難関大向け｜英語長文問題127（ナノテクノロジー）601語＋和訳・解答解説

Nanotechnology is often introduced through images of machines so tiny that they can operate inside a human cell. Such images are memorable, but they can obscure a more important feature of the field. At the nanoscale, where materials are measured in billionths of a meter, familiar substances may behave in unfamiliar ways because size influences properties such as strength, conductivity, and chemical reactivity. The practical promise of nanotechnology therefore lies not simply in making existing objects smaller, but in learning to control matter where small changes in structure can produce large changes in function. This raises a broader question: when does greater control over matter actually lead to better technology?

Consider medicine, where nanoscale materials can be designed to carry substances through the body or interact with particular biological environments. In principle, such precision could allow a treatment to act more selectively, reducing its effects on tissues that are not intended targets. Yet precision at the design stage does not guarantee precision after a material enters a complex living system. Particles may interact with proteins, move through organs, or change over time in ways that depend on their size, shape, and surface. The very properties that make a material useful can therefore also make its behavior difficult to predict.

A similar tension appears in environmental applications. Nanoscale materials may help filters capture pollutants or enable surfaces to break down unwanted chemicals more efficiently. These possibilities encourage the idea that advanced materials can solve environmental problems with less energy or fewer resources. However, evaluating such a solution requires looking beyond its immediate performance. Producing the material may consume energy, and particles released during manufacture, use, or disposal may enter environments where their effects are less well understood. A highly efficient filter, considered in isolation, may thus appear more sustainable than it does when its entire life cycle is taken into account.

This does not mean that uncertainty should prevent innovation. Nearly every technology develops under incomplete knowledge, and demanding complete certainty before practical use would make progress extremely difficult. The challenge is instead to decide which uncertainties matter enough to investigate early. This is particularly important with nanoscale materials because conventional categories may be misleading. Two materials with the same chemical composition can behave differently when their structures or particle sizes differ. Regulation and testing based only on what a substance is made of may consequently overlook how its physical form affects its behavior.

The issue also changes how we think about technological success. A material may perform exceptionally well in a laboratory yet prove unsuitable outside it because manufacturing it consistently is expensive, because it is difficult to recycle, or because its advantages disappear when produced on a larger scale. Conversely, a less impressive material may become more valuable if it is easier to produce, monitor, recover, and reuse. Innovation, from this perspective, is not a race to achieve the most remarkable property. It is a process of balancing performance with reliability, cost, environmental consequences, and the ability to manage uncertainty.

Nanotechnology is powerful precisely because small structures can have disproportionately large effects. But that principle applies to both benefits and problems. The most responsible approach is therefore neither to celebrate nanoscale innovation automatically nor to reject it because every consequence cannot be predicted. Its value depends on whether designers and institutions examine materials across their full life cycles, test the properties that actually determine behavior, and remain willing to revise applications as evidence develops. Mastering matter at a smaller scale is an impressive scientific achievement; deciding where and how that mastery should be used is the more demanding technological task.

Q1. What does the third paragraph suggest about environmental nanotechnology?

1. Nanoscale environmental solutions should be judged across their entire life cycles.
2. Greater filtering efficiency necessarily means lower overall environmental impact.
3. Manufacturing costs matter less when nanoscale materials reduce energy use.
4. Environmental risks arise mainly after nanomaterials have entered natural ecosystems.

Q2. What approach to uncertainty does the fourth paragraph support?

1. Existing chemical classifications are usually sufficient for evaluating nanoscale substances.
2. Uncertainty should be examined selectively rather than used to block innovation.
3. Complete knowledge is required before unfamiliar nanoscale materials are practically used.
4. Physical form matters less than chemical composition when assessing material behavior.

Q3. Which statement is NOT supported by the passage?

1. Nanoscale medical tools can behave differently once inside living systems.
2. Small structural changes can significantly alter how familiar materials function.
3. Laboratory success generally predicts whether a material will scale effectively.
4. Responsible use requires continued evaluation as knowledge about applications develops.