Making real science accessible and interesting for all people.
Friday, November 30, 2012
Global Climate Change: Thawing of the Arctic Tundra
The above is a great short video about the effects of the warming planet on Arctic tundra. Tundra by definition is ground that is permanently in a frozen state. During the short and few summer months, tundra only thaws on the surface. Deeper down however, the ground remains frozen year round. This only allows for small shallow rooted plants to grow and prevents larger plants such as trees from ever taking root into the frozen ground. The constantly frozen ground also does not allow plant materials to decay once they die. Dead plant materials simply die and other plants grow on top of them. This causes a thick accumulation of dead, un-decayed plant materials to pile-up, forming peat. The great expansiveness of peat in Arctic tundra is a gigantic holding place for a huge amount of carbon dioxide. The carbon dioxide simply remains locked up in the peat because of the cold and frozen conditions. Recent warming of tundra peat however has caused some thawing and therefore allowing decay to take place in this peat. As the decay takes place, carbon dioxide that was held in the peat is released into the atmosphere contributing to increased global temperatures. Anyway, check out the above video for a short look on a scientific experiment and some of the potential effects of a warming climate.
Monday, November 26, 2012
Huricane, Superstorm, Frankenstorm Sandy... What Made This Storm So Bad
Watch Inside the Megastorm on PBS. See more from NOVA.
The science and story behind the development of Superstorm Sandy is fascinating. The above video does a great job of explaining the development of this storm and how so many different weather elements came together to make this storm so bad. The combination of a hurricane, absence of the Bermuda High, higher than usual ocean temperatures, a Nor'eastern storm, high pressure of the coast of Greenland, an adjusted jet stream, and the storm making landfall at the full moon high tide all came together to make this frankenstorm. A hurricane or nor'eastern storm are bad enough, but the combination of these two along with everything else made this storm devastating. Though Sandy was quite a dramatic weather event, the above video gives a great education on weather in general. The big question now is, will superstorms like Sandy become more common in the future? In the next 100 years temperatures are expected to warm by about four degrees which would likely increase the number and intensity of storms throughout the world. Are storms like these a preview of what is to come in the future?
Friday, November 23, 2012
Thanksgiving and the Food Pyramid (or Choose My Plate)
The average Thanksgiving meal is about 3000 calories, or about one and a half days worth of calories. The average American eats about 4000 calories or more on Thanksgiving day, about twice as much as what is recommended daily. Of course, everyone is talking about all the extra calories eaten during Thanksgiving but I want to talk about how the average Thanksgiving meal lines up with the latest food pyramid. The latest food pyramid is actually a plate called Choose My Plate and can be found here. To do this we must first identify what actually is found in an average Thanksgiving meal.
An Average Thanksgiving meal
Turkey: 8oz.
Stuffing: 1 cup
Green bean casserole: 1/2 cup
Mashed potatoes and gravy: 1 cup
Cranberry sauce: 1 slice
Sweet potatoes: 1/2 cup
Pumpkin pie: 1 slice
Total calories: about 3000
The above meal contains about 1 and 1/3 times the recommended daily intake of protein, at most 1/5 the daily recommended intake of fruits and veggies, about two times the amount of recommended carbohydrates, and the absence of healthy oils and dairy products. So pretty much, the typical Thanksgiving meal is extremely carb and protein heavy. The bad thing about carbs is that they are less filling than protein and oils or fats, which means you can end up eating a lot more of them. So it is possible that the reason there are so many carbs in a typical Thanksgiving is because they are less filling, so people just end up eating more.
We won't even go into how to calculate how many hours of exercise it would take to burn these extra calories off, which is about 6 hours. But hey, this is only one meal a year so its not something to really beat yourself up over, especially if you are eating healthy on a regular basis.
Tuesday, November 20, 2012
Echinocereus sp.: The Hedgehog Cactus
Echinocereus engelmannii |
Echinocereus coccineus |
Echinocereus engelmannii |
Friday, November 16, 2012
Joshua Trees, Ice Age Sloths, Extinction, and Climate Change Today
With the end of the Ice Age, the giant Shasta ground sloth became extinct in our American Southwest deserts. This extinction happened as a result of the warming of the continent and invasion of humans into the land 13,000 years ago. Today, the sloth is long gone, but the consequences of its extinction are still being seen to this day. The Shasta ground sloth was intimately intertwined with every organism they ate, use, or associate with. Of course, all organisms that inhabit this earth are intertwined in the same way with all the organisms they eat, use, and associate with both directly and indirectly. This can be extended to show that all organisms are in one way or another connected. If one organism is removed from an ecosystem, such as the ground sloth, every other part is affected and must adjust their life accordingly.
Unfortunately, not every organism is able to adjust to every change in an environment. Such was the case of the Shasta ground sloth. As the climate warmed, plants that inhabited the Southwestern deserts changed, changing the sloths food sources. As food sources changed, the sloth could not adjust and as a result became extinct. As a result, the plants and animals affected both directly and indirectly by the sloth had to adjust to "life after the sloth". For example, the Joshua Tree was a major part of the sloths diet. At first it may seem that extinction of something that is eating you might be a good thing. At first, I could guess, the Joshua tree might have benefited greatly by the absence of a giant animal consuming it. Long term however, the Joshua tree suffered greatly and continues to suffer to this day. As the sloth ate the Joshua tree, of course this injured the plant. However, as the sloth ate, it also consumed the Joshua tree seed which would pass all the way through the sloths digestive tract without being damaged. Once passing though the sloths digestive tract the seed would find itself in a moist pile of fertilizer, which is an extremely ideal location to find yourself if you are a desert seed in desperate need of moisture and nutrients.
With this association of the sloth and Joshua tree, the sloth benefited with food by eating the tree. The
Joshua tree made a trade-off though, being damaged by the sloth as it was eaten, but benefiting from the sloth into the next generation. The sloth aided the success of the Joshua Tree by likely aiding germination and by carrying the seeds to new locations up to ten miles away. After the extinction, and up to the present day, only desert squirrels and packrats move Joshua tree seeds today, and only at a pace of about six feed per year. As a result, the Joshua tree cannot adjust its range anywhere near as quickly as it could before and its range has been shrinking for over 10,000 years now. How do we know all this? Scientists in the Southwest have examined caves where sloth dung which tells us what the sloth ate. Ancient packrat middens also have been examined which tell us where the Joshua tree was and when over the last 10,000 plus years.
With the ability to only change their range six feet per year, the Joshua trees range will continue to shrink in coming decades. Currently, the climate is warming far to fast for the Joshua tree to keep pace. This does not mean however the Joshua tree will go extinct. It will be able to survive in cooler high elevation locations. As the range of the Joshua tree is reduced however, organisms dependent on it will have to adjust. For example, many species of rodents are dependent on moisture from the tree during times of drought. These organisms access water from the tree simply by chewing through the bark to access water. With the trees gone however, there will be far less water available to support rodents. And so we see the continued consequence of the extinction of the sloth.
Joshua tree made a trade-off though, being damaged by the sloth as it was eaten, but benefiting from the sloth into the next generation. The sloth aided the success of the Joshua Tree by likely aiding germination and by carrying the seeds to new locations up to ten miles away. After the extinction, and up to the present day, only desert squirrels and packrats move Joshua tree seeds today, and only at a pace of about six feed per year. As a result, the Joshua tree cannot adjust its range anywhere near as quickly as it could before and its range has been shrinking for over 10,000 years now. How do we know all this? Scientists in the Southwest have examined caves where sloth dung which tells us what the sloth ate. Ancient packrat middens also have been examined which tell us where the Joshua tree was and when over the last 10,000 plus years.
With the ability to only change their range six feet per year, the Joshua trees range will continue to shrink in coming decades. Currently, the climate is warming far to fast for the Joshua tree to keep pace. This does not mean however the Joshua tree will go extinct. It will be able to survive in cooler high elevation locations. As the range of the Joshua tree is reduced however, organisms dependent on it will have to adjust. For example, many species of rodents are dependent on moisture from the tree during times of drought. These organisms access water from the tree simply by chewing through the bark to access water. With the trees gone however, there will be far less water available to support rodents. And so we see the continued consequence of the extinction of the sloth.
Tuesday, November 13, 2012
How to Make Sauerkraut
Every fall I start thinking about making my own sauerkraut. Making your own sauerkraut is really a very simple process once you are familiarized with the steps required. The process is very similar to making kimchi but kimchi is much more complicated in regards to spices and different steps, and for that reason I prefer to make sauerkraut. I have written about the process before on this blog (How to make sauerkraut) and will summarize briefly here:
- Shred your cabbage.
- Thought mix shredded cabbage with sea salt by hand. The salt will draw the liquid out of the cabbage. Do this in a crock or straight walled jar. There is not set ratio of salt to cabbage, this is simply a taste preference. You do need enough salt though to draw enough water out of the cabbage.
- Weigh and press down the cabbage so it is below the liquid mark.
- Cover the entire container so dust will not contaminate the process.
- Wait until bubbling stops before removing weight to taste sauerkraut. Press down on the weight daily to push out gas bubbles given off by fermentation. Bubbles generally stop before two weeks.
- Sauerkraut can be stored for weeks at or below room temperature if it is submerged below the water level.
- More salt will slow the entire fermentation process significantly but will preserve the sauerkraut for longer periods of time. It takes very little salt though to make sauerkraut and to preserve kraut with low salt, simply place it in the fridge. Adding more salt and refrigerating after bubbling has stopped a few days is the safest way of making sauerkraut for the first time. After doing this you can experiment with adding less salt.
- If temperatures are going to higher, say above 75 degrees add more salt. This helps control yeast and microbial growth.
- Lower temperatures require less salt because the lower temperatures help control yeast and microbial growth.
- Different temperatures and amounts of salt will change the flavor of the sauerkraut. Play around with these in different batches to see what tastes best to you. I prefer sauerkraut when average daily temperatures are in the 60's and with a low salt content.
- You can add any seasoning or vegetable to your batch as long as it doesn't add to much sugar or starch. For example, peppers, onions, garlic, radishes, and ginger can all be added.
- If your batch of kraut goes on bubbling for a long period of time after the initial two weeks, throw it out, it has gone bad. Do the same if it stops bubbling and then starts again.
- The sauerkraut should be a pale color unless you add veggies that have color in them like purple onions or purple cabbage. Then the sauerkraut will take on a purple color. If the sauerkraut takes on an off color or is brownish it has gone bad and you need to get rid of it.
- If the sauerkraut is slimy or smells weird it has gone bad.
- Any sauerkraut exposed to the air and not submerged under the liquid will go bad.
Friday, November 9, 2012
Easy Enzyme Experiments Anyone Can Do
The easy enzyme experiments have been some of the most popular posts on this blog so I'll be posting a summary of them today. These experiments really are easy enough for nearly anyone to do and to use to demonstrate the amazing work these molecules do. Unfortunately, most enzyme experimentation is extremely difficult and must be done in a science lab. I have come across several though that are rather simple and I am always looking for more simple enzyme experiments to post here.
One of the most common and easiest enzymes to work with is catalase. This enzyme is found in potatoes, spinach, and liver in high concentrations. To extract it all you have to do is blend some of these materials up with some water. Catalase functions to convert hydrogen peroxide into water and oxygen. This protects the body from the harmful effects of hydrogen peroxide, which is commonly produced as a metabolic by-product. You can conduct your own catalase experiments simply by adding hydrogen peroxide to your extract.
Another great and easy enzyme experiment is that of rennet and cheese making. Cheese is actually made by the enzyme called rennet. You can buy rennet off of Amazon, follow the directions that come with the packet, and make cheese in the process. Without rennet, we would only have a few different types of cheeses.
A very practical enzyme to our digestion is protease. Without this enzyme it would be impossible for us to digest protein of any kind. Protease can be found naturally in fresh pineapple, or in meat tenderizer (which contains protease found in pineapple). The reason fresh pineapple cannot be used in making gelatin is because the protease in the pineapple digests the gelatin protein, preventing the gelatin from solidifying. Pineapple or mango protease are also placed in pills that aid digestion.
Lastly, amylase is another protein that is important to carbohydrate digestion. By mixing ground-up crackers with spit (where amylase is typically found), you can actually witness how your spit digests carbohydrates.
If you know of other simple enzyme experiments, please let me know.
Monday, November 5, 2012
Barrel Cactus Part 2
California barrel cactus, Ferocactus cylindraceus. |
Red spines of the barrel cactus show up after being wet by rain. |
A barrel cactus that fell over due to leaning towards the southwest. Even though this cactus fell over, it continues to grow. |
Flower of the California barrel cactus Ferocactus cylindraceus. |
Friday, November 2, 2012
Barrel Cactus Part 1
Compass Barrel cactus |
In our next post we will talk about the leaning habit of barrel cacti.
California barrel cactus front left of picture. |