Fission vs. Fusion – Instant Egghead #5


Fusion and Fission are cousins, the ying and yang of nuclear physics. Both turn matter into energy using
the most famous equation in all of science E=mc2 The equation tells us that matter
can turn into energy and when it does, it gets multiplied
by the speed of light squared a very big number both fusion and fission
convert a little bit of matter into a lot of energy so how do they differ? Fission means to come apart Imagine a tablet of alka-seltzer
dissolving in a glass of water Fusion happens when atoms come together when two become one In both cases, we end up
with a little less mass than what we started with, that missing mass,
multiplies by c squared to become E. In Fission, the fission happens on its own. Radioactive elements such as uranium
and plutonium split apart without any proding from us. This makes fission
relatively easy to control. It’s why it’s used in all existing
nuclear power plants Unfortunately, the stuff that uranium
and plutonium fisses into is toxic and radioactive, creating the by-product
that we call nuclear waste Fusion is cleaner and more powerful,
but it’s much more difficult to achieve It requires slamming hydrogens ions together
with such incredible violence that they overcome the repulsive forces
pushing them apart As a result, they fuse into helium Today, fusion only happens in places
with incredible temperatures and pressures, like the center of the sun or a hydrogen bomb But scientists are trying
to squeeze hydrogen atoms together with powerful magnetic fields
or laser beams allowing us to control the fusion reaction
and extract its energy. Yet all the squeezing takes
a lot of energy, much more than we’ve been able
to get out of the process Because of this,
the first fusion power plants are decades, if not centuries away. Until then, fission has the only mc squared
we’ll be able to use for energy For Scientific American´s
Instant Egghead, I’m Michael Moyer