The vacuum flask, also known as a thermos flask, was invented by which scientist to help maintain very low or high temperatures?

Introduction / Context:
The vacuum flask is a double walled container with a vacuum between the walls, designed to greatly reduce heat transfer. It is widely used to keep liquids hot or cold. This question checks whether you know that the vacuum flask was invented by James Dewar, a physicist who needed such equipment for his low temperature experiments.

Given Data / Assumptions:
• The invention in question is the vacuum flask or thermos flask.
• Options include Charles Babbage, Alexander Fleming, Gregory Pincus, and James Dewar.
• Each of the other names is associated with a completely different field of science or technology.

Concept / Approach:
The correct approach is to link each name to its best known achievement. Charles Babbage is associated with early computing machines, Alexander Fleming with penicillin, and Gregory Pincus with work on the oral contraceptive pill. James Dewar, on the other hand, worked on liquefied gases and invented the vacuum flask to store them at low temperatures. This clear mapping makes Dewar the only suitable choice.

Step-by-Step Solution:
Step 1: Focus on the vacuum flask as a device that uses a vacuum layer to reduce heat loss or gain.
Step 2: Recall that James Dewar was a Scottish scientist researching liquid gases and needed containers that could keep substances very cold.
Step 3: Recognise that Charles Babbage is remembered for designing analytical engines, not thermal containers.
Step 4: Note that Alexander Fleming discovered the antibiotic penicillin.
Step 5: Understand that Gregory Pincus worked on hormonal birth control methods and is not linked to the thermos flask.

Verification / Alternative check:
To verify, think of how thermos flasks are often described in physics examples. Many sources explicitly refer to the Dewar flask, named after James Dewar, as the scientific version used in laboratories. This strong naming connection is a clear confirmation. The absence of any thermos related references in the biographies of Babbage, Fleming, or Pincus further strengthens Dewar as the correct answer.

Why Other Options Are Wrong:
Charles Babbage is wrong because he is associated with the concept of programmable computing machines. Alexander Fleming is wrong because he worked in microbiology and discovered penicillin. Gregory Pincus is wrong because he is recognised for his role in developing the oral contraceptive pill. None of these achievements involve the invention of a vacuum based thermal container.

Common Pitfalls:
Some students may confuse the names or pick a familiar scientist at random. To avoid this, remember key word pairs such as Dewar equals vacuum flask, Babbage equals early computer, and Fleming equals penicillin. This simple technique prevents mixing up very different scientific achievements and allows quick and confident responses to exam questions about inventions and discoveries.

Final Answer:
The vacuum flask was invented by James Dewar.