観測 and 観察: Stars, River Levels, and a Leaf Under a Magnifying Glass
Compare monitoring stars and river levels with observing a leaf surface and recording results. Read the overlapping observation meanings through their targets, rather than a tools-versus-no-tools rule.
Observing stars and monitoring a river level
観測 (かんそく) means observation or monitoring. 「屋上で星の動きを観測した。」 — “We observed the movement of the stars from the rooftop.” The movement of the stars is the object of a past observation from the rooftop.
「川の水位を毎朝観測して記録する。」 — “We measure and record the river level every morning.” The Japanese sentence reports observing and recording the river level every morning; the English quotation expresses the action as measuring and recording it. These examples focus on natural phenomena.
Viewing a leaf surface and recording observations
観察 (かんさつ) means observation. 「虫眼鏡で葉の表面を観察した。」 — “We observed the surface of the leaf with a magnifying glass.” The surface of the leaf was observed with a magnifying glass, so this example of 観察 includes a tool.
「毎朝の観察結果をノートに記録する。」 — “I record the results of my observations in a notebook every morning.” The sentence describes recording the results of observations in a notebook every morning. Recording those results does not itself state that a particular hypothesis was successfully verified.
Read the representative targets
Both words have observation among their English meanings. Here 観測 occurs with star movements and a river level, while 観察 occurs with a leaf surface and observation results. Follow each object and the action described.
Do not divide the words into numerical measurement for 観測 and unaided sight for 観察. The magnifying-glass example already shows a tool used for 観察. Read the stated target and recordkeeping without supplying extra measurement values or equipment.
Are 「観察した」 with a leaf and magnifying glass and 「観測した」 with star movements distinguished exclusively by tools or numbers?
Show the answer and why
No. The 観察 example itself uses a magnifying glass. Read the representative targets and actions: stars or river levels, a leaf surface, and recorded observations. Recording results alone does not establish successful verification of a hypothesis.