Wednesday, June 27, 2012

Cryogenics

The image that comes to mind when the word "cryogenics" is uttered is usually that of some person frozen in a blue, glass tube waiting to be revived decades in the future. Cryogenics, however, doesn't necessarily mean the preservation of human bodies for revival. The word technically means "the branch of physics that deals with very low temperatures". More specifically, it is the study of the production of very low temperatures (below -150C) and the behavior of materials at those temperatures.

Classic cryonics scene from Futurama

Cryogenics is used in rocket fuels, MRIs, electric power transmission, freezing foods, infrared cameras, blood banks, and of course preserving bodies. As conductive materials get colder, they become more conductive, at a certain point, these materials become "superconductive". Superconductivity is very important for transferring power and creating very powerful magnets, we use it all the time, whether we know it or not. Cryogenics is integral to creating superconductive materials because it is necessary to keep them cold. Cryogenics also has applications in something called "cryomilling". A lot of materials are extremely difficult to mill under standard conditions, but they become brittle at lower temperatures, meaning that cryogenics can make them easier to mill.

Superconductive magnets are much stronger than regular magnets

Cryogenics is divided up into several different fields, cryobiology (the study of the effects of low temperatures on organisms), cryonics (the medical technology to preserve bodies to be revived later), cryosurgery (using low temperature things to kill things like cancer) and cryoelectronics (the study of superconductivity).

The field is growing rapidly, currently much of the research is into the preservation of life, expanding into the realm of aiding heart attack victims among other things.

Tuesday, June 26, 2012

What's With the Helium Shortage?

If you didn't know already, let me be the first to inform you that we currently have a shortage of helium. This shortage has been going on for several years now, and it may never end, but first, lets get some perspective.
Helium is the wonderful, colorless, odorless gas that fills up all those party balloons and can make your voice become very high pitched and squeaky, but that's not all it does. Party balloons make up an insignificant portion of today's helium consumption. Helium has all kinds of uses, it can be used in cryogenics for cooling superconducting magnets and running MRIs, it can be used as a purge gas to clear out any number of systems, it's used as a protective environment for arc welding, for growing crystals to make silicon wafers, and for scientific research in the fields of quantum mechanics because of its small size and in low temperature research like superconductivity because it's relatively easy to get it extremely cold. With all these uses, cryogenics being the single largest, it's no wonder that party balloons and voice changing are insignificant.

Helium balloon

Today helium is one of the most important gases around, but we hadn't even observed it until 1868 during a solar eclipse, even then we didn't know what it was. It wasn't until 1895 that the element was formally discovered. Helium is the second most abundant element making up 24% by mass of observable matter in the universe, second only to hydrogen which makes up 75%. Helium is so prevalent that it outweighs all other heavier elements combined by a factor of 12. That's a lot of helium. The only problem is, this element is exceedingly rare on the earth. Helium is made in abundance in the fusion reactions inside stars, but our planet isn't a star. Almost all of the helium that we can get our hands on comes from the radioactive decay of uranium and thorium inside the earth and eventually ends up in natural gas deposits.
In 1903 it was accidentally discovered that the United States actually held massive reserves of helium just waiting around beneath the Great Plains, more than anywhere else in the world. It wasn't until World War I, however, that we began to seriously mine the substance. It was used to fuel barrage balloons and airships like the C-7 which had its maiden voyage on December 1, 1921.

C-7 airship

In 1925, the U.S. government had the smart idea to begin storing this helium. They called it the National Helium Reserve. Everything was going fine, but the government spent a lot of money building pipelines to the reserve and they eventually went into massive debt. After that, the U.S. Congress decided it was time to empty the reserve, and so they began selling off all their helium at artificially low prices. And that is why we have a helium shortage. The reserves are nearly gone, and no big suppliers are picking up the slack.
Luckily, the United States isn't the only country to have helium. Algeria and Russia both have sizable helium deposits. In as little as 30 years, Russia is expected to become the world's leading supplier of helium.

Helium, being a noble gas, glows when a current is run through it

The major problem is that supplies of helium on earth are very limited, and we keep letting it escape into our atmosphere, and eventually out into space. In enough time, even Russia will not be able to fill our helium needs, so what will we do then? Without helium, MRIs will be more difficult to run and scientific research will take a major hit. Plus, where are we going to get a safe, lighter than air gas to fill our children's party balloons? All hope is not lost, however. Recent research shows that the moon could have plenty of helium stored within it. While we won't be mining the moon in the near future, I am confident that we will advance enough that it can become a reality within a few decades. Here's to hoping.

The moon could supply us with helium in the future

Monday, June 25, 2012

Dwarf Planets

I've known a lot of people who were upset that Pluto was suddenly classified as a "dwarf planet" instead of a "planet" as it once was, but what exactly does that mean? The International Astronomical Union (IAU) defines a planet as: a celestial body that a) is in orbit around the Sun, b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly spherical) shape, and c) has cleared the neighborhood around it's orbit. All this really means is that a planet must orbit the sun, be massive enough that it's gravity makes it round (when not rotating) and have cleared its orbit of debris by either absorbing it, capturing it in orbit or by deflecting it.


Poor old Pluto is not longer a planet

So how does the definition of a dwarf planet differ from that of a regular planet? A dwarf planet is almost identical to a regular planet except for one thing, it hasn't cleared the neighborhood around its orbit (part "c"). And just so you don't get confused, if something that would otherwise be a dwarf planet is orbiting something besides the sun, it is not considered to be a dwarf planet.

Confirmed and likely dwarf planets

The question, that finally knocked Pluto from its position as a planet, of what exactly a planet is, was posed when we discovered a little celestial body in orbit beyond Neptune (known as a trans-Neptunian object, or TNO) known at the time as 2003 UB313 (Now called Eris). This object turned out to be bigger than Pluto, so someone had to decide if we were going to call it the 10th planet or not. It is the IAU that decides such things, so they convened to settle the matter. It was their decision that gave rise to the official definition of a dwarf planet and Pluto's fall from glory.

The International Astronomical Union is in charge of making big astronomy decisions

It turns out that there are a lot of objects orbiting our sun, and I don't just mean asteroids. So far we have found nearly 1,000 TNOs, of which a significant portion could be dwarf planets. 200 dwarf planets are expected to be found when we've explored the Kuiper Belt, and 2,000 more even farther out. Our solar system is filled with these less-than-planetlike objects.

Sunday, June 24, 2012

Have We Stopped Dreaming?

I've just recently come across this rather interesting video where Neil deGrasse Tyson talks a little more about space travel and its impact on our society in the past. I think it's sad that only 0.46% of the U.S. federal budget is spent on NASA, down from its height of 4.41% in 1966. This may only seem like a small change, but when you realize how much each percentage point represents, that's a staggering decrease. It gets even worse, currently the U.S. government is spending more on air conditioning for the military than it is on NASA. I know I've said all this before, but I still think it's important.

NASA and it's shuttle program inspired us to dream bigger and make a difference.

We could more than double NASA's budget by just spending one penny for every tax dollar. How hard would that be? Space travel is too important to shy away from just because it costs a little more money. And hey, if it means that we take away some money from war to do it, then that's just great. Together we can make a difference, I've run across a website called Penny4NASA where you can go to sign a petition and send a letter to your congress member. It's easy, I've already done it. If you are like me and think that the United States should continue to look to the stars, then I hope you'll join me and sign a petition or talk to your congress members. The least you could do is spread the word.


Friday, June 22, 2012

Planet X

I first came across mention of Planet X when I was watching an old Daffy Duck cartoon with my father when I was very young. The idea intrigued me then, and I was quick to learn the truth about this mysterious planet. After Neptune was discovered in 1846, there was an awful lot of speculation that other planets might exist beyond its orbit. This speculation was later fueled by the observation that the gas giants Neptune and Uranus had strange orbits that were not explainable given what astronomers knew at the time. In the 1890's a man by the name of Percival Lowell proposed that a planet, which he named Planet X, was responsible for the strange orbit of these gas giants. The search for the 9th planet was officially on.

Duck Dodgers in the 24-1/2 Century

When Pluto was later discovered in 1930, Lowell's hypothesis seemed to have some validity, until Pluto was shown to be too small to have a significant effect on the gas giant's orbit. This prompted still more searching, this time for the 10th planet. The search for Planet X continued all the way up to 1990 before Voyager 2 discovered that the reason the gas giants had unexplained orbits was merely due to an overestimation of Neptune's mass.

Planet X came about due to an overestimation of Neptune's mass

Nowadays, Planet X has been largely forgotten. It does not exist as we once thought it might, and Pluto isn't even a planet anymore. Some scientists still use Planet X as a term to denote any planet yet to be discovered, and a few have even revisited the hypothesis as a way of explaining some anomalies in the outer solar system. There may also be some questionable theories surrounding Planet X and the hypothetical dwarf star "Nemesis", but I won't go into that right now.

Wednesday, June 20, 2012

The World's Largest Battery

Very early this year, the world's largest battery was finished. Capable of storing 36 megawatt-hours of electricity, it is a battery of previously unseen size and power. The home of this battery isn't very surprising, Hebei Province, China.

The world's largest battery is about the dimensions of a football field

The battery has enough juice to power something like 12,000 homes for 1 hour in the case of a total blackout. That's some serious power. Ideally, however, this battery will soak up power during times of little power usage and supplement the power supply when demand is high. It has been tied into the smart grid so that power is never reduced to any home.

Basic idea of a smart grid

This facility cost a hefty $500 million to finally finish. It was only possible as a joint project between the State Grid Corporation of China (SGCC) and and BYD, an electric car company that was in it to find a way of making electric cars more practical. The battery is fed 140 megawatts from both a wind farm and a solar panel array. This battery is a big leap in green technology. We now have a place to store all the energy gained from green energy solutions.

Aside from being really cool, this battery is a very encouraging site for the future of technology everywhere. Who knows what'll be next?

Tuesday, June 19, 2012

Radon

Of all the diseases out there, I would have to say that cancer is probably the scariest. Your cells go crazy and start reproducing uncontrollably, in many cases causing death. But more than that, it is a disease for which we do not have a cure. Now, we all know that activities like smoking can lead to cancer, specifically lung cancer, but there is also an invisible cause of this horrible disease, radiation. Sunscreen serves a double purpose, it not only protects you from getting burned by too much sun exposure, it also protects you from harmful radiation that can cause skin cancer. But I'm not here to talk about sunscreen or ultraviolet radiation, no, what I'm here to talk about cannot be blocked out with a mere topical cream. Radon, the silent, odorless, colorless killer.

Radon, a radioactive gas

Radon is an unstable noble gas, meaning that not only does it not have color or smell, but it also decays into smaller particles, releasing harmful radiation in the process. What's unique about this gas is that it occurs naturally in large enough quantities to be a significant threat to the average person. Just so you know how big of a threat, radon is the second largest contributor to lung cancer, just behind smoking. The EPA has estimated that as many as 21,000 deaths per year in the U.S. are caused by radon. 

Radon is the second leading cause of lung cancer

Being 8 times denser than air at sea level, radon tends to accumulate in under-ventilated areas, like mines, basements and attics. This means that radon levels inside a house are significantly higher than outside a house, especially if you live in Iowa or the Appalachian mountains area. Usually this gas will enter your house through the ground. Radon is a decay product of uranium and thorium which can be found in deposits underground. When these decay, the radioactive gas is produced, and it will flow into any crack it can find. On average, every square mile of soil to a depth of 6 inches (2.6 km2 to a depth of 15 cm) contains 1 gram of radium (which decays to radon). That amount can vary widely by region, but radon is pretty much everywhere. Once radon finds its way out of the ground, it accumulates in poorly ventilated places and in water. The highest concentrations can be found in caves (like in mines) and in ground water because these places aren't open to the atmosphere and thus there is no where else for the radioactive gas to go.

Most mines now have radon reducing technology

Even though radon can easily get into our drinking water, we aren't in much danger from ingesting it. Radon concentrations in water tend to be fairly low, and we aren't exposed to it as often. Radon in the air, however, is a serious problem. Being one of the densest natural gases, radon gas can stick to dust particles and stick inside our lungs, exposing us to almost constant radiation. On the whole, radon concentrations in the air tend to be very low, and thus not much of a problem, but when there's an enclosed space, the radon level can get dangerous. This means that it's a good idea to test your own house for radon. The EPA recommends that an area should have a radon concentration of 4 pCi/L (picocuries per liter) or less, but lower levels can still be dangerous. Many test kits are readily available to the public so that you can test your own radon levels. Both long term tests (up to 1 year) and short term tests (2-7 days) are available, with a variety of techniques. It is best to start with a short term test, and then follow up with a long term test. If you do find that your house has high concentrations of radon gas, all you really need to solve the problem is proper ventilation. Just opening a window or turning on a fan might not work, however. Likely you'll need to instal a vent to pump the gas safely out of your house.

radon can be safely vented from a home

Whenever radioactive substances are mentioned a lot of people think of a glowing green material, just like we see in cartoons. In its gaseous state, radon does not glow, but, if you condense it down by lowering the temperature, it does begin to glow. It starts off with a yellow color and turns to darker orange-red as the temperature drops.
This is about the color of radon

I live in Iowa, where radon is in high concentrations, so I plan on devising my own way of measuring radon concentrations. If I succeed, I plan on posting my design, so stay tuned.

Friday, June 1, 2012

Planet Darwin

I found this interesting documentary on what we might expect when meeting life on another planet. In my personal opinion, we'll probably find more radically different behaviors and biologies, but I thought it was quite informative.