The far side of the moon

While spacecraft have sent back images of the far side of the Moon, until that was possible we could only see one side of it. Wayne Schlingman explains why that was.

Now the Moon takes one trip around the Earth in the same amount of time it takes to make one rotation around its own axis: about 28 days. From Earth, we always see the same face of the Moon; from the Moon, the Earth stands still in the sky.
…

All sides of the moon experience night and day just like we do here on Earth. All sides have equal amounts of day and night over the course of a single month. A lunar day lasts about two Earth weeks.

Here is a short video.

I wonder if the flat Earthers think that the Moon is flat too. You would think that the fact that we see only one side of the Moon would make a stronger case for the flatness of the Moon than the case they have for the flatness of the Earth.

The Extinction Rebellion protest in London

Over the past nine days, a group known as Extinction Rebellion has been blockading central London to highlight the problem of climate change and to protest lack of action on it. They just ended the protest.

Extinction Rebellion, which has been backed by senior academics, politicians and scientists during nine days of peaceful mass civil disobedience, said it would leave its remaining blockades, but added: “The world has changed … A space for truth-telling has been opened up.

“Now it is time to bring this telling of the truth to communities around London, the regions and nations of the UK, and internationally. In this age of misinformation, there is power in telling the truth.”

The group said it would like to “thank Londoners for opening their hearts and demonstrating their willingness to act on that truth”.

The statement added: “We know we have disrupted your lives. We do not do this lightly. We only do this because this is an emergency.”

The activists said protesters had “taken to the streets and raised the alarm” in more than 80 cities in 33 countries. “People are talking about the climate and ecological emergency in ways that we never imagined,” they said.

[Read more…]

The US is a great country in which to be a conman

If I were a conman, the US is definitely the country in which to try my luck. It has plenty of gullible and fearful people who have lots of disposable income and are easy prey for any smooth-talking huckster. The only question is what kind of scam one should pull. Religion is of course an obvious one. It does not have to be even Christian which is a crowded field. You can claim to be some kind of vaguely spiritual eastern mystic, something that appeals to a certain kind of disenchanted person.
[Read more…]

How can this be allowed?

A church is offering a ‘miracle cure’ that consists of drinking a solution containing bleach.

A group calling itself Genesis II Church of Health and Healing plans to convene at a hotel resort in Washington state on Saturday to promote a “miracle cure” that claims to cure 95% of all diseases in the world by making adults and children, including infants, drink industrial bleach.
…

The “church” is asking attendants of the meeting to “donate” $450 each, or $800 per couple, in exchange for receiving membership to the organization as well as packages of the bleach, which they call “sacraments”. The chemical is referred to as MMS, or “miracle mineral solution or supplement”, and participants are promised they will acquire “the knowledge to help heal many people of this world’s terrible diseases”.

[Read more…]

Dara O’Briain reviews the film 2012

I have not seen this film or even heard about it but after watching this hilarious review of it by the comedian, I don’t think I need to. Like most natural disaster films, there is an attempt to give a scientific explanation for the catastrophe but O’Briain says that this ludicrously over-the-top apocalyptic film offered one that was so utterly outlandish that he used it to insert a useful lesson about neutrinos.

“A Message from the Future”

Naomi Klein introduces a powerful seven-minute video daring us to imagine how the Green New Deal can take us to a future much better than the one we are currently on a path towards.

TODAY, THE INTERCEPT launches “A Message From the Future With Alexandria Ocasio-Cortez,” a seven-minute film narrated by the congresswoman and illustrated by Molly Crabapple. Set a couple of decades from now, it’s a flat-out rejection of the idea that a dystopian future is a forgone conclusion. Instead, it offers a thought experiment: What if we decided not to drive off the climate cliff? What if we chose to radically change course and save both our habitat and ourselves?

The problem with counting calories

I have a friend who is a dedicated calorie counter. In order to control her weight, she carefully notes the calorie value of all the food she eats and the amount of exercise she needs to take to burn it off. If she indulges in an extra treat, she will note it and compensate by working out more the next day, according to a formula that relates the type and duration of exercise to the amount of calories that need to be burned. This requires a lot of bookkeeping but she is a very organized person.
[Read more…]

Dilbert does not understand random sampling

Cartoonist Scott Adams, creator of the comic strip Dilbert, is a climate change skeptic who repeats the well-worn anti-science tropes of that community. Usually he attacks the credibility of the climate change models that are used to predict the scale of climate change and the potential consequences. But in this cartoon, he goes further and seems to be attacking the whole idea of random statistical sampling.
[Read more…]

The size of the photographed black hole event horizon

Obtaining the first-ever photograph of a black hole was an impressive feat. We tend to think of black holes as being tiny and they are. A black hole represents a singularity in space-time where gravitational field becomes so large that there is extreme curvature of space. But the ‘event horizon’ of a black hole, the region inside from which no light can escape, need not be tiny. It is the event horizon that gives rise to the dark region seen in the photograph and the size of the event horizon for any mass M is given by the Schwarzschild radius that is equal to 2GM/c2, where G is the gravitational constant and c is the speed of light.

The black hole at the center of the galaxy M87 that was photographed has a mass 6.5 billion times the mass of the Sun and thus its Schwarzschild radius is about 1.9×1010 km. This is quite large, about three times the distance of the planet Pluto from the Sun, which is 5.9×109 km.

How technology can improve without increased understanding

Archeologists sometimes find ancient artifacts that show considerable sophistication. These might cause us to infer that the people of that time had a better understanding of the underlying science than we had previously given them credit for. This is because advances in technology often go hand in hand with advances in science. Technological advances upon up new frontiers for scientific investigation while new scientific theories lead to new technologies. But that link may not always exist.
[Read more…]