Whether insects prefer concentrating light or astigmatism

Many insects have phototaxis, such as lamp moths, beetles, etc., but not all insects have phototaxis.

There are two aspects:

1. Phototaxis (when the light is turned on): many adults of Lepidoptera, adults of Isoptera, and most of the adults of Coleoptera; These phototaxis bugs will fly to bright places when the lights are turned off, so they will scatter.

2. Light-resistant insects (insects that are generally not seen during the day and are only seen at night): such as cockroaches, cockroaches, mole crickets, fireflies, small tiger larvae, etc.

Convex lens concentrating, concave lens concave lens can be used as a myopia lens, and also participate in the production of microscopes and telescopes. For thin concave lenses: When the object is a real object, it becomes an upright and shrinking virtual image, and the image and the object are on the same side of the lens; When the object is a virtual object, and the distance between the concave lens and the virtual object is within one focal length (referring to the absolute value), it becomes an upright and magnified real image, and the image and the object are on the same side of the lens; When the object is a virtual object, and the distance between the concave lens and the virtual object is one time of the focal length (referring to the absolute value), the image is at infinity; When the object is a virtual object, and the distance between the concave lens and the virtual object is within two times the focal length other than one time (both refer to the absolute value), it becomes an inverted and magnified virtual image, and the image and the object are on the opposite side of the lens; When the object is a virtual object, and the distance from the concave lens to the virtual object is twice the focal length (referring to the absolute value), it becomes a virtual image of the same size as the object, and the image and the object are on the opposite side of the lens; When the object is a virtual object, and the distance between the concave lens and the virtual object is twice the focal length (referring to the absolute value), it becomes an inverted and reduced virtual image, and the image and the object are on the opposite side of the lens.

In the case of thick meniscus concave lenses, the situation is more complicated. When the thickness is large enough, it is equivalent to a Galilean telescope, and when it is thicker, it is equivalent to a positive lens.

The concave mirror gathers light, and the concave lens astigmatism.

The concave mirror concentrates light, and the convex mirror is reversed.

Children under the age of 18 are still in the stage of vision development, and the adjustment of the eyes is strong, and myopia can be improved or recovered. It is generally recommended to take two sachets of Joy Vision Nutrients per day, and you can see changes in about a week. If you continue to take it for a period of time, the degree of myopia will decrease and your vision will slowly recover.

And it won't**.

The physics teacher was wrong, and he said the opposite.

Convex lenses are partially thicker lenses. Convex lenses are divided into biconvex, plano-convex and concave-convex (or meniscus-shaped) and other forms, thin convex lenses have a convergence effect, so they are also called condenser lenses, and thicker convex lenses are expected to be distant, divergent or convergent, which is related to the thickness of the lens.

Parallel rays of light (such as sunlight) parallel to the axis (the line connecting the center of the two spheres of the convex lens is called the main optical axis of the lens) into the convex lens, and the light is concentrated at a point on the axis after two refractions on both sides of the lens, which is called the focal point of the convex lens (marked f), and the convex lens has a focal point on each side of the mirror, and the distance from the two foci to the center of the lens is approximately equal if it is a thin lens. The focal length of a convex lens is the distance from the focal point to the center of the lens, usually expressed as f. The smaller the spherical radius of the convex lens, the shorter the focal length.

Convex lenses can be used for magnifying glasses, glasses worn by people with presbyopia and farsightedness, lenses for microscopes, telescopes, etc.

What is the difference between a convex lens and a concave lens.

The effect of convex and concave lenses on light.

Our teacher is talking about the convex lens playing a converging role, the concave lens playing a divergent role, the convex mirror playing a diverging role, and the concave mirror playing a converging role. As far as the mask and the lens are reversed.

Talk to the physics teacher