OK, technically this was from last night but I had neither opportunity nor inclination to write it all down at the time. These bits are from the tail end of “Death by Black Hole and other Cosmic Quandaries.” One thing that was brought immediately to mind was the unscientific fact that it’s often much harder to read on a topic that you know something about than one about which you are a complete novice. Of all the sciences, my grounding in astronomy is pretty solid (I have a state champion medal from the Academic Decathlon to prove that much) so when I pick up these books on astronomy it is with no small trepidation. The last thing I need is yet ANOTHER retelling of how stellar spectroscopy works. This forces me into a bit of a pattern of random skimming which makes it hard to find the bits that may be new to me. In the end, nothing struck me as particularly new but it was interesting to be reminded of a few amusing facts about the universe we live in. Let’s begin…
Like a large man with a dermatological condition, the sun is constantly shedding. This is surely not surprising as the sun does put out a hell of a lot of energy. You’ve got the constant onslaught of the cosmic wind and all that heat and light. What may be surprising is the magnitude of the shedding. Yes, boys and girls, it is calculated that the sun sloughs off 4 Million TONS of mass every SECOND. Yes, that’s every second. Not a typo. This gives one a right and appropriate scale of just how BIG the sun is. Welcome to the universe. Two million pickup trucks just gone into the vapor every time the second hand on your watch ticks.
Gravity, in the realm of the four basic forces of the universe, is a complete wuss. The somewhat pathetic example that the book gives is that if by some physically impossible process the Apollo astronauts had brought back the electrons (and just the electrons) from a thimble-full of moon dust then the electromagnetic attraction between those electrons and their orphaned protons back on the moon would have been greater than the gravitational attraction of the entire planet.
Totally unrelatedly, the book goes into some small detail about the so-called fourth state of matter, plasma. In short, plasma is just uber-excited matter. If you heat anything up enough then it’ll fall all over itself and become plasma. To those of us bound to the Earth this is most typically expressed as lightning. When lightning strikes, the air around the discharge becomes plasma and behaves according to a wonderously new set of rules. In my book, plasma is boring. What we really want to talk about is the TRULY degenerate states of matter. Let’s start with the stuff of dwarf stars. Think back to high school physics and chemistry and imagine the model of the atom. You’ve got the happy nucleus with its boisterous cloud of rotating electrons. That’s the stuff of normal matter but think for a moment what happens at the heart of super-dense stars. Eventually these massive furnaces run out of fuel. When they do, then they begin to collapse. A typical star is a constant battle between the energy pouring OUTWARD from nuclear fusion and gravity pulling INWARD. I won’t go into the details here but when a star begins to run out of fuel, then gravity begins to win the battle and slowly the star compresses. Eventually, the compression becomes SO intense that the atom itself is compromised. Rather than being comprised of a nucleus and a cloud of electrons, imagine the empty space being crunched down to the point where even the electrons are bound together in the nucleus and the nuclei are stacked right on top of each other. This is the stuff of the dwarf star. All the empty space has been most rudely removed leaving a super-dense material that the sci-fi aficionados refer to as “Dwarf Star Alloy”. Super dense and super tough, this is the no-nonsense material of the universe.
In some cases though, we go even further. If a dwarf star becomes TOO dense then it condenses even more. Based on the description of dwarf stars though, you may ask “how can this possibly be? There’s nowhere else for the matter to go?” And this is exactly true. Dwarf stars are comprised of matter packed tightly together to the nth degree. There’s no empty space left. Neutrons and protons and electrons are stacked on top of each other like a child’s building blocks. Beyond a certain point, the very laws of physics themselves are compromised. Above a certain mass the dwarf star actually punches a hole in the very fabric of spacetime. Once this happens, the star has become a black hole. At this point, the star has collapsed into a quantum singularity, a location of infinite mass and yet no volume. The very laws of physics have been violated. This is the stuff of which quasars are made; perhaps a good topic for another post. The point is, quite simply, that when your physics teacher lectured on solids, liquids and gases, he or she skipped the most entertaining states of matter.
Lastly, the book made some interesting statements about the Earth’s ‘radio bubble’. This is the sphere around the Earth that which has been exposed to radio transmissions from the radio and television age of the planet. Going back to the earliest transmissions this bubble has a radius of about 100 light-years and includes about 1000 total stars; many of which have been shown to have planets in orbit around them. So from a purely technical standpoint, it is entirely possible that a civilization somewhere is enjoying the first days of television on our planet. The problem, however, is one of reception not distance. Simply to detect the carrier wave of our signals a civilization at 100 light-years distance would require a radio telescope 15 times the size of our largest, Arecibo. To actually decode anything would require a radio receiver 20 miles in diameter. Sadly, the omni-directional nature of our transmissions works against us in a major way here. In the popular culture on the subject we like to show alien’s listening in on our every move with ease but in reality they would have to be pretty damn determined to do so.