If you’re superstitious, having a black cat in front of you is bad luck, even if you keep your distance. I can. Scientists have shown that this mysterious quantum effect applies not only to magnetic fields, but also to gravity. This is not superstition.
Normally, particles must pass through a magnetic field to feel its effects. But in 1959, physicists Yakir Aharonov and David Bohm predicted that the conventional wisdom would break in certain scenarios. Magnetic fields contained in the cylinder region can affect particles (electrons in this example) that do not enter the cylinder. In this scenario, the electron has no well-defined position, but is in a “superposition”, a quantum state described by the probability that the particle will materialize in two different positions. Each broken particle travels two different paths around the magnetic cylinder at the same time. Since the magnetic field never touches the electron, it does not exert any force on it, but as confirmed by various experiments, the magnetic field shifts the pattern of where particles are found at the end of this journey (SN: 1.3 .86).
The same sinister physics of gravitational fields are at work in the new experiment, the physicist said in January. 14 Science. “Every time I see this experiment, I think, ‘Wow, nature is like this,'” says Mark Kasevic, a physicist at Stanford University.
Kasevich and his colleagues threw rubidium atoms into a 10-meter-tall vacuum chamber, illuminated them with a laser, threw them into quantum superposition following two different paths, and watched the atoms fall. Surprisingly, the particles were not in the gravitational field-free zone. Instead, the experiment was designed to allow researchers to rule out the effects of gravity and uncover the mysterious Aharonov-Bohm effect. This work not only reveals well-known physical effects in new contexts, but also shows the potential to study subtle effects in gravitational systems. For example, researchers hope to use this kind of technique to more accurately measure Newton‘s gravitational constant, G, which indicates the strength of gravity. .
A phenomenon called interference is key to this experiment. In quantum physics, atoms and other particles behave like waves that can be added and subtracted. Just like two waves in the ocean merge to form a larger wave. At the end of the atom’s flight, the scientists recombined the two paths of the atom so that the waves interfered and measured where the atom landed. The landing position is very sensitive to changes that change where the wave crests and troughs land, known as phase shift.
If you’re superstitious, having a black cat in front of you is bad luck, even if you keep your distance. I can. Scientists have shown that this mysterious quantum effect applies not only to magnetic fields, but also to gravity. This is not superstition.
Normally, particles must pass through a magnetic field to feel its effects. But in 1959, physicists Yakir Aharonov and David Bohm predicted that the conventional wisdom would break in certain scenarios. Magnetic fields contained in the cylinder region can affect particles (electrons in this example) that do not enter the cylinder. In this scenario, the electron has no well-defined position, but is in a “superposition”, a quantum state described by the probability that the particle will materialize in two different positions. Each broken particle travels two different paths around the magnetic cylinder at the same time. Since the magnetic field never touches the electron, it does not exert any force on it, but as confirmed by various experiments, the magnetic field shifts the pattern of where particles are found at the end of this journey (SN: 1.3 .86).
The same sinister physics of gravitational fields are at work in the new experiment, the physicist said in January. 14 Science. “Every time I see this experiment, I think, ‘Wow, nature is like this,'” says Mark Kasevic, a physicist at Stanford University.
Kasevich and his colleagues threw rubidium atoms into a 10-meter-tall vacuum chamber, illuminated them with a laser, threw them into quantum superposition following two different paths, and watched the atoms fall. Surprisingly, the particles were not in the gravitational field-free zone. Instead, the experiment was designed to allow researchers to rule out the effects of gravity and uncover the mysterious Aharonov-Bohm effect. This work not only reveals well-known physical effects in new contexts, but also shows the potential to study subtle effects in gravitational systems. For example, researchers hope to use this kind of technique to more accurately measure Newton’s gravitational constant, G, which indicates the strength of gravity. .
A phenomenon called interference is key to this experiment. In quantum physics, atoms and other particles behave like waves that can be added and subtracted. Just like two waves in the ocean merge to form a larger wave. At the end of the atom’s flight, the scientists recombined the two paths of the atom so that the waves interfered and measured where the atom landed. The landing position is very sensitive to changes that change where the wave crests and troughs land, known as phase shift.
