Self-imaging of a molecule by its own electrons

One of the long-standing goals of research on the light-induced dynamics of molecules is to observe time-dependent changes in the structure of molecules, which result from the absorption of light, as directly and unambiguously ...

Scientists reveal the power behind the curtain—with neutrons

In a potential step forward for imaging technology, scientists from the National Institute of Standards and Technology (NIST) and Sandia National Laboratories have developed a way to use neutrons to detect electric fields ...

Physicists discover new magnetoelectric effect

Electricity and magnetism are closely related: Power lines generate a magnetic field, rotating magnets in a generator produce electricity. However, the phenomenon is much more complicated: electrical and magnetic properties ...

Finding a handle to bag the right proteins

Purifying specific protein molecules from complex mixtures will become easier with a simpler way to detect a molecular tag commonly used as a handle to grab the proteins.

Superconductors are super resilient to magnetic fields

A researcher at the University of Tsukuba has offered a new explanation for how superconductors exposed to a magnetic field can recover, without loss of energy, to their previous state after the field is removed. This work ...

Opto-thermoelectric microswimmers

In a recent report, Xiaolei Peng and a team of scientists in materials science and engineering at the University of Texas, U.S., and the Tsinghua University, China, developed opto-thermoelectric microswimmers bioinspired ...

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Electric field

In physics, the space surrounding an electric charge or in the presence of a time-varying magnetic field has a property called an electric field. This electric field exerts a force on other electrically charged objects. The concept of an electric field was introduced by Michael Faraday.

The electric field is a vector field with SI units of newtons per coulomb (N C−1) or, equivalently, volts per metre (V m−1). The SI base units of the electric field are kg·m·s−3·A−1. The strength of the field at a given point is defined as the force that would be exerted on a positive test charge of +1 coulomb placed at that point; the direction of the field is given by the direction of that force. Electric fields contain electrical energy with energy density proportional to the square of the field intensity. The electric field is to charge as gravitational acceleration is to mass and force density is to volume.

A moving charge has not just an electric field but also a magnetic field, and in general the electric and magnetic fields are not completely separate phenomena; what one observer perceives as an electric field, another observer in a different frame of reference perceives as a mixture of electric and magnetic fields. For this reason, one speaks of "electromagnetism" or "electromagnetic fields." In quantum mechanics, disturbances in the electromagnetic fields are called photons, and the energy of photons is quantized.

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