Science and Technology links (November 24th 2018)

  1. There is no association between birth order and personality traits:

    The results of both within- and between-family research designs revealed no consistent evidence of a link between birth order and the personality traits of extraversion, neuroticism, agreeableness, conscientiousness, and openness.

  2. Most modern cultures use numbers based on a decimal system (base 10). However, in many European languages (e.g., French and Danish) the number 20 is used as a base (eighty in French is four-twenty). We call such system vigesimal. They are common in Africa. The Maya counted in base 20. I am told that the Gauls used a vigesimal system, but I could not find a credible supporting source (the Gauls also used Greek and Latin).
  3. Can you build an airplane with no moving part? It turns out that you can. Researchers built a model airplane that moves the air using an electric field. (credit: degski)
  4. Many of our everyday plastic items (like plastic bottles) contain a chemical called BPA. Our bodies can ingest it, but it is evacuated within hours. There has been an intense lobby to ban it in the spirit of the precautionary principle; it does affect mice (causing genetic mutations in offsprings) but there is no proof that it harms human beings. Should you buy goods that are said to be BPA-free? They are made with alternative chemicals, so the question is whether these alternative chemicals are safer. Horan et al. provide evidence that the alternatives can be harmful.
  5. It is expected that Japan will grow more dependent on coal in the coming decades, it is currently generating a third of its electricity using coal. Germany produces 40% of its electricity using coal.

    Coal’s popularity can be explained in large part by how nuclear power is failing us.

  6. We subsidize electric cars because we assume that they are more environmentally friendly. They certainly lack an exhaust pipe which is great for people around the car. Electric cars make it easy to “export” pollution: you can keep dense cities or even entire countries cleaner… But the batteries and their toxic chemicals must still end up somewhere.

    What is the larger picture? If you care only about climate change, then electric cars are slightly beneficial, as long as you are not producing your electricity from coal…

    When powered by average European electricity, electric vehicules are found to reduce global warming potential by 20% to 24% compared to gasoline and by 10% to 14% relative to diesel under the base case assumption of a 150,000 km vehicle lifetime. Electric vehicules powered by coal electricity are expected to cause an increase in global warming potential of 17% to 27% compared with diesel and gasoline ICEVs. Hawkins et al., 2012

    Yet if you care about other types of environmental impacts, electric cars may be less beneficial…

    the acidification, eutrophication, human toxicity, and particulate matter formation caused by Electric vehicles are higher than those caused by internal combustion engines .
    (Bicer et Dincer, 2018)

  7. Professors get to spend only a tiny minority of their time on their own research.. The more experience the professor, the less time they have for their own research. PhD students have a lot more time for research.

    I believe that it is a form of institutional aging.

  8. Older people (age 75 and older) are often out of shape, but it gets worse during hospitalization. Staying in a hospital bed for a long time is bad for you. It seems that the ill effects of hospitalization can be reverse with an exercise routine.
  9. There is no scientific evidence that depression is due to a chemical imbalance:

    Thanks in part to the success of direct-to-consumer marketing campaigns by drug companies, the notion that major depression and allied disorders are caused by a “chemical imbalance” of neurotransmitters, such as serotonin and norepinephrine, has become a virtual truism in the eyes of the public (…) the evidence for the chemical imbalance model is at best slim (…) There is no known “optimal” level of neurotransmitters in the brain, so it is unclear what would constitute an “imbalance.” Nor is there evidence for an optimal ratio among different neurotransmitter levels. Moreover, although serotonin reuptake inhibitors, such as fluoxetine (Prozac) and sertraline (Zoloft), appear to alleviate the symptoms of severe depression, there is evidence that at least one serotonin reuptake enhancer, namely tianepine (Stablon), is also efficacious for depression (Akiki, 2014). The fact that two efficacious classes of medications exert opposing effects on serotonin levels raises questions concerning a simplistic chemical imbalance model.

  10. Some Intel processors can run at up to 5 Ghz. That is, they run through 5 cycles per nanosecond. We are not likely to see much faster speeds in the near or medium term.
  11. After rising from about 300$US in mid-2016 to over 20,000$US in early 2018, the price of Bitcoin is currently (as I write this) 4337$US, and falling.

Published by

Daniel Lemire

A computer science professor at the Université du Québec (TELUQ).

7 thoughts on “Science and Technology links (November 24th 2018)”

  1. Re: electric cars

    The 2012 study is a bit outdated, as solar and wind energy have increased substantially in the past few years, with even larger increases coming in the next 3-4 years. Wind generation alone is increasing in double percentage digits annually, with new projects being licenses without subsidies. Currently, about 30% of Europe’s energy needs are supplied by renewable sources.

    In May this year, Portugal run for 107 hours on renewable energy. In summer months, Germany regularly surpasses 50% of its energy requirements from renewables during weekends, with some weekends reaching 80%+.

    As for the second, more recent study, I couldn’t find the full text online, so I’m missing the full picture of the paper’s analysis, but comparing the manufacturing environmental impact is a flawed hypothesis. Even ignoring exhaust emissions, ICE powered cars produce a lot more pollution than their electric counterparts. How much lubrication oil will an ICE engine require over its lifespan? How many filter changes will it require? What about the environmental impact (toxic waste, etc) of refining the oil or gas needed to power the car for a given number of kms/miles?

    Unlike ICE engines, whose efficiency and pollution characteristics are defined (and largely locked) during the engine’s design, an electric car doesn’t care were it’s energy comes from (coal, fossil fuel, solar, wind). Car batteries have a second life in home or other similar static energy storage facilities, after reaching their end of life in a car. Even when the battery cells degrade to the point where they can’t be used for any practical application, the entire battery can be recycled as it’s full of valuable chemicals. The battery recycling sector is still new, and technologies are still nascent, as commercial viability depends largely on volume.

    An electric car itself can be easily fitted with a new battery with higher capacity, longer lifespan, less weight, less toxic chemicals, or any combination thereof. The cost per kwh of battery capacity is decreasing constantly. Musk said earlier this year that Tesla can lower their battery production costs by a further 20% just from production process optimizations of their current battery chemistry. With cheap enough batteries, electric cars can continue to circle for much longer than a comparable ICE powered car (ICE engines are becoming increasingly more expensive due to efficiency and emissions requirements).

    The whole ICE vs electric car debate is a lot more complex than a few simple studies about the environmental impact of production, or how they are powered at one point in time.

  2. I have been told that the Gauls used a vigesimal system

    We don’t know that much about the language of the Gauls, which wasn’t really written. The few inscriptions in Greek or Latin script are insufficient and may not even be representative of the everyday language. However, modern celtic languages use a vigesimal system, so the claim looks credible.

  3. Can you build an airplane with no moving part? It turns out that you can. Researchers built a model airplane that moves the air using
    an electric field. (credit: degski)

    Aircraft based on ion wind for propulsion have been demonstrated a long time ago:

    https://www.youtube.com/watch?v=GijJmIz1G7U

    Efficiency is low. There was no energy source with sufficient power and energy density for self-sustained flight without a power tether. Modern lightweight battery technology makes this airplane (just barely) possible. It is still very inefficient.

  4. The data for electric cars is out of date, as is the data for energy production.

    Ontario (for example) burns zero coal, and averages over 90% zero CO2 https://cns-snc.ca/media/ontarioelectricity/ontarioelectricity.html. Further, most cars will be re-charged at night, during off peak times. These times are more likely to be supplied by green energy.

    Further, as someone else stated, while (I have read) the initial manufacturing footprint is between 17 and 50% worse, the maintenance footprint is more than 50% better. J.D. Power has re-assessed their initial predictions to give a green payback in less than three years in the average north american jurisdiction.

    For those with high mileage and green electricity it is even shorter.

    1. There are two issues.

      One is CO2 emissions. This clearly depends on where the electricity comes from. If it comes from nuclear or hydro, you are doing well. However, as I outlined, if you live in Germany or Japan, it may be a false assumption to think that your electricity is “CO2-free”.

      Another issue is that of toxicity. The assumption seems to be that we will cleanly recycle batteries. When you make this assumption, everything is nice… However, this industry and technology does not exist currently. I think people ought to be more critical of such claims. It won’t arise out of thin air.

  5. The Welsh language also uses the vigesimal system.

    You could postulate that since Gaulish and ancient British (which has evolved into modern Welsh) share the same Celtic origin, that’s it’s possible the Gauls used a vigesimal system.

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