mathematics

Niels Erik Nørlund

Niels Erik Nørlund is a mathematics 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 Niels Erik Nørlund rather than just read about it. In short: Niels Erik Nørlund (26 October 1885, in Slagelse – 4 July 1981, in Copenhagen) was a Danish mathematician. His book Vorlesungen über Differenzenrechnung (1924, reprinted 1954) was the first book on complex function solutions of difference equations.

Key takeaways

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

Reference excerpt

Niels Erik Nørlund (26 October 1885, in Slagelse – 4 July 1981, in Copenhagen) was a Danish mathematician. His book Vorlesungen über Differenzenrechnung (1924, reprinted 1954) was the first book on complex function solutions of difference equations. His doctoral students include Georg Rasch. The Norlund Alps and Norlund Land in Greenland were named after him. He was also the brother of Margrethe Nørlund Bohr and brother-in-law of Nobel Prize winning physicist Niels Bohr.

Selected works Vorlesungen über Differenzenrechnung. Berlin: Springer-Verlag. 1924. with René Lagrange as editor: Leçons sur les équations linéaires aux différences finies. Paris: Gauthier-Villars. 1929. Vermessungsarbeiten in Grönland, Island und Dänemark. Darmstadt: Vereinigung von Freunden der TH Darmstadt. 1939. "The logarithmic solutions of the hypergeometric equation". K. Dan. Vidensk. Selsk. Mat. Fys. SKR. 5: 1–58. 1963.

See also Nörlund–Rice integral Inge Lehmann Indefinite sum

References

Further reading Mathematics and Mathematicians: Mathematics in Sweden Before 1950 Nørlund on Calculus of Differences

Illustrations

Worked examples

Example 1 — a first encounter with Niels Erik Nørlund

Start with the simplest possible case. Write down what Niels Erik Nørlund claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In mathematics, 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 Niels Erik Nørlund 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 Niels Erik Nørlund 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 Niels Erik Nørlund

In research: Niels Erik Nørlund appears in mathematics 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 Niels Erik Nørlund 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: Niels Erik Nørlund is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1885 births, 1981 deaths, 20th-century Danish mathematicians, so understanding it makes those chapters shorter.
In everyday life: Look for Niels Erik Nørlund 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Niels Erik Nørlund” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Niels Erik Nørlund in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Niels Erik Nørlund 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 Niels Erik Nørlund out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Niels Erik Nørlund in simple terms?

Why does Niels Erik Nørlund matter?

Because it connects several mathematics 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 Niels Erik Nørlund?

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 Niels Erik Nørlund.