The stars wibble and wobble as their planets go round
There are several ways of detecting planets that orbit stars other than our sun. One method, called Doppler spectroscopy, relies on the fact that an orbiting planet causes its star to wobble. Spectrometers are used to observe the spectral lines within the stars light, (see episode 44,) and measure changes in their red shift or blue shift, (see episode 46,) as the star wobbles.
@AntonyTheReal_ showed me a video recently, in which one of the folks was rather upset with NASA. It bothered him that they were presenting details of a planet orbiting another star, lightyears away, while at the same time, we’re still not certain whether or not there is a ninth planet within our own solar system. Today, we talk about the possible ninth planet—why it’s thought that there is one, and why the search for it is taking so very long.
Here’s an article put out back in 2016, describing the reasons for searching for Planet 9.
Irrational computers, investing, and racist robots
It’s easy to assume that computers and computer software, being without emotions, are more rational than we are. However, our software systems are like children of the mind, and they inherit our bias and irrationality. In fact, since they cannot judge context, they are less rational than we.
Here are a couple of talks on how computer programs, AKA. Algorithms, effect many aspects of our lives, despite being less than rational.
Complex analysis, the stock market, and seeing what you expect
Two theories about the stock market, the efficient market hypothesis and technical analysis, are each attempting to analyze the same complicated system—namely the stock market and the fluctuations of different share prices in different companies. Both theories start by assuming that the price always reflects all relevant information. Even though they both examine the same system, and start with the same assumption, they draw completely opposite conclusions. It’s just so terribly easy to see what you expect to see.
In 1933 Fritz Zwicky was studying the motion of galaxies within the Coma Cluster. He found that the motion could only be explained if there was considerably more mass present than what could be observed. Later, in the late 1970s, Vera Rubin was observing the rotational dynamics of the andromeda galaxy. She was attempting to verify theories of how such a galaxy should be spinning. Again, the motion didn’t fit the theory. Again, only having more mass there than could be observed could explain the motion. Thus, we have “dark matter”—a form of mass only observable by its gravitational effects.
Ep 51: What is “dark energy,” and is there really such a thing?
What is “dark energy,” and is there really such a thing?
In the early 1990s, two separate teams tracked the rate of expansion of the universe by using type Ia supernovas as standard candles, (see episode 41 and episode 42 for details on standard candle usage.) Each team found that the rate of expansion of the universe is increasing. Recent observations of type Ia supernovas suggest that they may not be as standard as previously thought. Although other observations have tended to support the notion of dark energy causing our universe to expand faster and faster, the analysis has been rather complicated, razing the possibility that the only reason we’ve seen more evidence for dark energy, is because we’ve expected it.
Here’s an article on how type Ia supernovas may not be as standard a standard candle as was believed.
Here’s an article on the results of the boomerang experiment, thought to support the notion of dark energy; but only when combined with the now somewhat suspect supernova studies.
And here’s an article that suggests that the universe is expanding, but not accelerating, though it suffers from the same issues regarding complex analysis.
The first manned flight of a hot air balloon took place in France in 1783. However, sky lanterns, paper and wood hot air balloons that don’t carry people, have been around in China since as early as 300 BC. Why did it take ever so long? During the research for episode 37, I became interested in the subject of balloon powered flight. Join me as I talk about what I found, just for fun.
Here’s an article on the BOOMERanG experiment, which is what got me on this kick in the first place.
In 2016, competitors came together to strive for the gold. The only thing is, these athletes used their brains, interfaced with computers, in order to compete.
Here’s an article about the cyborg Olympics that I first read when @seeingwithsound shared it on twitter.
What would eventually be called the theory of the big bang was first described by Georges Lemaître in 1927. This early description included predictions later verified in 1929, but it wasn’t until 1964, when the cosmic background microwave radiation was accidentally detected, that the theory was taken seriously by the mainstream scientific community.
Check out episode 47’s show page, where there are links that provide much of the background to this episode about the background microwave radiation.
In episode 42, we learned that in 1923, Hubble found out that spiral nebula are actually spiral galaxies, changing our understanding of the size of our universe. In 1929, using spectral lines, (see episode 44 and episode 46,) and building off of work previously done by Vesto Slipher, he discovered that the universe is not only bigger than we thought; it’s still getting bigger. This provided supporting evidence for the theory of the big bang.