Lovelock (1965): the paper, with reading support · Earth & Env Science

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Start here: the interactive reader

The paper with the reading supports built into it. It opens in a new window, so keep this page in the tab behind it for the glosses and the word list.

Open the interactive reader

Sign in with your school Google account. The reader is restricted to AISC accounts, so it will not open for anyone outside the school.

Definitions open where the word is used. Pick a language above and they appear alongside the English.

The argument, one step at a time

Nine short steps through what the paper says. Read these first if the paper is hard going, then go back to it knowing what you are looking for. This is not the paper, and your OPVL is on the paper.

Step 1 of 9

The question

It is 1965. NASA is planning to send spacecraft to other planets. Lovelock asks a simple question: if you land on Mars, how would you know whether anything there is alive?

Step 2 of 9

The usual plan

Most scientists said: look for life like ours. Land a probe, scoop up soil, test it for the chemistry Earth life uses. Lovelock thought this was weak. It can only find life that happens to be built the way we are.

Key words:

Find it in the paper: It is not surprising, in view of the vast expense

Step 3 of 9

His move

Do not look for the life itself. Look at what life does to the whole planet. That changes what you need to send, and what you need to know before you go.

Key words:

Find it in the paper: It is the object of this article to show

Step 4 of 9

What life does

Living things take in energy. They use it to build order inside themselves. Then they push the waste back out. They keep doing this, everywhere, for a very long time.

Key words:

Find it in the paper: Life is one member of the class

Step 5 of 9

A dead planet settles

On a planet with no life, the gases in the air react with each other until there is nothing left to react. Then the mix stops changing. That settled state is called equilibrium.

Key words:

Find it in the paper: The omnipresence of intense orderliness

Step 6 of 9

A living planet does not

On Earth, oxygen and methane are both in the air. Those two react with each other. They should not both still be there. They are, because living things keep making more of them.

Two atmospheres compared: a settled one where gases have finished reacting, and Earth's, where oxygen and methane coexist because life keeps replacing them.

Key words:

Find it in the paper: Extreme departures from an inorganic

Step 7 of 9

So here is the test

You do not need to land at all. Measure the gases in a planet's atmosphere from far away. If they look settled, the planet is probably dead. If they look strangely unsettled, something is holding them that way.

Find it in the paper: Atmospheric analysis. Search for the presence

Step 8 of 9

Then he tries it on Mars

In the last part of the paper he turns to Mars. It is dry. The air is thin, with almost no oxygen. As far as anyone knew in 1965, Mars looks settled. So he argues that looking for Earth-like life there is the wrong plan.

Key words:

Find it in the paper: Ordinarily one does not look for fish in a desert

Step 9 of 9

Now the part that is yours

You now know what the paper argues. That is the easier half. The work of this block is the other half: who wrote this, when, why, what it is good for, and what it cannot tell you. Start with the journal line, the acknowledgements, and the sentence about who paid for the work.

Find it in the paper: This work was supported by a grant

Read for Origin and Purpose

The title and author block
The Nature citation line
The Acknowledgements paragraph
The NASA grant sentence
The References list

The scanned PDF contains a couple of obvious errors where the scanner misread a letter, words that are clearly not what Lovelock wrote. The class reading tool corrects them back to the 1965 printed text. They are worth noticing anyway: you are reading a machine's copy of a printed page, not the page, and that belongs in your Origin.

Word list

All 30 words from the paper, in the order Lovelock uses them. The 10 tagged in the steps are the ones the nine steps above explain; the rest turn up elsewhere in the paper, so they are here for when you are reading it yourself.

unequivocal adjective

Having only one possible meaning. An unequivocal result cannot be argued about.
Lovelock wants a test whose answer nobody can dispute.
extra-terrestrial adjective in the steps

From beyond Earth.
geocentric adjective in the steps

Taking Earth as the centre or the standard. A geocentric question assumes other places work like Earth.
Lovelock uses this as a criticism. Watch how he turns it into a limitation of other people's experiments.
phenomenological adjective in the steps

Describing what you can observe, without claiming to explain the deeper reason why.
Lovelock calls his own method this. He is being honest about a limit, not apologising.
biochemistry noun

The chemistry of living things.
inorganic adjective

Not made by living things. Rocks and gases are inorganic.
entropy noun in the steps

How spread-out and mixed-up things are. Left alone, everything becomes more mixed up. Life pushes the other way.
The most important word in the paper. Lovelock's definition of life turns on it.
vortex noun (plural: vortices)

A spinning whirlpool of water or air.
Lovelock's counter-example: a vortex is orderly too, but it disappears quickly. Life does not.
thermodynamic equilibrium noun phrase in the steps

A settled state. Every reaction that could happen has already happened, and nothing is left to react.
A dead planet's atmosphere settles. Earth's has not.
chemical potential noun phrase in the steps

How much a substance still 'wants' to react with what is around it.
steady state noun phrase

A situation that stays the same overall, even though things keep moving through it.
Not the same as equilibrium. A river can be in steady state while water keeps flowing.
disequilibrium noun in the steps

The opposite of equilibrium. Things that should have reacted together are still sitting side by side.
Oxygen and methane in Earth's air. This is Lovelock's biosignature.
omnipresence noun

Being everywhere at once.
sterile adjective in the steps

Having no life at all.
primeval adjective in the steps

From the earliest times, before anything else.
flux noun

How much of something flows onto a surface each second. Solar flux is how much sunlight arrives.
appreciable adjective in the steps

Big enough to notice or measure.
spontaneous generation noun phrase

Life starting by itself from non-living matter.
gas chromatograph noun

A machine that separates a mixture of gases so each one can be identified.
mass spectrometer noun

A machine that weighs molecules to work out what they are.
polymer noun

A long molecule built from many identical small units joined in a chain.
molecular weight noun phrase

How heavy one molecule is.
exotherm noun

A burst of heat given out by a reaction.
differential thermal analysis (DTA) noun phrase

Heating two samples side by side and comparing them, to see if one reacts.
pyrolysis noun

Breaking a substance apart using heat, without burning it in oxygen.
hydrocarbon noun

A molecule made only of hydrogen and carbon. Petrol and methane are hydrocarbons.
alkane noun

A simple type of hydrocarbon with only single bonds.
abiotic adjective

Made without any living thing involved.
metastable adjective

Balanced for now, but one push away from changing.
Poisson distribution noun phrase

A standard pattern showing how often random events happen. Real data that does NOT fit this pattern is a sign something non-random is at work.

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