astronomy

John Lukens

John Lukens 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 John Lukens rather than just read about it. In short: John Lukens (1720 – c. 14 October 1789) was a surveyor and astronomer and a member of the Young Junto, elected in 1766. He was Surveyor-General of Pennsylvania and Delaware.

Key takeaways

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

Reference excerpt

John Lukens (1720 – c. 14 October 1789) was a surveyor and astronomer and a member of the Young Junto, elected in 1766. He was Surveyor-General of Pennsylvania and Delaware.

Life Born in Horsham Township outside Philadelphia, Pennsylvania, he joined the Young Junto, just before it became the American Society and then facilitated its unification with the American Philosophical Society (APS), to which he had already been separately elected. In 1763 Lukens was named surveyor general of the province, an office he held for much of his life. He was a founder of the Hatboro library and a subscriber to the Silk Society. He was also part of the APS committee chosen to observe the Transit of Venus, alongside David Rittenhouse, William Smith, and John Sellers. Lukens surveyed a route for a proposed Delaware-Chesapeake canal in 1769 and undertook a similar survey for a proposed Schuylkill-Susquehanna canal several years later. When the Marquis de Condorcet sent the APS a series of queries, Lukens was tasked with responding to two of them, though the American Revolution seems to have precluded his response. Lukens' term as surveyor general ended when the proprietary government dissolved in 1775–1776, but he continued to provide geographic information during the War for Independence and resumed his post as surveyor general of the new state in 1781. He conducted preliminary work to settle the Pennsylvania-Virginia border with APS member Archibald McClean, served as a commissioner of the Land Office and a city regulator, and surveyed western lands intended for Pennsylvania veterans. He also continued his astronomical observations, discovering a comet in 1784.

Family He married Rachel Robinson. His son Jesse Lukens was an APS member.

Works Smith, William; Lukens, John; Rittenhouse, David; Sellers, John; Smith, Doctor; Maskeline, Nevil (1769). "Account of the Transit of Venus over the Sun's Disk, as Observed at Norriton, in the County of Philadelphia, and Province of Pennsylvania, June 3, 1769". Philosophical Transactions. 59: 289–326. Bibcode:1769RSPT...59..289S. JSTOR 105839.

Legacy His papers are held at Pennsylvania State Archives, and University of Delaware.

References

Worked examples

Example 1 — a first encounter with John Lukens

Start with the simplest possible case. Write down what John Lukens 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 John Lukens 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 John Lukens 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 John Lukens

In research: John Lukens 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 John Lukens 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: John Lukens is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1720 births, 1789 deaths, 18th-century American astronomers, so understanding it makes those chapters shorter.
In everyday life: Look for John Lukens 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.

Affiliate

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

How to study John Lukens in 20 minutes

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

Frequently asked questions

What is John Lukens in simple terms?

John Lukens (1720 – c. 14 October 1789) was a surveyor and astronomer and a member of the Young Junto, elected in 1766. He was Surveyor-General of Pennsylvania and Delaware.

Why does John Lukens 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 John Lukens?

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 John Lukens.