astronomy

Kotaro Honda

Kotaro Honda is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Kotaro Honda rather than just read about it. In short: Kotaro Honda (本多光太郎, Honda Kōtarō), born on February 23, 1870, in Okazaki, Aichi Prefecture – February 12, 1954) was a Japanese metallurgist and inventor. He invented KS steel (initials from Kichiei Sumitomo), which is a type of magnetic resistant steel that is three times more resistant than tungsten steel.

Key takeaways

Kotaro Honda belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Kotaro Honda to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Kotaro Honda from memory before moving on to harder problems.

Reference excerpt

Kotaro Honda (本多光太郎, Honda Kōtarō), born on February 23, 1870, in Okazaki, Aichi Prefecture – February 12, 1954) was a Japanese metallurgist and inventor. He invented KS steel (initials from Kichiei Sumitomo), which is a type of magnetic resistant steel that is three times more resistant than tungsten steel. This material, which had 250 oersteds magnetic resistance, was developed through rigorous basic research on steel and alloys. Honda was born in the town of Yahagi (part of modern Okazaki, Aichi and was a graduate of Tokyo Imperial University. He was taught by the famous Japanese physicist Hantaro Nagaoka at the University of Tokyo. Honda's research on KS steel in 1917, and on improved KS steel in 1934 became the basis for his position that Japan's industrial development is dependent on basic research in major scientific fields. He later improved upon the steel, creating NKS steel. NKS steel was mentioned by Taiichi Ohno in his book as being one of the Japanese materials whose development was tied to World War II.

Honda, together with the academic Tokiatsu Hojo, setup up a research institute, which was supported by the Sumitomo family. It was later renamed Metallic Materials Research Institute. In 1931, he was appointed president of Tohoku Imperial University, where he taught physics for several years. He participated in establishing the (千葉工業大学, Chiba Institute of Technology) from 1940. He served as the first president of the Tokyo University of Science from 1949. Honda was nominated for the Nobel Prize in Physics in 1932, and was one of the first persons to be awarded the Order of Culture when it was established in 1937. He was also awarded the Franklin Institute's Elliott Cresson Medal in 1931 and became a Person of Cultural Merit in 1951. He was posthumously awarded the Grand Cordon of the Order of the Rising Sun. Honda died in 1954 in Bunkyo, Tokyo, and his grave is at the temple of Myogen-ji in Okazaki. On April 18, 1985, the Japan Patent Office selected him as one of Ten Japanese Great Inventors.

Books available in English Magnetic properties of matter / Kotaro Honda (1928)

References

Illustrations

Worked examples

Example 1 — a first encounter with Kotaro Honda

Start with the simplest possible case. Write down what Kotaro Honda claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Kotaro Honda before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Kotaro Honda ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Kotaro Honda

In research: Kotaro Honda appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Kotaro Honda in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Kotaro Honda is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1870 births, 1954 deaths, 20th-century Japanese inventors, so understanding it makes those chapters shorter.
In everyday life: Look for Kotaro Honda outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Kotaro Honda in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Kotaro Honda means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Kotaro Honda out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Kotaro Honda in simple terms?

Why does Kotaro Honda matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Kotaro Honda?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Kotaro Honda.