Tag Archives: science

The Dark Side of Gaia

I was reminded tonight of the Gaia hypothesis. It was quite a thing in the 1970s.

The Gaia hypothesis, named after the ancient Greek goddess of Earth, posits that Earth and its biological systems behave as a huge single entity. This entity has closely controlled self-regulatory negative feedback loops that keep the conditions on the planet within boundaries that are favorable to life. Introduced in the early 1970s, the idea was conceived by chemist and inventor James E. Lovelock and biologist Lynn Margulis.

This had a natural appeal in the early days of the environmental movement. I was skeptical back then, thinking of it as new age wishful thinking, and impossible to test. I was wrong: Its origins are far darker. Here is the abstract of Gas Guzzling Gaia, or: A Prehistory of Climate Change Denialism:

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Significant Figures

I found this post on Facebook: Why is it important to know so many digits of pi?.

My comment:

As someone who started computing with log tables and slide rules, the first question I ask is how many significant digits do the other variables in your calculation have? The smallest such number tells you how many digits of pi you need. With electronic devices there is no harm in using more in your calculation, as many as your device has, but do not let that give you a false idea of the precision of your result.

I learned about significant figures in my high school chemistry in 1967-68. (Thank you, Mr. Wheeler!). Use of appropriate significant figures, also from a chemistry class, clearly explains the concept and its use in practice.

I only first saw Star Trek (TOS) after high school, in reruns. Thanks to that chemistry class I gag every time I hear Mr. Spock reporting some calculation to an absurd number of decimal places. His input data could not possibly be that precise!

Water on the Moon

It’s confirmed. There is water on the Moon. OK, what’s the big deal? Water is very common in the cosmos and has been seen on the moon before. The difference is that previously it had been been only in craters near the lunar south pole, perpetually in darkness. Now, as the updated NASA announcement said, NASA’s SOFIA Discovers Water on Sunlit Surface of Moon, which will be much more accessible to future explorers.

How significant this is remains to be seen, but it has provided Katie Mack with some inspiration.

Phosphine on Venus: Not so fast

Last month I posted about a Possible Sign of Life on Venus, which reported on Phosphine gas in the cloud decks of Venus. Earlier this month I mentioned More about phosphine on Venus. The story is not over yet.

A Question of Phosphine links to Re-analysis of the 267-GHz ALMA observations of Venus: No statistically significant detection of phosphine. This team re-analyzed the same data used in the first Phosphine gas paper, but came to the opposite conclusion. So it comes down to a very complicated question of statistical analysis.

Professor Coles also linked to A stringent upper limit of the PH3 abundance at the cloud top of Venus by another team which included Jane Greaves, first author of Phosphine gas in the cloud decks of Venus.

More about phosphine on Venus

Following up on Possible Sign of Life on Venus. After that announcement some scientists took another look at 1978 data from the Pioneer Venus Multiprobe. At the time nobody was specifically looking for phosphine, but a new analysis of the raw data supports the possibility that there is phospine in the atmosphere of Venus. Details at Is Phosphine in the Mass Spectra from Venus’ Clouds?.

This has happened before in astronomy. After both Neptune and Pluto were discovered, astronomers looked at old records and found that their predecessors had seen both bodies, but had not realized they were significant. In the case of Neptune one of those predecessors was Galileo.

Possible Sign of Life on Venus

Yesterday I got an email from Cosmoquest about a science press conference (“presser”) where a new discovery would be announced. With all the new distance-based communication technology anybody could watch, rather than just those in a select room, however large. The event was put on by the Royal Astronomical Society today. I watched it on the Cosmoquest Twitch TV channel. I had never heard of Twitch TV before.

The occasion was that

An international team of astronomers, led by Professor Jane Greaves of Cardiff University, today announced the discovery of a rare molecule – phosphine – in the clouds of Venus. On Earth, this gas is only made industrially, or by microbes that thrive in oxygen-free environments.

The discovery was made by spectroscopy using two different radio telescopes. The significance of this is that the production of phospine by purely chemical processes is very unlikely in the atmosphere of Venus. The team looked at every possible chemical reaction they could think up, and failed to find any that could come close to producing the observed amount of phospine.

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