[MUSIC] Hello again. Welcome to Module 2. In the first module, we had a brief introduction to the electromagnetic spectrum. In the next couple of modules, we'll begin to explore each of the radiations in this spectrum in more detail. For each radiation, we will look at their source and how they are used. We will also do a little bit of myth-busting around some common, pervasive myths around these radiations. In particular, we investigate what is or is not dangerous and why, based on facts and up-to-date scientific research. Throughout these next modules, I want you to keep in mind two things that we learned from the last module. Firstly, remember that energy is directly proportional to the frequency of the radiation. As we learned before, the shorter the wavelength, the higher the frequency of the energy. Following from that, remember that the energy of the radiation is largely what determines whether it is or is not ionizing. As you know now, radiation is ionizing if it can cause electrons to be ejected from the atom and chemical bonds to be broken. Ionizing radiations can be dangerous, as it can cause damage to the cells in our body. We will look at these kinds of radiation in more detail later in the course. On the other hand, non-ionizing radiations have lower frequencies. They do not have enough energy to damage cells or DNA in our body. Nonetheless, they may have enough energy to excite atoms and molecules, and cause them to vibrate producing heat energy. In this particular module, we will be looking at the non-ionizing, long wave radiations. These are essentially radio-waves, which cover quite a wide range of frequencies and properties, and infrared waves. Non-ionizing radiations are not carcinogenic to humans or animals. However, there are still quite a few fallacies floating around about longwave radiations. For example, there is a common belief that you can get cancer from power pylons or mobile phone towers. Now, we will discuss why neither of these are true in later videos. But you might well wonder, "If there is indeed nothing to be concerned about, why are there so many people concerned?" To understand why, you need to reflect on something called cognitive bias. These are innate patterns of faulty thinking that affect our decisions and the decisions we make. One example is anchoring bias. This is when the first piece of information you see about something strongly influences all your future judgments and perceptions of that subject. Here, you anchor or compare all subsequent information to what you initially learned. So, if the first thing you learn about radiation is that it's harmful, then it will take a large amount of evidence and discovery of facts for yourself to change your belief. Another very powerful effect is confirmation bias. This means that subconsciously we prefer to pay attention to the information that fits with our preconceived beliefs and ignore or dismiss information that conflicts with them. So, whatever belief you initially form will be reinforced as you subconsciously seek out information to support and confirm it. Again, because of this it takes a lot of conscious effort to overturn these pervasive false beliefs. So, as we go through this module, I would like you to challenge your preexisting beliefs around longwave radiations. Think about why you may hold those beliefs in the first place. Consider how they stack up against the new knowledge you will learn. I really hope you will enjoy this module. [MUSIC]