I will be giving a talk on Saturday on Zoom

The annual Monterey Skepticamp is being held on Saturday, January 8th from 9:46am to 5:46pm California time. I will be giving a talk at 2:30pm.

Title: Why the age of the Earth has oscillated wildly over time

Summary: The age of the Earth seems to be a settled question in the scientific community, But estimates of its age have oscillated wildly in the past, starting with it being considered really old (even infinitely old) to becoming very young (of the order of thousands of years) to becoming sort of old (hundreds of millions of years) to younger again (tens of millions of years) to the current view of it being really old (of the order of billions of years). This talk will look at the interplay of scientific and religious thinking that was driving this fluctuation.

You can see the full schedule of speakers here.

It is free. You can RSVP here.

The Zoom link to join is https://us02web.zoom.us/j/88526995782

Tennis star Novak Djokovic in limbo in Australia

Tennis star Novak Djokovic has said that he is opposed to vaccinations. Australia now requires people entering the country to be vaccinated or apply for a special exemption. Djokovic had applied for and got an exemption from the Australian tennis body that issues such exemptions so that he could play in the Australian Open that takes place starting on January 17th. But later it turned out that he had applied for a visa that does not allow for medical exemptions. This caused a furore with people complaining that he was being given special treatment.

Australian prime minister Scott Morrison then stepped in and said only the federal government has the authority to decide who is allowed into the country and under what circumstances and that he was not eligible to enter. The Victorian state government also refused to weigh in in support of Djokovic’s exemption. Meanwhile, Djokovic and his entourage had already departed for Australia on a long flight and upon arrival he was separated from the rest and held isolated under an armed guard at the Melbourne airport while his case was deliberated. In the end, his visa was cancelled and he was asked to leave.
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Radiation paradoxes 10: Five scenarios for a charge and detector

(Previous posts in this series: Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9)

In the previous post, I quoted Fritz Rohrlich who said that asking whether an accelerated charge really radiates is meaningless and that we need to also look at the value of the Poynting vector at the location of the detector. In discussing the radiation from an electric charge that is freely falling in a gravitational field, the state of motion of the charge and the detector both have to be taken into account. and this requires transformations between frames and will depend on whether the detector is an inertial observer or not. The transformations to accelerating frames requires the use of the mathematical machinery of general relativity.

With that. in mind, let us consider a charge Q and a radiation detector D and see what happens under various scenarios that describe different states of motion of each. There are five possible scenarios of interest to consider. It should be borne in mind that these scenarios are hard to test experimentally and, as far as I am aware, have not been tested.
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A healthy lifestyle will not entirely protect you from covid-19

We have people who are opposed to vaccinations on ideological grounds, on partisan political grounds, on religious grounds, and who think that it undermines their ‘wellness’ attitude to health and believe that various dietary and mental therapies are the key to avoiding the disease and that vaccines interfere with that protection.

But there are those who do not fit into any of those categories and say that they are not opposed to vaccines as such but don’t get vaccinated because they think that vaccines are unnecessary if one lives a healthy lifestyle and do not have the comorbidities that make one a risk for serious illness and death, such as age or being immunosuppressed or having lung ailments. Younger and otherwise healthy people are likely to fall into this category of the unvaccinated.
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The pacing of the radiation posts

As long-time readers may have noticed, when it comes to complicated issues, as in the case of the current series on radiation paradoxes, I tend to post about it in installments. I have had many, many ten-to-twenty-or-more part series dealing with important questions, such as the Higgs, evolution, and the Big Bang. This doling out in small portions may be irksome to some, especially those who already know quite a bit about the subject, who may be impatient at my slow pace. They may wonder why I do not write out the entire thing first and post it in one long entry so that everything is settled once and for all.

There are several reasons for this. One is purely pedagogical. I think that it is hard to digest a lot of new and difficult material in one gulp. With small doses, where each post focuses on just one or more important issue, people can think and reflect on it, ask questions, and get things clarified in their own minds as best as possible and are thus more ready to move on to the next installment.
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Elizabeth Holmes found guilty of fraud

After a 15-week trial, a jury today found the founder of the Theranos company guilty on four of the 11 counts of fraud with which she was charged. In an earlier post I discussed how she had persuaded gullible wealthy people like Rupert Murdoch, George Schultz, and henry Kissinger that she had the makings of being the next Steve Jobs, an image that she carefully cultivated and a comparison that she encouraged by her dress and speech. She was found guilty on four of the 11 charges.

A jury convicted Holmes, who was CEO throughout the company’s turbulent 15-year history, on two counts of wire fraud and two counts of conspiracy to commit fraud after seven days of deliberation. The 37-year-old was acquitted on four other counts of fraud and conspiracy that alleged she deceived patients who paid for Theranos blood tests, too.

The jury deadlocked on three remaining charges, which a federal judge anticipates dismissing as part of a mistrial ruling that could come as early as next week. The split verdicts are “a mixed bag for the prosecution, but it’s a loss for Elizabeth Holmes because she is going away to prison for at least a few years,” said David Ring, a lawyer who has followed the case closely.

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Radiation paradoxes 9: The resolution?

(Previous posts in this series: Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8)

We saw in the previous post how Einstein’s Principle of Equivalence explained why two masses dropped from the same height in a gravitational field will fall at the same rate and hit the ground at the same time. It also seemed to resolve the paradox about whether an electric charge will fall more slowly than a neutral particle in a gravitational field. The answer arrived at was ‘no’ because since according to the PoE, the situation with the falling accelerating charge in the frame of the Earth E was equivalent to the charge being stationary in the inertial frame of space S, the charge would not radiate energy, contrary to naive expectations that any accelerating charge would radiate. On the surface, that seems to resolve the paradox that started this series of posts. The price we have paid is that we must abandon Postulate #2 and conclude that accelerating charges do not radiate when falling freely in a gravitational field.
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Webb telescope successfully passes critical test

The Webb telescope team reported that a major step had been successfully completed on schedule. The telescope was launched on December 24th and all its components had to be folded into a small space to fit into the rocket nose cone and then opened up once it was in space, After seven days, the schedule called for the five-layered tennis court-sized silvery heat shield to be opened up and it did so.

The shiny silver shield measures 69.5 feet long by 46.5 feet wide (21.2 by 14.2 meters) when fully deployed — far too large to fit inside the protective payload fairing of any currently operational rocket. So it was designed to launch in a highly compact configuration and then unfold once Webb got to space.

That deployment is an elaborate, multistep process with many different potential failure points that could sink the entire mission.

“Webb’s sunshield assembly includes 140 release mechanisms, approximately 70 hinge assemblies, eight deployment motors, bearings, springs, gears, about 400 pulleys and 90 cables totaling 1,312 feet [400 m],” Webb spacecraft systems engineer Krystal Puga, who works at Northrop Grumman, the prime contractor for the mission, said in a video about Webb’s deployments that NASA posted in October.

Over the next six days, the rest of the telescope will get unfolded, starting in three days with the deployment of the secondary mirror support structure. And then it heads to its destination, the second Lagrange point which it should reach after 29 days.

You can see the sequence of steps in this short video.

It is a truly remarkable piece of engineering.

The coronavirus illustrates evolution on action

The pandemic has given us a crash course on evolution. Evolution deniers must be having a hard time explaining away the evolution-suffused news dealing with mutations, growth rates, and the like. But it also provides an opportunity to explain some of the mathematics of the phenomenon.

You would think that if a mutation had a slight advantage over its predecessor, then it would over time grow in size relative to the other but the older one would still be around. But that is not what happens. We see how some new variant, if it has some advantage over its competitors such as greater transmissibility, rapidly becomes dominant in the population, pushing the previously dominant ones into the background.

This graph shows the different peaks due to the different variants at the current time.


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Radiation paradoxes 8: The Principle of Equivalence

(Previous posts in this series: Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7)

We have now acquired most of the background knowledge needed to start directly addressing the question that this series of posts started with, as to whether an electric charge and a neutral particle dropped from the ceiling will hit the ground at the same time. The first stage of that is what is known as the Principle of Equivalence.

Recall the Postulate #1 we started with that said that all objects falling freely in a gravitational field will fall at the same rate and hit the ground at the same time. We were able to explain this by saying that it followed from the fact that gravitational and inertial masses were equal. But we did not explain why they should be equal. The two masses were arrived at, after all, by distinct methods using different operational definitions. But by considering accelerating frames and the Principle of Equivalence, we have a simple explanation for it.

Consider two objects floating freely in space that are at rest with respect to each other and to an observer S, to signify space. No suppose we enclose the two objects in a closed room and accelerate the room ‘upwards’ (i.e., in the direction from the ‘floor’ to the ‘ceiling’) with a value g. We will call this frame E to signify an elevator or Earth. Then in the frame E, both objects will seem to be accelerated ‘downwards’ (i.e., towards the floor of the room) with a value g, just as if they were falling freely on Earth, and will both hit the floor at the same time. They will behave just as if they were falling down near the surface of the Earth and since they hit the floor at the same time, we can infer that their gravitational and inertial masses are equal, rather than tacitly assuming it to be the case as we did before.
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