Nuclear fission is one of several ways to release a tiny bit of an atom's mass, but most of the stuff remains in the form of familiar protons, neutrons and electrons. One way to turn an entire block of material into pure energy would be to bring it together with antimatter.
Particles of matter and antimatter are the same, except for an opposite electrical charge. Bring them together, though, and they will annihilate each other into pure energy.
Unfortunately, given that we don't know any natural sources of antimatter, the only way to produce it is in particle accelerators and it would take 10 million years to produce a kilogram of it.
Particle accelerators studying fundamental physics are another place where Einstein's equation becomes useful. Special relativity says that the faster something moves, the more massive it becomes. In a particle accelerator, protons are accelerated to almost the speed of light and smashed into each other.
The high energy of these collisions allows the formation of new, more massive particles than protons — such as the Higgs boson — that physicists might want to study. Which particles might be formed and how much mass they have can all be calculated using Einstein's equation. It would be nice to think that Einstein's equation became famous simply because of its fundamental importance in making us understand how different the world really is to how we perceived it a century ago.
But its fame is mostly because of its association with one of the most devastating weapons produced by humans — the atomic bomb. The equation appeared in the report, prepared for the US government by physicist Henry DeWolf Smyth in , on the Allied efforts to make an atomic bomb during the Manhattan project.
The warping of spacetime, in the General Relativistic picture, by gravitational masses. The fact of mass-energy equivalence also led Einstein to his greatest achievement: General Relativity.
Imagine that you've got a particle of matter and a particle of antimatter, each with the same rest mass. If two objects of matter and antimatter at rest annihilate, they produce photons of an extremely If they produce those photons after falling deeper into a gravitational field, the energy should be higher.
If we want to conserve energy, we have to understand that gravitational redshift and blueshift must be real. Newton's gravity has no way to account for this, but in Einstein's General Relativity, the curvature of space means that falling into a gravitational field makes you gain energy, and climbing out of a gravitational field makes you lose energy. Where p is momentum. Only by generalizing things to include energy, momentum, and gravity can we truly describe the Universe.
When a quantum of radiation leaves a gravitational field, its frequency must be redshifted to Only if gravitation itself is linked to not only mass but energy, too, does this make sense.
Matter has an inherent amount of energy to it, mass can be converted under the right conditions to pure energy, and energy can be used to create massive objects that did not exist previously. Thinking about problems in this way enabled us to discover the fundamental particles that make up our Universe, to invent nuclear power and nuclear weapons, and to discover the theory of gravity that describes how every object in the Universe interacts.
And the key to figuring the equation out? A humble thought experiment , based on one simple notion: that energy and momentum are both conserved. The rest? It's just an inevitable consequence of the Universe working exactly as it does. This is a BETA experience. You may opt-out by clicking here. More From Forbes. Jul 23, , am EDT. Jul 15, , am EDT. The speed of light squared is 8. Instead, his equation shows that a change in the mass of an object requires a change in its energy.
When protons and neutrons split off from atoms during nuclear fission, they release energy. Humans got a taste of that frightful energy when we invented the atomic bomb. The enormous amount of energy released by the Little Boy nuclear weapon was equivalent to the mass of less than a gram of its radioactive fuel. You extract energy from matter every time you light a candle though the mechanism there is a chemical reaction, rather than a nuclear one.
But the light and heat that comes from a candle is but a sliver of the energy contained within. A single candle might light up a romantic dinner, but the energy equivalent to all of the mass inside would be sufficient to level an entire city. Though the energy-mass equation might appear simple, there are some special cases that appear to challenge its assumptions. Take the case of photons, for example.
These particles, which represent packets of light, have zero mass, but still contain energy. The paradox is resolved with a slightly expanded, lesser-known version of the equation.
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