2. TEMPERATURE
What is Temperature?
Temperature is the measure of the warmth or coldness of an object or material. Temperature is the expression of thermal energy.
What's the science behind it? Well, the scientific temperature definition involves energy, and this is what makes temperature different to measuring heat. Temperature is actually a measure of the kinetic energy of particles in an object. Particles are always moving, the faster/higher the energy, the higher the temperature. With temperature, higher equals warmer.
What is Used to Measure Temperature?
Temperature is measured using a device called a thermometer. The most common type uses a long thin tube that is filled with liquid mercury, or sometimes alcohol. Why are they used? Mercury and alcohol will remain liquids over a wider range of temperatures than other liquids. The mercury will rise when the temperature is warmer, and fall when the temperature is colder. So, say a room is warm, the temperature causes a slight change in the volume of the liquid used in the thermometer. This causes it to rise up the tube, now reflecting a higher temperature.
How is Temperature Measured?
Temperature is measured with three different degrees.
Celsius: The most common form of measuring temperature in day-to-day situations. The Celsius scale is used to measure temperature in the UK.
Fahrenheit: The less common form of measuring temperature, although some countries (United States) use this scale as their main temperature units.
Kelvin: Kelvin is used in cases of extreme heat or cold - most often in scientific environments. 0 Kelvin is also known as absolute zero, theoretically, this is where particles are not moving at all, although this would never be observed naturally.
What Happens in Lower Temperatures?
In lower temperatures, particles move at a slower rate and have less kinetic energy, causing less friction, hence the lower heat. Material will also usually shrink, harden or freeze in lower temperatures, with many substances changing state. For example, in temperatures below zero degrees Celsius, liquid water will freeze to become ice as there will be no thermal energy.
In many places on Earth, it's during the winter months that we experience colder temperatures, and at both poles of the Earth. This is because the Sun is further away at these points/times.
What Happens in Higher Temperatures?
In higher temperatures, particles move faster and have higher kinetic energy, causing more friction, and therefore more heat. Depending on the structure, the material may also begin to break apart, melt or expand.
In hot temperatures, water will change state, turning into gas and evaporating. This is why deserts are common around the equator of the Earth - the warmest parts of the world.
Temperature and the Human Body
Temperature affects a number of physical processes, it's therefore really important in keeping our bodies healthy and functioning properly.
The normal temperature of a human body is 36.5–37.5°C. At this temperature, bodies are able to function normally.
When our temperature rises, this can be an indication that we're unwell - this is called a fever. This is because our bodies are working harder to fight off an infection. Your levels of white blood cells increase to fight the infection, and this affects the hypothalamus. The hypothalamus is the part of the brain that controls a number of things, including temperature.
What Happens to Our Bodies in Warmer Weather?
As temperature rises, our heart rate increases and blood flow increases to, it's pumped to the skin's surface and we begin the sweat. This is our bodies way of cooling us down, and as the sweat evaporates, it takes the heat with it.
If our body temperature rises too high, our muscles begin working slower and heat exhaustion can occur. Above 41°C, our bodies can begin to shut down as chemical processes that occur in the body are affected.
What Happens to Our Bodies in Colder Weather?
Our bodies will begin to shiver in colder weather. This is our muscles acting to warm us up by generating heat. If our body temperatures drop too low, our heart rate slows and our regular body functions can't work normally. This is called hypothermia.
Fun Temperature Facts
Want to know what some of the hottest, and coldest, things in the world are?
The core of the Sun can reach 15 million degrees Celsius!
A lightning bolt is 27,727°C.
Earth's core is 5,377°C.
100°C is the boiling point of water.
The highest recorded temperature on Earth was in Death Valley, United States where it reached 56.7°C in 1913.
-15°C is the melting point of ice cream.
Liquid hydrogen is the coldest substance known to man at -400°C.
Antarctica is the coldest place on Earth, with the lowest recorded temperature at -94.7°C.
The highest recorded temperature in the United Kingdom is 38.5°C.
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2. TEMPERATURE
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