Science and Technology links (February 9th, 2019)

  1. Though deep learning has proven remarkably capable in many tasks like image classification, it is possible that the problems they are solving remarquably well are just simpler than we think:

    At its core our work shows that [neural networks] use the many weak statistical regularities present in natural images for classification and don’t make the jump towards object-level integration of image parts like humans.

    This challenges the view that deep learning is going to bring us much closer to human-level intelligence in the near future.

  2. Though we age, it is unclear how our bodies keep track of the time (assuming they do). Researchers claim that our blood cells could act as time keepers. When you transplant organs from a donor, they typically behave according to the age of the recipient. However, blood cells are an exception: they keep the same age as the donor. What would happen if we were to replace all blood cells in your body with younger or older ones?
  3. A tenth of all coal is used to make steel. This suggests that it might be harder than people expect to close coal mines and do away with fossil fuels entirely in the short or medium term.
  4. Elite powerlifters have suprising low testosterone (male homone) levels. This puts a dent in the theory that strong men have high testosterone levels.
  5. Chimpanzees learn to crack nuts faster than human beings. This challenges the model that human beings are cognitively superior.
  6. It seems that the male brain ages more rapidly than the female brain.
  7. Grant argues that vitamin D supplements reduce cancer rates, but that medicine is slow to accept it.
  8. Women prefer more masculine looking men in richer countries. I do not have any intuition as to why this might be.
  9. Geographers claim that the arrival of Europeans to America, and the subsequent reduction of population (due mostly to diseases) lead to a global cooling of worldwide temperatures. It seems highly speculative to me that there was any measurable effect.
  10. The New York Times has a piece of a billionnaire called Brutoco who says that “he spends much of his time flying around the world lecturing on climate change” and lives in a gorgeous villa surrounded by a golf course. There is no talk of his personal carbon footprint.

Published by

Daniel Lemire

A computer science professor at the University of Quebec (TELUQ).

4 thoughts on “Science and Technology links (February 9th, 2019)”

  1. Elite powerlifters are probably the biggest users of PEDs after elite bodybuilders. Drug testing is pretty lax in powerlifting compared to olympic sports (and even there testing is being evaded). The self-report on steroid use isn't reliable, and neither is the Testosterone/LH level (for example, LH levels are affected by SERMs, which are commonly used). (Also, I believe testosterone is temporarily depressed after extreme physical exertion, though I'm not sure it would be substantially different between powerlifting and weightlifting.)

  2. Some of coal consumed in making steel is used for heat, some of it is used to reduce the iron oxides to iron and the rest usually ends up as part of the alloy.

    There are places where there is a source of “stranded gas” that cannot be practically exported by pipeline or tanker. Sometimes a steel mill is constucted nearby that converts the natural gas to hydrogen and then uses it to reduce iron ore and yield carbon-free steel. With the (big) exception reforming natural gas to hydrogen, the process is carbon-free. Regular carbon steel can also be produced by a similar process but there is some demand for carbon-free iron in metallurgy that commands a higher price so until that demand is satisfied this would probably not be done.

    Technically, hydrogen can be produced by nuclear or solar sources to create carbon-free or even carbon negative steel (as carbon becomes part of the alloy). The scale of hydrogen production required is mind boggling. The hundreds of millions of tonnes of hydrogen currently used in Haber-Bosch plants for producing fertilizers would be preferably displaced by such hydrogen sources before anyone would dream of using hydrogen for steel production anywhere other than by a stranded gas field.

  3. If you inject testosterone for some period, your body will produce less and your balls will shrink as a result. When you stop or taper off, it will take some time for your body to get back in gear with normal endogenous testosterone production. That could explain the low testosterone in powerlifters.

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