Despite the fact that methane is a powerful greenhouse gas itself and burning it produces carbon dioxide there is currently quite a bit of research on extracting methane hydrates from the sea floor as an alternative to the traditional fossil fuels because there is just so much of it. Discovery Channel has an interesting video on the topic where they burn some methane hydrate ice.
Methane releases from the arctic and sea-floor could also trigger rapid climate change. Recent discoveries suggest that global warming is warming the arctic so much that the permafrost is melting an releasing a lot of methane into the atmosphere. If the arctic atmosphere continues to warm, more methane will be released, causing more warming …. This positive feedback loop would accelerate global warming. Some scientists worry that warmer ocean waters can melt methane hydrates at the sea floor releasing them into the atmosphere in a similar positive feedback loop.
The BBC has an excellent video demonstration by Maggie Aderin-Pocock of how to demonstrate how additional carbon dioxide in the air results in global warming. She uses baking soda and vinegar to create the CO2 and lamps for light (putting the bottles in the sun would work just as well). You’d also probably want to use regular thermometers in the bottles if you don’t have ones that connect to your computer.
Blood Falls, Antarctica. Note the tent in the lower left for scale. From the U.S. Antarctic Program.
For millions of years, cut off from the atmosphere and the sun by an immense continental glacier, microbes survived in a lake of salty water under the ice. No air and no sunlight means no oxygen, so the water became anoxic and able to dissolve iron out of the rocks and sediment beneath the lake. But sometimes the lake breaches and the iron rich water comes to the surface where it is exposed to the air once again and the iron reacts with the oxygen to form a red mineral, hematite (rust). A template for life on Europa? Maybe. Blood Falls, Antarctica.
On the last morning of our immersion trip we had a choice between going to Hot Springs, Arkansas, with its geothermal springs and another museum, or hiking at Lake Catherine where we had spent the night. Since we’d been to two museums on the previous day, we pretty unanimously chose the hike. And it was great.
Conchoidal fracture in quartz (image by Eurico Zimbres FGEL/UERJ via Wikimedia commons)
We took the Falls Branch Trail, which follows a couple of young, boulder-choked creeks that have are carving steep-sided valleys through nice clean limestone bedrock. The students were constantly bringing me rocks to identify, and they were almost invariable limestone, with a few pieces of quartz thrown in. The limestone was so clean that it was near translucent (fairly close to marble) and the cobbles in the stream bed were easy to mistake for smoky quartz, particularly if they were rounded enough that you could not look for quartz’s characteristic, curved, conchoidal fracture. Quartz also tends to be a lot harder than limestone, but the ultimate test, which the students really wanted to see, is to put acid on the rock. Limestone fizzes. I did not have any limestone on this trip (note to self: get some HCl for next time), but this little experiment is a nice follow up for our discussions of ionic bonding in chemistry. We have some limestone samples back at school so I plan on doing this as a follow-up.
Quartz vein (white) cutting through a limestone boulder.
Because Lake Catherine is very close to Hot Springs, it would not be surprising to find some quartz. The hot water that’s coming out of the springs flows up through cracks (faults) that extend deep beneath the surface. The deeper basement rocks are silicates, the granitic rocks that make up the continental crust, so the hot water dissolves some of that silicate material, and when the water cools down, ever so slightly, as it approaches the surface, some of those silicates will precipitate out to coat the walls of the faults with quartz. Sometimes they even fill up the faults entirely, leaving quartz veins.
The stream bed, being of young geological age, was a series of small waterfalls culminating in the five meter high drop that gives the trail its name. The water was clear and cold but with that beautiful aquamarine tint of dissolved limestone. There’s a whole lot more I could say about plunge pools and migrating nickpoints, but I’d probably go on too long. Besides we did not take the time to talk about those since there was so much else to see.
Interference pattern in ripples.
When we reached estuary of Falls Creek and Lake Catherine, the lake’s water was so calm that the kids started trying to skip stones. This of course provided a beautiful opportunity to look at water waves and interference patterns. As the ripples from each skip of the stone expanded, they melded. The constructive interference was easier to see in the field because it made for bigger ripples. But the photos show the destructive interference very nicely.
This was an excellent hike. We were a little pressed for time since we needed to get back to school before the end of the school day, but next time, I think, I’ll have us pack our food in and have lunch on the trail overlooking the waterfall and the lake. The ability to use these types of outdoor experience to integrate the academic work is one of the main reasons I enjoy the Montessori approach to middle school. All through the trip back though I kept thinking about how I could organize things so that we would never need to see the inside of the classroom again.
Tom Leher has a number of really entertaining science related songs. Here he does the elements and someone (unknown unfortunately) has made a video to go with it, where the elements all pop up on the periodic table as he sings. Since there is no apparent pattern to order in which he sings the elements, this is more a “strike the imagination” type thing rather than anything else.
The Voyager spacecraft, launched in 1977, are still going and making new discoveries. They are after all the man-made objects that are furthest away from the center of the solar system, beyond the orbit of Pluto, and are now approaching interstellar space.
Where does the solar system end and interstellar space begin? Well, the Sun gives off light, but it also emits a plasma of charged particles (protons and electrons typically) that’s called the solar wind. These charged particles are launched from the Sun pretty fast, but as they get to the edge of the solar system they start to slow down, because the solar system is moving through a magnetic cloud, and, as we all know, charged particles are affected by magnetic fields.
The solar wind, assisted by the Sun’s magnetic field, pushes against the interstellar magnetic cloud, creating a bubble, called the heliosphere (helio=sun, sphere=sphere) that is pretty much the edge of the solar system.
Both Voyager spacecraft are approaching the heliosphere, and we’ve recently discovered that as the solar system moves through the interstellar magnetic cloud, the heliosphere is pushing against the cloud and the cloud is pushing back quite a bit. As a result, the heliosphere is shaped like the bow wave of water around a speeding boat.
It is difficult not to personify these two lonely spacecraft as the get further and further away from home, with no way to get back, but sending signals that tell of their discoveries and ensure their immortality.
Why have I not found this site before, Evil Mad Scientist Laboratories. A place where people will put serious thought, rigorous design and atrocious single-mindedness to create, well I’m not sure I can call it anything other than, “very interesting” projects. Applications of robotics that would make Asimov cry (probably with joy at human ingenuity, probably).
They carefully detail how to create such wonderful projects as:
I like to do as much science as I can using everyday materials. When it comes to basic chemistry the vinegar and baking soda reaction is one of the easiest, safest and useful you can come across. Wayne from www.apple-cider-vinegar-benefits.com has a great page on simple experiments from basic volcano building, to stoichiometry (using a balloon) and demonstrating endothermic reactions (but you’ll need an accurate and fast thermometer).
