Yes except when it diffracts, refracts, reflects or come under strong gravity force.
The word "diameter" is a noun. It refers to a straight line passing through the center of a circle or sphere that connects two points on the circumference.
When light travels from one medium to another, it means that light is passing from one material or substance to another material or substance, each with its own refractive index. The change in medium can cause the light to refract or bend.
Une onde, or l'onde means "the wave" (as in microwave, radio waves or in a poetic way, the waves of the sea - in that latter sense, that could also be used for "water").
Scientists use the term "refraction" to describe the bending of light as it passes through different mediums, such as air, water, or glass. This bending occurs due to the change in the speed of light as it travels through substances with varying densities.
The proper word is reflected. Light is an electromagnetic wave and so the conductive surface of the mirror experiences an oscillating electric field. That changing field causes the electrons on the surface to oscillate back and forth. The oscillating electrons then themselves create an oscillating electromagnetic wave and we perceive that as light reflecting off the surface. Other types of surfaces also reflect light, such as water and glass. It happens that the slower light travels in a medium the greater the amount of light that is reflected. For example light travels slower in glass than in water and so glass reflects more light then water. It turns out that light travels the slowest in metals and that is one of the reasons it is used in mirrors. It reflects almost all of the light that hits it.
lasers
The word straight does have an antonym, which is crooked. So perhaps a crooked line is the opposite of a straight line.
The word is "light-year".
You need to word the question better. Electricity derived from a battery is always DC as batteries are a DC power source.
for example a straight line.(is it straight up and down)
for example a straight line.(is it straight up and down)
Nonlinear
Ray.
Line up outside the ship.Make sure you line these up straight.
The word straight doesn't really apply to an equation. However the graph of a linear equation is a straight line.
Kinked.
You're referring to the word 'plumb' - as in plumb line.