laws apply at the Galactic Center, not Newton’s.
The plasmoid is “quiet” while storing electromagnetic energy. The persistent high-energy flux comes from synchrotron radiation from the circulating charged particles in the plasmoid. Experiments indicate that as soon as the particle densities in the plasmoid filaments reach some critical value, collisions begin to dominate and the plasmoid begins to decay. The density is greatest in the bundle of axial filaments, so that is where the stored energy is released in the form of thin axial jets of neutrons, charged particles and radiation. In the process the axial current is “pinched off,” which could focus upon the plasmoid some of the prodigious electromagnetic energy stored in the intergalactic circuit. The plasmoid becomes an Active Galactic Nucleus.
A couple of serious problems have been found with the black hole scenario. One is called “the paradox of youth.” It is a:
“mystery surrounding the existence of massive young stars in the inner few hundredths of a parsec around the central black hole of the Galaxy. The problem is that according to standard scenarios of star formation and stellar dynamics the stars cannot be born in such an extreme environment because of the strong tidal shear, but are also too short-lived to have migrated there from farther out. None of the solutions proposed so far for the puzzle of the young stars are entirely satisfactory. Their spectral properties are identical to normal, main sequence B0-B9 stars with moderate (≤150 km/s) rotation.” “The stellar orbits appear overall random, in marked contrast to the ordered planar rotation observed for the much more luminous emission line stars farther out. In addition the stars in the central 0.02 parsec appear to have higher than random eccentricity.”
These recent discoveries demonstrate the bankruptcy of gravitational theory.
Stars are an electrical phenomenon. Stars are not formed by gravitational accretion but in the incomparably more powerful plasma z-pinch. The galactic plasmoid is a concentrated z-pinch with the complex morphology shown earlier. As a z-pinch subsides, experiment shows that a number of consolidated objects that formed along the pinch scatter like buckshot. So stars born in the plasmoid will initially have random eccentric orbits. Stellar rotation is imparted by the pinch vortex and should be similar in the group. The stars beyond 0.02 parsec from the Galactic Center show different kinematics and stellar properties from those stars inside that limit. It indicates a discontinuity in the properties of the plasma environment rather than something intrinsic to the stars.
Infrared image of the mini-spiral at the Galactic Center obtained with the Kuiper Widefield Infrared Camera on the Kuiper Airborne Observatory. Credit: H M Latkavoski et al., Cornell U.
The hallmark of plasma phenomena is their scalability over an enormous size range, from microscopic to galactic. The natural form of the largest visible plasma discharge in the universe, the spiral galaxy, is seen repeated here at the heart of our own spiral electric galaxy.
Scientists hope that future very high resolution imaging of the Galactic Center will enable them to detect the features expected of a black hole with a “Schwarzschild radius” of 10 million miles. It is supposed to “open up a new window for probing the structure of space and time near a black hole and testing Einstein’s theory of gravity.” Given that the Schwarzschild radius “is not a distance of any kind,” I confidently predict continuing surprises, puzzlement and theoretical legerdemain in attempts to make the facts fit the unscientific black hole theory. It seems impossible for the courtiers to perceive that the emperors of science have no clothes. Reality is a shared illusion.
I suggest we stop wasting tens of billions of dollars searching for new particles and forces invented by mathematicians chasing fame and a Nobel Prize and spend one percent of that sum investigating the dense plasma focus. Science used to be about simplification. It is the way of the ELECTRIC UNIVERSE®. It is the way out of science’s black hole.
Messages from some Dissident Witnesses at the Emperor’s Court
“Modern astronomers busy themselves applying accepted theories to new observations in deliberate disregard for the unexpected. They may as well reprint previous papers, close the telescopes, and save the taxpayers’ pennies. They’ve ceased looking for new ideas and have become technicians of the rote.
Astronomy has become a science of answers, of ‘secure knowledge,’ of ritual. It can be contained on a hard drive. It’s a science for robots or parrots. Answers are victories that soon become dead leaves of reminiscence, dry pages of textbooks and scriptures.
A science for humans is a science of questions, of learning, of possibilities and opportunities. Its aim is not to fold the unquestioned into the envelope of the given but to learn new words and to write new narratives.”
“It’s all about attitude, really. There are scientists who think they may be able to derive a set of equations they boldly term “The Theory of Everything”. Then there are those, like me, who admit to themselves and others that what we don’t know will always significantly exceed what we do. So it comes down to this: Do we believe the evidence of our eyes, to the extent that it should form the basis of theories in cosmology, or do we rather depend upon our imaginations, expressed in convoluted mathematical dialects, to express our eternal optimism that some day, some how, we might persuade ordinary folk that this is how they should be seeing it.”
—Hilton Ratcliffe, Declaration of Intent: Swimming with the salmon, dining with the bears.
“The worse things get, the more scientists meet together internationally in the interest (supposedly) of progress. But, as Tommy Gold points out, perpetually meeting together locks people’s beliefs together into a fixed pattern, and, if the pattern is not yielding progress, the situation soon becomes moribund. These considerations provide ample motivation for attempts to preserve the status quo in cosmology: religion, the reputations of the aging, and money. Always in such situations in the past, however, the crack has eventually come. The Universe eventually has its way over the prejudices of men, and I optimistically predict it will be so again.”
—Sir Fred Hoyle, Home is where the wind blows (1994).
Could there be planets orbiting black holes? What effect would that have on them?
Anything can orbit a black hole. The planet would be subject to tidal forces which, depending how far the planet was from the black hole, could potentially rip it apart or simply heat it through internal stress like Jupiter's moon Io.
The main thing is that without a star, it would get rather cold, unless the black hole had an accretion disk and jet which were producing sufficient light to heat the planet.
The tidal forces on the planet would be the same as if it were orbiting any same mass object. Just want to point that out to avoid potential confusion that they are in any way unique to black holes.
accretion disk and jet which were producing sufficient light to heat the planet.
Wouldn't that make for a spectacular night sky!
The planet would be subject to tidal forces which, depending how far the planet was from the black hole, could potentially rip it apart
Just to be more specific, that's the case with stellar-sized black holes. Orbiting a supermassive black hole is slightly different, since there is virtually no significant tidal forces outside the event horizon (none that a human or planet would notice, anyways).
unless the black hole had an accretion disk
How large do the accretion disks of stellar black holes typically get? Would they be a danger to a planet orbiting the same distance as Earth? (assuming its inhabitants had bought plenty of space heaters)
Question: the fact that "the gravity of a black hole is so immense that not even photons can escape" is often trotted out in front of the general public (myself included). You're saying that it's possible for black holes to emit enough radiation to heat an orbiting body?
But if there was a black hole there that mean there was a supernova. So wouldn't that mean any planets orbiting the star would have been destroyed? Or would enough matter linger around the black hole to be able to reform planets?
Could there be a planet orbiting a Black Hole that somehow has liquid water and a not too disturbing radiation situation? Could there be biological life on such a planet?
If the Sun magically went black hole, without losing any mass, the orbits of all planets would not change at all.
Whether a star is in its normal state, or it's a black hole, makes no difference, as long as the total mass remains the same. Gravity only depends on mass.
The only difference would be that the resulting black hole would be much, MUCH tinier than the original star, and all the funky phenomena would only occur in that small space immediately surrounding the BH. Further out, at normal distances, things would remain unchanged.
I thought gravity was dependent on energy and momentum?
Generally, the formation of the black hole would ensure that no planets would be left behind.
If you put a planet around a black hole by magic, itɽ behave the same way as it did with the original star. Black holes are less massive than their parent stars and are not cosmic vacuum cleaners.
Supposing, hypothetically, you had a star orbiting a black hole as close as reasonably possible, and a life-bearing planet orbiting that star. What would the Black hole look like in the day and night skies?
Yes we are actually one of them! Our entire galaxy is orbiting a black hole, we are just far enough away to avoid being sucked in.
I need to clarify this: we (the solar system) are orbiting the central supermassive black hole only in the sense that it happens to be in the middle of our orbit, but not in the sense that the black hole's gravity is actually important at all to us. The supermassive black hole has something like a million times the mass of the sun, but the Milky Way as a whole has something like a hundred billion times the mass of the sun. It's more accurate to say the solar system is orbiting the central bulge of the Milky Way, with the supermassive black hole making up a very small portion of that.
More mystery objects near Milky Way’s giant black holeView larger. | Astronomers are tracking these mystery “G-objects” in the direction of the Milky Way’s center. They appear to be orbiting our galaxy’s central, supermassive black hole. Image via Keck Observatory.
Astronomers said on June 6, 2018, that they analyzed 12 years of data gathered at the W. M. Keck Observatory in Hawaii to discover several more of the bizarre objects known as G-objects. Only two examples were previously known of these strange galactic inhabitants, which are located behind a shroud of galactic dust, near Sagittarius A* (pronounced Sagittarius A-star), the supermassive black hole at our Milky Way galaxy’s heart. Astronomers discovered the first G-object – G1 – in 2004 and the second – G2 – in 2012. Both were thought to be gas clouds until they made their closest approach to the black hole. Both G1 and G2 somehow managed to survive the hole’s gravitational pull, which wouldn’t have happened if they were gas clouds a 4-million-solar-mass black hole like Sagittarius A* can shred gas clouds apart. Now these same astronomers report three more of the strange G-objects – which they’ve labeled G3, G4 and G5 – near the galaxy’s heart. The astronomers said they:
… look like gas clouds, but behave like stars.
Astronomer Anna Ciurlo – a member of the Galactic Center Orbits Initiative at UCLA – led a team that reached this conclusion. She announced the team’s result at the American Astronomical Society meeting going on this week in Denver, Colorado. Ciurlo said in a statement:
These compact dusty stellar objects move extremely fast and close to our galaxy’s supermassive black hole. It is fascinating to watch them move from year to year. How did they get there? And what will they become? They must have an interesting story to tell.
Randy Campbell is science operations lead at Keck Observatory. He developed software called OsrsVol, short for OSIRIS-Volume Display, resulting in a custom volume rendering tool that let the astronomers separate G3, G4, and G5 from the dusty background in the direction of the galaxy’s center. Once the 3-D analysis was performed, the team could clearly distinguish the G-objects, which allowed them to follow their movement and see how they behave around the supermassive black hole. Campbell explained:
We started this project thinking that if we looked carefully at the complicated structure of gas and dust near the supermassive black hole, we might detect some subtle changes to the shape and velocity. It was quite surprising to detect several objects that have very distinct movement and characteristics that place them in the G-object class, or dusty stellar objects.
Astronomer Mark Morris of UCLA added:
This composite image features both X-rays from NASA’s Chandra X-ray Observatory (purple) and radio data from NSF’s Very Large Array (blue). You can see the position of Sagittarius A* (Sgr A* for short). Image via Chandra.
If they were gas clouds, G1 and G2 would not have been able to stay intact. Our view of the G-objects is that they are bloated stars – stars that have become so large that the tidal forces exerted by the central black hole can pull matter off of their stellar atmospheres when the stars get close enough, but have a stellar core with enough mass to remain intact. The question is then, why are they so large?
These astronomers pointed out that something must have caused these stars to swell up. It’s possible they’re the result of a collision between two stars orbiting each other. Collisions like this could happen near the galaxy’s center, as the gravity of the giant black hole exerts its influence on the surrounding space. Over a long period of time, the astronomers said, the black hole’s gravity alters the orbits of the two stars in a binary system until the duo collides. A G-object could be a combined object, resulting from this violent merger. Morris said:
In the aftermath of such a merger, the resulting single object would be puffed up, or distended, for a rather long period of time, perhaps a million years, before it settles down and appears like a normal-sized star.
So the G-objects may be showing us some of the strange scenarios taking place at our galaxy’s center, among objects orbiting near Sagittarius A*. And they’re showing us that these events are happening quickly, relative to a typical astronomical timescale. A million years, for example, is a blink on that timescale, and yet we now see five of these objects. How many more are there, still to be discovered?
The team said they’ll continue to follow the size and shape of the known G-objects’ orbits, which could provide important clues as to how they formed. They said they’ll be paying close attention when these dusty stellar compact objects make their closest approach to the supermassive black hole. And that’s the bad news for us humans, because – although the events at the galaxy’s center are happening quickly on an astronomical timescale – still, outer space doesn’t operate on anything like a convenient human timescale. This close encounter is expected to occur 20 years from now for G3, and longer for G4 and G5.
Yet we know astronomers will be watching, because, as their statement explained:
View larger. | The Galactic Center Orbits Initiative (GCOI) is headquartered at UCLA and led by astronomer Andrea Ghez, with additional members at University of Hawaii’s institute for Astronomy, California Institute of Technology, W. M. Keck Observatory, and Thirty Meter Telescope. Pictured here are members of GCOI in front of Keck Observatory on Maunakea, Hawaii, during a visit in 2017. Image via Keck Observatory.
This will allow [us] to further observe their behavior and see whether the objects remain intact just as G1 and G2 did, or become a snack for the supermassive black hole. Only then will they give away their true nature.
Bottom line: Two previously known G-objects – G1 and G2 – came incredibly close to the Milky Way’s central black hole, yet survived. Now astronomers report 3 more of these mystery G-objects – which they’re calling G3, G4 and G5 – near the heart of our galaxy.
Hypothesis 6) An Orbiting Black Hole Disk
I had hoped that we could make an alignment more likely by putting the black hole in orbit around Boyajian’s Star, but it turns out that makes things much harder. In addition to the low probability of such a binary companion in the first place, the chances that it would be in a part of its orbit such that we would see it are very low, like 1 in a million low. Since Kepler only looked at 100,000 stars, and since every star does not have such a companion, this one doesn’t work.
Subjective verdict: not likely.
OK, enough with the black holes. Next time: Circumstellar material.
Update: Commenter Herp McDerp (obviously their real name) points to this Nature article by Alastair G. W. Cameron (Bethe Prize winner and originator of the Giant Impact Hypothesis for the formation of the Moon). In it, Cameron tries to explain the eclipses of the ε Aur system with our Hypothesis 6! I’d write “great minds think alike” but I’m totally out of my league on this one, so I’ll just write that we’re in very good company with this hypothesis!
Feeding a Black Hole
After an isolated star, or even one in a binary star system, becomes a black hole, it probably won’t be able to grow much larger. Out in the suburban regions of the Milky Way Galaxy where we live (see The Milky Way Galaxy), stars and star systems are much too far apart for other stars to provide “food” to a hungry black hole. After all, material must approach very close to the event horizon before the gravity is any different from that of the star before it became the black hole.
But, as will see, the central regions of galaxies are quite different from their outer parts. Here, stars and raw material can be quite crowded together, and they can interact much more frequently with each other. Therefore, black holes in the centers of galaxies may have a much better opportunity to find mass close enough to their event horizons to pull in. Black holes are not particular about what they “eat”: they are happy to consume other stars, asteroids, gas, dust, and even other black holes. (If two black holes merge, you just get a black hole with more mass and a larger event horizon.)
As a result, black holes in crowded regions can grow, eventually swallowing thousands or even millions of times the mass of the Sun. Ground-based observations have provided compelling evidence that there is a black hole in the center of our own Galaxy with a mass of about 4 million times the mass of the Sun (we’ll discuss this further in the chapter on The Milky Way Galaxy). Observations with the Hubble Space Telescope have shown dramatic evidence for the existence of black holes in the centers of many other galaxies. These black holes can contain more than a billion solar masses. The feeding frenzy of such supermassive black holes may be responsible for some of the most energetic phenomena in the universe (see Active Galaxies, Quasars, and Supermassive Black Holes). And evidence from more recent X-ray observations is also starting to indicate the existence of “middle-weight” black holes, whose masses are dozens to thousands of times the mass of the Sun. The crowded inner regions of the globular clusters we described in Stars from Adolescence to Old Age may be just the right breeding grounds for such intermediate-mass black holes.
Over the past decades, many observations, especially with the Hubble Space Telescope and with X-ray satellites, have been made that can be explained only if black holes really do exist. Furthermore, the observational tests of Einstein’s general theory of relativity have convinced even the most skeptical scientists that his picture of warped or curved spacetime is indeed our best description of the effects of gravity near these black holes.
Key Concepts and Summary
The best evidence of stellar-mass black holes comes from binary star systems in which (1) one star of the pair is not visible, (2) the flickering X-ray emission is characteristic of an accretion disk around a compact object, and (3) the orbit and characteristics of the visible star indicate that the mass of its invisible companion is greater than 3 MSun. A number of systems with these characteristics have been found. Black holes with masses of millions to billions of solar masses are found in the centers of large galaxies.
the disk of gas and dust found orbiting newborn stars, as well as compact stellar remnants such as white dwarfs, neutron stars, and black holes when they are in binary systems and are sufficiently close to their binary companions to draw off material