Engineers bend light to enhance wavelength conversion

Electrical engineers from the UCLA Samueli School of Engineering have developed a more efficient way of converting light from one wavelength to another, opening the door for improvements in the performance of imaging, sensing ...

New method found for moving tiny artificial swimmers

Princeton researchers have debuted a novel way of generating and potentially controlling locomotion in tiny objects called artificial swimmers. These swimmers have sparked considerable interest for their potential applications ...

Making bendable ice by growing single-crystal microfibers

A team of researchers working at Zhejiang University in China has developed a way to grow water ice that is elastic and bendable. In their paper published in the journal Science, the group describes how they grew their single-crystal ...

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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