This is a very interesting article about why the naked mole rat can’t feel pain from acid burns. Apparently it was already known that they don’t feel the pain; their hypothesis about why it happened—that the acid sensing ion channels that tell neurons to transmit pain would be missing—was not true.

Because it turns out that mole rats — despite being the only known vertebrates that are insensitive to the painful stimulus of acid — have the same two fully-functional, acid-sensing channels regulating their pain receptors as the rest of us, and even produce the channels in similar quantities. And this is where things get interesting.

Now they know the actual reason. There’s another way neuron-firing can be controlled, and it is this (sodium) channel that is highly inhibited in the naked rat mole. Similar phenomenons are observed in humans too:

Furthermore — and this doesn’t happen often — humans lacking the Nav1.7 channel have been known to feel no pain whatsoever.

Very interesting, yes, but my question is this: the naked rat mole is insensitive to pain due to acids; but does that mean that it is in fact unaffected by acids? It does not seem so—the phenomenon is purely neurological, and there seems to be nothing physiological that would protect the rat against acids.

Does this not make this a counterproductive adaptation? Why would this adaptation survive? Is it because the natural environments of these rats are entirely devoid of harmful acids, thus making that pain sensation redundant? (Is this also why they’re “naked”, rather than furry?)

Intriguing.

A composite image created by combining data from the Chandra X-Ray Observatory and the Hubble Space telescope, this is a stunning image of two galaxies colliding. Both of them are spiral galaxies, and they are on the verge of a collision—with their disks oriented at 90 degrees to each other!

Well, “on the verge” is in galactic time scales, which means they’ll collide in a few million years. And considering that this is 450 million lightyears away from us, the event has already occurred—we just haven’t seen it yet.

A detailed description of the image is present as a caption with the photo itself. Go see it!

To the modern web user, passwords are usually a nightmare, especially with the modern trend of “your password must contain every possible category of keys”. Well, how effective is that sort of thing?

Here’s a take on that.

(By the way, a measure of a great publication of any sort is when you end up “liking” and “sharing” most of its content. XKCD is one such.)

Of course, the flip side of the argument in the comic is: most users don’t think of random sequences of words, but most often come up with the easiest-to-guess phrases. In this case, some security is better than no security.

(Oh, and don’t forget to mouseover over the comic itself. And do that over every xkcd comic. You’re welcome.)