Archive for November, 2020

Nov 05 2020

Crop Yield with Higher CO2

Published by under General Science

One of the arguments often put forward by global warming deniers is that CO2 is not a pollutant, and in fact higher CO2 is good for crop yield. This point is invoked during their shifting defense – the planet is not warming; well, OK, it’s warming but it’s not due to humans; alright, humans are to blame but this won’t necessarily be a bad thing. See – CO2 is good for plants.

While this core claim is somewhat true, it needs to be put into perspective. First, as a risk vs benefit, raising global CO2, with all the downstream negative effects, is a terrible way to increase crop yield. But a new study looks at 30 years of data to address the underlying premise – what is the net effect of rising CO2 levels on crop production? The short answer is, while some crops increase yield, the overall effect is complicated.

The first distinction we need to make is between C3 and C4 crops, which refers to the type of photosynthesis used. In the C4 pathway some of the energy is used to concentrate CO2 in the chloroplasts, resulting in a higher efficiency of turning light into energy. C4 plants include corn and sugarcane. For these crops there is no benefit in yield from higher CO2 levels. C3 plants do not have this adaptation and they are more dependent on ambient CO2 levels, and they do benefit from higher CO2. But there are some important caveats to this.

What the study showed is that the overall average increase in yield among C3 crops to rising CO2 in the last 30 years is 18% “under non-stress conditions”. That last bit is important because that increase is significantly reduced if there is not enough nitrogen available to take advantage of the higher CO2, which is the case in most of the non-industrialized world. Further, the rising temperature that accompanies the higher CO2 decreases the yield, and also increases loss to pests. Wet conditions, which are also important for yield, reduce the benefit from CO2, however, which is greatest under drought conditions. So overall there has been a modest increase in yield in some crops in industrialized farming where increased nitrogen if available.

Continue Reading »

No responses yet

Nov 03 2020

Magic Amulets Do Not Prevent COVID

Published by under Pseudoscience

Retraction Watch has an interesting article about a very curious paper published in Science of the Total Environment. In fact, the paper and communication from the lead author are so bad I have to wonder if its a Sokal-like prank. If not, it is more evidence that the world has become so weird there are many things which are beyond satire. But let’s take this at face value. The title of the paper is: “Can Traditional Chinese Medicine provide insights into controlling the COVID-19 pandemic: Serpentinization-induced lithospheric long-wavelength magnetic anomalies in Proterozoic bedrocks in a weakened geomagnetic field mediate the aberrant transformation of biogenic molecules in COVID-19 via magnetic catalysis.”

Many scientific publications are extremely technical and require very long technical descriptions, but my “gratuitous jargon” alarm went off at this title. The paper itself is worse – I get the distinct impression it is using jargon not to be precise, but to impress and befuddle. But wading through the jargon, the claim here that has caught attention is this – “Nephrite-Jade amulets, a calcium-ferromagnesian silicate, may prevent COVID-19.” What? Wearing a jade amulet may prevent COVID-19? You are going to have to do better than dazzling with jargon to make that claim stick, or even to get it taken seriously. The fact that the authors reference Traditional Chinese Medicine (TCM) does not help either.

The co-founder of Retraction Watch, Ivan Oransky, wanted to get to the bottom of it also, so he wrote the following e-mail to the corresponding author, Moses Turkle Bility, PhD. Oransky wrote:

“Dr. Bility
I blog at Retraction Watch. Can you confirm that you co-authored this paper?”

That was it – a very simple query to confirm authorship. This is pretty standard in academia, just dotting all the i’s. This was Dr. Bility’s response:

Dear Dr. Ivan Oransky, yes, I published that article, and I kindly suggest you read the article and examine the evidence provided. I also suggest you read the history of science and how zealots have consistently attempted to block and ridicule novel ideas that challenge the predominant paradigm from individuals that are deem not intelligent enough. I not surprised that this article has elicited angry responses. Clearly the idea that a black scientist can provide a paradigm shifting idea offends a lot of individuals. I’ll be very candid with you; my skin color has no bearing on my intelligence. If you have legitimate concerns about the article and wish to discuss, I’ll address; however, I will not tolerate racism or intellectual intolerance targeted at me.

Whoa, where is that coming from? I suspect that Dr. Bility has already received some pushback prior to getting the very innocent query from Retraction Watch, but such a response is extremely telling. Bility immediately goes for the “small minded bigots can’t appreciate my paradigm-shifting brilliance” card. Sorry, Dr. Bility, but with that reaction you just branded yourself a crank and a pseudoscientist. Perhaps that’s not fair, but neither is this massively out-of-proportion response.

Continue Reading »

No responses yet

Nov 02 2020

Earth-Sized Rogue Planet Discovered

Published by under Astronomy

I like to keep my mental model of the universe updated as much as possible. One of the things I learned not too long ago about the universe is the frequency of “rogue” planets. These are planets that are not bound to any star. The dominant current theory is that most of these rogue planets formed in stellar discs just like bound planets but then at some point in their history interacted with another large body and were flung out of their stellar system. In fact, most planets that form in a stellar system may have unstable orbits that will doom them over the cosmological short term to either collide with another body, fall into their parent star, or get flung out of the system. Only those planets with stable orbits remain, and so eventually systems will settle down with a relatively few planets in stable orbits.

How many rogue planets (also called FFPs for free floating planet) are there in the Milky Way? We don’t know, and estimates vary wildly. The most cited recent estimate based upon computer simulations suggest that there are at least 50 billion rogue planets in the Milky Way. This is not much, actually, as there are between 100 and 400 billion stars, so that’s less than on per star. Still, that is a lot of rogue planets wandering the vast darkness of interstellar space. But other estimates of the number of rogue planets are much higher. At the high end one estimate put the number at 100,000 times greater than the number of stars. That seems implausible. But it suggests the number could be much higher than 50 billion. Even if on average there are several rogue planets for each stellar system, that would create hundreds of billions of such planets in our galaxy. And we have to include all the dead stars whose planets are still roaming interstellar space.

As an aside, any such estimate has to include a size parameter – how many FFPs of size greater than or equal to X. The estimates above use Pluto as the lower end of the size range. The lower you go, however, the greater the number.

What we need is some observational data to supplement the theoretical simulations. If we can do a survey looking for rogue planets then the number of such worlds we find can be plugged into our simulations to come up with better estimates for the total number. But how, you may be wondering (if you don’t know already) can we find a cold dark planet at the vast distances of interstellar space? Right now we find exoplanets by using a few methods. One method is the transit methods – we look at the dip in light output from a star as a planet passes in front of it. Another is the wobble method – we look for the wobble in the path of a star that indicates it is being tugged by a large planet going around it in its orbit. We might also be able to directly image a planet by looking at the reflected light off of it and removing the glare from the parent star. None of these methods will work for a rogue planet.

Continue Reading »

No responses yet

« Prev