Question

what is the meaning of this passage, please don't copy from another source.

Without chemical reactions, there could be no life.

Or could there?

It was a long-standing problem. Early in planning Wildlife, the question had been posed: How do you study a life totally unlike any you know? How would you even know it was alive?

This was not an academic matter. Biology, as George Wald had said, was a unique science because it could not define its subject matter. Nobody had a definition for life. Nobody knew what it was, really. The old definitions – an organism that showed ingestion, excretion, metabolism, reproduction, and so on – were worthless. One could always find exceptions.

The group had finally concluded that energy conversion was the hallmark of life. All living organisms in some way took in energy – as food, or sunlight – and converted it to another form of energy, and put it to use. (Viruses were the exception to this rule, but the group was prepared to define viruses as nonliving.)

For the next meeting, Leavitt was asked to prepare a rebuttal to the definition. He pondered it for a week, and returned with three objects: a swatch of black cloth, a watch, and a piece of granite. He set them down before the group and said: “Gentlemen, I give you three living things.”

He then challenged the team to prove that they were not living. He placed the black cloth in the sunlight; it became warm. This, he announced, was an example of energy conversion – radiant energy to heat.

It was objected that this was merely passive energy absorption, not conversion. It was also objected that the conversion, if it could be called that, was not purposeful. It served no function.

“How do you know it is not purposeful?” Leavitt had demanded.

They then turned to the watch. Leavitt pointed to the radium dial, which glowed in the dark. Decay was taking place, and light was being produced.

The men argued that this was merely release of potential energy held in unstable electron levels. But there was growing confusion; Leavitt was making his point.

Finally, they came to the granite. “This is alive,” Leavitt said. “It is living, breathing, walking and talking. Only we cannot see it, because it is happening too slowly. Rock has a lifespan of three billion years. We have a lifespan of sixty or seventy years. We cannot see what is happening to this rock for the same reason that we cannot make out the tune on a record being played at the rate of one revolution every century. And the rock, for its part, is not even aware of our existence because we are alive for only a brief instant of its life span. To it, we are like flashes in the dark.”

He held up his watch.

His point was clear enough, and they revised their thinking in one important respect. They conceded that it was possible that they might not be able to analyze certain life forms. It was possible that they might not be able to make the slightest headway, the least beginning, in such an analysis.”

Answer 1

The meaning of the above passage:

The passage above means that there is no single definition that could define "life". It is in line with the notion that biology is a science of exception. Going by the present definition of life forms, it is possible that there might be many living forms may get excluded. We may try to define life by newer definitions, but there always will be some exception hard to explain.