How a melted candy bar led to the microwave oven

By Sohail Khan 4 September 2026, 10:01 pm

Benchmarks
Nifty23,897.7024.25

Precious Metal
Gold (MCX) (Rs/10g.)153,280.00-2495.0

Enter search text:

Business News›News›International›Global Trends›In 1945, Percy Spencer noticed something unusual while working on radar equipment: the candy bar in his pocket had melted. The engineer began experimenting with popcorn and an egg, eventually setting him on the path to developing the microwave oven.

Read Today's Paper

In 1945, Percy Spencer noticed something unusual while working on radar equipment: the candy bar in his pocket had melted. The engineer began experimenting with popcorn and an egg, eventually setting him on the path to developing the microwave oven.
Synopsis

In 1945, Percy Spencer made a casual observation that led to a major change in food preparation. Standing next to a magnetron one day, he noticed that a candy bar in his pocket melted. This caused him to wonder if the energy from radio waves could be used to cook food. He placed popcorn kernels near the tube; within minutes, he was snacking on the world's first microwave popcorn.

Percy Spencer microwave invention<br> — Spencer was already an experienced engineer when the discovery happened

In 1945, engineer Percy Spencer was working with radar equipment at Raytheon when he noticed something strange. A candy bar he had been carrying in his pocket had melted. Spencer suspected that the magnetron he was working with might have caused it.

The magnetron was an important part of radar technology, producing microwave energy that could be used to detect objects. Spencer wondered whether that same energy could also heat food. Instead of dismissing the melted candy as an odd accident, he decided to investigate.

ALSO READ: He built Hawell’s from one ice cream shop to 22 branches. Why is he selling the $6 million business after 27 years?

Spencer tested the idea with popcorn

Spencer placed popcorn kernels near the equipment and watched what happened. The kernels began to heat up and pop. That gave him a much stronger clue that the microwave energy was responsible for the heating.

He conducted another experiment using an egg. When the egg was exposed to the microwave energy, pressure built up inside it until it eventually exploded.

The experiments suggested that the energy from the magnetron could heat food rapidly. What began as a melted candy bar was starting to look like something much bigger.

Percy Spencer's curiosity turned that unexpected moment into a series of experiments.

The radar technology behind the discovery

The story of the microwave oven is closely connected to World War II and the development of radar.

Magnetrons were essential components in radar systems because they generated high-frequency radio waves. These waves could be transmitted and reflected back from objects, helping radar operators detect aircraft and ships.

Spencer was already deeply familiar with the technology. His work at Raytheon involved improving the production of magnetrons, giving him the technical knowledge to understand what might have caused the candy bar to melt.

Spencer established that microwave energy could heat food

The discovery wasn't simply about accidentally putting candy near a machine. Spencer recognized an unusual effect and then designed experiments to understand it.

From experiment to microwave oven

Once Spencer established that microwave energy could heat food, Raytheon began developing a practical way to use the discovery. The company built a metal enclosure around the microwave-producing equipment, allowing the energy to be contained and used for heating food.

Spencer and Raytheon eventually patented the process. But the first microwave ovens were a long way from the compact appliances found in kitchens today.

The first microwave was huge

The first commercial microwave oven, known as the Radarange, appeared in 1947. It was enormous compared with modern microwave ovens. Early models were around 6 feet tall and weighed hundreds of pounds. They were also extremely expensive.

That meant the technology wasn't immediately suitable for the average household. Instead, early microwave ovens were more practical for commercial settings where speed and convenience could justify their cost.

Over the following years, engineers worked on making the machines smaller, more affordable and easier to operate.

When microwaves entered homes

The microwave gradually moved toward the household kitchen as the technology became more practical. One important milestone came in 1967, when Amana introduced a countertop Radarange priced at $495.

It was still expensive, but it was dramatically more convenient than the giant commercial machines that came before it.

As prices fell and consumers became more familiar with the technology, microwave ovens began appearing in more homes. The appliance eventually became a staple for reheating leftovers, preparing frozen meals and making quick snacks.

A surprising invention born from radar

The history of the microwave oven is unusual because its roots have little to do with traditional cooking. The technology came from radar research, while the crucial clue came from something as ordinary as a candy bar.

Percy Spencer's curiosity turned that unexpected moment into a series of experiments. Popcorn helped demonstrate the heating effect, while the exploding egg provided another striking piece of evidence.

From there, engineers transformed the discovery into a machine that could deliberately use microwave energy to heat food. Today, millions of people use microwave ovens without giving much thought to how they work.

Add as a Reliable and Trusted News Source
Add Now!

(You can now subscribe to our WhatsApp channel)

(You can now subscribe to our WhatsApp channel)

Read More News on
Percy Spencermicrowave ovenmicrowave inventioncandy barpopcorn experimentegg experimentmagnetronradar technologyRaytheonPercy Spencer microwave invention

Enter search text:

Continue reading with one of these options:
Limited Access
Free
Login to get access to some exclusive stories

& personalised newsletters
Login Now

Unlimited Access
Starting @ Rs120/month
Get access to exclusive stories, expert opinions &

in-depth stock reports
Subscribe Now

Unlock Access to All Exclusives with ETPrime FREE TRIAL

15 Days Free: Unlock All ETPrime Exclusives, Market Tools & ePapers

Trial offer expiring in00 : 05 : 00

I'd rather pay ₹2599 now

Uh-oh! This is an exclusive story available for selected readers only.

Worry not. You’re just a step away.

Prime Account Detected!

It seems like you're already an ETPrime member with

Log out of your current logged-in account and log in again using your ET Prime credentials to enjoy all member benefits.

Unlock ETPrime's Exclusive Stories Today!

Subscribe to gain powerful insights on business, stock market and industry trends.

Big Price Drop! Flat 40% Off

Student Only Offer

Already a Member? Sign In now

Already a Member? Sign In now
Already a Member? Sign In now

Offer Exclusively For You

Save up to Rs. 700/-

ON ET PRIME MEMBERSHIP

Avail Offer

Offer Exclusively For You

Get 1 Year Free

With 1 and 2-Year ET prime membership

Avail Offer

Offer Exclusively For You

Get 1 Year Free

With 1 and 2-Year ET prime membership

Avail Offer

Offer Exclusively For You

Get Flat 40% Off

Then ₹ 1749 for 1 year

Avail Offer

Offer Exclusively For You

ET Prime at ₹ 49 for 1 month

Then ₹ 1749 for 1 year

Avail Offer

Special Offer

Get flat 40% off on ETPrime

Avail Offer
Avail Offer

Claim NowAlready a Member? Sign In now

Need Assistance?

Connect with an ETPrime expert for personalized support and guidance

+91 9484700004

' + h3 + '

' + h4 + '

' + listing + '

What’s Included with

ETPrime Membership

1Exclusive Insights That Matter

Uncover the truth with our investigative stories

Make strategic moves using the real-world case studies

Read industry-specific stories to identify emerging trends

Spot opportunities with in-depth insights that matter

Trump temper on H-1B visas is forcing Indians to do these things to stay put in US

What Adani’s US indictment means for India Inc’s overseas fundraising
Why veterans like Reliance, L&T are on acquisition spree? Aswath Damodaran has an answer.

Will China’s dollar bond sale in Saudi Arabia trump the US in financial world?
Huawei launches its own OS to compete with Google and Apple. But can it win beyond China?

The problem with lab grown diamonds
Why a falling rupee is a better option for the economy

A list of top 20 momentum stocks that have delivered massive returns in one year