Radiation paradoxes 4: Stars, space, and rotating frames

How do you tell if you are in an inertial frame or not? According to Newton’s model of a fixed space, an inertial frame is one which is at rest or moving with constant velocity through that fixed space. We saw that determining this required us to observe the state of motion through that space of an object Q that was known to be not under the influence of any forces. If you observe Q to be at rest or moving with constant velocity, then you are in an inertial frame. If however, even in the absence of forces, the freely floating object Q appears to be accelerating in some direction with respect to you, you could conclude that this must be because you are in a frame that is an accelerating in a straight line in the opposite direction and hence you are not in an inertial frame.
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Radiation paradoxes 3: Identifying genuine inertial frames

As a computational matter, when we are in a rotating frame such as the Earth, we have a choice. We could work with inertial frames where Newton’s laws and Maxwell’s equation are valid, use real forces only, and make sure to include all the accelerations introduced due to the rotational motions. Or we could use a frame that is embedded in the Earth and thus rotating but treat it as an inertial frame by including via the fictitious Coriolis and centrifugal forces the non-inertial effects caused by its rotation. The two methods are mathematically equivalent but conceptually different. It is sometimes easier to treat the Earth as an inertial frame that is not spinning and incorporate fictitious forces and that is often done in the field of meteorology.

It is the search for genuine inertial frames that is of interest in this series of posts because it is important in the resolution of the radiation paradoxes.
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Cuba’s vaccination production effort pays off

One of the appalling things about the current pandemic is the great inequality in vaccine availability around the globe, highlighting once more how the wealthy nations are able to corner the market on valuable resources. In this case, since many of the companies that are the biggest producers of vaccines are private ones and they seek to make as much money as they can, they have entered into contracts to mostly supply wealthy nations like the US that are able to pay more, while the WHO consortium that sought to provide vaccines to poorer countries through its COVAX program has found it hard to get adequate supplies.
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Radiation paradoxes 2: Space and inertial frames

In trying to understand and resolve the paradox I wrote about in the first post in this series, I will be taking a somewhat circuitous route in order to lay some important groundwork before we can directly confront the paradox.

We can start the journey by looking at one of the most fundamental concepts in physics, that of the nature of space. On the surface, space seems like a very straightforward concept. It is seen as a kind of container in which everything in the universe exists. But difficulties arise when one asks questions such as whether space can be viewed as something positive, a tangible entity that has its own properties that can be detected, or whether it is viewed as something negative, that signifies the absence of matter in a region. Another way of posing the distinction is asking whether, if one can conceive of removing all the matter and energy in the universe, what would we be left with? Just ’empty space’? In the absence of matter, would such a thing have any meaning at all?
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Wellness and woo

The concept of ‘wellness’ has been gaining ground in the US. It is a vague term and, as I understand it, it means taking proactive steps to maintain one’s health, such as eating healthily, getting exercise, avoiding harmful practices like smoking, getting enough rest, and so forth. The idea is that by doing so, one can stave off some of the ailments and illnesses that can affect one’s wellbeing.

An additional layer is laid on in the name of holistic’ approaches to health, with the idea that the mind and body are connected and that one should also try and maintain a healthy mindset. These could include practices like yoga, meditation, relaxation techniques, and other activities that seek to reduce stress, blood pressure, and the like.

All that is perfectly reasonable.
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Radiation paradoxes 1: Do electric charges and neutral particles fall at the same rate?

I have recently fallen down a rabbit hole in physics trying to resolve some paradoxes that I stumbled upon. In spending a lot of time and mental effort trying to understand what is going on, I realized that although I have spent my life studying and teaching physics, I did not fully understand some very fundamental aspects of space and motion and the way that the laws of physics operate. That is part of the fascination that physics provides, that it can always surprise you, leading you to learn new things.

In an occasional series of posts, I will share with readers my journey through this maze, trying to make things as clear as possible to the non-physicists out there. This will not be easy because an important prerequisite to explaining something to someone else is for you to understand it first. I cannot claim to understand completely what I am going to be writing about, for which I apologize in advance. But it is well known among teachers that it is in trying to explain something to someone else that one starts more deeply understanding what one is trying to say. Like many teachers I have used students as sounding boards for tentative ideas.
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Don’t they carefully vet the White House physician?

The White House physician is an important job, since he is supposed to supervise the health of the US president. So it is surprising that Ronny Jackson, who held that post under both Barack Obama and Donald Trump, is a proponent of wild conspiracies, the most recent of which concerns the Omicron variant.

Roughly 24 hours after most people in America first heard about the Omicron variant of Covid-19, Texas Rep. Ronny Jackson (R) offered a conspiracy theory to explain what was happening.

“Here comes the MEV – the Midterm Election Variant,” tweeted Jackson, who, not for nothing, is also a physician. “They NEED a reason to push unsolicited nationwide mail-in ballots. Democrats will do anything to CHEAT during an election – but we’re not going to let them!”

And then there was this from Fox News personality Pete Hegseth: “Count on a variant about every October, every two years.”

The idea here is clear: The emergence of Omicron is a political gambit by Democrats designed to aid them at the ballot box.

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The covid-19 variant naming system

As with any virus, the Covid-19 virus will mutate over time and this requires scientists to give each variant labels to distinguish among them. Since they want to keep track of even the smallest changes, they require a system that can identify the nature of the changes and their location on the virus. But that technical name is hard for the general public to keep track of and so the WHO has adopted the Greek alphabet sequentially to label as they appear just those variants that they think most likely to affect the public and that we need to keep track of, that they call ‘variants of concern’. There are now seven of them. So the variant with the scientific name B.1.617.2 is called Delta and the latest variant B.1.1.529 is called Omicron. The earlier Alpha has the scientific label B.1.1.7 and Beta has the label B.1.352.
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The Omicron variant

The news about South African scientists detecting a new variant of the covid-19 virus that has been labeled the ‘Omicron’ has been worrying to say the least. What has caused scientists and the WHO to express concern is the large number of mutations that it has, over 50 overall and more than 30 on the spike proteins that the virus uses to invade out bodies’ cells. That makes it hard to predict what it can and will do without further study. But it is far too early to press the panic button.

There have been many examples of variants that have seemed scary on paper, but came to nothing. The Beta variant was at the top of people’s concerns at the beginning of the year because it was the best at escaping the immune system. But in the end it was the faster-spreading Delta that took over the world.

Prof Ravi Gupta, from the University of Cambridge, said: “Beta was all immune escape and nothing else, Delta had infectivity and modest immune escape, this potentially has both to high degrees.”

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The tricks of memory

I keep getting reminded of how unreliable memories can be, especially about things that happened a long time ago. While forgetting details and even entire incidents are common, more concerning is when we ‘remember’ things that did not happen. The latest such incident occurred when a few days ago I was watching the 1947 film The Secret Life of Walter Mitty starring Danny Kaye. I was a huge fan of Kaye’s comedies as a boy, which often showcased his ability to sing comic songs, and this film had two of them. I recall watching it a long time ago and enjoying it so when I saw that it was streaming, I decided to take a second look.

The film is about a timid, milquetoast of a man who is bullied by his mother, his boss, and his fiancee and who escapes into daydreams where he is the hero of adventures. Like so many films that we recall from our childhood, it did not age well. (It was remade in 2013 with Ben Stiller in the title role). I would have stopped watching after about ten minutes but what kept me going was that I distinctly recalled that right at the beginning, while he is waiting at a traffic light, he daydreams that he is the pilot of a military plane that is flying through a major storm. Despite the dangerous conditions and the plane being buffeted by the strong winds, he remains calm and collected and his crew admiringly tell each other that they are confident that he is the one person who can pull them through. In the background, the engine makes a ta-pocketa-pocketa-pocketa sound, a recurring background machine sound in almost all his daydreams.
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