KUNR - FM 88.7 Reno, NV became helium. Nuclearbinding energy was released, heating the surface of the Sun, producing the light that began to bathe the young Earth. And at some point in that story, around four billion years ago, that transformation of energy led to the origin of life on Earth. Around kilometres south of Radio, this is Lake Taal. Despite its sleepy, languid appearance, this landscape has been violently transformed by energy. When I think of a volcano, I usually think of a pointy, fiery mountain with a little crater in the top. Probably a bit like that one. But actually this entire lake is the flooded crater of a giant volcano. It began erupting only about , years ago, and in that time it's blown billion cubic metres of ash and rock into the Earth's atmosphere. KUNR - FM 88.7 Reno, NV This crater is kilometres across and in places metres deep. That's a cube of rock five kilometres by five kilometres by five kilometres just blown away. It's a big volcano. Taal Lake is testament to the immense power locked within the Earth at the time of its formation. Since the lake was created, a series of further eruptions formed the island in the centre. And at its heart is a place where you can glimpse the turmoil of the inner Earth, where energy from the core still bubbles up to the surface producing conditions similar to those that may have provided the very first spark of life. The water in this lake is different from drinking water in a very interesting way. See, if I test this bottle of water with this, which is called universal indicator paper, then you see immediately that it goes green. And that means that it's completely neutral. It's called PH in the jargon. But then look what happens when I test the water from the lake. Now the indicator paper stays orange. In fact, it might have gone a bit more orange. So that means that this is acid. It's about PH. At the most basic level, the energy trapped inside the Earth is melting rocks. And when you melt rock like this you produce gases. A lot of carbon dioxide, and in this case of this volcano, a lot of KUNR - FM 88.7 Reno, NV. Now, sulphur dioxide dissolves in water and you get HSO, sulphuric acid. Now, what I mean when I say that water is acidic? Well, water is HO hydrogen and oxygen bonded together. But actually when it's liquid it's a bit more complicated than that. It's actually a sea of ions. So Hplus ions, that's just single protons. And OHminus ions, that's oxygen and hydrogen bonded together, all floating around. Now, when something's neutral, when the PH is seven, that means that the concentrations of those ions are perfectly balanced. When you make water acidic, then you change the concentration of those ions and, to be specific, you increase the concentration of the Hplus ions of the protons. KUNR - FM 88.7 Reno, NV So, this process of acidification has stored the energy of the volcano as chemical potential energy. The volcano transforms heat from the inner Earth into chemical energy and stores it as a reservoir of protons in the lake. And this is the same way energy is stored in a simple battery or fuel cell. These bottles contain a weak acid and are connected by a semipermeable membrane.