Why your hair dulls the sharpest razor blades
Ever wonder how soft hair can dull a steel razor? So did scientists at MIT.
- Steel is fifty times harder than hair, yet shaving razors dull in a hurry.
- A new study finds much of this is caused by hair cracking razors at points of imperfection.
- The findings may lead to new ways of making razors that last longer.
Everybody who shaves regularly knows that most razors only last a few shaves. Given that hair is not nearly as hard as steel, this tendency seems odd. Why should soft hair degrade steel? Until now, the assumption had always been that each shave dulled the blade to the point of it losing its sharp edge.
Now, a curious new study out of MIT finds that this isn't what happens at all. Instead, your hair can crack stainless steel under the right circumstances.
An extremely magnified image of a razor blade cutting hair.
Lead author Gianluca Roscioli grew his facial hair out for three days before shaving. He then brought his razors into the lab to examine them under an electron microscope. While the team expected to see even dulling on the blade edge, they instead noticed strange C-shaped chips missing. Intrigued, they attached a camera to the microscope so they could record the blade cutting the hair. At the same time, they investigated the properties of the razors at the microscopic level.
This apparatus revealed that, when the razor blade hit the hairs at non-perpendicular angles, small cracks formed. These tended to develop in boundary areas between where the steel was harder and where it was softer due to differences in the properties at each location caused by the manufacturing process. Over time, these cracks grew into chips. While these chips are too small to see with the naked eye, they were large enough to reduce the blade's effectiveness.
Roscioli told NPR, "The size of the chips are about 1/10 of the diameter of a human hair."
The chips can be caused by hair of any thickness and appear to be unavoidable in blades with standard imperfections.
The finding surprised other scientists, who also quickly accepted the explanation. Professor Suveen Mathaudhu of UC Riverside explained to NPR that he had expected a larger role in the dulling process to be played by corrosion but that the findings made a great deal of sense. Other scientists expressed how impressed they were by the quality of the images and the difficulty of the study.
How can we possibly use this information?
The study determined that part of the reason for this chipping is the imperfections in the steel used to make the blades, specifically the lack of uniformity in the composition of the steel at the microscopic level. At least partly, these imperfections are due to the nature of the production process and can be reduced through alternative methods. This study's research team is also working on a new material with more structural uniformity as a possible solution.
These findings may one day lead to longer-lasting razor blades. Given that Americans throw out two billion blades each year, such a discovery's environmental impact would be tremendous.
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Researchers documented the most common negative side effects of smoking weed, and who might be most susceptible.
- A team of researchers identified a total of 26 possible adverse reactions to cannabis use.
- Coughing fits, anxiety, and paranoia are among the top three most common adverse reactions to smoking weed.
- It was the people who smoke on a less frequent basis who were more likely to have had the bad experiences.
The most common adverse effects of pot<p>As it turns out, coughing fits are among the top three most common adverse reactions to cannabis use, along with anxiety and paranoia, according to a new study published in the <em>Journal</em><a href="https://jcannabisresearch.biomedcentral.com/articles/10.1186/s42238-019-0013-x" target="_blank"><em> of Cannabis Research</em></a>. </p><p>Now that weed is legal in the state, a team of researchers at Washington State University sought to document potential negative reactions to cannabis in order to paint a detailed picture of the effects of smoking weed for newbies. The authors surveyed more than 1,500 college students on the specific type and frequency of adverse reactions they had experienced while using pot. Additionally, the students in the study were surveyed about their demographics, personality traits, reasons for using cannabis and their use patterns. </p><p>Despite marijuana's <a href="https://bigthink.com/sex-relationships/marijuana-sex" target="_self">numerous benefits</a>, the team identified a total of <a href="https://jcannabisresearch.biomedcentral.com/articles/10.1186/s42238-019-0013-x/tables/2" target="_blank">26 possible adverse reactions to</a> the drug. More than half of the study participants reported having coughing fits along with anxiety and/or paranoia while using cannabis. The most frequently occuring of these were the coughing fits, along with chest/lung discomfort and body humming. A subset of the study group reported these reactions occurring around 30–40% of the time they were using pot. On the flip side, the three <em>least</em>-commonly reported reactions to cannabis use were fainting, visual hallucinations and cold sweats. </p><p>"There's been surprisingly little research on the prevalence or frequency of various adverse reactions to cannabis and almost no research trying to predict who is more likely to experience these types of adverse reactions," <a href="https://news.wsu.edu/2020/03/30/new-research-sheds-light-potentially-negative-effects-cannabis/" target="_blank">said Carrie Cuttler</a>, assistant professor of psychology and an author on the paper, according to WSU News. "With the legalization of cannabis in Washington and 10 other states, we thought it would be important to document some of this information so that more novice users would have a better sense of what types of adverse reactions they may experience if they use cannabis."</p><p>The most distressing of the 26 negative reactions were panic attacks, fainting, and vomiting. Yet, the survey data suggested that cannabis users generally do not find even acute adverse reactions to cannabis to be severely distressing.</p>
What causes a bad reaction?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjkwOTEwOC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNTQ5MDQ2Mn0.S2Pkbh3VAgB4Gk5tkavamMv0_4t76dg65yGWpCHG17U/img.jpg?width=1245&coordinates=0%2C1872%2C0%2C1252&height=700" id="dee45" class="rm-shortcode" data-rm-shortcode-id="df6e30ecae156ba0012f4773a374800c" data-rm-shortcode-name="rebelmouse-image" />
But most city dwellers weren't seeing the science — they were seeing something out of Blade Runner.
On Sept. 9, many West Coast residents looked out their windows and witnessed a post-apocalyptic landscape: silhouetted cars, buildings and people bathed in an overpowering orange light that looked like a jacked-up sunset.
India finishes last of 60 countries in environment and sustainability, as ranked by the expats who work there.
- How 'green' is life in your work country?
- That's the question InterNations asked its network of expats.
- The United States ended 30th out of 60 countries.
Nordics on top<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU2NjgyNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NTczNzkyOX0.VgfqyjAa9avw6gFOE0qlgSgKuBN7DJmzOc5lzFGLm8g/img.jpg?width=980" id="1f0dc" class="rm-shortcode" data-rm-shortcode-id="b27458cf472d26cf1f87cb91623a0621" data-rm-shortcode-name="rebelmouse-image" alt="Evo Hiking Area, H\u00e4meenlinna, Finland." />
Evo Hiking Area in Hämeenlinna, Finland. Great nature, clean air, clean water? Check, check and check.
Credit: Kanta-Hämeen kuvapankki on Flickr/ Public Domain.<p><br><strong>1. Finland</strong></p><p>The Nordic country scores at or near the top in all categories surveyed, including the quality of the natural environment (say 96 percent of expats in Finland), water and sanitation (96 percent) and air (95 percent). <br></p><p><strong>2. Sweden</strong></p><p>Swedes lead the world in environmental awareness (84 percent versus just 48 percent globally). Perhaps not surprising, for the homeland of <a href="https://bigthink.com/politics-current-affairs/greta-effect" target="_blank">Greta Thunberg</a>. This is reflected by government policy. Sweden currently gets more than 50 percent of its power from renewable sources and wants to go 100% renewable before 2040. "I've been here for over 20 years and I clearly see the benefits of my taxes paid coming back to me and the rest of society," says one American expat.<br></p><p><strong>3. Norway</strong></p><p>"The beautiful nature, the clean air and tap water, and the focus on the environment," are what one Ukrainian expat enjoys most about Norway. With 76 percent of expats happy with the availability of green goods and services, Norway's 'weakest' category is still 13 percentage points above the global average. <br></p><p><strong>4. Austria</strong></p><p>The first non-Nordic in the global ranking, Austria places in the Top 10 for each category and comes in first for the availability of green goods and services (90 percent). <br></p><p><strong>5. Switzerland</strong></p><p>Swiss nature is the most appreciated in the world (98 percent versus 83 percent on average). Switzerland also gets stellar results for air and water quality and the availability of green energy and green goods and services. </p><p><strong>6. Denmark</strong></p><p>Danes are very much into green causes, as is their government, say 83 percent resp. 84 percent of expats. "Organic food is readily available, and they are good with recycling," observes a South African expat. And they love cycling: 9 out of 10 Danes own a bike.</p><p><strong>7. New Zealand</strong></p><p>85 percent of expats agree that the New Zealand government takes green issues seriously. In fact, New Zealand plans to use 90 percent electricity from renewables by 2025. The country also scores high on the quality of its natural environment and all other categories – albeit slightly less on the quality of its water and sanitation.</p><p><strong>8. Germany</strong></p><p>"I enjoy the rising awareness about environmental issues and the alternatives the government and society are developing," says one Colombian expat. Indeed, 80 percent of expats agree the German government is pro-environment (versus 55 percent globally). <br></p><p><strong>9. Canada</strong></p><p>The only North American destination in the Top 10, thanks especially to expat appreciation of Canada's natural environment (96 percent), but also the quality of its water and sanitation (90 percet) and the availability of green goods and services (80 percent). <br></p><p><strong>10. Luxembourg</strong></p><p>"Access to nature for hiking and bicycling" is a definite boon for one American expat. In fact, the country's natural environment, although ranking 13th out of 60, is its lowest-rated subcategory. Luxembourg does even better when it comes to green energy, waste management, and the quality of its air and water.</p>
Taiwan, most sustainable destination in Asia<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU2Njg1Ni9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1NzkxMDAxNH0.Roy7h_Od1cmaqBmamk-DP4rKMpLjTM-qIajG96alZAg/img.jpg?width=980" id="00799" class="rm-shortcode" data-rm-shortcode-id="dab52370e1edb5da5ebb0f5631027b1c" data-rm-shortcode-name="rebelmouse-image" alt="\u200bEternal Spring Shrine in the Taroko Gorge, Hualien County, Taiwan." />
Eternal Spring Shrine in the Taroko Gorge, Hualien County. Outside of Taipei, Taiwan can be surprisingly green and beautiful.
Credit: Zairon, CC BY-SA 4.0<p><strong>11. Taiwan</strong></p><p>The highest-scoring expat destination in Asia, Taiwan boasts 92 percent approval of its waste management and recycling, and 80 percent of the availability of green goods and services. But "the air pollution (in Taipei) is getting worse because it is too crowded," one expat complains.</p><p><strong>12. Netherlands</strong></p><p>Green goods and services are widely available, agree 82 percen of expats, as is green energy. However, 13 percent rate the Dutch environment negatively, 4 percet above the global average. <br></p><p><strong>13. Portugal</strong></p><p>Well ahead of its neighbor Spain (#20), the country scores high for air quality (91 percent) and natural environment (95 percent). "I like the opportunity for gardening and growing our own food," says one expat. <br></p><p><strong>14. Estonia</strong></p><p><strong></strong>Estonia scores in the Top 20 for every category and gets its highest marks for its natural environment. "A beautiful country with excellent air quality and open spaces," praises an Indian expat.<br></p><p><strong>15. Costa Rica</strong></p><p><strong></strong>Both the government and the people are very supportive of green policies, find 82 percent, resp. 67 percent of expats. "It's easy to live a healthy lifestyle with regard to the food, climate, clean air and water," says one. Costa Rica won the 2019 UN Champion of the Earth award and has pledged to go carbon neutral by 2050.<br></p><p><strong>16. Czechia</strong></p><p><strong></strong>"The beauty of the environment" is one of the best things about living in Czechia, says a Russian expat. No less than 97 percent of expats agree.<br></p><p><strong>17. France</strong></p><p><strong></strong>77 percent of expats are happy about the availability of green goods and services in France, which is 14 percentage points above average. The country also scores well for waste management and recycling. In short, France has a "good, green and clean environment," one Iranian expat finds. <strong><br></strong></p><p><strong>18. Australia</strong></p><p><strong></strong>While ranking high on the quality of its nature, water and air, Australia scores low when it comes to government support for green issues (51 percent). Fortunately, expats see more interest among the general population (68 percent). </p><p><strong>19. Singapore</strong></p><p><strong></strong>Expats rate the government's interest in green issues higher than globally average (77 percent versus 55 percent), but the Singaporean public's engagement for the same less than average (40 percent versus 48 percent). Of course, in a small, crowded place like Singapore, "(nature) spots are limited."<br></p><p><strong>20. Spain</strong></p><p>Spain's "scenery, diversity of places to visit and healthier environment" are what rate highly with one British expat. Its weak point is governmental and public support for green issues – but still slightly above the global average. <br></p>
London is "polluted and noisy"<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU2Njg4Ni9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NDg3NjkyOH0.3ySSD7jFBfAWA07u-EN-oL9x9cq9FZn06iz5aV0hEOw/img.jpg?width=980" id="f5630" class="rm-shortcode" data-rm-shortcode-id="80c9fa119e7ff3acc91e027b7529bfed" data-rm-shortcode-name="rebelmouse-image" alt="\u200bEven at 2:30pm, London gets clogged." />
Afternoon traffic jam in London.
World map for the 'sustainable expat'<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU2Njg5MC9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYzMzAyNjQ2MH0.hjRiMDmOSnn9EvKJtx_tlzql3Gf7ph8lt8bL6dPCft4/img.png?width=980" id="def5d" class="rm-shortcode" data-rm-shortcode-id="149be2f5a19cc625cb555d8078f62ce2" data-rm-shortcode-name="rebelmouse-image" alt="The best & worst destiations for the sustainable expat" />
Sixty expat destinations ranked for sustainability, from best (orange) to worst (light blue). In between: fairly okay (brown), middling (grey) and not that great (dark blue).
South Korea's "rather horrible" air<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU2NjkxNS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY2MTY1MjIwNn0.2e6eBIc38sAZLFQGKw4UL3-SY3hA9NthX0Uj9L4ibZA/img.jpg?width=980" id="c10db" class="rm-shortcode" data-rm-shortcode-id="cba918e6e5455c2e5ff4f9d5caf54775" data-rm-shortcode-name="rebelmouse-image" alt="\u200bSmoggy Seoul" />
Seoul's air quality is so bad you can picture it. Only India's air is perceived as worse than South Korea's, according to the expat survey.
Bad, worse, India<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU2Njk0MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NTcyMTczMH0.Pt2bGDrpSKSwVjimMK_iK0Jejpu8ILn77VEzHTdzQQ4/img.jpg?width=980" id="28411" class="rm-shortcode" data-rm-shortcode-id="8b8b602261a168a46b05c53e09ab1b02" data-rm-shortcode-name="rebelmouse-image" alt="man standing surrounded by garbage" />
India scores worst in all three categories, but to be fair – some of its problems were imported from more developed countries.