Our Sun's nuclear Nirvana

While writing about India joining the Iter project, I couldn't resist getting lost in talking about the fusion processes, so I decided to make an elementary post dedicated to it. :-)

To achieve fusion on earth, scientists will use Hydrogen isotopes: deuterium and tritium. Isotopes are part of the same atomic species as their parent atom but with extra neutrons; therefore with a higher mass.

Fusion is routinely happening within the sun, thanks to the high temperatures (15 million °C) and huge pressure, hydrogen (simplest element, atomic number 1: H) atoms are transformed into Helium (atomic number 2: He, heavier element) by a proton-proton chain. Our Sun is made up of 92% hydrogen, 7.8% helium, and the remaining 0.2% is a mixture of other elements, this helps understand how it can continue to shine for another 5 billion years or so.

Well, that doesn't really give you any perspective compared to our Earth, so let's approach it differently; the Sun alone carries 98% of the total mass of our entire solar system, you can easily fit 1,3 million Earths in it (volume), a 100 times the diameter (disk surface), 300.000 times the mass and the density is eight times that of gold. Sounds big? Think again, our Sun is just a little dwarf within the star's realm; there are billions of stars out there hundreds of time bigger!

Now that we have a better understanding of the proportions, let's get back to our topic. Each second the sun produces 4 million tons of energy by transforming 600 million tons of H into 596 million tons of He. The produced energy is split as follows: 50% is infrared or heat energy, 40% comes out as visible light and most of the remaining is ultraviolet light.

What's even more impressive is that, due to the extreme density of the plasma core, it takes anywhere between 150.000 an a million year for that energy (mostly gamma rays, at the time, which is the highest energetic form of an electromagnetic radiation) to finally escape from the core and make its way to the outer regions of the sun (photosphere and chromosphere), the good news is that by then it has, among other things, been transformed into visible light and heat. About 8 minutes later, we can all enjoy the show on Earth!

As this is a rather complex and exciting topic, it is now clear that several posts will be required to fully appreciate the beauty of such dynamics. In later posts, I will approach, on a modest level and in a simplified way, fusion in more depth. How are the heavier elements of the periodic table forged? Which quantum principles are involved? What forces are at play?

Meanwhile, check out some stunning space-themed wallpapers: Space Wallpapers

To be continued...