Windows to New Worlds
Scientists use a wide variety of tools to observe and measure the world around them, from the incredibly small to the unimaginably distant. These tools are extensions of our senses, allowing us to see what is normally invisible.
The Microscope: Exploring the Small
A microscope is an instrument used to see objects that are too small for the naked eye. The most common type used in a school lab is the compound light microscope.
How it works: It uses a combination of at least two lenses and a light source to magnify an object. Light from a lamp passes through the specimen on a slide. The light then travels through the objective lens (the one closest to the specimen), which creates a magnified image. This image is then magnified again by the eyepiece lens (the one you look through).
Magnification: The total magnification is found by multiplying the power of the objective lens by the power of the eyepiece. If the eyepiece is 10x and the objective is 40x, the total magnification is 10 * 40 = 400x.
The Telescope: Exploring the Distant
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation (such as visible light). The goal of a telescope is not just to magnify, but more importantly, to gather as much light as possible, which allows us to see very faint and distant objects.
Refracting Telescope: This type uses a large lens, called the objective lens, to bend and focus light to a point. Eyeglasses and magnifying glasses work by refraction.
Reflecting Telescope: This type uses a large, curved mirror to gather and focus light. All major research telescopes today are reflectors because mirrors can be made much larger, lighter, and more perfectly shaped than lenses.
Spectroscopy: Decoding Light
How do we know what stars are made of, even though they are trillions of miles away? We use a tool called a spectroscope.
Spectroscopy is the science of splitting light into its component colors (its spectrum). A simple prism creates a spectrum from white light.
The Big Idea: Every chemical element, when heated, emits light in a unique, specific pattern of colors, like a fingerprint. Similarly, a cool gas will absorb light in that same unique pattern.
By looking at the spectrum of light from a distant star and seeing which 'fingerprints' are present, astronomers can determine exactly what elements the star is made of without ever leaving Earth.
Other Essential Tools
Balance: Used to measure mass. A modern electronic balance can measure mass with extreme precision.
Thermometer: Used to measure temperature.
Graduated Cylinder/Pipette: Used to measure volume accurately.