You may not think about the Sun all that often outside of the heat of summer, or recently getting a sun burn. I mean what is there to know? It’s the Sun- it’s hot, big, makes the daytime, do you need to know more? The Sun, despite its dominant position in our Solar System, is not very well understood.
So what is the Sun? It’s a massive ball of mostly Hydrogen, about a fifth Helium, and some trace amounts of heavier metals like Carbon and Iron. It’s core is undergoing nuclear fusion, fusing Hydrogen atoms into Helium atoms and releasing tremendous amounts of energy. This energy trickles up to the surface as photons bouncing between atoms in the roiling plasma until it reaches the surface where it blasts out in all directions as Sunshine. Plasma is a form of matter like solid, liquid, and gas that is defined as being energetic and ionized so electromagnetic forces dominate its behavior (as opposed to mechanical forces with solids, liquids, and gases). This process from core to surface can take 100,000 years, so the light we see from the Sun was formed long before written history.
Nuclear fusion only takes place in the core, and surrounding it are several layers which have different properties. Outside the core is the Radiative zone, where the plasma is too dense for individual atoms to move around, so all energy is transmitted via radiation. Outside of the Radiative zone is the Convective zone, where the density of the plasma is low enough that atoms can move around and transport energy by moving from hot to cold zones. Near the surface is the Photosphere and Chromosphere, where energy returns to its form as photons and high energy particles and escape the Sun.
The Sun is a fairly typical star, so knowing more about the Sun can reasonably be extended to similar stars. Our star is a G-type Main Sequence star. On the smaller side are Red Dwarves, and on the larger side are Giants and Super Giants. The size of a star dictates many aspects of its behavior. Small Red Dwarves are typically convective all the way through, so the fusing Hydrogen is continually mixed. This extends their lifetime to many dozens of billions of years. They are also by far the most numerous type of star in our galaxy. Our star is 4.6 billion years old and is expected to remain in a similar state for another 5 billion years. Giant stars have all kinds of different behavior including cores of inert Helium and fusing shells of Hydrogen, or even fusing cores of Helium. They burn their fuel much faster and only live several million years or less. They are more rare and explode often, spreading heavy metals all over the galaxy and producing planets like Earth.
Our Sun has a complex magnetic field that is changing all the time due to the movement of the plasma within the Sun. This magnetic field causes features on the surface such as sunspots and solar flares. Solar flares are filaments of solar material spinning around a magnetic field that moves and shifts, blasting solar material out into space. That material can escape the Sun and hit the Earth, causing a geomagnetic storm that can affect electronics on Earth.
Even though it’s the biggest thing in our solar system and it’s right there, there’s a lot we don’t know about the Sun. The Sun goes through roughly eleven year cycles, and a lot of work is put into predicting and estimating that cycle, but we don’t know enough to get it right- it’s like predicting weather here on Earth. We’ve launched missions to observe the Sun from different orbits and using different instrumentation. We’ve even launched missions into our own magnetosphere to understand its interaction with solar particles.
So just because it’s so obvious and constant, the Sun is actually an amazing and mysterious thing. So learn some more about the Sun, and don’t forget to use sunscreen!
There’s a new study out about the risk of American Tackle Football (heretofore called simply football) and Chronic Traumatic Encephalopathy (CTE) or some spelling idk. Basically humans are not mountain goats, though scientists continue to work tirelessly.
All sport carries risk of injury. What makes CTE insidious is that it’s cumulative and invisible for years. You can break a bone and it resets and you can recover 100%. You can recover from most skeletomuscular injuries to regain your pre-injury performance. The problem both with CTE and football, as opposed to other violent sports like hockey, is that the purpose of the sport is to put your head in danger to make the violent play. There are bad collisions in sports like hockey, lacrosse, soccer, but they are less frequent, and typically in a play for the ball or puck. It has violent potential, but is not combative.
We are in the middle of a planet finding bonanza. In just the past five years, we’ve discovered more planets outside our solar system than in the rest of history combined! And as for finding more planets, the sky is literally the limit! What is an exoplanet and how do we find them?
An exoplanet is simply any planet discovered outside our solar system. Even finding planets within our own solar system is no simple task. Only Mercury, Venus, Mars, Jupiter, and Saturn have been seen with the naked eye and have been known since ancient times. In fact, we started discovering Jupiter’s moons before we finished discovering every planet in our own solar system. Jupiter’s first four moons (Io, Europa, Ganymede, and Callisto) were all discovered in 1610, and it wasn’t until 1781 until Uranus was discovered. Pluto was discovered in 1930, then unceremoniously demoted to dwarf planet in 2006. By then we had well begun identifying planets beyond our solar system.
So how do we find exoplanets? The most simple method to detect a planet direct imaging: point a very powerful telescope toward a star and view the planet orbiting the star. Even with the most powerful telescopes we have we can only directly image huge planets (larger than Jupiter) that are close enough to a star bright enough to reflect light for a telescope to directly image.
That’s great, but we’re more interested in smaller, Earth-like planets that could exhibit features like our planet and even possibly harbor life. Finding definitive evidence that a planet outside our system harbors life is the holy grail of planet hunting! Currently we are finding plenty of planets slightly larger than ours that we’ve called Super Earths, that we can’t see directly but can infer their existence from other means.
If we can’t see a Super Earth, how can we detect it? The method coming into fashion for detecting planets big and small is the Transit method. Direct imaging is detecting the light reflected off a planet, transit method is detecting the absence of light from the star when a planet crosses in front of it. If the alignment is right, a planet orbiting in front of a star will make that star’s brightness temporarily decrease in a predictable fashion. If the star’s brightness is graphed over time, the size and shape of the dip of brightness will give us information about the planet’s size and orbit. A planet close enough to its star will orbit quickly, and we can track the trends of the star’s brightness to get information about its orbit shape, which in turn can tell us if liquid water, and thus life, are possible on the planet!
Another indirect method that was popular before the Transit method took dominance is the wobble method or if you prefer jargon, the radial velocity method. This method is somewhat limited to larger planets and smaller stars. Basically- planets don’t orbit their stars so much as both the planet and star orbit the system’s center of mass, so a large planet actually tugs a star around in a wobbly path. The size and frequency of the star’s wobble can tell information about the tugging planet. This method works best if the star is smaller relative to the planet (so it gets tugged more) and the two bodies are close (so they wobble quickly enough to be detected and modeled).
There are some other novel methods, but Transit is king today, and the method used to detect seven planets in one system, called TRAPPIST-1. That stands for Transiting Planets and Planetesimals Small Telescope, a “backronym” that pays homage to the discovering nation’s chief cultural export, namely Belgium, who makes Trappist style beer. TRAPPIST-1 has seven planets, all roughly Earth-sized or smaller, and three of these planets are within their parent star’s habitable zone which simply means it’s the right temperature, given the star’s heat, to hold liquid water. The parent star is a red dwarf which is a smaller and cooler star than our own, so the habitable zone is much closer to the star. TRAPPIST-1’s parent star is only 8% the mass and 11% the diameter of our Sun.
TRAPPIST-1 is “only” 39.5 light years away, which suggests that solar systems like ours are fairly common, that planets are everywhere, and improves the chances that life exists elsewhere in our galaxy and universe. More and more powerful telescopes continue to come online, the techniques get more refined, and there are even some methods to detect the composition of exoplanet’s atmospheres coming around. It is a very exciting time for planet hunters, perhaps you’ll find one, or a whole system of them!
I live in the capital of sprawl, Houston. I buck the trend by living in town and commuting backward to NASA in Clear Lake- take THAT commuter society! Nevermind my commute is 20 miles each way (but it’s backward so I go pretty fast!..). I scoff at the suburban dweller, nay, hermits, who retreat daily to their free standing single family homes to lock the door and pluck some brain cells to place into a jar until the day repeats anew.
I am “woke” to the depleting nature of suburban bedroom communities. I don’t need a car to get to the grocery store- provided I can get what I need from the michoacana up the block. Great news- tacos, again! It’s not a food desert! (If you’re reading Scott McClelland I will perform acts for an HEB east of downtown) I don’t retreat to my self-imposed prison because my prison is smushed up against other ones in an arrangement called townhomes. I get the best of both worlds: high price and no privacy!
Even better- my neighborhood is a rapidly transitioning area from blue collar warehouses/factories/shotgun homes to white collar purchased townhomes to probably eventually no-collar rented townhomes. Instead of windy streets that require a car (snort!) to get around, we have a grid where drivers are free to accelerate to 50+, and a railroad goes literally right down my street. It shakes the house in the morning. Not across the street. Down it, like oh hello I’m driving next to a giant train full of lumber; no arm is preventing me from embracing the void and veering under it. We live across the corner from a hummus factory- how many white bread subby kids can say that? In Spanish? They probably have a good Spanish teacher at their school…
I honestly love my neighborhood and flail against the Undeniable Likelihood that we’ll end up in the suburbs “for the schools”. I tell myself “Chaz won’t start school for six years and by then brick and mortar schools will be Disrupted™ with School Prime by Amazon” and we can continue to live like quasi-hip artists-cum-yuppy near downtown. I tell myself we’re here to get in on the gold rush of Houston’s new hip EaDo neighborhood, but promise to sneer at the term EaDo and prefer “second ward” or if I’ve had a Corona, segundo barrio. I hate what I’ve become.
I did want a townhome in an urban environment, and kind of had a loose list of priorities in living:
- Prefer proximity to amenities over land or yard potential
- Really no yard is tops- I hate lawnwork
- Prefer mixed neighborhood to bedroom community
- Walkability like NYC or Amsterdam!
- Prefer upcoming neighborhood to mature neighborhood
- Cheaper, speculative
I’d say for the most part I hit the nail on the head with our house, but the nail is in fact several nails of mixed quality and I pay well over $1000 a month for a gentle tap upon one of them.
I told a liquor store owner I bought a house nearby and she said “Puedes retirarse en dos años” which was not the case. I bought my house when oil began its free fall. Another fun thing you pick up against your will when you live in Houston is learning a laymans introduction to the oil business. Like when Johnny Depp went to prison for weed in Blow and learned cocaine. You are forced to listen to that or sports if you must talk to other men in Houston. Houston sports are bad enough that oil can dominate a conversation by default. Downstream’s doing great I’ve heard. That’s another column.
I realized now I’m not talking about the title of my rant. I guess there is a lesson inside reading and writing this article tangent to the actual content is that you can’t have it all, and your plans become minute tactical moves instead of grand designs you dreamed of. Instead of a self-reliant bungalow in a mixed urban environment where I can walk/bike/train to a park, grocery, bar, whatever, basically I Want To Live In Amsterdam But Maybe A Bit More Room is replaced with mundane decisions of what to do about the dang garage door sumbitch weather strip fell off and it’s $300 to replace a rubber tube whose only job is to keep my garage clean? Which it wasn’t in the first place and never will be?
Fuck every time I start an article it spirals into an existential I’m-jaded-with-western-capitalist-society-and-want-to-move-to-the-trees-in-a-commune-that-miraculously-rejects-pathological-quasi-religious-nuttery. Maybe I should write an article about my shit eating idea of a utopian oh god dammit.
Rockets are the sticks that go boom on one end and fly real fast the other. They range from the little bottle rocket on the 4th of July to the football-field-tall Saturn V which took astronauts to the Moon.
You’ll notice that the Saturn V rocket has a few segments. We call these segments stages. Why do rockets have stages? Why are there rocket engines inside the rocket?
The short answer is: to save mass to go faster. Why do we have to save mass? Think of it this way, you can roll a bowling ball much faster than a boulder.
Rockets need to go very fast in order to reach orbit. They need to go even faster if they are to escape orbit and go to other places. The notion of orbiting itself can be a bit tricky: It’s moving so fast that you are falling down at the same rate as the surface of the earth is curving away from you, so you end up falling around the Earth.
Have you ever dropped a coin in one of those big funnels and watched it spiral down into the hole? Orbiting is essentially the same thing: the coin falls around the hole and gently slows down and spirals into the hole. In space there is no friction to slow the spacecraft down, so it would be like the coin just rolling around in a circle forever.
So the difference between going to space and going into orbit is speed. Space is just up- orbit is going and staying up. Going back to staging- a rocket is basically made of three things: the tanks, the engines, and the fuel. The fuel is by far the heaviest thing on board, but requires tanks to hold it. When a tank empties, you continue to carry the empty tank.
Staging allows you to shed the mass of emptying tanks, so you can push the remaining pieces of the rocket even faster. Second to that (and the focus of a future article), the rocket engines for different stages are designed to best work either at the ground, going really fast, or going really fast in space. By dropping early engines you can start up new engines that are best suited for that phase of the mission.