A nuclear salt-water rocket (NSWR) is a theoretical type of nuclear thermal rocket which was designed by Robert Zubrin. In place of traditional chemical propellant, such as that in a chemical rocket, the rocket would be fueled by salts of plutonium or 20 percent enriched uranium. The solution would be contained in a bundle of pipes coated in boron carbide (for its properties of neutron absorption). Through a combination of the coating and space between the pipes, the contents would not reach critical mass until the solution is pumped into a reaction chamber, thus reaching a critical mass, and being expelled through a nozzle to generate thrust.


(A group of researchers found the risk of coronavirus spreading among people sitting together eating was five times higher when they were seated next to each other, compared to when they were sitting opposite.)

Styrketräning kan förlänga livet och minska risken för hjärt- och kärlsjukdomar, diabetes och cancer. Även minnet förbättras. Ändå har styrketräning hamnat i bakvattnet av konditionsträning. Är det dags för en förändring?

This story has been doing the rounds since 1996, and it has never been verified. It seems to have first appeared in a book called Competing For The Future by Gary Hamel and C. K. Prahalad, and by “appeared” I mean it was just made up. The authors never provided a source. None of the authors who have referred to the experiment in the past eighteen years have provided a source either. None of the appealing memes or infographics that describe the story now provide a source. Suffice to say, there is no source, because the experiment never happened.

There is a good reason for colonizing another planet, which is to avoid extinction if the Earth is hit by a 10km or larger asteroid, as has happened many times in the Earth's history. Colonization of Mercury appears to be a very real and practical possibility, whereas colonization of Mars or the other planets, moons or asteroids is really more in the realm of fantasy.

Humans can't see UV light, but birds can. By combining spectral light with UV, researchers proved that birds can differentiate between those colors. This means that when the birds look at objects we can see as spectral light, they are likely seeing many more colors because that fourth cone gives the ability to see more color combinations.

The actual study is here.

We show that for thousands of years, humans have concentrated in a surprisingly narrow subset of Earth’s available climates, characterized by mean annual temperatures around ∼13 °C. This distribution likely reflects a human temperature niche related to fundamental constraints. We demonstrate that depending on scenarios of population growth and warming, over the coming 50 y, 1 to 3 billion people are projected to be left outside the climate conditions that have served humanity well over the past 6,000 y. Absent climate mitigation or migration, a substantial part of humanity will be exposed to mean annual temperatures warmer than nearly anywhere today.

Humans have gotten a lot done in 300,000 years: We invented agriculture, developed writing systems, built cities, created the internet, and shrugged off gravity to land on the moon. These innovations make our past seem long—and stuffed with significance. But in the brief history of life, everything we’ve ever accomplished fits into a tiny sliver of time—just 0.008 percent of the entire continuum shown below. This is how the rise of the animal kingdom stretches out compared with our relatively insignificant existence.

“It’s not too soon to talk about this,” said Dr. Amesh Adalja, an infectious disease specialist at the Johns Hopkins Center for Health Security. “We know that respiratory viruses are especially difficult to control, so I think it’s very possible that the current outbreak ends with the virus becoming endemic.”

Experts see two possibilities, each with unique consequences:

“Seriously people — STOP BUYING MASKS!” the surgeon general, Jerome M. Adams, said in a tweet on Saturday morning. “They are NOT effective in preventing general public from catching #Coronavirus, but if health care providers can’t get them to care for sick patients, it puts them and our communities at risk!”

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