Over the ages mankind has looked up into the sky at night to wonder at the pinpoints of light that seemed to shimmer, or twinkle, or waver, by their billions. Countless in number, the stars above seemed to the ancients to be all of one accord. Whatever they were, they all acted the same and must be made of the same material and follow the same physical laws of the universe.
But then in the 1920s scientists discovered that the twinkle in most stars was merely the atmosphere of our planet playing tricks on our eyes. So it was decided, once again, that all stars are the same; they are just viewed through different lens and so appear in different ways.
But we know now that not all stars are created equal. They don’t all act the same way.
Astronomers in the early 1960s began looking at stars by means of other wave lengths than just the visible light spectrum. They discovered that some stars do indeed flicker and twinkle on their own. With a regular oscillation that puzzled and fascinated observers. Because these particular stars pulsated in a metronomic style, they were named pulsars.
How pulsars come about
Here’s how scientists see the creation of a pulsar:
It starts with a sun at least ten times larger than our own Sun. Like all suns, it eventually burns through all its nuclear fusion fuel (normally hydrogen reacting with helium.) At that point it collapses in on itself – like a balloon suddenly deflated. But in this case the balloon shrivels into a super tight mass that heats up several billion degrees and begins spinning at nearly impossible speed. This creates a super magnetic field. The matter at the center of this colossal carousel becomes so dense that protons and neutrons are literally forced to occupy the same space, which forces the ejection of billions of neutrinos into space – like pollen from a plant. At this point the star core can shrink no more, and the tidal wave of neutrinos blows away the outer atmosphere and stardust in a massive explosion that can be seen clearly from millions of light years away. This is a super nova.
After the explosion the outer gases and dust spread out for millions of miles. And the ‘corpse’ of the star itself is now nothing more than a bundle of tightly packed neutrons. Extremely hot and spinning madly, this neutron star possess such strong gravitational pull that it distorts time and space. Time literally slows down on the star’s surface, and light rays are bent and distorted around it.
We can’t see this happening, of course. Anyone or anything close enough to observe this phenomena would be obliterated. And even our strongest telescopes and most inquisitive satellites are stymied by the vast distances involved. Plus, scientists cannot predict with any certainty exactly when any particular star is going to go nova. It’s a matter of millions of years in the making. So astrophysicists use quantum physics and complex mathematical models to estimate when this might happen to any given star, as well as what exactly is the composition of those neutron stars already in existence.
It will give you some idea of how little researchers still know about the exact composition and structure of neutron stars to be told that this phenomena is labeled by scientists, with a straight face, as ‘nuclear pasta.’
We mentioned quantum physics a moment ago. When it comes to something as bizarre and inexplicable as a neutron star, Isaac Newton’s laws of physics, on which our world rested so smugly for so long, and which Albert Einstein began picking at a century ago, must be jettisoned for quantum physics – in which, among other things, two objects like neutrons may not only occupy the same space but in which one object like a neutron may be in two places at the same time. The mathematics and involved theories that quantum mechanics and physics call for are far beyond the scope of this article. Suffice it to say that only through this relatively new scientific discipline can such seeming anomalies as neutron stars be tolerated and explained in our imagination and in our existence.
Quantum physics posits that the exclusion principle, which states that two objects cannot be in the same place at the same time, is somehow overridden to create degenerate matter in the core of a neutron star. Degenerate matter is kind of like anti-matter, the kind that Geordie La Forge has to deal with all the time on Star Trek: The Next Generation. It reacts with regular matter in strange ways – crushing it or transforming it, and giving off huge bursts of energy while doing so.
All pulsars are neutron stars that spin at the incredible rate of forty-thousand times a minute. As they do so they throw off an incredible amount of radiation. Most of it in the form of gamma rays. These rays are thrown out so fast that they enter the visible light spectrum of incandescence. They are narrow beams, not vast clouds, of light. Like the light a lighthouse emits on its rockbound shore. Revolving so fast, these shafts of light appear to our telescopes as blinks of light. Pulses of light. Pulsars.
They are the metronomes of the universe. Remnants of once powerful and proud stars. What purpose they may serve in the future of space travel or anything else is still a blank slate.