Macro lenses are expensive. There is a cheap alternative, though, that can transform a regular lens into a macro lens: extension tubes. Extension tubes are simply hollow tubes that you put between the lens and the body of the camera. Optically inert, they shorten the focal distance and depth of field and bump up magnification, at the price of a loss of light.

If I told you that the emergence of blogs, Twitter and Facebook have changed our societies in more profound ways than we imagine, you’d be justified in telling me that I’m being neither original nor very pertinent. There is certainly something to be said about the amplification effect those services have on self-centeredness and gossip, and how those are sometimes more powerful than the few examples we have of new media spreading freedom, truth and democracy. Still, I think we are seeing the first signs of a profound revolution, one that is remodeling society in a way that is more in tune with our evolutionary origins. One where the notion of tribe makes a comeback, but with a couple of twists.

The date and time have come and gone and you are still here. As we are waiting for the rationalization from Harold Camping, it is time to ponder what this means for you. A few possibilities:

• You are not a True Christian. You should probably enjoy life while you still can.
• Rapture is postponed to another date. Redo Harold Camping's calculations and prepare new signs for whatever date you come up with.
• The whole thing was the crazy ravings of a religious nut. What else could turn out to be a house of cards built on extremely bad premises without any regard for reality?

You have heard about "Botox Mom", haven't you? This charming lady claimed on TV that she was giving her 8-year old daughter Botox shots in order to remove imaginary wrinkles and prepare her for some of those horrible "beauty" pageants.

Portals are not Aperture Science's only remarkable scientific accomplishment. Among their other inventions is the Light Bridge, that provides a stable and seemingly immaterial surface that people can stand on. The bridge can also be turned on or off instantly.

You heard it like me, someone just asked about the physics of Aperture Science's neat Portal Gun. I'll try to give an account of what we know from the material that Aperture recently made available and from what can be deduced from demonstrations of the product.

Sir Martin Rees said this right after receiving a huge pile of money from the Templeton Foundation:

[…]I think just as religion is separate from science, so is ethics separate from science. So is aesthetics separate from science. And so are many other things. There are lots of important things that are separate from science.

I just read Brian Dunning's post about the Fukushima explosion and was about to comment there but they are blocking comments from behind proxies, which is incredibly stupid on their part. So there, new post.

Here is a little experiment. I have built a bunch of programmed agents that are using a variety of strategies to try and predict the outcome of a randomized event. The event in question is the roll of a dice. The twist is that the probabilities of all sides of the dice are not equal: there is a distribution of probabilities that is itself decided randomly before the experiment.

Apologetics is the systematic defense of a position. It's usually done by religious people in defense of their dogma.