How the maglev train works

The maglev train that can run at high speeds by ‘floating’ above the track is an engineering marvel that people in the US unfortunately have no direct experience with, thanks to the gas and automobile lobbies effectively killing the train system so that what exists here is an embarrassment when compared to what exists in other parts of the world. Eric Laithwaite, known as the father of the maglev train for his development of the magnetic levitation process, takes us step-by-step through the design of the system.

Maglev (magnetic levitation) trains are elegant and audacious works of engineering that operate by harnessing the power of magnetic repulsion and electromagnetism to move traincars that quite literally float above the track – today, often at speeds of hundreds of miles per hour. In this lecture at Imperial College London from 1975, the British engineer and professor Eric Laithwaite (1921-97) deconstructs the fascinating physics at work behind his plans for a maglev train, which he first modelled in 1940s and perfected in the 1970s. Well-regarded in his time as both a lecturer and an engineer, Laithwaite presents a series of demonstrations that build, step by step, until he finally unveils a small maglev train model. The first commercial maglev train debuted at Birmingham Airport in 1984, and today Laithwaite’s engineering breakthroughs help power many of the world’s fastest trains.

What will the future say about us?

It is a conceit of each generation to think that they live in a particularly unusual period of history, seeing the troubles they experience as somehow particularly difficult and looking back nostalgically to the past. For example, some conservatives in the US look back on the 1950s and 1960s as a wonderful period that they wish they could return to. Trump’s slogan of ‘Make America Great Again‘ was designed to appeal to them by echoing that sentiment. In reality, that period was one of deep segregation, racism, sexism, and homophobia, not to mention living with the fear of nuclear war that required taking part in drills. It was by no means an idyllic time.

The reality is that there is a mix of the good and the bad in each generation’s lives and how they view the past depends on which segment of the population they descended from, whether it was the ins or the outs.

But we can sometimes identify some unique characteristics that can be overlaid on each generation’s experiences. I have been trying to think of what, some day in the future, people are going to look back at this current time and see as its identifying characteristic. I think that it may be to wonder how it could be that so many people in the US who had access to good information could, and urged on by major political leaders, refuse to recognize the existence of a deadly virus that was causing a pandemic and affecting people all around them, refuse to take the vaccine that had significant evidence of being able to prevent death and serious illness, fight against common-sense preventative measures, and then when they do get sick, decide to put into their bodies all manner of untested treatments. I do not know if anything even remotely similar has happened in the past or in any other country.

This is a level of irrational behavior that speaks to some deep-seated problems in the national psyche.

How much land would be needed to power the world with solar energy?

Harvard University has announced that its massive endowment fund is divesting from fossil fuels. Many other universities had already done so under pressure from their students and alumni and others are likely to follow.

Academic endowments are entering a new normal after Harvard University, the richest school in the world, said it would divest from fossil fuels.

The decision wasn’t made lightly. The nearly $42 billion endowment succumbed to years of pressure from students and climate activists, a massive protest at a 2019 football game, and a string of legal efforts. President Lawrence Bacow in the past has said the endowment shouldn’t be used for political ends. Earlier this month he changed his tune.
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A cascade of similar announcements has followed in Harvard’s wake, with Boston University, the University of Minnesota and the $8 billion MacArthur Foundation pulling the plug on fossil fuels. And there are more to come.

“We’re going to see this ripple out in the coming months,” said Richard Brooks, climate finance director at the nonprofit Stand.earth. “The financial arguments have never been stronger, with declining demand for oil, gas and coal. The social acceptability has now shifted as well.”

Divestment activists now have turned their focus to Yale, the University of Pennsylvania, Princeton, Boston College and the University of Wisconsin-Madison, none of which have fully abandoned fossil fuels.

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A pixel is not a tiny square

I had thought of a ‘pixel’ as the smallest unit of digital space, like a tiny square, and that digitial images are made of up such units. This article says it is not that simple and that it is related to Fourier transforms, in which any wave form can be decomposed into the sum of sinusoidal waves of different frequencies.

Perhaps the most unexpected person in this story – at least for readers in the United States – is Vladimir Kotelnikov, the man who turned Fourier’s idea into the pixel.
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Early in his career, Kotelnikov showed how to represent a picture with what we now call pixels. His beautiful and astonishing sampling theorem, published in 1933, is the foundation of the modern picture world.
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A pixel exists only at a point. It’s zero-dimensional (0D), with no extent. You can’t see a pixel.

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Death and the universe

John Horgan writes that he thinks physicists are drawn to the multiverse idea (which he dislikes) because they cannot bear to think that our universe will end at some point. He postulates an explanation for why multiverse theories are so popular among physicists despite the lack of any supporting evidence for them.

Here is my guess: physicists are freaked out by the mortality of our little universe. What was born must die, and according to the big bang theory, our cosmos was born 14 billion years ago, and it will die at some unspecified time in the far future. The multiverse, like God, is eternal. It had no beginning; it will have no end.

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Which animals kill the most humans?

Human beings are easily the biggest killers on the planet, killing not only other members of their own species but also of other species. The number of homicides alone is close to 500,000 per year. But what animal is the biggest killer of humans? It turns out that it is the mosquito, causing the deaths of about twice as many people as humans do. But the mosquito is not really the killer, it just serves as a vector for diseases. If one eliminates vector-carriers such a mosquitoes, flies, bugs, snails, and worms, the top four killers are in the order: snakes, dogs, crocodiles, and hippos.
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Why not switch the two lights?

Jason Torchinsky writes that the left-turn signal on the back of the Mini has an arrow that points to the right while the right-turn signal points to the left.

The reason for this design choice is so that the two lights taken together is supposed to look like the British flag, the Union Jack.

If the idea was to playfully invoke the image of the Union Jack, it failed as far as I was concerned because I did not recognize the two lights as the flag until it was pointed out to me. A representative from the company said that he did not think other drivers would be confused as to the direction in which the car was planning to move. That may well be so but it does seem to be an unnecessary distraction. Switching the two designs would be simple and make a lot more sense.

Is requiring phone charger uniformity a good idea?

The European Union is planning to require uniformity in phone cord chargers.

The European Union announced plans Thursday to require the smartphone industry to adopt a uniform charging cord for mobile devices, a push that could eliminate the all-too-familiar experience of rummaging through a drawer full of tangled cables to find the right one.

The European Commission, the bloc’s executive arm, proposed legislation that would mandate USB-C cables for charging, technology that many device makers have already adopted. The main holdout is Apple, which said it was concerned the new rules would limit innovation, and that would end up hurting consumers. iPhones come with the company’s own Lightning charging port, though the newest models come with cables that can be plugged into a USB-C socket.

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This was so sad and so unnecessary

Watch as 67-year old Joe McCarron, hospitalized with Covid-19 in Ireland, is urged by a fanatical anti-vaxxer and covid-denier to check himself out of the hospital while a doctor calmly, kindly, and patiently explains why that would not be a good idea for someone in his condition and urges him to stay, saying that he was very ill and could die if he went home. But the person with McCarron badgered him to leave and he finally acquiesced. Two days later, he was back in the hospital with breathing problems and subsequently died.


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