For those of you who are here from Skepchick (and the rest of you too), HI! Here is a little plug for other places you can follow Emma. Being a school teacher and applying to grad school, she has a number of compartmentalized blogging personas. This is where she explains interesting phenomena in science to lay non-scientists. She also rants about her life and her activism at http://sigstarskeptic.wordpress.com/ (which is quite new at the moment) and blogs about high-level chemistry (paper summaries for grad school and research) at http://blog.curiouschemist.net/. You can follow her at https://twitter.com/#!/sigmastarstate.
You’ve heard it all before, we need to find a new, sustainable, clean source of energy, and fast. People are looking to wind, solar, nuclear, and biofuels. But what do these things mean, really?
Today, I will discuss solar.
The sun is the main source of energy for this entire planet. We get much of our energy from coal and oil which is made of millions-of-years-old plant and animal matter. Animals get their energy from plants, which get their energy from the sun. The wind blowing your hair in your face and turning the wind turbines? That’s from the difference in temperature in different locations (due to the sun) and the rotation of the earth. Hydroelectric power like that made at the Hoover Dam? That’s from rainwater filling up a high altitude river source. What causes rain? The evaporation of water by heat from the sun, of course. As you can see, there are few sources of energy (nuclear and geothermal being the primary exceptions) which are not directly related to energy recently emitted from the sun. The problem with all of these forms of energy is that there is a “middle man” between the sun’s energy and usable electricity. Solar cells, which have been around since the mid-1950’s, attempt to dispose of the middle man allowing us to directly harness the power of the sun.
Today’s post is about nuclear bombs. Big boom. Mushroom clouds. Yep, those bombs. In our last post, we discussed the basic mechanism behind the uranium fission chain reaction. We also briefly talked about the difficulties involved in making it a continuous, feasible reaction. In this post, I’ll talk about the basic principles behind the design of a nuclear fission bomb. We’ll see two classic designs – the designs of the Hiroshima and the Nagasaki bombs, known as Little Boy and Fat Man. I assume that you have read the previous posts, or are familiar with basic scientific terminology related to nuclear reactions.
In the previous post, I described the basic principles behind radioactivity. In today’s post, I will describe nuclear fission reactions – the technique through which we can deliberately induce heavy atoms to break apart into smaller fragments, releasing energy in through radiation. In the previous post, we talked about half-lives and what happens to radioactive atoms if one were to leave them alone and let them naturally decay. As it turns out, there are other ways to make atoms break apart; one can slam atoms with proton and neutrons to make them more unstable, causing them to fragment. The energy released from this fragmentation can be harnessed in a controlled manner in nuclear reactors, or can be deployed destructively in the form of a nuclear fission bomb. Read More…
The recent earthquake and tsunami in Japan and the subsequent crisis at the Fukushima nuclear power plants have propelled nuclear reactors and nuclear energy to the top of every media outlet across the world. In light of this increased interest in nuclear energy, I have decided to write about radioactivity. Radioactivity is a natural physical phenomenon that is a consequence of the weak nuclear force, strong nuclear force and the electromagnetic force – three of the four fundamental forces of nature. It commonly refers to the process by which an unstable atom decays or transmutates to one or more atoms with an accompanying release of energy. In this article, I will try to explain what radioactivity means and what natural phenomena it describes, why some atoms are radioactive, what radiation is and how it relates to radioactivity.
This is a continuation of my post on homeopathy in which I talked about the history of homeopathy and how it is scientifically tested. I ended the post wondering why there was so much public acceptance for such an ineffective product. In this post, I will discuss the various cognitive biases that allow well-intentioned individuals to falsely believe that homeopathic interventions have positive effects.
Usually, when I write one of these posts, I write a short, snappy introduction using an interesting hypothetical situation. I shall not do so for this post. In this post, I will discuss homeopathy – an “alternative” medical intervention that is entrenched or gaining traction in a number of countries around the world such as India, Germany, the UK and the United States. This is quite a serious topic and I wish to go over it in a reasonably serious way. This post of for those who have heard about homeopathy during a television commercial (flu remedies, Zicam etc.) or knows of a family member who uses it but doesn’t quite know what it is. I will go over the history, the underlying principle behind homeopathy, and a scientific examination of it. I will also discuss some of the current explanations that homeopaths provide that attempt to explain or justify the efficacy of homeopathic medicine. This is going to be a pretty detailed post – so hang in there!