Posts about science explained

Lots of Bacteria are Always Living in Our Bodies

My response to a question on Reddit – Ask Science:

Let’s say you get infected with a bacterium that causes annoying, but totally non-dangerous symptoms. If you just try to “live with it,” will your immune system eventually kill it, or does killing bacteria require antibiotics in all cases?

Your body definitely kills lots of bacteria.

Your body also has tons of bacteria all the time (many doing much more good than they do harm). These bacteria also compete with each other.

So your “existing” bacteria kill off others all the time too (you have lots of different types of bacteria full time in your body – they often settle into niches and fight off any others , which is normally good as they are long term residents your body has learned to live with them).

Also like everything bacteria die off themselves – though if the conditions are right they are multiplying like crazy so that exceeds die off.

An astonishing number and variety of microbes, including as many as 400 species of bacteria, help humans digest food, mitigate disease, regulate fat storage, and even promote the formation of blood vessels.

According to estimates, phages destroy up to 40 percent of the bacteria in Earth’s oceans each day.

Staphylococcal food poisoning – an example of bacteria infection my body dealt with quickly.

People talk about genetics impact on getting cavities and impact of brushing and flossing well. Also the makeup of bacteria can help or hurt. If your mouth is home to certain bacteria tooth decay is less likely, home to others it is more likely. They tend to remain fairly steady (a certain makeup of bacteria will be consist for a person over the long term – not perfectly that way but tend that way). A UCLA microbiologist developed a mouthwash to try and ceed your mouth with good bacteria and oust the bad guys.

Related: People Have More Bacterial Cells than Human CellsHuman Gene Origins: 37% Bacterial, 35% Animal, 28% Eukaryotic

The Feynman Lectures on Physics Available Online

The Feynman Lectures on Physics are now available to read online. They are a great collection of lectures covering physics and touching on many areas including: the Mechanisms of Seeing, Semiconductors and Algebra. This is a fantastic resource for learning about physics.

You can also get a boxed set of The Feynman Lectures on Physics for those that like paper. It is fantastic but not cheap.

Bill Gates bought the rights to the rights to The Character of Physical Law, 7 lectures Feynman gave at Cornell University (these are separate from the lectures listed above) and made them available online, which is great. Unfortunately the website is based on Microsoft tools and therefore quite a bother for many (or maybe even impossible with Linux computers – I am not sure). I guess since he made all his money via Microsoft it isn’t that surprising but it would have been nice if he provide the content in a more easily accessible way (even if they didn’t do the fancy additions they did on the Microsoft site. These are great enough videos to probably be worth the bother of installing proprietary Microsoft software in order to view them.

Related: Video of Young Richard Feynman Talking About Scientific ThinkingFeynman “is a second Dirac, only this time human” (Oppenheimer) – Classic Feynman: All the Adventures of a Curious Character

Science Explained: How Cells React to Invading Viruses

This illustrated webcast introduces the microscopic arsenal of weapons and warriors that play a role in the battle for your health.

TED education has been putting out some good videos which is a wonderful thing to see. It is wonderful to let people everywhere (kids and adults) that are interested in learning (and that have internet access) can learn about the world around us. Traditional educational institutions have not done much with this opportunity to broaden their impact.

The video looks at the cells reaction to a virus infiltrating the cell.

Related: Cells AliveScience Explained: Cool Video of ATP Synthase, Which Provides Usable Energy to UsThis webcast is packed with information on the makeup and function of eukaryotic (animal) cellsCool Animation of a Virus Invading a Person’s BodyCell Aging and Limits Due to TelomeresWebcast of a T-cell Killing a Cancerous Cell

Explaining the Higgs Boson Particle Again

comic illustration explaining the Higgs-boson particle

Excerpt from Piled Higher and Deeper by Jorge Cham – go see the entire illustration.

Related: 5% of the Universe is Normal Matter, What About the Other 95%?At the Heart of All MatterThe god of small thingsCERN Pressure Test FailureNinja ProfessorsFriday Fun, CERN Version

Learn About Biology Online

Very cool site for learning about biology. I have tried the courses offered by Coursera but they are too structured for my taste. I want to be able to learn at my pace and dip into the areas I find interesting. Coursera is more like a real course, that has weekly assignments and the like.

Survivebio is a resources that matches my desires exactly. You can go and learn about whatever topics you desire, when you desire. The site offers webcasts, games, flashcards, chapter outlines, practice tests and a forum to discuss the ideas.

In this webcast, Paul Andersen discusses the specifics of phylogenetics. The evolutionary relationships of organisms are discovered through both morphological and molecular data.

The aim of the SurviveBio web site is to aid AP (and college) biology students. But it is also a great resource to learn about biology if you are interested in that topic. Hopefully they will add more webcasts. The site uses webcasts from Bozeman Science which has a huge number of very good videos on biology and also, chemistry, physics, earth science, statistics, anatomy and physiology.

Related: Great Webcast Explaining the Digestive SystemsCell Aging and Limits Due to TelomeresHuman Gene Origins: 37% Bacterial, 35% Animal, 28% Eukaryotic

Science Explained: Momentum For String of Metal Beads

Fun video with an explanation of the physics behind what might seem like the surprising action shown in the video.

Related: The Science Behind Hummingbird FlightScience and Optical IllusionsGravity and the Scientific MethodHow do Plants Grow Into the Sunlight?

How Do You Lose Weight While You Sleep?

In this interesting webcast, Derek Muller, (a physics teacher in Perth, Australia) explores how much weight you lose while you sleep. As physics teacher he asks the sensible question: how do you lose weight while you sleep, what weight do you lose?

His conclusion is you lose weight through perspiration, water vapor in your breath and expelling carbon dioxide. Losing the water weight is pretty straight forward. The process of adding carbon to the breath we expel is not something I thought of. He calculates that we lose about 100 grams of carbon during a night of sleep. In his somewhat scientific experiment (measuring himself for several days) he lost about 150 more grams, which he attributes to water vapor and perspiration.

It seems to me the amount of carbon we lose during sleep is probably much more consistent than the amount of water weight we lose (both between people and variation between different days).

Related: Can You Effectively Burn Calories by Drinking Cold Water?CDC Urges Reducing the Amount of Salt We EatWhy is it Colder at Higher Elevations?How Caffeine Affects Your BodyWhy Does the Moon Appear Larger on the Horizon?

Building A Better Bed Bug Trap Using Bean Leaves

Building A Better Bed Bug Trap

An old folk remedy involving hairy bean leaves strewn around the bedroom may have a new life as a modern bed bug trap, according to new research from the University of California, Irvine and the University of Kentucky.

Although its mechanisms weren’t known at the time, the tactic dates back to at least 1678, when the English philosopher John Locke wrote of placing kidney bean leaves under the pillow or around the bed to keep bed bugs from biting as he traveled through Europe.

In the early twentieth century, the approach was also common throughout the Balkans, according to a 1927 report from the Imperial and Royal Austro-Hungarian Army. That report suggested the leaves stunned the bloodsucking bugs as they traveled from hiding places to their sleeping hosts during the night; in the morning, the bug-covered leaves were removed and burned.

“The inconvenience of bean leaves is that not everyone wants them scattered around their bed room.” Synthetics mimicking the surface of the bean leaf, however, could be placed “as a ring around the bed legs, a floor mat at the door, a strip on the bed board, it could be something one put’s in one’s suitcase,”

Very cool. The chemical assault on bed buds is failing all over the world. A new vector to assist in the fight against bed bugs will be most welcome. It is interesting to learn the scientific reasons that explain why some folk remedies work.

Related: Bed Bugs, Science and the MediaAntibiotics Breed Superbugs Faster Than ExpectedPigs Instead of Pesticides

Human Gene Origins: 37% Bacterial, 35% Animal, 28% Eukaryotic

The percent of human genes that emerged in various stages of evolution: 37% bacterial, 28% eukaryotic, 16% animal, 13% vertebrate, 6% primate. The history that brought us to where we are is amazing. Eukaryotes include animals, plants, amoebae, flagellates, amoeboflagellates, fungi and plastids (including algae). So eukaryotic genes are those common to us and other non-animal eukaryotes while those classified as animal genes are shared by animals but not non-animal eukaryotes.

We are living in a bacterial world, and it’s impacting us more than previously thought by Lisa Zyga

Bacterial signaling is not only essential for development, it also helps animals maintain homeostasis, keeping us healthy and happy. As research has shown, bacteria in the gut can communicate with the brain through the central nervous system. Studies have found that mice without certain bacteria have defects in brain regions that control anxiety and depression-like behavior. Bacterial signaling also plays an essential role in guarding an animal’s immune system. Disturbing these bacterial signaling pathways can lead to diseases such as diabetes, inflammatory bowel disease, and infections. Studies also suggest that many of the pathogens that cause disease in animals have “hijacked” these bacterial communication channels that originally evolved to maintain a balance between the animal and hundreds of beneficial bacterial species.

Scientists have also discovered that bacteria in the human gut adapts to changing diets. For example, most Americans have a gut microbiome that is optimized for digesting a high-fat, high-protein diet, while people in rural Amazonas, Venezuela, have gut microbes better suited for breaking down complex carbohydrates. Some people in Japan even have a gut bacterium that can digest seaweed. Researchers think the gut microbiome adapts in two ways: by adding or removing certain bacteria species, and by transferring the desired genes from one bacterium to another through horizontal gene transfer. Both host and bacteria benefit from this kind of symbiotic relationship, which researchers think is much more widespread than previously thought.

We want badly for the message in ‘Animals in a bacterial world,’ to be a call for the necessary disappearance of the old boundaries between life science departments (e.g., Depts of Zoology, Botany, Microbiology, etc.) in universities, and societies (e.g., the American Society for Microbiology, etc.). We also want the message disseminated in college and university classes from introductory biology to advanced courses in the various topic areas of our paper.”

Very cool stuff. This amazing facts scientists discover provide an amazing view of the world we live in and how interconnected we are to other life forms in ways we don’t normally think of.

Related: People’s Bodies Carry More Bacterial Cells than Human CellsMicrobes Flourish In Healthy PeopleTracking the Ecosystem Within UsForeign Cells Outnumber Human Cells in Our BodiesBacteria Beneficial to Human Health

How to Walk on Ice

infographic explaining how to walk on ice - walk like a penguin

Infographic by Tablet. Falling on ice leads to many injuries and even 60 deaths a year in the USA (about the number that will die due to tornados). The graphic encourages thinking like a penguin. Penguins walk well on ice (in some ways) and they also fall well.

Seeking to keep your weight well supported (short strides) is wise (and sliding instead of picking up your feet can help). Falling well is also important. It is basic physics, you want to lower your center of gravity if you are start to slip and avoid any excessive force (so sliding is better than trying to stick out your hand and support all your weight). The elderly are especially susceptible to injuries – avoiding taking direct shocks to the wrist, knees or hips is wise). It does seem kind of silly to learn how to fall but it is very helpful in avoiding injuries.

On sidewalks if you are going to fall and there is snow piled up off the sidewalk, falling into the pile of snow may well be softer than falling directly onto the sidewalk.

On ice you have lower friction so strategies that require friction are not useful – quick moves often rely on very sturdy bases (which are based on the friction of our shoe on for example concrete [which normally is good - though business shoes are not very good] and on ice [where it is very poor - sliding and gradual moves are better]).

Related: Falling SafelyMinistry of Silly WalksMake Crosswalks More VisibleWhy Wasn’t the Earth Covered in Ice 4 Billion Years Ago – When the Sun was DimmerScience Toys You Can Make With Your Kids

Why is the Sky Dark at Night?

The answer isn’t quite as simple as it seems. I find the wording in the video a bit confusing.

The point I believe, is that the sky is dark instead of light. But not that the brightness would be huge (so for example, you couldn’t necessarily read my book outside just by starlight). The light would be very faint, it is just that it would be lightish instead of blackish, due to the reasons explained (redshift etc.). At least that is my understanding.

Related: Why is it Colder at Higher Elevations?Why Does the Moon Appear Larger on the Horizon?Why is the Sky Blue?Why Wasn’t the Earth Covered in Ice 4 Billion Years Ago – When the Sun was Dimmer

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