Pepper plant responding to being watered. These images were taken over the course of two hours.
During class on Friday, I watered my Chinese five-color hot pepper plant for the first time in three days. It responded quite well, helping to illustrate one reason (to maintain their rigidity/prevent wilting) why plants need water. I did this because I was curious about how fast plants respond to water, and with the data from the images I should be able to demonstrate what a scientific report should look like.
The full plant’s response:
Notes
The original camera images were cropped for the gif-animation using Imagemagick’s convert
convert $i -crop 500x400+1550+1100 crop-$i
The image file sequences were converted to mp4 video using ffmpeg (instructions here):
Groundwater tends to be a common property resource. In places like Yemen, where ownership rights are not clearly defined it tends to be overexploited. So much so, that they’re looking at running out within the next 10 years. Peter Salisbury has an article in Foreign Policy.
Most potable water in Yemen is produced from a series of deep underground aquifers using electric and diesel-powered pumps. Some of these pumps are run by the government, but many more are run by private companies, most of them unlicensed and unregulated. Because of this, it is nigh on impossible to control the volume of water produced. By some (conservative) estimates, about 250 million cubic meters of water are produced from the Sanaa basin every year, 80 percent of which is non-renewable. In recent years, the businessmen who produce the water have had to drill ever-deeper wells and use increasingly powerful pumps to get the region’s dwindling water reserves out of the ground.
This summer’s arctic ice cap is the smallest since we’ve started watching it from space in the 1970’s, and the summer isn’t over yet.
Over the last few years, the rate at which the ice is melting is accelerating, probably due to the ice-albedo feedback. Albedo refers to how reflective a surface is; the average of the Earth is about 31%, while snow and ice has an albedo closer to 90%.
When the albedo is high, a lot of sunlight is reflected back into space, but when it’s lowered, such as when the sea-ice melts, the surface absorbs a lot more sunlight, which heats it up. Of course, more heat melts more ice which further decreases the albedo which causes more warming which melts more ice …. And you can see the problem.
The ice albedo feedback takes a small change (melting ice) and accelerates it. That’s a positive feedback, although the effects are usually not what you want, because they take the system (the Earth’s climate in this case) away from it’s current equilibrium. This is not to say that there are no benefits; the NorthwestPassage will open up eventually, if it has not already.
Extent of Arctic sea-ice at the end of August 2012. The orange line shows the average extent (1979-2000). We're a bit on the low side at the moment. Data from the National Snow and Ice Data Center.
Composition of the atmosphere from the formation of the Earth. Image ᔥJoel Cayford ↬Ethan Siegal
Joel Cayford has posted a nice image showing the composition of the atmosphere over time — since the formation of the Earth.
Note that, although the Earth is 4.5 billion years old, and life has been around for over 4 billion years, there has only been oxygen in the atmosphere for about 2 billion years.
Oxygen is an extremely reactive gas, which is why we use it when we “burn” carbohydrates for energy. But it also means that any free oxygen added to the atmosphere would easily react with rocks, water, and other gasses in the atmosphere, so would not be available in the quantities needed for air breathing organisms until it slowly accumulated.
Also, you need a lot of oxygen in the atmosphere to produce enough ozone to form the ozone layer that protects life at the surface from high-energy, cancer-inducing, ultra-violet radiation from the Sun.
I took a half-day trip during spring break (somewhere around the 31st) to the Shaw Nature Reserve in Gray Summit. I was hoping to find some books on native, Missouri, flora and fauna, and see if the Reserve would be a good place for a field trip (they have sleeping facilities so even overnight trips are a possibility).
I found a number of books, including a nice one on mushrooms, and while I could have, I did not pick up one on wildflowers (of which there were several). Of course, spring is the perfect time to see wildflowers, especially since we ended up hiking the Wildflower Trail, so I’m probably going to have to go back sometime soon.
The lady at the main office (where you pay $5/adult) recommended we take the Wildflower Trail and then cut down south to the sandbar on the Meramec River, which is an excellent place for skipping rocks. She also recommended I take my two kids to their outdoor “classroom” for some real, unstructured play.
Without a reference book, I’ve had to resort to the web for identifications, with only a little success, so I’ll post a few of my photographs here and update as I identify them.
The following two pictures are of a flower that was found covering the hillslope meadows; open areas with short grass.
Beautiful reddish-orange blooms on this small herb.This picture better captures the growth form and leaves of this hillslope, meadow flower.A yellow petalled variant.
Like little stars in the daylight, these small, white flowers meadow flowers almost sparkle.
Small, white, meadow flowers.
Pretty, small, yellow, meadow flowers.
Yellow, meadow flowers.
These bent-over flowers can be found on the lower, shadier edges of the hillslope meadows.
These guys like the shadier areas.I love the texture of the charred wooden stump behind the flower. The meadow itself is possibly the result of a burn.
Iris’ were also in bloom.
Small iris.
Another herbaceous, yellow flower.
Pretty yellow flowers.
More, tiny, delicate flowers.
Found in the shadier, moister parts of of the slope.
Once you get under the canopy, you run into some broader leaved plants and their own, interesting flowers.
Bell-shaped flowers in broad-leaved herbs/shrubs.
We ended up spending a lot of time on the sandbar, learning to skip rocks and hunting for clams, but I save that for another post. And we never did get to the play area; that’ll have to wait for the next trip.
Fresh daffodil pollen grains seen under 1000x magnification.
For the record: Daffodil flowers have both male and female parts, which make them good subjects for dissection. And, it’s pretty easy to collect daffodil pollen samples to look at under the microscope. 1000 times magnification seems necessary to be able to make out structures.
Since prehistoric pollen, collected from places like the bottom of lakes, are one of the easiest ways of finding past climates, a study of more recent samples might make for a good student research project in biology or environmental science. They’d need to design the study so they could avoid having to use nasty acids (hydrochloric or hydrofluoric) to concentrate the pollen grains, but that should be possible. Perhaps an ongoing survey using pollen traps, akin to the European Pollen Monitoring Program.
Jason Shankel has an article on how we could go about changing the surface of Mars into something humans can live on. He does an excellent job of condensing the not insignificant literature on terraforming the red planet.
Starting with an explanation of Mars’ geologic history, Shankel addresses Martyn Foggs’ list of critical challenges:
The surface temperature must be raised
The atmospheric pressure must be increased
The chemical composition of the atmosphere must be changed
The Martian Surface as seen by the rover Opportunity. Image Credit: NASA/JPL-Caltech/Cornell/ASU
The article is expansive in its detail, provides a wonderful primer on the red planet, and demonstrates an excellent application of planetary system science (as opposed to Earth system science) to what would be an enormous geoengineering project. For example, to warm up the planet, Shankel starts with several approaches:
so how do we warm up the Martian poles? Several approaches have been suggested, from spreading dark material on the poles to lower their albedo, to industrial ice farming to good old fashioned thermonuclear detonations.
