NEUTRON STAR FORMATION
Billiard enthusiasts, you should like this piece.
Space is apparently filled with something like giant cue balls, about 8 miles across, rotating and emitting a beam of particles, sort of like a lighthouse on America's shores emitting a rotating beam of light.
They are called "neutron stars" which have become "pulsars."
That's nice. What does that mean?
Well, it's like this: A star starts out as a great big ball of hydrogen gas which begins to accumulate as gravity generated by all of the hydrogen particles together begins to pull each of the hydrogen particles in toward a common center.
The hydrogen particles, individually, "don't like" this arrangement one little bit. Like people jammed into a subway car on a hot Friday evening during rush hour, the hydrogen particles start angrily pushing and shoving against each other, getting hotter and hotter, until they start ramming each other hard enough for each of their centers, a proton, to start sticking together like Siamese quadruplets -- 4 hydrogen particles smash together and form a "4-ball unit" made of 2 protons and 2 other protons which have been forced by the smashing together to become neutrons.
When that flip occurs, from protons to neutrons, 2 electrons are fired out, as well as a whole bunch of other hot, dangerous stuff which in a sense used to be the ingredients which made those to neutrons be protons.
That stuff flying out of the particles when they turn from 4 protons into one "Siamese quadruplet" particle comprised of 2 attached protons attached to 2 attached neutrons actually -- a helium nucleus -- is what makes hydrogen bombs destructive.
So, stars are great big balls of hot hydrogen gas being squeezed into hot helium gas, and giving-off a whole lot of heat in the process.
As time passes, as more and more hydrogen gets turned into helium in the star, the larger number of helium particles jumping around means that other kinds of substances will be made as the "rush hour crowd" of particles angrily bang into and squeeze each other.
But these other substances are all hotter.
The increasing heat makes the star get bigger.
As the star gets bigger, it begins to cool -- the "rush hour crowd" of particles get less angry because they feel less jammed-into the "subway car," so to speak.
And the star reaches maximum heat and size.
Our Sun will do this someday, swallowing up all of the planets out to Jupiter as it does so.
But when the star is big and hot like this, it burns up fuel like crazy.
Finally, the star runs out of fuel to burn, like a car running out of gas. (Once I was able to role up to the pump empty after momentum carried it the last one-quarter mile down the highway after the engine stopped! I just wanted to brag about that!)
At the moment this occurs, all of the particles comprising the star suddenly have no violent star heat holding them up, and the gravity of all of them starts pulling each of them toward one mathematical point, the center.
And not only that, because gravity is strongest at the surface of any planet or star, gravity is pulling the hardest on the portions of the star farthest from the center, so that everything tends to arrive at the mathematical center point at exactly the same moment.
Scientists are waiting for that to happen to the huge star in the constellation Orion, Betelgeuse, right now.
When that happens, it's like two hands smashing together so hard they explode.
There is a tremendous outpouring and inpouring of energy from the point in the mass at a distance above the center where the energy of the smacking-together is hottest and greatest.
That inpouring shrinks and crushes the inside of that star like God's mightiest punch. Foom! At that moment, if the insides of the star being mashed together have just the right weight, they get smashed into a perfectly smooth ball of neutrons 8 mile wide. The conversion of protons back into neutrons releases gigantic quantities of energy, adding to the overall explosion to the point where, for a short time, it is as bright as an entire galaxy. This is called a "supernova."
As the remaining tiny 8 mile wide ball of neutrons cools and settles down, it is doing something funny.
If the star was rotating on its axis before the falling inwards, then the falling inwards was like a pirouetting ice skater pulling-in her spread arms. The collapsed-inward mass spins even faster.
Our wonderful nerdy astronomers tell us that the numbers suggest that 1,000 times per second is the greatest rate of rotation possible for a neutron star. (I guess after that their own centrifugal force starts throwing them apart.)
So, if we were in a space ship, and if we came upon a neutron star, and if we could see it -- and there's room for doubt about that last "if" for a few reasons -- then it might look like a ridiculous perfectly smooth cue ball rotating hundreds of times per second.
A CLOSER LOOK AT THE FINAL PRODUCT
First, it is beginning to appear that every neutron star spins. Why? Because it is almost impossible that its parent star was a perfect non-spinner. For the neutron star to be a non-spinner, the parent star would have to be an absolutely, positively perfect non-spinner, because when that big ol` parent-star "ice skater" draws in her "arms" during the supernova, the shrinkage from 400,000,000 miles across at greatest extent down to 8 miles across as a neutron star multiplies rotation speed gigantically. To put it another way, "50 million times even almost nothing = something impressive."
So, again, odds are that every single neutron star spins.
Next, as all of my friends will stampede this Blog to tell you, no one, not even yours truly, is perfect pure.
Well, neutron stars have the same problem.
Just about all neutron stars have impurities in them, being squeezed and releasing a constant stream of energy.
From where, on the neutron star?
Apparently, through a crack.
The excess energy is fired out of the crack like a beam of light from a lighthouse. And it goes out a very, very, very long distance.
As the beams sweep past the Earth, they make our radio telescopes go "click." Radio telescopes are like the Arecibo telescope and the Very Large Array...
...which you can see in the movie Contact (which I recommend to all who don't mind the mild sex scene in it). Several of the radio telescopes have recorded the clicks of various spinning neutron stars, called "pulsars." You can hear them here...
There's something I haven't fully worked out to my own satisfaction, yet -- the effect of what is called "relativistic time dilation" on the whole thing.
In fact, time is slowed down by gravity. The more powerful the gravity, the more time slows down. This effect is called "relativistic time dilation."
So, if a neutron star happens to pass by earth close enough for a magnified view through a telescope, scientists watching the spaceship going to the neutron star through a telescope on Earth would see the spaceship travelling toward the neutron star at normal speed, then they would see a space-walking astronaut start being sucked-into the neutron star by its gravity.
Even though, at the neutron star, the space walker is being pulled-in faster and faster, back on Earth, because at the neutron star time is slower, the scientists, in their normal gravity looking through their telescopes, see the astronaut falling into the neutron star going slower and slooooooower and sloooooooooooooooooooower.
That's the strange effect of relativistic time dilation.
Well, what effect does this same phenomenon have on the beam of particles coming out of the neutron stare's time dilation?
How can more beam flashes be on the outside of the time dilation field than rotations in the time dilation field?
In any event, above I asked the question, Could neutron stars be seen by the eye, if a neutron star were to pass close by Earth?
Well, first, aside from the particle beam being squeezed out of the crack, pulsars don't have a light-emitting mechanism.
Normally, when we see something, light from an external source strikes the molecules of the object. Electrons orbiting the object jump into a more excited state momentarily, but then they extremely quickly lose their excitement, and fall back into a more stable electron orbit or "shell," emitting a new light particle or photon or quantum (whatever you want to call it), at a the same moment. When that newly emitted light particle strikes our eye, we "see" the object. (Light particles don't actually "bounce off" like rubber balls.)
Neutron stars are neutron stars because they have no electrons.
But electrons in their shells around the middle of their home atom, or nucleus, are the light-absorbing-and-emitting mechanism.
So, it appears that neutron stars may neither absorb light nor emit light.
How can our eyes "see" one?
Second, Even if they had a light-emitting mechanism, the relativistic time dilation will cause the wavelength of the light to become enormously different, making it the kind of light we can't see. The wavelength of visible light would become the wavelength of invisible light.
Finally -- and this is the coolest, most intriguing question of all, in this article, as far as I am concerned -- is the 8-mile-wide neutron star "below the quantum limit."
Here is what I mean.
Something magical happens all around us, but very few people know about it.
The tinier something is, the more powerful our microscope has to be to look at it.
However, this only works so much. It is not because our tools aren't good enough. Rather it's because of something called "the quantum limit."
Individual subatomic particles can't be looked at, because below a certain size they are always "quantum probability clouds." About such particles it's best to say, "They are 'there,' but not quite exactly there." Instead, the particle's "there-ness" is best described as a "probability cloud" -- "at time W, more likely than anything else at that point with coordinates X, W and Z."
When scientists began looking for the place where "probability-cloud-ness" ended and visibility began, they found even that all lone atoms and even some packages of multiple atoms -- "molecules" -- lacked "there-ness" and instead were invisible probability clouds.
Now here's my at-first-seemingly-ridiculous question: Since a neutron star is like a giant nucleus of a single atom, despite its 8 mile diameter is it "below the quantum limit" -- is it visible?
I don't know.