Sperm Journey

An educational video for you, from Japan. [Video Link. Thanks, Heather!]

Why do dog farts stink so bad?

Because puppies are filled with love ... and also hydrogen sulfide.

Your brain is all squishy: An anatomical demonstration

This video was made by the University of Utah Brain Institute to teach medical students about what a brain looks and feels like before it gets preserved in formalin and takes on the texture of a hard rubber ball.

The big takeaway message: Your brain is seriously squishy. So squishy, in fact, that a finger can dent it. As professor Suzanne Stensaas explains, this is one of the reasons why cerebrospinal fluid is so important. Your brain has to float in that fluid. If it didn't, it would come to rest against the side of your hard skull and quickly end up deformed.

Seriously, this is a fascinating (if extremely graphic) video. (Hilariously, given that fact, it opens with an image of a student eating.) Definitely worth watching!

Tongues aren't just for smelling

After you spent all that time in grade school conditioning yourself to know that snakes stick out their tongues in order to smell things, it turns out that those tricksy animals were also tasting with their tongues, all along.

How to: Sex your crocodile

Can you properly distinguish between a male and female crocodile? This research paper, published in 2007, will help — pointing out the sometimes subtle differences between external genitalia. It's chock full of pictures of erect crocodile penises, so you'll learn what those look like, but what particularly interested me was the diagram above.

Cloacas are sort of multi-purpose orifices found in certain species of birds and reptiles. Instead of having separate biological tools for poop, pee, and sex, these animals manage all three functions with the same hole. Males also have cloacas and will either have a penis or pseudo-penis that comes out of it for mating. I've known this for a long time, but had a lot of trouble picturing how all of that anatomy fits together. This diagram (Figure 4 in the paper) is the first image that made the internal structure of cloacas really make sense to me. The more you know!

Real lemmings don't commit mass suicide

Earlier this week, Republican representative Devin Nunes referred to his colleagues in the US House of Representatives as "lemmings with suicide vests". I would like to propose that this characterization is vastly unfair. To the lemmings.

That's because real lemmings, such as the adorable little creature pictured above, aren't actually suicidal. If anything, their problem is that they're just too damn horny. [Insert new political analogy here.]

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Popular Science answers your TMI questions

Fun fact you might not be aware of if you are not the owner of a uterus: Periods go hand-in-hand with pooping. Not every person who gets a period will end up with diarrhea, but it's not uncommon because the same hormone that makes a uterus contract (a necessary step in the whole period process) can also end up making your intestines contract. Francie Diep explains this effect — as well as the other hormone-related reason why periods and poops can be linked.

Two good reasons to question the claim that alien life has been found in Earth's atmosphere

First, neither the authors of the paper, nor the journal its published in, have the best track record for careful work, well-documented research, or non-hyperbolic results. More important, the actual paper, itself, makes claims it can't back up. Case in point, says Phil Plait, the alien in question is a particle the authors assume is part of a diatom — a single-celled plant. The paper actually says "assume", and, from the sounds of things, they haven't even checked out that basic, important idea with a diatom expert.

Lady squid dress in drag

The opalescent inshore squid (which, if you've eaten squid in the US, then you've probably eaten before) can change color just like octopuses can. In fact, scientists found that female squid can give themselves a white stripe that looks an awful lot like the testicles of their male counterparts. It's probably some kind of defensive measure, but the scientists are more interested in how the squid change color, not why. That's because the mechanism is unique, and fascinating.

Enormous timescales made graspable by graphs

Wait But Why has a fantastic series of graphs that aim to help us wrap our heads around the enormous timescales on which forces like history, biology, geography and astronomy operate. By carefully building up graphs that show the relationship between longer and longer timescales, the series provides a moment's worth of emotional understanding of the otherwise incomprehensible.

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Insect with gears on its legs

Meet Issus coleoptratus, an insect whose larva have interlocking meshed gears connecting their back legs. The gears help coordinate leg movements, helping the larva to jump fast and far.

Video Link

True tales of a laboratory safety officer

Science journalist John Rennie is an amazing story teller. In this recording from Story Collider, he explains how he became the lab safety officer in his post-undergrad biology laboratory in the early 1980s (it involves being the only person who was concerned when other people started scooping up mercury with their bare hands). The peak of his experience: The day he stuck his arm, up past the elbow, into a barrel of liquid nitrogen. Good times.

Audio link

When the octopus says, "ouch"

Given that people are going around doing things like cutting off octopus limbs in order to understand their distributed neuron processing system, it's worth asking some questions about how octopuses perceive pain, as well. That's more complicated than you might think. As Katherine Harmon explains, it's likely that octopuses have some kind of awareness of when they're touching something unpleasant. But just how that works, and how similar it might be to the way we vertebrates understand "pain", is a big mystery.

Revealed: the questing, flexible, ramified business-end of a mosquito

Valérie Choumet at Paris's Institut Pasteur anaesthetized a mouse, stuck a microscope in a flap of its skin, and induced a mosquito to bite it. The result is the best footage yet of the weird, flexible, questing mouth of a mosquito, which can bend and twist and fork as it seeks out blood vessels.

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Don't touch that hot stove!

The complicated process that allows your brain to quickly cancel an order and replace it with another.