John Baez Wrote
Science journalists are acting like all hell has broken loose... because they're more interested in click bait than actual science:
Breaking the Rules: Heavy Chemical Elements Alter Theory of Quantum Mechanics
Extremely Rare Periodic Element Behaving Like It's from an 'Alternative Universe' (there's no such thing as a "periodic element")
A Rare Element From The Edge of The Periodic Table Is Breaking Quantum Mechanics
Nope, nope, nope. Chemists did some experiments with a very heavy element. And they discovered that everything works just like standard physics says it should!
Starting in 1928, Dirac and others figured out how to combine quantum mechanics and special relativity. When stuff moves really fast, special relativity becomes important. Electrons in light elements don't move very fast. But in heavy elements, they move close to the speed of light... so relativity makes a big difference.
This has been tested experimentally many times - even in light elements like hydrogen. In hydrogen, the electron moves at about 1/137 times the speed of light. This is enough to cause tiny relativistic effects. They've been measured to extreme accuracy, and yup - our theories work fine.
What's new? Chemists have done experiments with 13 milligrams of a very rare, very radioactive element called berkelium. It's element 97 on the periodic table, so it's very heavy. So, its electrons move really fast... so relativity matters a lot for this element.
Great! My headline would be:
Yet Again, Physics Works As Expected
But journalists are acting shocked. Because it sells. And because they don't realize how well we actually understand the universe.
In 1928, Dirac figured out how to reconcile quantum mechanics and special relativity. Before then, the Schrödinger equation was our best way of describing how particles behave in quantum mechanics. It says they're actually waves that vibrate at a rate equal to their energy.
We still believe this. But originally, the formula for the energy didn't take special relativity into account. Special relativity says that as a particle gets closer and closer to the speed of light, its energy grows indefinitely. This keeps things from going faster than light.
The Dirac equation takes this into account. More interestingly, it takes into account the electron's spin - and also the fact that it has an antiparticle, the positron. It does all this in an incredibly elegant way: in modern notation, Dirac's equation takes just 9 symbols to write!
Feynman once asked Dirac: "How did you find your equation?"
Dirac replied: "I found it beautiful."
The Dirac equation is good enough for almost all of quantum chemistry. It needs to be refined to quantum field theory when we deal with processes where pairs of particles and antiparticles annihilate each other... or get created. Even subtle effects of this sort have been seen in hydrogen.
There are certainly mysteries left to solve, but if someone says that heavy elements are "breaking the rules", it's because they don't know the rules.
The Dirac equation should have been headline news... back in 1928. Skip the silly article - learn something profound instead:
Science journalists are acting like all hell has broken loose... because they're more interested in click bait than actual science:
Breaking the Rules: Heavy Chemical Elements Alter Theory of Quantum Mechanics
Extremely Rare Periodic Element Behaving Like It's from an 'Alternative Universe' (there's no such thing as a "periodic element")
A Rare Element From The Edge of The Periodic Table Is Breaking Quantum Mechanics
Nope, nope, nope. Chemists did some experiments with a very heavy element. And they discovered that everything works just like standard physics says it should!
Starting in 1928, Dirac and others figured out how to combine quantum mechanics and special relativity. When stuff moves really fast, special relativity becomes important. Electrons in light elements don't move very fast. But in heavy elements, they move close to the speed of light... so relativity makes a big difference.
This has been tested experimentally many times - even in light elements like hydrogen. In hydrogen, the electron moves at about 1/137 times the speed of light. This is enough to cause tiny relativistic effects. They've been measured to extreme accuracy, and yup - our theories work fine.
What's new? Chemists have done experiments with 13 milligrams of a very rare, very radioactive element called berkelium. It's element 97 on the periodic table, so it's very heavy. So, its electrons move really fast... so relativity matters a lot for this element.
Great! My headline would be:
Yet Again, Physics Works As Expected
But journalists are acting shocked. Because it sells. And because they don't realize how well we actually understand the universe.
In 1928, Dirac figured out how to reconcile quantum mechanics and special relativity. Before then, the Schrödinger equation was our best way of describing how particles behave in quantum mechanics. It says they're actually waves that vibrate at a rate equal to their energy.
We still believe this. But originally, the formula for the energy didn't take special relativity into account. Special relativity says that as a particle gets closer and closer to the speed of light, its energy grows indefinitely. This keeps things from going faster than light.
The Dirac equation takes this into account. More interestingly, it takes into account the electron's spin - and also the fact that it has an antiparticle, the positron. It does all this in an incredibly elegant way: in modern notation, Dirac's equation takes just 9 symbols to write!
Feynman once asked Dirac: "How did you find your equation?"
Dirac replied: "I found it beautiful."
The Dirac equation is good enough for almost all of quantum chemistry. It needs to be refined to quantum field theory when we deal with processes where pairs of particles and antiparticles annihilate each other... or get created. Even subtle effects of this sort have been seen in hydrogen.
There are certainly mysteries left to solve, but if someone says that heavy elements are "breaking the rules", it's because they don't know the rules.
The Dirac equation should have been headline news... back in 1928. Skip the silly article - learn something profound instead:
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