May 29, 2020

# The water of Venus | Science

He problem of candies and boxes raised last week It is trivial if we limit ourselves to three flavors – strawberry, orange and lemon – and two candies of each flavor, as it is evident that in this case, and whatever the distribution of candies in three boxes with two candies per box, we can always Get one of each flavor by taking a candy from each box. Just look at all the possible distributions: FF NN LL, FF NL NL, FN FN LL, FN FL NL, FL FL NN … But the thing is complicated by expanding the number of flavors and boxes, as well as the number of candies in each taste. Let's see, in this regard, the reflection of Francisco Montesinos, who raised this interesting problem:

“The case of 2 candies / box is observed that extracting 1 candy from a box of flavor say s1 and then if the 2nd of that box is of flavor s2 some other box contains the other one of that flavor. We go to that box and we extract it. If continuing in this way we managed to extract the m candies of different flavors, we are finished. If we have only been able to extract k from k different flavors and k different boxes, the process begins in the remaining m-k boxes containing m-k flavors… ”(See comment nº100 of Solar day and sidereal day).

The classic approach to the marriage theorem, which is one of the ways to address the problem of candy, is somewhat macho, and when formulating it, the will of women is not usually contemplated, as if the mere fact of having several suitors guaranteed They are going to get married. Since this is not the case, there is always the possibility that some (or several, or all) want to remain single no matter how much suitors you have. The discussion raised by the marriage theorem can be seen in the comments of last week (especially in nos. 13, 15 and 17).

### Our infernal brother

And after this sweet wedding and candy break, let's return to the fascinating issue of water in the Solar System. In previous weeks we have talked about the presence of ice at the poles of the Moon, Mars and Mercury, so it seems inexcusable to deal with our remaining cosmic neighbor, the planet Venus.

With a mass and volume slightly lower than terrestrial (its radius is just over 6,000 km), Venus has always been considered the "sister planet" of the Earth, and it is likely that about 700 million years ago it had large oceans of liquid water. But currently its atmosphere, with huge amounts of CO2 and other greenhouse gases, it retains solar heat to such an extent that the temperature on the planet's surface exceeds 460º C, which, together with a pressure about 90 times higher than the earth's and its abundant clouds of sulfuric acid, make it in a “hellish” planet very unfit for life as we know it, and where water is only in the form of steam, and already in small quantities, since solar radiation breaks it down into hydrogen and oxygen. Even so, there could be extremophilic bacteria in the inhospitable Venusian atmosphere.

But the most recent observations suggest that there could be liquid water on Venus for about 2 billion years, enough time for the appearance of primitive life forms similar to terrestrial ones.

Given all of the above, would it make sense to try installing a base on Venus? How should it be and how useful would it be? I invite my sagacious readers / es to contribute with their suggestions to the hypothetical colonization of our infernal brother.

Carlo Frabetti He is a writer and mathematician, a member of the New York Academy of Sciences. He has published more than 50 popular science works for adults, children and young people, including Damn physics, Damn math or The big game. He was a screenwriter of The Cristal ball.