Tag Archives: biochemistry

Chemtrails conspiracy theory gets debunked

Contrails or ‘chemtrails’? The myth has just been debunked

Since 1996, there has existed a niche group of conspiracy theorists in western countries that believes that the government (or some other authority) is spraying compounds out the back of commercial/military aircraft for a plethora of reasons. Seventeen percent of Americans believe a hilariously-named “SLAP” project (secret large-scale atmospheric program) exists in the United States, and 2% are ‘certain’ of its existence. Conspiracy theorists photograph normal aeroplane contrails and upload them to the internet, calling them ‘chemtrails’, and using them as evidence of SLAP.

The conspiracy theorists cite “mind control”, “radar mapping”, and “chemical weapons testing” among suspected motives, and they even have detected elevated concentrations of barium and aluminium in soil and atmosphere at certain locations. Conspiracy theorists use these chemical data to support their belief in the SLAP idea.

Just this month, the results of a comprehensive review of all the so-called evidence for contrails was conducted – by an impressive 77 experts in atmospheric chemistry – and they’ve concluded that the conspiracy theory seems highly unlikely to be true.

First, what are contrails?

Contrails are ice-clouds that emerge from the backs of jet engines on aeroplanes. They vary in width, colour and persistence depending on the temperature, air pressure and humidity.

Combustion in jet engines produces two products: water vapour, H2O(g), and carbon dioxide, CO2(g). These gases exit the jet engine and quickly lose momentum, eventually forming a trail in the air behind the aeroplane. The freezing cold temperatures at aeroplane altitudes freezes the water vapour in its tracks (but not the carbon dioxide – it’s not that cold!). A contrail is essentially a trail of snowflakes!

What did the scientists find?

Seventy-seven experts found 100% agreement that SLAP was not the simplest/most likely explanation for the following phenomena:

Source: http://www.ess.uci.edu/~sjdavis/SLAP/

Why am I mentioning this?

The ‘chemtrails’ conspiracy emerged as one of the most recent forms of chemophobia. It originated in 1996 when a paper was published by the United States Air Force called Weather as a Force Multiplier: Owning the Weather in 2025 suggested spraying compounds from aeroplanes to help engineer the climate. This seeded the conspiracy, and ebbing public trust of experts/scientists helped it to balloon out of proportion from there.

Until this study was conducted, the scientific community had no credible evidence to the contrary: we had no rebuttal to offer the ‘chemtrails’ crowd. This study finally puts the overwhelming majority of evidence (and 76 of the 77 experts involved) in favour of there being no such SLAP project – and no ‘chemtrails’ to speak of.


It’s widespread, irrational, harmful, and hard to break. One excerpt from a New York Times article on this story said:

“The goal, the researchers say, is not so much to change the minds of hard-core believers, but to provide a rebuttal — the kind that would show up in a Google search — to persuade other people to steer clear of this idea.”

This study, it seems, is aimed at the neutral 60%. This is exactly how we need to be fighting chemophobia.

Question: Have similar studies been conducted for the other forms of chemophobia that exist?

Subscribe to Chad Jones’ New Chemistry Podcast

collapsed wavefunction logo
New podcast ‘Chemical Dependence’ is hosted at The Collapsed Wavefunction

I first came across Chad Jones when I did an interview with him on The Collapsed Wavefunction back in 2013. We discussed ingredient labelling, chemophobia and my motivations for making the Ingredients of an All-Natural Banana poster series.

Chad Jones works at Intel Corp. in Utah, USA. He’s the founder and chief science writer for The Collapsed Wavefunction, a science advocacy podcast featuring episodes on science instruction, science in popular culture, and current science news items.

In 2016, Chad’s launched his latest venture in chemistry outreach with a fantastic new podcast called Chemical Dependence. In each of the podcast’s punchy, 5-minute episodes, Chad explores interesting chemical compounds and how they’re used in society. The podcast is a great source of interesting facts to liven up any chemistry lesson. All Chemistry teachers should subscribe!

He’s even teamed up with Andy Brunning from Compound Interest for his latest episode on pipeline. Check it out here.

Check out all the episodes and subscribe to the podcast on iTunes here. Support the podcast via Patreon here.

Combining Chemicals And Students Safely

Chemistry lab. Image supplied by National Laboratory Sales
Image supplied by National Laboratory Sales

In science education, chemistry is one of the disciplines that involves regular hands-on work in a laboratory. While teaching students the intricacies of chemistry presents no exceptional risk, the very real dangers posed by many chemicals demand a higher level of safety consciousness and preparedness. This general overview outlines sensible security precautions for high school and college chemistry labs.

The Importance Of Documentation

Fortunately, in a classroom setting, all of the chemicals being used will be well understood. This means information on their potential risks is widely available. This information must be used to ensure that each substance used is treated with the proper respect for the dangers it poses.

The first source of information for any chemical is the label it carries. These always describe their hazards, but labeling may be incomplete. A more authoritative source for hazard information is the material safety data sheet (usually referred to as an MSDS) for the substance. A comprehensive reference collection of MSDSs is an integral part of every laboratory, and this collection needs to be freely available to all teachers using the classroom’s chemical supply.

Equipment And Facilities

At the high school or college level, chemistry experiments demand their own dedicated laboratory spaces. These labs should meet all state and national safety requirements and cannot be used for teaching other subjects. Even the scheduling of laboratory use must be geared towards safety. Adequate free periods must be included every day for cleaning the lab and disposing of chemicals.

Chemicals need a dedicated, lockable storage room equipped to contain them safely. A prep room is also required for teachers to use. This needs equipment similar to the lab room albeit on a smaller scale. For all three of these spaces, ventilation is a critical concern. Ventilation hoods should be used in the lab itself and all of the air removed from the lab must be vented outside.

Full safety equipment needs to be available for everyone in the laboratory while chemicals are in use. This includes both permanent safety facilities (e.g. eyewash stations, first aid kits, etc.) and personal protective equipment (PPE), including goggles. Goggles for use in chemistry labs must conform to stricter standards than other forms of eye protection to ensure that they protect against both flying debris and liquid splashes.

Planning And Preparing

Every chemistry lab needs thorough safety plans for both general and specific chemical risks. While standardized materials including the safety documentation discussed above can be used to prepare safety plans, each teacher responsible for leading classes in the lab has a responsibility to set out his or her own safety measures.

Customized safety preparations should take the specifics of the facility and the coursework into consideration. Methods for calling for help, evacuating the lab, and documenting incidents will vary based on the layout of the facility and its resources. By designing their own safety plans, teachers will be better prepared to enact them in the event of an accident.

The Teacher’s Role

A chemistry teacher has many responsibilities beyond instruction and safety planning. One of the most important of these responsibilities is teaching his or her students to share a healthy respect for the hazards posed by chemicals. Teaching and testing them on basic safety precautions and lab-specific emergency procedures is just a start.

Students should learn to understand the intricacies of chemical labeling before working with hazardous chemicals. (For example, the terms danger, warning, and caution are each distinct, indicating decreasing levels of risk.) At the college level, where students may be working independently and designing their own experiments, teaching them to read the MSDS is strongly recommended. For younger students teachers can often make use of intermediate-level warning documentation (e.g. CLIPs, Chemistry Laboratory Information Profiles) to give them adequate chemical reference materials.

Keeping students safe in the laboratory is not a difficult job. It requires a heightened sense of awareness and an amount of preparation commensurate with the hazards posed by the chemicals involved. When preparedness is combined with proper facilities, equipment, and training, schools labs can be safe places to learn through direct experimentation with all but the most dangerous of chemicals.

Whether you’re building a new Lab or upgrading your existing one, you will find a remarkable selection of Casework, Workstations, Fume Hoods and related lab products at National Laboratory Sales.

Happy Mid-Autumn Festival! New infographic: Chemistry of MOON CAKES

Chemistry of MOON CAKES infographic jameskennedymonash

Mid-Autumn Festival (中秋节) is a traditional Chinese festival celebrated on the 15th day of the 8th lunar month each year (a full moon night in September). It started as an agricultural tradition (like harvest festival in western cultures) around 1000 BC in the Zhou Dynasty, and was formally acknowledged as a festival during the Northern Song Dynasty (between 960 and 1279 AD).

Today, Mid-Autumn Festival is celebrated with moon cakes, family reunions and three days off work. Moon cakes are circular to represent the full moon that always occurs on the Mid-Autumn Festival. Watch the video below to learn about the story behind the festival:

Moon cakes consist of crust, filling and an egg wash. The crust is made from flour, the polysaccharides in which bind together at oven temperatures to form a strong, intricate network (also including proteins) that allows the moon cake to keep its all-important circular shape.

The crust also contains invert sugar syrup, which is chemically similar to both honey and golden syrup. Invert sugar syrup is made by hydrolysing sucrose into its constituent monomers, glucose and fructose. The result is a sweeter-tasting, gooey liquid that doesn’t crystallise during cooking. This gives the moon cake a smooth mouthfeel.

Peanut oil (a blend of mostly monounsaturated triglycerides) is added to the crust for two reasons. First, it is a non-volatile liquid at room temperature, which prevents the moon cake from drying out. Second, the peanut oil molecules disrupt the protein matrix in the crust and give it an even smoother texture (not a doughy texture).

Maillard reactions are caramelisation reactions involving the removal of two hydrogen atoms from a sugar aldehyde or ketone. The resulting compounds are yellow/brown in colour because they contain carbon-carbon double bonds (C=C), which absorb violet and UV light (λmax ≈ 190 nm). The moon cake is usually also given an egg wash, which provides extra protein necessary for Maillard reactions to occur. More egg wash will provide a deeper brown colour to the dough.

Alkaline water (枧水) is a common ingredient in Guangdong-style cuisine. Chemically, it’s a ~0.020 molar solution of potassium carbonate and can be considered as the ‘opposite of vinegar’. It raises the pH in the moon cake, which accelerates the Maillard reaction, which is favoured by alkaline conditions. Alkaline water thus makes the crust more brown!

Finally, the fillings can be very diverse. Lotus seed with salted duck egg yolks is a common filling, but “five kernels”, red bean and green tea (with beans) are also quite popular. Lotus seed filling, for example, is made by soaking dried lotus seeds in alkaline water, pulverising and adding sugar. The resulting paste is then cooked with more oil and sugar before being used to fill a moon cake. ●

Artificial vs Natural Peach

Artificial vs Natural Peach jameskennedymonash

This artificial vs natural foods phenomenon has grown somewhat since the All-Natural Banana.

This infographic explores the differences between the natural, “wild peach” and its modern, artificial relative. It explores how the ancient Chinese developed a small, wild fruit (that tasted like a lentil) into the juicy, delicious peaches that we eat today.

This image also pays homage to the thousands of years of toil that farmers put into developing the Peach regardless of whether they were aware of it consciously or not.

After the wild peach was domesticated in 4000 B.C., farmers selected seeds from the tastiest fruits for re-planting. They tended to the trees for thousands of years, and the fruits became bigger and juicier with each generation. After 6000 years of artificial selection, the resulting Peach was 16 times larger, 27% juicier and 4% sweeter than its wild cousin, and had massive increases in nutrients essential for human survival as well.

Which one would you rather eat?

Meet the Terpenes: A Visual Introduction from Isoprene to Latex

Inspiration for Meet the Terpenes came from the rhetological fallacies graphic over at Information is Beautiful, while motivation came from a 45°C heat wave this week that prevented any sensible Australians from going outside. So I stayed at home and did this.

Meet the Terpenes - A Visual Introduction from Isoprene to Latex
Click to download 200dpi JPEG (5.4Mb)

It took about three days to sketch, research and create.

Three days ago, I knew nothing about terpenes. My undergraduate phytochemistry class was really difficult. The teacher was a genius, and put huge amounts of effort into his tutorials, giving us thick booklets at each seminar filled with his hand-written notes and dozens of chemical structures. But for some reason, I just didn’t get it.

So this week, I decided to make the graphic I wish I’d had when I took the phytochemistry class many years ago. Having this poster on my wall would have answered all my questions and made the class much more enjoyable. I hope you find it useful, too.

As always, I welcome all feedback, corrections, suggestions and comments, etc.

Enjoy 🙂 James

12 things I learned from my 23andMe results

Just before Christmas, I spat into a plastic tube and sent it to 23andMe: a genetic testing company in California.

23andMe Logo


23andMe tests one million SNPs (minor changes) in a person’s genome, many of which are linked with known, inherited traits. Their results reveal a wealth of information about your health and ancestry, ranging from eye colour and bitter taste perception to the presence of major genetic diseases and your extended family tree. Meaningful results are then sent to you by email within a few weeks.

All this is priced well-below cost, at just $99 plus shipping. It was totally worth it. Here’s a list of the 12 most interesting things that 23andMe revealed about me.

1. No carrier status

Fortunately, I carry none of the 48 diseases for which 23andMe tests. That’s good news! None of these diseases will affect me, nor will they be passed on to my children.

2. HIV-resistance: CCR5 +/Δ32

This is awesome—I carry one copy of the HIV-resistance allele! A very small percentage of people are lucky enough to have this allele. The virus which heterosexual, monogamous vegans almost never encounter just got even harder to get.

3. Can’t taste bitter: TAS2R38 -/-

The TAS2R38 gene encodes the receptor that detects PROP and related bitter plant compounds. I have a relatively common mutation that is insensitive to PROP. My version of this gene improves the taste of bitter foods—including poisonous ones.

4. Can digest lactose: MCM6 +/+ (regulates LCT)

I don’t like milk, but at least I can digest it. I have two fully-funcional copies of the lactase enzyme, and both will remain active throughout adulthood.

5. Slow caffeine metabolism: CYP1A2.

Caffeine is primarily metabolized by the liver enzyme cytochrome P450 1A2. My version of this enzyme metabolises caffeine slowly (just like 99% of people). I learned that I’m not one of the 1% of people who are virtually insensitive to caffeine.

6. Ancestry

British and Irish: 67.6%; French and German: 5.8% (4 gen); Scandinavian: 0.1% (10 gen); Northern European: 24.0% (2 gen); Southern European: 1.2% (6 gen); Other European: 1.1% (7 gen); Middle Eastern/North African: 0.1% (10 gen); unknown: 0.1%.

James Kennedy ancestry results
Click to enlarge.

I calculated generations by taking the percentages, log base 2 and multiplying by -1.

Most of my ancestors were from “Britain/Ireland”, or “North Europe”, which includes Britain and Ireland. But interestingly, there was a little more diversity than I expected. one of my (great-?)great-grandparents was either French or German (see number 11). Six generations ago, there was someone from South Europe in the family. Ten generations ago, there was one person from Scandinavia, and one person from the Middle East or North Africa.

7. My blood group: A Rh(-) Di(a-b+) K-k+ Kp(a-b+) Jk(a+b+)

I already knew my blood group, but it was interesting to learn that blood groups are a complicated business. For everyday purposes, though, I’m an A-negative.

8. 3.1% Neanderthal DNA (very high)

Neanderthals looked like caricatures of Celts: white, brutish, red-haired and freckled. The average Caucasian has 2.5% neanderthal DNA, and I have 3.1%, putting me in the 98th percentile. It means that I’m “whiter” than most white people.

9. Maternal haplotype: H3 (Western Europe)

H3 is a minority European haplotype found in Western Europe. (Most natives are H1 haplotype.) Over the last 10,000 years, H3 declined in Europe due to random genetic drift, but remains prevalent today in the Basque region (probably because they mixed less frequently with outsiders). There’s almost no phenotypic difference between H1 and H3, so until further research is done, this is merely an interesting fact.

Maternal haplotype H3 map
Maternal haplotype H3 map
10. Paternal haplotype: R1b1b2a1a2f2 (Ireland)

Obviously. My paternal family is Irish and my paternal haplotype proves it. R1b1b2a1a2f2 is distinctively Irish.

11. One arm of Ch1 is entirely French/German

This is very interesting. I’m British, so while having a little French/German DNA is normal, having it all on one arm of one chromosome indicates that it probably all came from one, recent ancestor (no more than 4 generations ago). Given that French/German DNA is unique in going mostly undetected using 23andMe’s testing methods, and that the possibility of inheriting an entire chromosomal arm halves with each generation, this French/German ancestor was probably a great-grandparent. I didn’t know this.

James Kennedy French/German DNA
My French/German DNA (dark blue) is mostly on one chromosome.
12. Eight chromosomes contain one arm with no British/Irish DNA at all.

Chromosomes 1, 8, 9, 10, 11, 18, 20, and 22 contain one arm with no British/Irish DNA at all, and one arm with almost 100% British/Irish DNA. Given that one arm is inherited from each parent, this indicates that either I (or each of my parents) had one parent who was purely British/Irish, and one who was a more mixed “Northern European”.

James Kennedy's British/Irish DNA from 23andMe
Eight chromosomes have one arm with no British/Irish DNA (dark blue) at all. This indicates one recent family member of mixed, Northern European origin, not just from Britain and Ireland.

Additionally, 23andMe found 833 distant cousins who have also had their DNA tested. I share great-great-grandparents with the closest of these cousins, but none of them have surnames that I recognise. Some of them live in Wales, but that’s probably just a coincidence. The process of trying to link the family trees, if I do it, would be a long one.

I wanted to do this years ago, but it used to be too expensive: $999 plus a monthly subscription (whatever for?) The price then dropped to $499, $299 then $249 (last year), before finally hitting $99 before Christmas 2012—without any monthly fees. That final price drop prompted me (and nearly a million others) to buy the test.

I highly recommend 23andMe. The data arrives little by little, so there’s something to look into (and reference papers to read) each day. Anyone interested in their own health or ancestry should give it a go.

Book: Molecular Biology of the Cell (Alberts’)

Molecular Biology of the Cell
Each edition changes colour. Fifth edition is red. Fourth edition is grey.

The KitchenAid of biology. All other biology textbooks are just accessories.
1392 pages, ★★★★★

Molecular Biology of the Cell, or “Alberts'”, as it’s known colloquially, is the cornerstone of a university education in biology. All biology undergraduates will have seen it, most of them will buy it, yet none of them will actually read it. They should.

Alberts’ details every aspect of cell biology, and delves deeply into physiology, neurology and pharmacology as well—rendering some undergraduate textbooks in those fields redundant.

Illustrations are crisp, clear and never excessive. Colour is used for clarity but not for aesthetics. The text is prose-heavy and reads like a story so it can be read cover-to-cover quite comfortably (albeit slowly). And that’s exactly what students should do.

Many students will use Alberts when they need to learn about something quickly, such as, “what shape is a mitochondria?”, “what does kinesin do?”, or “in what order does the electron transfer chain take place?” If you haven’t read this book from cover-to-cover already, then finding those answers is going to take much longer than you think. Alberts is not a reference book—it’s a comprehensive background story. Quick answers can be found on Google, but genuine understanding comes from a cover-to-cover reading of Alberts. ★★★★★