"I just finished re-reading Orwell's 1984, and if you haven't read it (or it's been a while), I can't recommend it enough.
It has incredibly relevant and predictive elements that describe things we're starting to see in today's culture. Here are some examples ..."
Sarah A. Downey
The really scary part is that political polarization is so bad now that most people won't acknowledge the similarities ...
taking bids now ...
Recently, artist Salvatore Garau sold an 'immaterial sculpture' for 15,000 Euros (about 18,300 USD).
After thinking long and hard, I made the difficult decision to auction off the above masterpiece from the artist formerly known as Daily Llama, which I obtained many years ago. I am taking bids now ...
However, I reserve the right to sell the other masterpiece from the same artist as an NFT.
Apollo 11
In 1969 'the Eagle has landed' on the Moon and a few days later the upper section of the lunar module brought Armstrong and Aldrin back to the command and service module, which finally brought the astronauts back to Earth.
But what happened to the lunar module? Does it still circle the Moon five decades later?
If you find this question interesting you may like this YouTube video.
I think it is a great example of what dedicated space and science enthusiasts can do ...
But what happened to the lunar module? Does it still circle the Moon five decades later?
If you find this question interesting you may like this YouTube video.
I think it is a great example of what dedicated space and science enthusiasts can do ...
hyperpower
Consider the equation xxx.. = 2.
How do you find x in this iterated exponentiation, a.k.a hyperpower?
The solution is quite easy: Consider the 'tower' above the bottom x, ie. xx...
But it is the same as the original 'tower', so we know it is 2.
Therefore x2 = 2 and it follows that x = sqrt(2).
But there is a problem if we now consider the equation xxx.. = 4.
Using the same argument we find x4 = 4, with the same solution x = sqrt(2).
Clearly there is a contradiction; it seems that we just proved that 2 = 4 if we equate the 'towers' of sqrt(2).
I found this math exercise and the solution to the puzzle here.
How do you find x in this iterated exponentiation, a.k.a hyperpower?
The solution is quite easy: Consider the 'tower' above the bottom x, ie. xx...
But it is the same as the original 'tower', so we know it is 2.
Therefore x2 = 2 and it follows that x = sqrt(2).
But there is a problem if we now consider the equation xxx.. = 4.
Using the same argument we find x4 = 4, with the same solution x = sqrt(2).
Clearly there is a contradiction; it seems that we just proved that 2 = 4 if we equate the 'towers' of sqrt(2).
I found this math exercise and the solution to the puzzle here.
failure
We tend to think about the history of science as a series of breakthroughs and successes, from Galileo to Einstein ...
But mistakes and failure were always part of it, from Galileo's explanation of the tides to Einstein's unified field theories.
In physics there were Blondlot's N-rays, planet Vulcan, Fermi's trans-uranium (he even got a Nobel for it [*]) and many more - but every science has its fair share.
A few years ago I read When Science Goes Wong, an entertaining little book about big blunders of science.
If there should ever be a new edition, the laboratory in Wuhan should have its own chapter. And if this story will be made into a movie, Brad Pitt should play Dr. Fauci...
[*] Much later another Nobel prize winner became famous for his predictions, which turned out to be mostly wrong. But he was not really a scientist.
But mistakes and failure were always part of it, from Galileo's explanation of the tides to Einstein's unified field theories.
In physics there were Blondlot's N-rays, planet Vulcan, Fermi's trans-uranium (he even got a Nobel for it [*]) and many more - but every science has its fair share.
A few years ago I read When Science Goes Wong, an entertaining little book about big blunders of science.
If there should ever be a new edition, the laboratory in Wuhan should have its own chapter. And if this story will be made into a movie, Brad Pitt should play Dr. Fauci...
[*] Much later another Nobel prize winner became famous for his predictions, which turned out to be mostly wrong. But he was not really a scientist.
convivial links
Herve Zwirn proposes 'convivial solipsism' as a plausible interpretation of quantum theory.
I think he should have used LaTeX instead of an 80s version of WordPerfect to format his paper...
Michael Penn looks at a geometric proof of Fermat's little theorem.
He has lots of interesting stuff on YouTube...
Remy explains the current economy and financial markets.
Very trading ... such amaze ...
Goehring & Rozencwajg estimate the carbon footprint of electric vehicles.
Obviously, their results contradict the Exeter, Nijmegen & Cambridge paper...
Glenn Greenwald writes about yet another corporate media tale.
I have my own theory why US media evolved from news reporting to political propaganda...
I think he should have used LaTeX instead of an 80s version of WordPerfect to format his paper...
Michael Penn looks at a geometric proof of Fermat's little theorem.
He has lots of interesting stuff on YouTube...
Remy explains the current economy and financial markets.
Very trading ... such amaze ...
Goehring & Rozencwajg estimate the carbon footprint of electric vehicles.
Obviously, their results contradict the Exeter, Nijmegen & Cambridge paper...
Glenn Greenwald writes about yet another corporate media tale.
I have my own theory why US media evolved from news reporting to political propaganda...
holes
We can collect light from a large but far away fusion reactor to generate electricity.
A better way could be to use the heat from the nuclear reactor we inhabit.
But in order to do this we would need to drill holes up to 10km deep through granite in many places and this is a surprisingly difficult problem.
Surprisingly, because we are able to dig tunnels through mountains and we can drill deep enough holes to produce oil and gas.
However, existing rotary drilling technology is not sufficient to unlock geothermal energy in most places.
A research project at the University of Leoben, Austria, investigates an alternative drilling technology using water jets, which looks promising.
But perhaps it will take a billionaire and plasma jets (YouTube, fwd to 43:30) to solve this problem: link.
A better way could be to use the heat from the nuclear reactor we inhabit.
But in order to do this we would need to drill holes up to 10km deep through granite in many places and this is a surprisingly difficult problem.
Surprisingly, because we are able to dig tunnels through mountains and we can drill deep enough holes to produce oil and gas.
However, existing rotary drilling technology is not sufficient to unlock geothermal energy in most places.
A research project at the University of Leoben, Austria, investigates an alternative drilling technology using water jets, which looks promising.
But perhaps it will take a billionaire and plasma jets (YouTube, fwd to 43:30) to solve this problem: link.
learning and understanding
CIP asked "from what books did you learn QM, QFT, and GR?"
I guess it depends on your definition of "learning" ...
I read several pop.sci. books as a kid, including Misner, Thorne & Wheeler 8-)
So I had some idea what physics was about before I went to university.
But I would say I learned relativity from the books of two Austrian physicists, Sexl & Urbantke.
I learned quantum theory from the Berkeley lectures and Landau & Lifshitz.
And I learned QFT from xeroxed lecture notes and Ryder.
Of course there are many good books available now and some really good online lectures, e.g. Lenny Susskind.
Wald, Zee and Zwiebach are good books imho.
But I should also mention that I learned a lot about quantum theory in a seminar with Anton Zeilinger, which included eye opening interference experiments with slow neutrons at a research reactor in Vienna.
I think I really learned relativity during my master thesis, writing a program to numerically integrate the equations to simulate the gravitational collapse of a scalar field into a black hole.
And I really learned something about QFT by writing programs to simulate lattice field theories; including attempts to simulate quantum gravity. We did not really succeed, but I learned quite a lot along the way ... in some sense moving from Itzykson & Zuber to Itzykson & Drouffe.
Last but not least, I should mention that our best theories contain several unsolved mysteries: naked singularities, closed timelike loops, the 'interpretation problem' of quantum theory (*), Landau poles, the 'direction of time' etc.
They are ultimately incomplete and even inconsistent and therefore one might say that nobody really understands them ...
(*) Physicists cannot agree if quantum theory describes one or many worlds, while I prefer a zero worlds interpretation.
I guess it depends on your definition of "learning" ...
I read several pop.sci. books as a kid, including Misner, Thorne & Wheeler 8-)
So I had some idea what physics was about before I went to university.
But I would say I learned relativity from the books of two Austrian physicists, Sexl & Urbantke.
I learned quantum theory from the Berkeley lectures and Landau & Lifshitz.
And I learned QFT from xeroxed lecture notes and Ryder.
Of course there are many good books available now and some really good online lectures, e.g. Lenny Susskind.
Wald, Zee and Zwiebach are good books imho.
But I should also mention that I learned a lot about quantum theory in a seminar with Anton Zeilinger, which included eye opening interference experiments with slow neutrons at a research reactor in Vienna.
I think I really learned relativity during my master thesis, writing a program to numerically integrate the equations to simulate the gravitational collapse of a scalar field into a black hole.
And I really learned something about QFT by writing programs to simulate lattice field theories; including attempts to simulate quantum gravity. We did not really succeed, but I learned quite a lot along the way ... in some sense moving from Itzykson & Zuber to Itzykson & Drouffe.
Last but not least, I should mention that our best theories contain several unsolved mysteries: naked singularities, closed timelike loops, the 'interpretation problem' of quantum theory (*), Landau poles, the 'direction of time' etc.
They are ultimately incomplete and even inconsistent and therefore one might say that nobody really understands them ...
(*) Physicists cannot agree if quantum theory describes one or many worlds, while I prefer a zero worlds interpretation.
alien math
Perhaps we should think more about alien math (pdf), since they seem to be everywhere now (see my previous post).
Or perhaps we should just try to solve some weird math problems, like this one:
"One day it started snowing in the morning at a heavy and steady rate.
A snowplow started out at noon, going 2 miles in the first hour and 1 mile in the second hour."
What time did it start snowing?"
You should assume that the snowplow's speed is inversely proportional to the height of snow.
You can find the solution here and I post this problem and link mostly for Lee, who likes math puzzles.
I think MindYourDecisions is a great source ...
Or perhaps we should just try to solve some weird math problems, like this one:
"One day it started snowing in the morning at a heavy and steady rate.
A snowplow started out at noon, going 2 miles in the first hour and 1 mile in the second hour."
What time did it start snowing?"
You should assume that the snowplow's speed is inversely proportional to the height of snow.
You can find the solution here and I post this problem and link mostly for Lee, who likes math puzzles.
I think MindYourDecisions is a great source ...
mostly harmless
Unfortunately, free speech on US social media officially ended yesterday;
the good people will no longer have to endure the opinions of those other 74 million.
Consequently, my own small contributions on US controlled websites shall remain mostly harmless ...
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Avi Loeb is publishing a book about Oumuamua, arguing that it is the object of an alien civilization.
Recently, SETI picked up a mysterious signal from Proxima Centauri and several strange monoliths appeared in different places.
Naturally, I wonder what to make of all those reports about UFOs and alien artifacts popping up now.
Perhaps they just don't want to miss the series finale of Earth, planet of the crazy apes ...
Elon Musk thinks that the most entertaining outcome is the most likely - as seen from their perspective, not ours, unfortunately.
the good people will no longer have to endure the opinions of those other 74 million.
------
Avi Loeb is publishing a book about Oumuamua, arguing that it is the object of an alien civilization.
Recently, SETI picked up a mysterious signal from Proxima Centauri and several strange monoliths appeared in different places.
Naturally, I wonder what to make of all those reports about UFOs and alien artifacts popping up now.
Perhaps they just don't want to miss the series finale of Earth, planet of the crazy apes ...
Elon Musk thinks that the most entertaining outcome is the most likely - as seen from their perspective, not ours, unfortunately.
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