Once upon a time, there were six different species of early humans.

That's not science fiction, and they all belonged to the genus Homo, but only we Homo sapiens have survived. What killed  H. habilis, H. ergaster, H. erectus, H. heidelbergensis, and H. neanderthalensis? Nature exists to kill and birth so that seems a more likely culprit than conquest, and a new paper points the blame at one aspect of nature that dominated science media before the coronavirus pandemic - climate change.

A new study finds that people are more motivated to use face masks and keep our distance not because experts or government bureaucrats say we should, but because we have empathy for vulnerable people.

In two surveys in the United States, the United Kingdom, and Germany, participants were asked on a scale from 1 to 5 how concerned they are about those who are most vulnerable to SARS-CoV2, the 2019 form of coronavirus that erupted in Wuhan, China and spread worldwide. Subsequently, they were asked about the extent to which they themselves avoid social contact due to the coronavirus. The relationship was clear. The higher the degree of empathy, the greater the focus on reducing social contact. 

There are calls to ban vaping because it has pleasant flavors and an addictive component and that combination may lead to disease but while there are zero deaths attributable to nicotine so far, there is an actual socially acceptable carcinogen that also uses flavors to increase use - alcohol.

Yet the future looks bleak if recent survey results hold true. They find that compared to just a generation ago, college students - and alcohol, like smoking, is most often a pediatric condition - are drinking less alcohol.

Mosquitoes spread malaria but because wealthy nations wiped it out before declaring insecticides bad, it's easy to forget that insecticides are the only effective way to control the mosquitoes that spread a disease which still kills 400,000 each year in developing nations.

For poorer countries, there is good news. Scientists have created a new crystal form of the pyrethroid pesticide deltamethrin that is up to 12 times more effective against mosquitoes. Insecticides such as deltamethrin and DDT can prevent the spread of diseases carried by mosquitoes and are often sprayed indoors and on bed nets. Though DDT, for example, is banned in the United States for political reasons, our EPA writes the book on how to spray it indoors where malaria still exists. 

This year’s Nobel prize in chemistry was awarded for a genuine revolution in modern science. The Crispr-Cas9 gene-editing tool allows scientists to precisely alter DNA by cutting and pasting sections of it.

For some reason today I remembered that 11 years ago (wow time flies) I wrote a two-parts piece on advices for PhD students doing a thesis in experimental particle physics. As I checked it out, I found that I mostly share the views I had back then (TBH that's not necessarily a good thing - consistency requires you to be as ignorant as you were earlier on). Since I think that stuff I posted over 10 years ago are otherwise lost in oblivion and not picked up by generic google searches, I decided it is time to recycle that text - here it is below, unamended but collated into a single longish article. Enjoy!

Have you been told you have a greater risk of heart disease based on family history? What does that even mean?

Like with kids, when it comes to galaxies adolescent blemishes disappear over time.

Exponential disks, common in spiral galaxies, dwarf elliptical galaxies and some irregular galaxies, appear smooth and have an exponential fade. How did they get it way?

It's not possible to know but using inference, simulations help provide insight. 


Graohic showing how two sample star orbits are scattered from nearly circular orbits by the gravity of massive clumps within galaxies. Image: Illustration by Jian Wu/Iowa State University. Galaxy image from the Sloan Digital Sky Survey.

Marco Fulvio Barozzi (b.