Myth: Duck’s quack has no echo

Posted on March 14, 2018

Since I was a little boy, I have heard many times that ducks do not produce any echo when they quack. With the arrival of the internet, this myth has been amplified, so the general public started to think that this was true. I have been teaching my students about the electromagnetic spectrum these days, and we had a lesson about sound and its properties. So let's start with the basics:   What is sound? Sound is a vibration that ...

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Mad Scientist Book bundle in

Posted on March 10, 2018

If you like videogames, I am sure you know the webshop They offer bundles of games, and they allow you to pay what you want for them. They usually offer them in different price tiers (if you pay more than X, then you also get this and that). They are currently offering a bundle of Science books, focused on teaching Science and do experiments with household items, as well as introduction to programming in Arduino. I've ...

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Hypothesis, Theories and Laws: what’s the difference?

Posted on February 21, 2018

The basis of Science relies on the Scientific Method, the best method we have to understand nature. Everything starts with an observation (e.g. plants do not grow well -or at all - in heavy metal-contaminated soils)  that leads us to make a question (how well can a plant grow in heavy metal-contaminated soils?). A scientific hypothesis is formulated according to this question, and it is the first step in any experimental research. A hypothesis ...

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Where does the salt from the oceans come from?

Posted on August 28, 2016

Have you ever considered where does all the salt of the oceans come from? Think about it. We assume that the oceans are salty, but most of the people never thought about the cause of it. Some hypothesis considered that oceans are salty because of all the tears cried by sharks that only wanted to cuddle. As much as I love sharks, I have to admit that that hypothesis can be easily discarded. The most abundant salt in the ocean water is ...

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Photomicrography competitions

Posted on June 22, 2016

Nikon has been organizing a photography contest of the microworld since 1975. They accept any image produced with a light microscope (compound or steroscopic), no matter the subject (you can read more about the rules here). As a photography enthusiast and a scientist, I can only delight my eyes with such a beautiful images like these ones: The deadline for the 2016 contest is already closed, but while we wait for trying our best ...

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Bacteria growing seem a lot of fun!

Posted on November 6, 2014

Every living organism is born, grow and multiply. Some organism are very boring to see while they grow, like century-living turtles. Others, like bacteria, multiply in a time-window of minutes or hours. Commonly, a bacterial culture follow different steps or phases: Lag phase: nothing happens here. There is no food or bacterial cells to allow any growth or development. Exponential phase: when we add food, the bacteria are happy and they ...

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Some people think scientist exclaim Eureka!

Posted on January 31, 2014

We are always pursuing the magic moment of saying “Eureka”!. Our imagination is easily filled with images of money raining from the sky, fame and who knows, even a congratulation word from your PI. However, most of the time when we do experiments we say very different things. I feel totally identified with this comic. The image belongs to Twisted Doodles.

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Bacterial photography

Posted on July 17, 2012

When we think in bacteria, one of the less probable thing we could imagine would be to take photos with them, right? I'm not referring to take photos of bacteria, but to take photos using bacteria. Using photo-sensitive bacteria, it is possible to make different patterns. The extreme sensitivity to light of some strains of bacteria, both natural and engineered ones,  make this possible. The position of the bacteria in the agar plate in ...

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How to create and use a scientific bibliography

Posted on April 3, 2012

I am really surprised about how many people are entering all the references in their text manually. It has become common to me to observe how much time my colleagues waste on write any single reference in their text and in the bibliography, instead of doing in automatically with software. This article would show you how to create and organize your scientific papers library, and how to enter the references in your text via software. For this ...

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Electricigens, when bacteria produce electricity

Posted on March 1, 2012

Electricity is a part of life. Electrical impulses coordinates the neural system in animals and even some species are able to use electrical discharges as a defense mechanism. And of course, electrical energy is involved in many cellular metabolic processes. In 1911, M.C. Potter affirmed that "The disintegration of organic compounds by microorganisms is accompanied by the liberation of electrical energy". But, what is a electricigen? Basica...

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