What is Life?

This might sound like a philosophical question, but I intend it more like a scientific question.  We’ve discussed this somewhat before, like in our post about the universe’s habitable zone, but I want to focus in a little closer on what life really is, on what makes one thing alive and one thing not alive, how we might go about defining the difference, and whether what we call life deserves the distinction we have hitherto applied.

Space Debris Economics

Why should a private company make a business out of space debris removal?  Alternatively, can space debris removal be made into a viable business model?  This is one of those complicated questions that I recently saw reduced to a gross oversimplification in a news article.  There were a lot of issues with the article, and I don’t want to dwell on it, but I think the biggest problem was its underlying, unstated assumption that the only viable business case for space debris removal as a commercial service was if the government was the customer, or regulated private space industry into becoming customers.  The underlying argument of the article, therefore, is that there is no viable business model based on space debris removal.

Conservation and Cycles

In any closed system, quantities must be conserved.  Thermodynamics inform us that energy is conserved.  Linear and angular momentum are both conserved, whether we’re looking at billiard balls in a Newtonian paradigm, or photons in a quantum system.  Special relativity expands conservation even further to the equivalence between matter and energy.  In a closed system, where nothing can escape, quantities are inevitably conserved.