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Freeman Dyson Has Died

nytimes.com

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Re: Freeman Dyson Has Died

#131

Post by morphle »

dr_dshiv wrote: post #85

A few years ago, I asked Freeman Dyson what we should teach our children so there would be more Freeman Dyson's. He gave a surprising answer. He said we should teach children to genetically "play" with plants. He thought we needed that kind of creativity as a human species if we would ever be able to populate the asteroid belt. He said that most of the surface area of the solar system is in the asteroid belt -- but t…

Freeman at his best [1] when he is thinking blue thoughts [4,5] in the blue plane. Thermogenic plants have already evolved [2]. We need to make them grow an anti-desiccant film and be more efficient like living stones [3].

[1]https://www.youtube.com/watch?v=_yzgPMwshqE

[2]https://www.damninteresting.com/warm-blooded-plants/

[3]https://www.youtube.com/watch?v=EC4onPf_htQ

[4] Alan Kay's explanation of Arthur Koestlers creative thinking (link will follow later).

John Cleese explains how [6]. Point of view is worth 80 IQ points, the best way to predict the future is to invent it.

[5] Arthur Koestler (link will follow later).

[6] John Cleese explains why in a funny way.

Re: Freeman Dyson Has Died

#132

Post by mhh__ »

With the exception of his views on climate change, he was probably my favourite living physicist. 94 years is an extremely good (I realise this now that I have a single grandparent left, one down before I was born) innings, but what a shame.

Re: Freeman Dyson Has Died

#133

Post by aeorgnoieang »

cowboysauce wrote: post #108
m0zg wrote: post #60

Earlier quoted context omitted.

>> Excess carbon in the air is good for plants, and global warming might forestall another ice age. How is it not "rooted in science" that excess carbon is good for plants? We're already seeing significant global greening, and yields are up. Excess CO2 also reduces the amount of water the plants need.

It's akin to saying "Why is everyone concerned about this Volcano erupting? Plants will flourish in the resulting rich, volcanic soil" The statement is completely true, but it misses the point as to why people are concerned and glosses over a lot of negatives.

I interpret his point being less about denying that some people will be harmed by global warming but that most (or 'all') people will be.

I agree with what I think Dyson believed: that it's NOT obvious that global warming is net-negative (long term).

Another ice age would be pretty terrible too.

Re: Freeman Dyson Has Died

#134

Post by aeorgnoieang »

djsumdog wrote: post #69
m0zg wrote: post #60

Earlier quoted context omitted.

>> Excess carbon in the air is good for plants, and global warming might forestall another ice age. How is it not "rooted in science" that excess carbon is good for plants? We're already seeing significant global greening, and yields are up. Excess CO2 also reduces the amount of water the plants need.

He's gone, so this isn't really the place for this discussion at all. However, I'm glad this is mentioned and how it shows that there are a lot of intelligent people who have concerns with the current science debate. Consensus isn't science, it's politics, and challenging ones ideas is how we both reinforce the truth as well as dispel myths.

Why isn't this an appropriate venue for this discussion? It seems perfectly germane.

Re: Freeman Dyson Has Died

#135

Post by ck2 »

May seem trivial but the Dyson Sphere was the most amazing thing I ever learned about though Star Trek, awe inspiring in that it really is theoretically possible for us to build in thousands of years.

Re: Freeman Dyson Has Died

#136

Post by aeorgnoieang »

theothermkn wrote: post #45
mcrider wrote: post #25

Earlier quoted context omitted.

Huh, I'd be curious to see that source. I know he somewhat recanted the idea of a Dyson sphere , as it is completely impractical even with unimagined technology (re: tensile strength of the materials, and preventing such a megastructure from falling into the sun whenever a rock hits it). But he later proposed the idea of a Dyson swarm , an extremely large array of solar-sucking satellites orbiting the sun as an idea…

One thing that's slightly interesting about Dyson Sphere's is that spherical shells of matter exert exactly no gravitational pull at any point in their interiors. That is, the integral of gravitational pull over the whole shell is identically 0 for every point inside the shell.* This goes for any force that falls off by the inverse square rule, e.g. the electrostatic force. In short, there's no practical way to stick…

> there's no practical way to stick an atmosphere, much less a civilization composed of life forms that depend on gravity, to the inside of the sphere

Why not spin the sphere? Given the immense surface area, it wouldn't even matter that the centripetal force would only be strongest around the 'equator'.

So, the plan would be:

1. Create a giant rotating sphere around our Sun.

2. Create a ring world around the 'equator' of the inside of the sphere (i.e. a ring of walls high enough to hold in the resident's preferred atmosphere).

3. Install solar panels everywhere else.

4. Profit!

Re: Freeman Dyson Has Died

#137

Post by m0llusk »

m0zg wrote: post #60
melling wrote: post #28

Started writing "later” in life: “Life begins at 55, the age at which I published my first book,” he wrote in “From Eros to Gaia,” Never got his PhD. Taught physics at Cornell. Thoughts on climate change: "Relishing the role of iconoclast, he confounded the scientific establishment by dismissing the consensus about the perils of man-made climate change as “tribal group-thinking.” He doubted the veracity of the climat…

>> Excess carbon in the air is good for plants, and global warming might forestall another ice age. How is it not "rooted in science" that excess carbon is good for plants? We're already seeing significant global greening, and yields are up. Excess CO2 also reduces the amount of water the plants need.

The situation is more complex than that. Plants with accelerated metabolism and growth from increased CO2 burn through minerals and other nutrients so fast that they experience a kind of crash that leaves them stunted and vulnerable.

Re: Freeman Dyson Has Died

#138

Post by snowwrestler »

aeorgnoieang wrote: post #133
cowboysauce wrote: post #108

Earlier quoted context omitted.

It's akin to saying "Why is everyone concerned about this Volcano erupting? Plants will flourish in the resulting rich, volcanic soil" The statement is completely true, but it misses the point as to why people are concerned and glosses over a lot of negatives.

I interpret his point being less about denying that some people will be harmed by global warming but that most (or 'all') people will be. I agree with what I think Dyson believed: that it's NOT obvious that global warming is net-negative (long term). Another ice age would be pretty terrible too.

Global warming is a net negative for all people if the rate of change exceeds the rate at which we can adapt our society. That shows up in our economy as a cost, and when costs exceed revenue, society runs into trouble regardless of whether the atmosphere is 15% more conducive to plant growth.

The most obvious cost is the threat to densely populated real estate along coasts as sea level rises. You have to build sea walls or move. Building walls is a huge direct cost. But forced moving creates huge indirect costs as the price of real estate above the new waterline soars--at the same the people with land under the waterline all file flood insurance claims (or go bankrupt).

Freeman Dyson was a brilliant physical scientist, but the problems of global warming will be primarily social, not physical.

Re: Freeman Dyson Has Died

#139

Post by yellowapple »

EForEndeavour wrote: post #101
dr_dshiv wrote: post #85

A few years ago, I asked Freeman Dyson what we should teach our children so there would be more Freeman Dyson's. He gave a surprising answer. He said we should teach children to genetically "play" with plants. He thought we needed that kind of creativity as a human species if we would ever be able to populate the asteroid belt. He said that most of the surface area of the solar system is in the asteroid belt -- but t…

Isn't the large total surface area of the asteroid belt overwhelmed by drawbacks like unusability of most of it for most purposes (uneven, unstable, unshielded, etc.), and the fact that humans do really poorly in microgravity?

One question I really hope we can answer someday: exactly how little gravity do humans need before it becomes too "micro"? Can humans stay healthy on Mars? On the Moon? On Ceres or Enceladus or Pluto or Charon or yet smaller bodies?

But yeah, I don't think "surface area" is the right angle to look at. More like "volume within a sufficient depth". A lot of (most?) asteroids and comets consist primarily of water ice, and water happens to be pretty darn good at radioactive shielding, so if we build habitats inside the asteroids we'd have a solid chance of significantly addressing that particular hazard (and also have plenty of water for drinking / agriculture / fuel).

Re: Freeman Dyson Has Died

#140

Post by robotresearcher »

cowboysauce wrote: post #108
m0zg wrote: post #60

Earlier quoted context omitted.

>> Excess carbon in the air is good for plants, and global warming might forestall another ice age. How is it not "rooted in science" that excess carbon is good for plants? We're already seeing significant global greening, and yields are up. Excess CO2 also reduces the amount of water the plants need.

It's akin to saying "Why is everyone concerned about this Volcano erupting? Plants will flourish in the resulting rich, volcanic soil" The statement is completely true, but it misses the point as to why people are concerned and glosses over a lot of negatives.

The Goklany report that Dyson was discussing deascribes the evidence for many of the potential negatives. I don't vouch for the quality of the report one way or the other but I just skim-read it and it addresses the potential costs of increased CO2 directly.

edit: the report has 18 pages on the benefits and 12 pages on the costs of elevated CO2.

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