What is Celsius? (History, definition, scale)

Temperature is one of the most important measurements in our daily lives, whether we are checking the weather, cooking food, or studying science. Among different temperature scales, Celsius is one of the most widely used systems in the world today. But what exactly is Celsius, how did it start, and why is it so important? Let’s explore its history, definition, and scale in detail.

Definition of Celsius

The Celsius scale, also known as the centigrade scale, is a temperature measurement system in which water freezes at 0 degrees and boils at 100 degrees under standard atmospheric pressure. This makes it very easy to understand and apply in everyday situations.

In the Celsius scale:

  • 0°C = Freezing point of water
  • 100°C = Boiling point of water

Everything in between is divided into 100 equal steps (degrees), which is why it is often called a “centigrade” scale (centi = 100).

The History of Celsius

The Celsius scale was created in 1742 by Anders Celsius, a Swedish astronomer and scientist. Interestingly, his original scale was the reverse of what we use today:

  • He marked 0°C as the boiling point of water.
  • He marked 100°C as the freezing point of water.

After his death, other scientists, including Carl Linnaeus, reversed the scale to the more logical version we use now, where 0°C represents freezing and 100°C represents boiling. This change made it much easier to apply in science and daily life.

Why is it Called Celsius?

The scale is named after Anders Celsius to honor his work. It was originally called “centigrade,” but in 1948, the term Celsius became the official name, as recognized by international standards.

The Celsius Scale in Use

The Celsius scale is part of the metric system (SI units), which is the standard measurement system used by most of the world. Only a few countries, like the United States, still rely on the Fahrenheit scale for everyday use.

Celsius is commonly used for:

  • Weather forecasts (temperature of the air and seasons).
  • Cooking and baking (oven settings and recipes).
  • Science and medicine (body temperature, lab experiments, chemistry, physics, and more).

Relationship with Other Temperature Scales

Celsius is often converted into other temperature scales, especially Fahrenheit and Kelvin.

  • Celsius to Fahrenheit formula:
    F = (C × 9/5) + 32
  • Celsius to Kelvin formula:
    K = C + 273.15

For example:

  • 0°C = 32°F = 273.15 K
  • 100°C = 212°F = 373.15 K

This makes Celsius a central point of reference when comparing different systems of temperature measurement.

Advantages of the Celsius Scale

  1. Easy to Understand: Based on the freezing and boiling points of water.
  2. Global Standard: Used almost everywhere in the world except the US and a few regions.
  3. Scientific Accuracy: Works well with the metric system, making it ideal for scientific research and education.

Final Thoughts

The Celsius scale is more than just a way to measure temperature—it is a universal standard that connects science, daily life, and global communication. Created by Anders Celsius in the 18th century, it has become the most common temperature system worldwide. Whether you are checking the weather, cooking a meal, or conducting a scientific experiment, the Celsius scale provides a simple, logical, and reliable way to measure heat and cold.

Celsius to Fahrenheits FAQs

The Celsius scale was invented by Anders Celsius, a Swedish astronomer, in 1742.

Water freezes at 0°C and boils at 100°C under standard atmospheric pressure.

Yes, the Celsius scale was originally called “centigrade” because it is divided into 100 degrees. The official name “Celsius” was adopted in 1948.

Celsius is part of the metric system, which is widely used for science, education, and everyday life in most countries.