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Freeman Dyson Has Died

nytimes.com

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Re: Freeman Dyson Has Died

#191

Post by DoreenMichele »

oska wrote: post #189
DoreenMichele wrote: post #89

Earlier quoted context omitted.

There are plant species that are dependent upon fire for reproduction. Such species begin to die if all fire is suppressed. https://en.wikipedia.org/wiki/Pyrophyte https://www.gardenguides.com/97493-eucalyptus-trees-australi... https://www.bushheritage.org.au/species/grass-trees https://www.nationalforests.org/our-forests/your-national-fo... https://www.quora.com/What-seeds-need-fire-to-germinate-like... https://thek…

> When I was pursuing environmental studies, there was a cartoon in one of my textbooks depicting microbes giving off oxygen and some of the microbes protesting that they were destroying their environment and needed to stop. Microbes that off-gassed oxygen are how we got an oxygen atmosphere on earth. Yes, that is called the Great Oxidation Event [1] and it was the Earth's first major extinction event. The microbes w…

Thank you for the link to The Great Oxidation Event and for the name of it. Have an upvote for that perfectly chromulent information.

Re: Freeman Dyson Has Died

#192

Post by photon_lines »

astrophysician wrote: post #5

About 4 years ago, I was a grad student in astrophysics at Princeton. Dyson worked at the Institute for Advanced Study which, while not officially part of the university was essentially an extension of the various departments (shared colloquiums, any researcher there was a valid thesis adviser, etc.). The grad students have a tradition (or used to) called “Thunch” (Thursday Lunch) where they invite someone to come ha…

Actually, he was one of the main motivators for me to do something which I just finished today: to explain what Maxwell's equations mean in simple terms. I read his paper a few months ago explaining why Maxwell's equations were so hard to grasp, and I was awe struck at how great of a writer and communicator he was: https://www.researchgate.net/publication/4317784_Why_is_Maxw...

Rest in piece Mr. Dyson - you're a legend and you'll always be remembered.

Re: Freeman Dyson Has Died

#193

Post by asdkjh345 »

titzer wrote: post #166
asdkjh345 wrote: post #154

Earlier quoted context omitted.

>the ridiculously hot summers in Australasia Are no hotter than many other years, decades ago. >resulting in bushfires, famine and drought There is no evidence linking the fires to "climate change". And I can find no evidence of any such famine even existing. Droughts are caused by depleting the water supply, not by warm weather. Warm weather increases rain. >seas taking over the cities Has not happened. The rate of…

>>the ridiculously hot summers in Australasia > Are no hotter than many other years, decades ago. Well there is a whole damn Wikipedia article about the subject if you are into reading. https://en.wikipedia.org/wiki/Climate_change_in_Australia And yeah, the summers are ridiculously hot and are actually hotter than many other years, decades ago, and keep getting hotter. One outlier from the 1970s doesn't invalidate th…

>Well there is a whole damn Wikipedia article about the subject

Wikipedia is not science.

>And yeah, the summers are ridiculously hot and are actually hotter than many other years, decades ago, and keep getting hotter

Repeating it won't make it so.

>Bull

Look at the data for yourself.

>Please go argue with the thousands of people whose work the distilled news articles and Wikipedia articles are based on.

Why? What possible benefit would that have? I am not going to stop a multi-billion dollar industry by telling wikipedians to care about reality.

Re: Freeman Dyson Has Died

#196

Post by tmearnest »

photon_lines wrote: post #192
astrophysician wrote: post #5

About 4 years ago, I was a grad student in astrophysics at Princeton. Dyson worked at the Institute for Advanced Study which, while not officially part of the university was essentially an extension of the various departments (shared colloquiums, any researcher there was a valid thesis adviser, etc.). The grad students have a tradition (or used to) called “Thunch” (Thursday Lunch) where they invite someone to come ha…

Actually, he was one of the main motivators for me to do something which I just finished today: to explain what Maxwell's equations mean in simple terms. I read his paper a few months ago explaining why Maxwell's equations were so hard to grasp, and I was awe struck at how great of a writer and communicator he was: https://www.researchgate.net/publication/4317784_Why_is_Maxw... Rest in piece Mr. Dyson - you're a lege…

Is this a manuscript you just finished? I’d love to read it if so.

Re: Freeman Dyson Has Died

#197

Post by matheist »

A couple of years ago I got interested in an old paper of his, "Continuous Functions Defined on Spheres", where he proves that for any continuous function defined on the sphere, there are four points forming an equatorial square (ie four points equally spaced along some great circle) on which the function takes equal values.

Interestingly, this theorem can be used to prove the Wobbly Table theorem, that any square table can be rotated on a (possibly bumpy) floor so that all four legs touch the ground simultaneously.

I found the theorem interesting, and it has the flavor of the Borsuk-Ulam Theorem (commonly explained as "there are always a pair of antipodal points on the Earth that have the same temperature and pressure"), but it bugged me that the proof was not at all similar to the standard proofs of the Borsuk-Ulam Theorem.

So I found my own proof of Dyson's theorem, in the spirit of the Borsuk-Ulam Theorem. Wrote it up but didn't publish traditionally — it's at https://haggainuchi.com/wobblytable2.html — but it never occurred to me to send it to Dyson or that he might be interested.

Too late now, sadly.

Re: Freeman Dyson Has Died

#198

Post by [deleted] »

AQuantized wrote: post #183
m0zg wrote: post #144

Earlier quoted context omitted.

> Trusting the consensus of people trained in an area is always better That's what they said when Galileo Galilei was on trial for not trusting the "consensus" about geocentric view of the world. To use a more recent example, that's what they said of Dr. Barry Marshall who discovered that it was Heliobacter Pylori, and not "stress" that's causing ulcers in the stomach. Dude was very nearly laughed out of his field, t…

I think you'll find those people were actually trained in their respective fields and not fielding essentially uneducated opinions, however.

[deleted]

Re: Freeman Dyson Has Died

#199

Post by bitexploder »

aaronharnly wrote: post #119
astrophysician wrote: post #5

About 4 years ago, I was a grad student in astrophysics at Princeton. Dyson worked at the Institute for Advanced Study which, while not officially part of the university was essentially an extension of the various departments (shared colloquiums, any researcher there was a valid thesis adviser, etc.). The grad students have a tradition (or used to) called “Thunch” (Thursday Lunch) where they invite someone to come ha…

Some friends invited him to dine with us as undergrads at Princeton – he came, was sparkling and smart, told us about his eccentric "metabolism before replication" ideas about the origin of life, and was just wonderful to listen to and talk with. He is a true intellectual hero of mine, and the world is much poorer for his absence.

He left behind a wealth of ideas and works that will live on. His generation of scientist are all true pioneers that broke so much ground in science. They have left the world a richer place.

Re: Freeman Dyson Has Died

#200

Post by bagacrap »

rtrunck wrote: post #2

“It is remarkable that mind enters into our awareness of nature on two separate levels. At the highest level, the level of human consciousness, our minds are somehow directly aware of the complicated flow of electrical and chemical patterns in our brains. At the lowest level, the level of single atoms and electrons, the mind of an observer is again involved in the description of events. Between lies the level of mole…

I thought the observer effect of particle physics fell out of favor. This author gives a pretty persuasive argument that, at least from a theoretical physics point of view, consciousness does not create the universe.

https://www.paulanlee.com/2017/04/14/consciousness-and-the-m...

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