Through a hole darkly

Ready for this? Black holes. I’ve got some nifty Gif images. And this stuff is easier to understand than the last couple topics (at least for me).

Fig. 1 A simulated black hole over a starry
background. Background stars behind and
near the line-of-sight become a blended
ring caused by gravitational lensing.
(Courtesy NASA)

Believe it or don’t, the first recorded mention of even the possibility of a black hole-like body dates all the way back to 1783. English geologist John Michell described the light-absorbing properties such a body might possess. Keep in mind that this was only 50-some years after Isaac Newton died, and he was the one who first described gravity. Surprised the heck out of me. Here I’d been thinking it dated back only to the 1979 Walt Disney movie.

French mathematician Pierre-Simon Laplace suggested similar star-body properties in 1796, but the notion was then shelved through much of the 1800s.

It wasn’t until shortly after Albert Einstein proposed his theory of general relativity in 1915, suggesting the physics for such an occurrence, that the concept was revived. German physicist Karl Schwarzschild and Dutch physicist Johannes Droste, working independently, developed specific formulas that would begin to define the nature of the body which could overcome the speed of light by an extraordinarily intense gravity field.

Fig. 2  Simplified model of a black hole,
cut away to show the event horizon (A)
and the singularity (B). Outside of the
event horizon light (red arrows) can
move in any direction, but within the
event horizon, the singularity's gravity
pulls light, and everything else, inward.

Because such a body, conceptualized as a single point, has the unusual effect of altering normal light and gravitational rules, it is called a singularity, in other words, a single point unlike anything else. In fact, things become so singular that time actually may stop in a black hole. The term singularity also is used because, with neither light nor anything else able to escape, nothing can be known about these bodies through direct observation.

Another significant term defining the anatomy of a black hole is event horizon. This describes the edge or surface of the spherical area surrounding the singularity at which limit gravity overcomes the speed of light; the singularity itself is the "core" of a black hole while the event horizon is its outermost "skin." Think of it like the outer edge of the atmosphere around the earth. For a black hole singularity, this surface is described as an event horizon because, once you pass it, everything changes (not necessarily in a fun way).

Fig. 3  Plasma jets erupt from the super-

energized accretion disk as it meets the

event horizon. (Courtesy NASA)

As all this implies, the singularity is called a black hole because it sucks in all light that comes within its event horizon, leaving no way to directly observe it. Technically, it’s invisible, though there are a few ways to “see” one. We’ll get to that later.

What causes a black hole?

In a nutshell, a whole lot of particulate matter squeezed down into a very, very, very small space. The most common are probably collapsed stars, though theoretical physicists suggest several sources. Again, more on that after a bit.

If you took our sun (Hey, who can tell me our sun’s stellar name? Answer next week.), if you take our sun (about 1.4 million miles across) and crush it down until it could fit into the Grand Canyon (which is 1 mile deep), the sun would become a black hole (the Grand Black Hole?). All of the matter in the sun would be packed together so densely that it would have a gravitational field that even light couldn’t escape. And since nothing can travel faster than light, I’d stay away from the Grand Black Hole, if I were you.

In reality, though, our sun does not contain enough mass to develop the force of the collapse necessary to become a black hole. It may take a star with up to 20 times the mass of the sun to collapse into a singularity.

Fig. 4  A small star (L) has its stellar matter
drawn into the accretion disk of a nearby
black hole (R)  (Courtesy **)

Where do black holes come from?

The more popular theories suggest four types of singularities.

1. Super-massive black holes (SMBH), which occupy the center—and likely help form—most spiral galaxies like our own. An SMBH continuously draws stellar material into itself, always enlarging from the mass of the material it accumulates. The source of SMBHs is uncertain. One theory suggests they are the result of colliding masses of stars, such as head-on galaxy smash-ups (they happen). An SMBH can have as much mass as several million to several billion stars the size of our sun (our sun = 1 “solar mass”).
2. Stellar black holes are formed after an aging star uses up all of its expansive energy-producing matter—sometimes exploding in a supernova in its death throes—while all of its remaining matter collapses in on itself. Stellar black holes may contain five to twenty times the mass of our sun (5 to 20 solar masses, opinions vary) compressed into a single point (don’t try this at home).
3. A highly theoretical type (though evidence of their existence is mounting) is the intermediate mass black hole (IMBH), perhaps containing 100 to 1000 solar masses. Their existence is the hardest to explain; the jury is still out.
4. Micro or miniature black holes, possibly formed from colliding material right after the Big Bang, may be smaller than an atom but contain the same amount of mass as Mount Everest; also highly theoretical.

Fig. 5  Simulation of "Einstein Ring" gravitational lensing as a black hole

passes in front of a distant galaxy. (Courtesy **)

Here are some methods by which we can detect black holes.

Stellar black holes, SMBHs and IMBHs are surrounded by flattened accretion disks (picture track and field’s throwing discus) made up of the accumulated stars, stellar gas and dust, or other cosmic material being drawn toward the singularity at its center. This material becomes more and more compressed, and thus hotter and hotter, as it approaches the event horizon. Accretion disks are easily observable and are a primary indicator of a singularity. (Examples, Figs. 4 & 6)

As the accreted material, now energized in the extreme, approaches the event horizon, it can throw off visible plasma jets perpendicular to itself and along the line of the polar axis of the spinning singularity, another way black holes can makes themselves known. (Examples, Figs. 3 & 6)

Black holes cause gravitational lensing, a topic mentioned, in passing, in an earlier essay. This distortion of light passing near the event horizon is caused by the singularity's intense gravity. It can help in the detection of a black hole that is viewed against other cosmic background objects. (Examples, Figs. 1 & 5)

Stellar black holes may give themselves away when their gravitational allure causes a nearby star to enter an off-center orbital dance that betrays the singularity’s presence. The singularity may also be seen to draw stellar gas away from the partner star toward itself. (Example, Fig. 4)

Fig. 6  Approaching an SMBH (super-
massive black hole) of the type thought
to be at the center of  many galaxies
like our own. Note the doughnut-shaped
"torus", a bulging accumulation of
material near the center of the accretion
disk, and the plasma jets. (Courtesy NASA)

What would a visit to a black hole be like?

On the bright side, death would be instantaneous. The event horizon is not a friendly place for carbon-based life forms—or much else. Things would happen so fast that there wouldn’t be time to notice; actually, there may not be time in any form. It’s been suggested that, as your body crossed the event horizon, it would be sucked immediately toward the singularity in a long string of individual atoms, though some particles might first be thrown off at the event horizon into the hot plasma jets—to be shot a hundred light years into intergalactic space. The rest of you would be smashed into unrecognizable sub-atomic smithereens, melding none-too-gently into the ultra-solid mass of the singularity. So you probably won’t need a sweater.

?

Twist tie theory

The other day I was complaining about twist ties in an e-mail to my friend, the Otter:

You know what gets my guts in an uproar? That American industry can't set a standard for which way twist ties are applied. Is that so freakin' complicated? I mean, how many years . . . ? But every darn time you get a twist-tied package, you have to figure out which way you have to twist it. We're not talkin' rocket surgery here. I know which way to twist open my prescription meds, a bottle of bleach, a jar of jelly, a radiator cap, the clean-out access on a sewer line, a darned five-gallon container of dishwasher sanitizer, but a loaf of bread—no-o-o-o-o-o! First one way, then the other. Have I cross-threaded it? Or is it twisting open? Nope, getting tighter. Okay, guess it's the other way.

Twist ties (Courtesy **)

The Otter, in his offhand way (he much prefers to discuss economic theory), responded with a series of optional solutions, none of which actually plumb the depths of this problem. Well, he hasn’t heard the last of it.

However, the issue of twist ties brought to mind a remarkable mystery (at least to me) of particle physics: string theory.

Here’s the notion of string theory as I likely misunderstand it:

Back in the day, we learned that atoms were made up of electrons, protons and neutrons and that these were the smallest particles of matter. Well—surprise, surprise—they aren’t the smallest particles. Nor are they these tiny balls of energy that were always depicted in representations of the atom.

Current theory has it that they are actually one-dimensional oscillating lines, “strings,” that are made up of a variety of even smaller particles, like bosons, fermions, gluons and other theoretical bits.

“One dimensional,” did you catch that part? I’m not quite sure how one wraps his or her mind around a concept like one dimensional; it's almost not quite there to be wrapped.

A graphic projection of String Theory?
(Courtesy **)

It gets worse. String theory doesn’t work unless there are at least seven more unobservable dimensions in addition to the four dimensions of spacetime that we’ve already discussed. That’s right, now we have a minimum of 11 dimensions (which, I…uh…I’ll explain, yeah, on the back side of this page).

Seriously, though, something tells me that there’s a bunch of really tricky mathematics behind all this.

And there’s more.

Turns out that the whole negative-positive electromagnetic charge system that was supposed to hold atoms together, as I learned in high school science, actually would cause them to fly apart. So particle physicists had to come up with something else besides electromagnetism and gravity to explain what held atoms together. To deal with the conundrum, they proposed the existence of two more forces, the strong force and the weak force. (Really? Must have been a Friday afternoon when they came up with those names.)

Have you noticed that I am totally incapable of explaining any of this stuff, but that by telling you about it, it makes me seem smart?

Just two or three more concepts, then.

Strings are generally thought to loop in on themselves, which I think is what that pinkish graphic, above, is supposed to represent. But sometimes strings may be attached to “branes,” the particle edges (membranes) of these other seven dimensions, and then they do not loop, just oscillate, like a worm on a fishhook.

Much as it might seem unlikely, due to the apparent opposite ends of the cosmic scale that they occupy, string theory is important to understanding the activity of black holes, too (oh yeah, black holes are not science fiction, fellow voyagers).

Named for 19th century German mathemati-

cian August Mobius, one of its discoverers,

the Mobius strip has only one side. You can

construct one with a long strip of paper. Put

a half twist in the strip and fasten the ends

together in a loop; paper glue or cement

works best for purposes. Now you can mark

a line along the entire surface length of the

strip, meeting your starting point, without

lifting your pencil from the paper. This has
nothing at all to do with particle physics; it's
just for fun! (Image courtesy **)

String theory has given rise to superstring theory, which is not, as I first thought, about very long strings. Rather, it is a theoretical model attempting to generate a formula that can tie together general relativity and quantum mechanics into a unified theory, also known as the theory of everything (I kid you not!).

Enough! I’m still stuck on the one-dimensional object. I mean, even a Mobius strip has edges.

Anyway, do you see why I was reminded by twist ties?

[?]

Physics and Magic 001: A Quantum Primer

Today, I’m going to tell you everything I know about quantum mechanics. It won’t take long.

For the lay person, like myself, quantum mechanics is best explained by using analogies, metaphors and similes, because the science part of it is really, really complicated; even the simple explanations come nowhere near being simple. So this approach to quantum mechanics will be a little like knowing that snow is white because it is cold.

Much of the foundation of quantum theory was laid down by a number of really smart theorists in the first quarter of the twentieth century. Among them was Max Planck, a German physicist who was studying thermal radiation.

There was an unexplained variable in such radiation for which Dr. Planck proposed a mathematical solution. His formula depended on a certain assumption of fixed energy productions that he said were “quantized.” He was awarded a Nobel Prize for his work. So were several other physicists who developed the field in the early years of the last century.

Where it gets tricky is that all of these scientists were working on notions about things they couldn’t even see yet: the atom and its parts. Look at it this way:

Imagine you’ve never seen nor heard of the famous coiled-wire toy, the Slinky™. (Can you hear the ad jingle, still resonating in you memory? “It’s Slinky™, it’s Slinky™, oh what a wonderful toy….”) Anyway, imagine you’ve never seen or heard of it. Now imagine you are sitting in a chair, blindfolded, in the middle of a room with a stairway nearby. Someone starts a Slinky™ into its only entertaining trick, coil-hopping down the stairs (in contrast to its single un-entertaining trick, getting tangled into a ball of useless bailing wire).

Okay. You can hear a staccato ringing whine, a regular series of thumps, and you can tell the sound is coming from the direction of the stairs, but you are blindfolded, so you can’t see anything or know exactly where the sound is coming from.

Now, imagine having to describe what is causing the noise, what is happening to cause it, and what you might do to keep the whole thing from entering an “un-entertaining” state. Please show the calculations you use to reach your answer. (Use the back of the page as necessary.)

That’s sort of what the early years of quantum theory development were like. At least in my understanding.

So why do we need quantum theory? Is it just to supply plot devices for Star Trek?

Not exactly. Here’s the central difficulty:

Classical physics, that is, the physics we are all unconsciously familiar with, that explains everything from JELL-O™ to the phases of the moon, has significant shortcomings when it comes to explaining some things on the sub-atomic level. So, when we get right down to electrons and neutrons and protons—and all their more recently discovered siblings and cousins—classical physics falls flat on its face.

For instance, classical physics assumes that you can precisely measure both the momentum and the position of the Slinky™ as it clang-clumps down the stairs. Quantum physics knows that you can’t. (Though, for purposes, this doesn’t really become significant until you’re dealing with individual atoms.) This very, very loosely describes what is known as the Heisenberg Uncertainty Principle, first proposed by Werner Heisenberg, another German theoretical physicist, from his work in the mid- to late 1920s; Heisenberg also received a Nobel Prize. His uncertainty principle states that, by measuring one factor, let’s say momentum, you can only estimate the other factor, position.

Another remarkable discovery of quantum physics is that all matter, including you, me and the sun, exhibit the qualities of both particles (Duh!) and waves (Huh?).

One of the fun controversies (well, I think it’s fun) of quantum theory is called entanglement. It is derived from the work of Austrian physicist Wolfgang Pauli (yup, Nobel Prize) which he described in 1925 and it soon became known as the Pauli Exclusion Principle. It says that two electrons in one system cannot be in the same quantum state; if one electron assumes one state, the other electron automatically assumes the other.

As a consequence, further development of the Pauli Exclusion Principle posited the notion of quantum entanglement. Where the fun comes in is that entanglement suggests that this automatic change will take place no matter how far apart the two electrons are. I mean, they could be really, really far apart.

Here’s an example:

You and your twin both need new shoes. However, the shoes you want are only available in Australia and the shoes your twin wants are only sold in Iceland. Before you leave, though, your father gives you each a smallish gift-wrapped box, a present to entertain you while you’re in your respective hotel rooms in Sidney and Reykjavik.

Father tells you that the gift is a Slinky™, one of your favorite toys. (This will replace your last one, which ended up as a hopeless snarl of colorful wire.) He says that the store only had two left, a red one and a blue one, but he’s not sure which is which, since the gift-wrapping was done by the clerk in the store’s back room. Because of TSA regulations, the gifts will have to be packed in your checked luggage so you won’t be able to open them until you reach your hotels.

What neither you, your twin nor your father knows is that the Slinky™ in each box has no color, but it can only become either red or blue, and one must assume each color because that’s what the store’s inventory stated.

Your flight to Australia is direct, but your twin must make connections in Atlanta. Consequently, you reach your hotel room in Sidney while your twin is still riding in a cab from the Reykjavik airport.

As you begin to tear the decorated paper from the box, you cry excitedly, “I hope it’s the blue one.” At which point yours becomes blue and your twin’s Slinky™, on the opposite side of the earth, instantly becomes red. (Hmm? Entanglement. Maybe Slinky™ wasn’t the best example.)

However, Albert Einstein (Nobel Prize) who had made his own contributions to the need for quantum mechanics, had trouble swallowing this idea whole; he referred to it as “spooky action at a distance.” But, remember, he’s been wrong before.

There might be one or two other things we could cover, but I think this is more than enough for now. Certainly it goes way beyond my area of competence. Maybe you should just read the Wikipedia entry on quantum mechanics—like I did. Then maybe you could explain it to me.

—  -  —  -  —  -  —  From the news  —  -  —  -  —  -  — 

Ultrafast Quantum Computer Closer: Ten Billion Bits of Entanglement Achieved in Silicon

ScienceDaily (Jan. 22, 2011) — Scientists from Oxford University have made a significant step towards an ultrafast quantum computer by successfully generating 10 billion bits of quantum entanglement in silicon for the first time -- entanglement is the key ingredient that promises to make quantum computers far more powerful than conventional computing devices. (Link to article)

—  -  —  -  —  -  —  -  —  -  —  -  —  -  —  -  —  -  —  -  —

[?]

Out on a limb: Looking at dark energy from outside the box

The other day, I was considering this formula (figure 1) for gravitational lensing, i.e., the distortion of light caused by gravity. Though the formula has more to do with dark matter rather than dark energy (two entirely different things, say the physicists who can’t describe either), it got me to thinking about the expansion of the universe.

Figure 1

See, not only is the universe expanding, but the expansion is accelerating, a fact that was only discovered in 1998. Up to that time there were two popular contemporary theories on the subject:

1. The size of the universe was static (not really all that popular).
2. The universe was expanding, but the expansion was decelerating and would eventually lead to an inversion, collapsing in on itself, sort of a reverse of the Big Bang (much more popular, in a morbid sort of way).

The general theoretical assumption is that the accelerating expansion is being driven by this ubiquitous and unaccountable dark energy, the existence of which is mainly premised on the fact that the universe is expanding at an accelerating velocity. (Is that a bit of circular logic, or is it just me?)

Now let me ice the cake.

Since the universe is expanding, and since the laws of physics firmly prohibit the creation of new matter and energy, the expansion is left with but one alternative—the creation of new space. (I really want to say “Go figure” right here, but it just doesn’t seem scientific enough for this blog.)(Ah, what the hey.) Go figure.

Now that one really freed my mind. In this realm of scientific definitions, where matter and energy are everything and space is the nothingness between them, it seems to me that the expansion of the universe is really creating more—nothing!

Can you understand, now, why people become physicists? Isn’t this more fun even than watching The Daily Show?

Realizing how wide open astrophysics and cosmology were to this sort of sideways thinking (as MAD Magazine used to call it), I figured I would jump right in.

I took another look at the gravitational lensing formula (figure 1). I then reversed and inverted the formula (figure 2).

Figure 2

Do you see what I mean?

Right! It makes no sense at all. I’m just goofing around. (But it makes this essay look a bit more science-y, doesn't it?)

However, I do have a serious point, even though it may not sound serious.

Generally, astrophysicists are reluctant to consider anything outside of the universe. This would include any presumed events or conditions prior to the Big Bang and, well, anything outside of the universe since that event, because there is no way of knowing, sensing, measuring or testing anything in those supposed realms. Even to speculate is largely pointless.

I, however, am not limited by such considerations.

And I got to thinking: what else could be responsible for the increasing velocity of the universe’s expansion?

In letting my mind wander over the question, I eventually pictured Newton’s fabled apple, accelerating as it approached the gravity-fraught earth. (Fraught really isn’t the best word here, but it’s come into more popular use lately, and I’ve determined to employ it in each of my blogs; one to go. Now, back to Newton’s apple.) And I thought: Eureka!

It would make much more sense if there were something outside the universe, drawing the universe toward it, than to have to explain some illusory dark energy that exists but cannot be sensed, measured or tested. It has the added benefit of being outside the universe and, therefore, neither provable nor disprovable. However, I can offer the expansion of the universe as evidence in its favor.

I’ll name this force expaneity. (Hey, you try making up a relevant-sounding word that isn’t in use somewhere else on the internet.)

Remember, you heard it here first.

[?]