We know how the extinction of the dinosaurs completely changed the balance in nature and led to the emergence of large mammals.

But they are not the only large animals to play such a significant role. In this clip from Ted Radio Hour, George explains how returning wolves to Yellowstone National Park in 1995 after a 70-year absence affected so many aspects of the ecology there, transforming it. [Read more…]

Everyone has seen M. C. Escher’s famous lithograph Ascending and Descending of the perpetually ascending and descending staircase. Of course, we all know that this is an optical illusion and that such a thing could not be made in real life.

Or could it? [Read more…]

Although I am a strong supporter of solar energy, I had not been following developments in that area so I was pleasantly surprised at this news report that a new solar cell had broken a new efficiency record with 44.7%. What this means is that 44.7% of the light from the sun, from ultraviolet through to the infrared part of the spectrum, is converted into electrical energy. [Read more…]

GPS navigation systems are undoubtedly helpful. But at the same time, having those devices and following the instructions obviates the need for having a mental image of where you are and where you want to go, the way that a paper map gives you. A study finds that as a result you may be less efficient at getting to your destination. [Read more…]

By ‘habitable’ I mean planets that are neither too cold nor too hot but occupy a sweet spot that would be conducive to life as we know it existing. By combining actual data, from the Kepler space observatory launched by NASA in 2009 to look for Earth-like planets orbiting other stars, with statistical analysis, scientists have come up with an estimate of 15-30 billion habitable planets in our Milky Way galaxy alone. That seems like a lot, even if that number is tiny compared to the estimated 10¹¹ stars in the galaxy. [Read more…]

That excellent independent investigative journalistic outfit ProPublica has been running a series of articles about the dangers posed by people not knowing what harm Tylenol and other acetaminophen-based drugs can do to them if they are not careful about its use, and says that the FDA hasn’t acted quickly enough to alert people to the dangers and the need to be really careful about dosages. [Read more…]

Periodically one encounters the question of whether this or that topic or discipline is a science or not a science. This is a venerable problem that even has its own name (the demarcation problem) that I have written about extensively in the past (see my 2011 series of posts on the Logic of Science) and the consensus has been that it is impossible to specify both necessary and sufficient conditions that are necessary to do so. In most cases this inability to construct a strict demarcation rule does not really matter in any tangible way. After all, what does it matter what label you give something? But unfortunately it is the case that being considered ‘scientific’ adds a certain authority to statements, which is why people invoke it so frequently. [Read more…]

In Newtonian physics, mass is an invariant, by which I mean that any observer would measure the same value for the mass of an object, irrespective of how fast the observer was moving. Also, the relationship between momentum (p) and mass (m) was given by momentum equals mass times velocity (v). i.e., p=mv. [Read more…]

With all the stories about the NSA spying on the communications of people all over the world, we may have an exaggerated sense of the NSA’s code-breaking capabilities. Matthew Green, the cryptography researcher at Johns Hopkins University who was temporarily censored, explains that there are three ways to get past encryption. [Read more…]