- We know that some fraction of people who catch COVID-19 don’t develop symptoms, and a study published earlier this year by researchers at Scripps puts a lower bound on this number at ~1 in 3. This is probably not far from the true asymptomatic rate (for populations that are demographically similar to the populations they sampled). They got this number by reviewing several surveys where randomly-selected participants were tested for SARS-CoV-2 antibodies (to determine whether they’d had COVID-19 in the past) and asked whether they’d ever developed symptoms. The highlight of the study is in table 2, which summarizes the results of the highest quality population surveys using antibody tests. Covered in the press at Forbes magazine.
- A study indicates that a significant fraction of Earth’s carbon was not captured when the planet was formed, but was acquired later from interstellar space. Rocky planets generally may lose most of their carbon as their metallic components merge, and may have to acquire what carbon they have elsewhere. I wonder, however, how this squares with our observation of moons like Titan, where carbon seems to be abundant.
- There has been a great deal of speculation about the nature of the oumanama object, which is passing through our solar system and has a very odd shape. Contrary to those who insist that it’s aliens, the leading theory is that it’s a shard of a small rocky planet from another solar system that was ejected in an asteroid impact.
- 10 year after the press hubbub surrounding on the “discovery” of arsenic-based DNA (how time flies!), Dr. David Sanders provides a retrospective on the whole ordeal, and warnings about how flawed science can nevertheless make a massive splash in the press.
- One major difference between the Earth and Mars is that the Earth has active plate tectonics. Wired has an excellent article discussing the impact of plate tectonics on life on earth. Researchers at Caltech suggest that the Martian surface may have lost much of its water, not to space, but to the surface of the crust, where the water remains trapped. On related news, a volcanic eruption in Iceland may serve as a model for volcanism on Mars.
- Life’s Edge: The Search for What It Means to Be Alive is a new book by Carl Zimmer looks to be a very accessible account of the topics that we discuss on this blog. Reviewed here by the New York Times.
- Scott Siskind discusses the observed tragedy that “official sources” of information on matters of any complexity are usually vague to the point of being useless. Related to the discussion in the previous link roundup about the failures of public health messaging during the pandemic. Take, for example, the description of drug side effects on WebMD:
WebMD is the Internet’s most important source of medical information. It’s also surprisingly useless. Its most famous problem is that whatever your symptoms, it’ll tell you that you have cancer. But the closer you look, the more problems you notice. Consider drug side effects. Here’s WebMD’s list of side effects for a certain drug, let’s call it Drug 1:
Upset stomach and heartburn may occur. If either of these effects persist or worsen, tell your doctor or pharmacist promptly. If your doctor has directed you to use this medication, remember that he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Tell your doctor right away if you have any serious side effects, including: easy bruising/bleeding, difficulty hearing, ringing in the ears, signs of kidney problems (such as change in the amount of urine), persistent or severe nausea/vomiting, unexplained tiredness, dizziness, dark urine, yellowing eyes/skin. This drug may rarely cause serious bleeding from the stomach/intestine or other areas of the body. If you notice any of the following very serious side effects, get medical help right away: black/tarry stools, persistent or severe stomach/abdominal pain, vomit that looks like coffee grounds, trouble speaking, weakness on one side of the body, sudden vision changes or severe headache.
And here’s their list of side effects for let’s call it Drug 2:
Nausea, loss of appetite, or stomach/abdominal pain may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. This medication can cause serious bleeding if it affects your blood clotting proteins too much. Even if your doctor stops your medication, this risk of bleeding can continue for up to a week. Tell your doctor right away if you have any signs of serious bleeding, including: unusual pain/swelling/discomfort, unusual/easy bruising, prolonged bleeding from cuts or gums, persistent/frequent nosebleeds, unusually heavy/prolonged menstrual flow, pink/dark urine, coughing up blood, vomit that is bloody or looks like coffee grounds, severe headache, dizziness/fainting, unusual or persistent tiredness/weakness, bloody/black/tarry stools, chest pain, shortness of breath, difficulty swallowing.
Drug 1 is aspirin. Drug 2 is warfarin, which causes 40,000 ER visits a year and is widely considered one of the most dangerous drugs in common use. I challenge anyone to figure out, using WebMD’s side effects list alone, that warfarin is more dangerous than aspirin. I think this is because if WebMD said “aspirin is pretty safe and most people don’t need to worry about it”, people might use aspirin irresponsibly, die, and then their ghosts might sue WebMD. Or if WebMD said “warfarin can be dangerous, be careful with this one”, people might refuse to take warfarin because “the Internet said it was dangerous”, die of the stuff warfarin is supposed to treat, and then their ghosts might sue WebMD. WebMD solves this by never giving the tiniest shred of useful information to anybody.
- From Ewine van Dishoeck, an overview of everything we’ve learned about water in interstellar clouds from the observations of the Herschel space observatory. According to coverage at astrobiology.com:
The paper shows that most of the water is formed as ice on tiny dust particles in cold and tenuous interstellar clouds. When a cloud collapses into new stars and planets, this water is largely preserved and quickly anchored into pebble-sized dust particles.. In the rotating disc around the young star, these pebbles then form the building blocks for new planets.
Furthermore, the researchers have calculated that most new solar systems are born with enough water to fill several thousand oceans.
