Is it possible to define the biological, chemical and physical functions that separate cells, plants and even humans from inanimate objects? In his new book, Paul Nurse, Nobel prize winner and director of the Francis Crick Institute, addresses a question that has long plagued both philosophers and scientists – what does it really mean to be alive? Speaking to Madeleine Finlay, Paul delves into why it’s important to understand the underlying principles of life, the role of science in society, and what life might look like on other planets
Tagged with “chemistry” (5)
Tom Sutcliffe with Sir Robert Lechler, Jo Dunkley, Bernie Bulkin and Elizabeth Pisani.
There is nothing new for chemistry to discover, says Bernie Bulkin. In Solving Chemistry: A Scientist’s Journey, the former Head of Science at BP argues that an unprecedented event has happened: a branch of science has made all the major discoveries it is likely to make. He tells Tom Sutcliffe what this means for chemistry - and for science more broadly.
Medicine is in the midst of ‘a biomedical revolution’ says Professor Sir Robert Lechler. His own field of kidney transplants has been transformed by our new understanding of the immune system. He has helped to curate Spare Parts, an exhibition at the Science Gallery that poses the question: how many transplants could we have before we were no longer ourselves?
Elizabeth Pisani has watched interest in different diseases rise and fall. As an epidemiologist she charts the impact that press attention and public grants have on medical research, with some becoming fashionable while in others treatments lag behind. And she warns that scientists too often fail to take account of the human context when delivering medicines.
Astrophysicist Jo Dunkley assesses our understanding of the universe in a concise new guide. But the universe is 85% dark matter - and we still know very little about this. She draws attention to the brilliant female scientists who contributed to breakthroughs in physics, but whose contributions have been forgotten along the way.
If we find, anywhere in the universe, one more instance of life besides what evolved on Earth, then we are bound to conclude that life is common throughout the vastness of this galaxy and the 200 billion other galaxies.
The discovery would change how we think about everything.
Most of the search for life beyond Earth, Porco explained, is the search for habitats.
They don’t have to look comfy, since we know that our own extremophile organisms can survive temperatures up to 250°F, total desiccation, and fiercely high radiation, high pressure, high acidity, high alkalinity, and high salinity.
In our own Solar System there are four promising candidate habitats—Mars, Europa (a moon of Jupiter), Titan (a moon of Saturn), and Enceladus (“en-SELL-ah-duss,” another moon of Saturn).
They are the best nearby candidates because they have or have had liquids, they have bio-usable energy (solar or chemical), they have existed long enough to sustain evolution, and they are accessible for gathering samples.
On Mars water once flowed copiously.
It still makes frost and ice, but present conditions on Mars are so hostile to life that most of the search there now is focussed on finding signs of life far in the past.
Europa, about the size of Earth’s Moon, has a salty ocean below an icy surface, but it is subject to intense radiation.
Photos from the Hubble Space Telescope revealed that occasional plumes of material are ejected through Europa’s ice, so future missions to Jupiter will attempt to fly by and analyze them for possible chemical signatures of life.
The two interesting moons of Saturn are Titan, somewhat larger and much denser than our Moon, and tiny Enceladus, one-seventh the diameter of our Moon.
Both have been closely studied by the Cassini Mission since
Titan’s hazy atmosphere is full of organic methane, and its surface has features like dunes and liquid-methane lakes “that look like the coast of Maine.”
But it is so cold, at 300°F below zero, that the chemical reactions needed for life may be too difficult.
Enceladus looks the most promising.
Cassini has sampled the plumes of material that keep geysering out of the south pole.
The material apparently comes from an interior water ocean about as salty as our ocean, and silica particles may indicate hydrothermal vents like ours.
“I hope you’re gettin excited now,” Porco told the audience, “because we were.”
The hydrothermal vents in Earth’s oceans are rich with life.
Enceladus has all the ingredients of a habitat for life—liquid water, organics, chemical energy, salts, and nitrogen-bearing compounds.
We need to look closer.
A future mission (arriving perhaps by the 2030’s) could orbit Enceladus and continually sample the plumes with instruments designed to detect signs of life such as complexity in the molecules and abundance patterns of carbon in amino acids that could indicate no biology, or Earth-like biology, or quite different biology.
You could even look for intact organisms.
Nearly all of the material in the plumes falls back to the surface.
Suppose you had a lander there.
“It’s always snowing at the south pole of Enceladus,” Porco said.
“Could it be snowing microbes?”
(A by-the-way from the Q&A:
Voyager, which was launched 40 years ago in 1977, led the way to the outer planets and moons of our Solar System, and five years ago, Porco pointed out, “It went beyond the magnetic bubble of the Sun and redefined us as an interstellar species.”)
In the fall of 1902, twelve young men in suits regularly gathered for dinners in the basement of a government building in Washington, D.C. The men ate what they were served, even though they knew that their food was spiked with poison. The mastermind behind these experiments was Harvey Washington Wiley. Before you condemn him, though, you’d be surprised to know that you probably owe him a debt of gratitude. Incidentally, Wiley is the founding father of the Food and Drug Administration.
Inside the Episode:
The intention of these experiments was not to induce digestive discomfort for its own sake. Rather, they were part of an extensive study on how chemical preservatives in food — before regulations existed — could harm human beings over time. You might cringe at what was once used to keep food “fresh.”
Producer Sruthi Pinnamaneni gave us a closer look inside the story. About diving deep into archival materials, she says,
“I spent hours [at the Library of Congress], reading thousands of [Wiley’s] letters and squinting at his tiny journals. It is when you know every curve and squiggle of a man’s handwriting that you feel as though you’re starting to get to know him!”
One surprising fact that she discovered while researching the piece was that while Wiley’s experiments contributed so much to food regulation, today’s practices still leave something to be desired:
“…The FDA doesn’t really test food additives anymore. There are more than five thousand additives commonly found in processed food and most of them haven’t been tested on animals and almost none (except for dietary supplements) have been tested on humans.”
Sruthi sent us some photographs of the Poison Squad, Wiley, and some (how shall I put this?) unconventional tools that were used during the experiments.
William Carter with Wiley and the Poison Squad
Wiley in his lab
A letter showing interest in participating
A fecal drying machine“None but the brave can eat the fare.” Are you brave enough? Full serving of intrigue and radio in this piece. Bon appetit.
The Poison Squad won Best Radio & Podcast Media at the Jackson Hole Science Media Awards in 2014.
The Poison Squad was produced by Sruthi Pinnamaneni with sound design by Brendan Baker. It was hosted for this episode of Transistor by Genevieve Sponsler and mixed for Transistor by Erika Lantz.
All photos: FDA
English scientist, philosopher and theologian Joseph Priestley conducted experiments that led to the discovery of oxygen. But he was also central in the politics and religious life of England and early America. We talk about Priestley with author Steven Johnson.