The confirmed detection of gravitational waves within the past decade was one of the more exciting news in physics. However, like observatories based on electromagnetic waves, only a narrow frequency band of gravitational waves can be detected by the kilometers-long gravitational observatories we have. These can detect black hole mergers, but they have no hope of detecting gravitational waves that are suspected to have been sloshing around our universe right after the Big Bang.

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The president of South Korea had declared martial law under patently false premises in a transparent attempt to suppress political opposition. Fortunately, it has been rescinded after members of the South Korean parliament who were present unanimously voted against the declaration of martial law, despite obstruction by the police and the military.

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Today I learned of cosmic latte. It is the color computed to be the average of all the light emitted from objects throughout the universe as perceived from Earth.

One image which keeps coming up in my mind is a US president striking out an area with a sharpie on a forecasting map of an impending disaster, just because he misspoke and left out the area previously. In fact, since he can’t allow anyone to admit he made a mistake, federal aid would be withheld from the area once it’s struck by disaster.

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Following up on a previous exposition of the twin paradox in special relativity, this time I am going to use an animated spacetime diagram to explain what it would be like from the traveling twin’s perspective.

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