Complexity shapes our view of the universe
From Carl Zetie, Raleigh, North Carolina
Stephen Wolfram’s suggestion that the universe is essentially a computer calculating a succession of states reminded me that, for as far back as we can tell, humans have described the physical world by comparing it to the most complex thing they know at the time (18 July, p40).
In prehistory, this was ourselves, so we explained the universe in terms of malicious gods and capricious spirits who were pretty much like us. The scientific revolution of Isaac Newton, Nicolaus Copernicus and Galileo Galilei spawned physical laws based in differential calculus, equations with (theoretically) precise solutions, and so the universe was described as the most complex piece of clockwork imaginable.
In the 19th century, with the rise of statistical theory and the industrial revolution, we thought of it in terms of thermodynamics – like an incredibly complex steam engine. And in the 20th century, the digital computer arrived – no surprise, then, that we came to understand the universe in terms of information theory and computability. I predict it is only a matter of time and wider familiarity before the universe is compared to a quantum computer.
Whenever we are presented with a model of what the universe is really like, we should pause and ask ourselves whether we are looking at a new idea or an old mistake.
Thoughts on the world’s speediest spider
From Talia Morris, Cape Tribulation, Queensland, Australia
You report that a species of huntsman spider found in Queensland, Australia, has been crowned the world’s fastest. As a resident of Cape Tribulation in Queensland and a longtime friend of our local huntsman spiders, I can offer an additional explanation for their speediness: temperament. Huntsman spiders are shy and nervous by nature. Fleeing is their main survival strategy. A huntsman will bolt at a sudden noise, a puff of air blown on them or a shift in lighting. Now you see them, now you don’t (4 July, p16).
From John Newton, Rous Lench, Worcestershire, UK
On the wooden floor of my kitchen in the UK, I observe small spiders moving very fast indeed. They are less than 2 millimetres across, too small for me to identify. Surely speed should be judged in relation to body size?
Stimulating work in my 70s improved my memory
From George Wallace, Farnborough, Hampshire, UK
I read your article about superagers, those who retain an unusually keen memory into their 80s and 90s. I am 71 years old. Before I retired, aged 70, from working on complex systems, my brain seemed to be slowing down. My job, though it sounds grand, wasn’t that demanding. I found that I would forget things and people’s names (20 June, p38).
My retirement lasted only four days. I was soon contacted by a tutoring company to teach maths. I started picking up students, but found I had to take my GCSE maths again since it had changed so much. Once I had done so, I started on my A level maths. This kept me busy alongside my students. After about a year, I started to notice a profound change: my memory started to become very sharp and I could remember things that were a blur before. I have also kept myself fit by race-walking 40 miles a week.
Adapting to climate change means embracing nuclear
From Mark Pickin, Easingwold, North Yorkshire, UK
In “Rising heat”, you say we must act quickly to adapt to climate change. It is clear to me that the only way out of this mess is for us to invest in an environmentally sensible carbon-free energy source that can produce what we need on demand and at a cost to the consumer that makes fossil fuels economically unviable (Leader, 4 July).
The only technology that really makes sense is fusion, but that remains too far off. We need to embrace that, in the short to medium term, small modular fission reactors are the only off- the-shelf solution that can help fill the gap, and that fossil fuels will remain a significant energy source for at least the next 20 years. That leaves us no choice but to buy time and find some way of at least slowing climate change down. It is indisputable that volcanic eruptions can substantially cool Earth, and it would therefore seem logical to use geoengineering to emulate this effect.
We underestimate SpudCell at our peril
From Peter Bickerton, South Wootton, Norfolk, UK
Michael Le Page informs us of SpudCell, a prototype synthetic cell partly capable of replicating itself. The article asks whether it could be dangerous and boldly answers “no” (11 July, p8).
But surely we aren’t so arrogant as to assume that we can prevent evolution? Microorganisms swap bits of genetic information all the time, and can avert our best efforts to repress them. Synthetic biologists are overconfidently toying with something we aren’t even close to fully understanding, and have crossed way beyond the line of hubris.
A grisly end for an Iron Age tribal leader?
From John Woodgate, Rayleigh, Essex, UK
You write that archaeologists have found evidence that a woman interred in Iron Age Britain may have had her brain removed after death. I can imagine a scenario where the woman was a prominent tribal leader and the teenage boy buried with her was her heir. Perhaps they were killed by a rival tribe in an ambush and the woman’s bones were desecrated. Later, her remains and those of the boy were recovered and she was re-buried with honour (20 June, p 13).
Pure speculation, of course; the film and TV rights are for sale.
After 50 years of reading, there is still more to learn
From Dave Holtum, Bath, UK
I have been reading 91av on and off for more than 50 years, and always enjoy the new perspective it brings. It isn’t often, though, that two articles about things I have never heard of are presented in the same issue. I am referring to coacervates, the mysterious droplets found in our cells, and the strange state of matter known as many-body localisation (20 June, p30 and p34).
It reminded me how little I know and that I, and science in general, still have a fair way to go yet.
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