Thousands of years ago, our ancestors hunted or scavenged food from animal carcasses. Since fire had not yet been invented, they were used to eat the raw food. Once fire was discovered and our human ancestors understood how to harvest it, our eating habits evolved. Fire proved to be one of the most important discoveries in human history. This remarkable discovery helped our ancestors set up the world we know today.
The earliest evidence of modern cooking was found in China, which is believed to be around 20,000 years old. Some earthen pots were discovered in archeological sites and are believed to be cooking pots based on the scorch marks and soot found on their outer surface. In the 15th century Europeans started the use of cast-iron stoves. Gas stoves were invented during the 1820s, which quickly were upgraded to the electric version during the early 1900s. Microwave cooking was invented by the mid-1950s.
Let us learn about the brief history of microwave ovens before learning the science behind it.
Interesting Science Videos
History of Microwave Oven
As many other inventions in human history, microwave oven was also an accidental invention.
- Percy Spencer, a self-taught engineer, submitted the first microwave oven patent application in 1945, according to the American Physical Society.
- While working with a live radar set that was emitting microwave signals, Spencer observed a candy bar in his was pocket melting rapidly. He later found that the chocolate was being heated by the radar’s small cavity magnetron tube.
- After experimenting with heating foods by aiming the magnetron tube at items like popcorn and eggs, he made a metal box to hold the microwaves that included a hole for the tube to pass through.
- Spencer created an amateur prototype of the contemporary microwave by including a door to the metal box.
- Raytheon developed the first commercially viable microwave oven, the “Radarange,” in 1947, and the rest is history.
How Does Microwave Ovens Work?
Here we are going to learn about the basics of how microwave ovens work.
- Since microwaves are waves of electrical and magnetic energy traveling through space together, this makes them a type of “electromagnetic” radiation. From very long radio waves to very brief gamma rays, electromagnetic radiation includes an expansive spectrum.
- Three characteristics unique to microwave enable their use in cooking: they are absorbed by food, they are reflected by metal, and their radiation can pass through objects like glass, paper, and plastic.
- A main component (electron tube) known as a magnetron produces microwaves inside the microwave oven.
- These waves oscillate through the interior of the microwave.
- The metal inside the oven reflects the microwaves, which are then absorbed by the food.
- By making the food’s water molecules vibrate at microwave frequencies (2.4 GHz), the microwave oven cooks food.
Science of Microwave Cooking
The temperature of an object is affected by the degree of vibration of its individual particles. Heating raises the temperature by increasing the intensity of particle vibrations. Microwave ovens apply the science of dielectric heating while cooking the food. In this method, the molecules of the food are made to vibrate using the microwaves which helps the food cook.
- Microwave ovens cook food by vibrating the water molecules in it at microwave frequencies (2.4 GHz).
- With the oxygen (O) atom at its core, the water molecule (H2O) exhibits a folded “V” shape. Thus, the entire molecule’s charge distribution is an electric dipole with a small positive and negative bias.
- After being exposed to a high-frequency electrical field, these water molecules rotate, vibrate, and produce heat through friction with one another when the electrical field reverses.
- Microwave energy is simply absorbed by water molecules which in return cooks the food for us.
Safety Guidelines For Using Microwave Ovens
Microwaves emitted from the oven are not enough to do any damage to human body. However, there have been the reports of accidents with the severe burns and the fire incidents all around the world. So, we must be careful with how we use and maintain our ovens. So, in this section we will take a brief look about the safety tips for using our microwave ovens.
(1) Proper Placement and Ventilation
- When choosing a spot for your microwave oven, take into account the surrounding area, including any cabinets and appliances in the vicinity. Make sure there is adequate room surrounding the device to allow for adequate airflow and ventilation. The microwave oven could overheat without adequate airflow, which could be disastrous.
(2) Appropriate Cookware
- Picking a suitable cookware option is a must while using your microwave oven. Not every container is safe to use in the microwave, and using the incorrect materials might result in mishaps, harm to the device, and even health hazards.
(3) Safe Handling of Food Containers
- It’s important to exercise caution when taking hot food containers out of the microwave to avoid steam burns. Always cover your hands and fingers from the heat by using oven mitts or a towel. To keep the container from slipping and spilling its hot contents, make sure you hold onto it tightly. Plastic containers that aren’t microwave friendly should not be used since they may deform and leak hazardous chemicals into your food.
(4) Avoid Metal and Aluminum Foil in Microwaves
- Avoiding the use of metal or aluminum foil in microwaves is crucial. There is a risk of sparking and fire if metal gets heated in a microwave. Additionally, aluminum foil might ignite and might damage the appliance. Use food containers and cookware that are safe to use in the microwave instead of metal or aluminum foil.
Health Hazards of Microwave Ovens
The maximum quantity of microwave radiation that can escape from an oven over its lifetime is 5 milliwatts (mW) per square centimeter, which is about 2 inches from the oven surface, according to safety standards. This limit is significantly lower than what is known to be harmful to humans. Additionally, the distance from the radiation source causes a sharp drop in microwave energy. However in case of accident these can be the hazards:
- Just as microwave radiation can heat food, it can also heat bodily tissue. Excessive microwave exposure might result in a severe burn.
- The eyes and testes are two parts of the body that are especially sensitive to RF heating because their blood supply is comparatively limited, making it difficult for them to release the extra heat.
- Furthermore, the eye’s lens is extremely susceptible to high temperatures, and cataract may form from prolonged exposure to microwave radiation.
- But only prolonged exposure to high levels of microwave radiation can result in these kinds of damage, such as burns and cataracts.
Additionally, the standard requires that every oven have two separate interlock mechanisms that, when the door is opened or the latch is released, instantly stop producing microwaves. A monitoring system also prevents oven operation in the event that one or both of the interlock systems malfunction. So, these type of hazards are rare.
Microwave Ovens and Pacemakers
There was initially fear that some electronic cardiac pacemakers might be affected by radiation leakage from microwave ovens. Similar issues were brought up with electric shavers, auto ignition systems, and other electrical devices interfering with pacemakers. Although the FDA does not mandate that microwave ovens have warnings for pacemaker users, this issue has mostly been fixed because modern pacemakers are made to withstand this kind of electrical interference. Pacemaker users are advised to speak with their doctors if they have any concerns, nevertheless.
How to Clean Microwave Ovens?
Ensuring the hygiene of your microwave is crucial for both its safety and best performance. If food residue is left in the microwave, it might shorten the appliance’s durability and ignite a fire. To keep your microwave clean, you can follow these tips:
- After each use, you should wipe the interior of the oven with a damp cloth or sponge in order to remove any food residue.
- Over stubborn stains, place a bowl of water with a few slices of lemon in a microwave for a few minutes to break up what’s left before cleaning it off.
- Any detachable components, such the turntable, should be taken out and cleaned with warm, soapy water.
- Remember to keep the microwave’s exterior clean, including the handles and buttons, as these areas may house bacteria and germs.
- Avoid using harsh chemicals or abrasive items that could scratch the microwave’s surface.
Maintenance and Servicing
Maintaining your microwave oven on a regular basis is essential to its safe and effective operation. It avoids any possible safety risks in addition to extending the appliance’s lifespan. It’s crucial that you stick to the the manufacturer’s maintenance guidelines as specified in the user handbook.
Child Safety With Microwaves
There are a few things to consider when it comes to oven safety for kids. Let’s see how can we ensure the safety of our children’s around microwave ovens:
- Above all, it’s critical to keep an eye on kids whenever they use or are near microwaves. This will guarantee that they are not inadvertently hurting themselves or other people while using the oven.
- Another key feature to look for in microwave ovens is the kid lock option. This prevents kids from unknowingly turning on or opening the microwave while it is in operation, which could lead to burns or other accidents.
- Make sure you read the user manual and understand how to set up the child lock feature on your specific appliance. It may require a certain button combination or be managed from the settings menu.
Let us know what you think about our article on the microwave oven.
Also Don’t Forget to Check
Video Reference
Other References
- https://www.whirlpool.com/blog/kitchen/history-of-microwave.html
- https://www.fda.gov/radiation-emitting-products/resources-you-radiation-emitting-products/microwave-ovens
- https://www.tdk.com/en/tech-mag/inductive/how-does-a-microwave-oven-work
- https://www.explainthatstuff.com/microwaveovens.html
- https://home.howstuffworks.com/microwave.htm
- https://www.townappliance.com/blogs/town-appliance-official/microwave-oven-safety-tips
