Shine back at the stars

Today's post is just a fun calculation. Sadly, that means no polemics.

So I was walking home last night, looking up at the stars shining. I wondered how much I'm shining back?

I started by assuming I'm a black body radiating at human body temperature.

T = 37 °C

I considered just my head i.e. a sphere with circumference of an average male human head.

C = 57 cm

I found the surface area of the idealized sphere representing my head.

A = 4πr² = 0.103418882 m²

I plugged these into the Stefan-Boltzmann law to find the photon flux from my head.

N = (1.5205 * 10¹⁵ m^-2 s^-1 K^-3) * T³ * A = 4.691 * 10²¹ photons per second

I looked up a number I'm comfortable with for the distance to the furthest naked-eye visible star.

D = 16308 light-years

And I assumed these stars have on average a similar diameter to our Sun.

d = 1.3914 billion meters

I found the angular diameter of this idealized far-away star.

𝛿 = (206265) * (d / D) = 3.03362676 * 10^-7 arcseconds = 5.167 * 10^-10 degrees

And converted this angle into square degrees.

Ω = πr² = π * (𝛿/2)² = 5.5771095 * 10^-21

Finally I used this solid angle to find the average rate of photons intercepted by the idealized star.

N / (41253 / Ω) = 0.0238439 photons/s = one photon every 42 seconds

So spend a about a minute looking at the stars, and you're shining back at them. At least a little bit.

You contain more protons than neutrons

I just recently read this book The Greatest Story Ever Told by Lawrence Krauss. And I loved it! Normally I keep detailed book notes, especially on non-fiction books. This book was so interesting that I was paying close attention to its contents and neglected my notes. But I did write one thing down to research later on.

In chapter 10 Krauss says that neutrons

... make up most of the mass of heavier nuclei and thus most of the mass in our bodies.

This struck me as odd, because hydrogen has no neutrons and most of our body is made of water i.e. most of the atoms in our bodies are hydrogen. Sure, all other elements in our bodies have a ratio neutrons to protons is greater than one. But I wondered, which effect is larger? The extra neutrons from heavier, rarer elements, or the lack of neutrons from the most abundant element?

I won't keep you in suspense: he got it wrong. Protons win the popular vote for king of the nucleons. But it's a close race!

Element	Abundance	Z	Average N	N:Z Ratio	Protons	Neutrons
Oxygen	65.0%	8	8.00440	1.00055	5.200	5.202860
Carbon	18.5%	6	6.01100	1.00183	1.110	1.112035
Hydrogen	9.5%	1	0.00020	0.00020	0.095	0.000019
Nitrogen	3.2%	7	7.00400	1.00057	0.224	0.224128
Calcium	1.5%	20	20.11563	1.00578	0.300	0.301734
Phosphorus	1.0%	15	16.00000	1.06667	0.150	0.160000
Potassium	0.4%	19	20.13472	1.05972	0.076	0.080539
Sulfur	0.3%	16	16.09290	1.00581	0.048	0.048279
Sodium	0.2%	11	12.00000	1.09091	0.022	0.024000
Chlorine	0.2%	17	18.48000	1.08706	0.034	0.036960
Magnesium	0.1%	12	12.32000	1.02667	0.012	0.012320
Trace	0.1%	82	126.00000	1.53659	0.082	0.126000
Total	100%				7.353	7.328874

I started by finding the relative abundance by weight of different elements in the human body. Here you can see why the race is so close. Most of the atoms in your body are hydrogen but these atoms are so light that by weight they constitute less than 10% of your body mass.

Also, while every other element has an N:Z (neutron-to-proton) ratio greater than one, thy are all pretty darn close to one so the effect size is small. I was as generous as possible and assumed trace elements were all Lead-208, which has the highest N:Z ratio of stable isotope.

I think the moral of the story is to remember that nature can get complicated. We don't want to jump to a conclusion given one reasonable-sounding argument. Sometimes we have to work the problem all the way out to find the answer.

Or maybe Lawrence Krauss is prejudice against hydrogen?

Minute Physics hasn't solved the grandfather paradox

I like the channel Minute Physics a lot. Their videos tend to contain quick physics lessons which are fun and accessible to a lay audience. However, I was greatly disappointed by their latest video called Solution to the Grandfather Paradox which unfortunately contains pure pseudoscience in place of the advertised solution.

The video starts off with a great description of the Grandfather Paradox. In short, this paradox arises if you go back in time to kill your grandfather. Being quite dead, he never has grandchildren and so you were never born. This leads to a logical contradiction: if you were never born, who killed your grandfather?

The video goes on to propose a solution whereby you kill your grandfather in an alternate timeline, so he wasn't really your grandfather to begin with. But this solution is summarily dismissed.

"But that's boring because it just avoids the paradox." (0:34)

Fair enough. There's plenty of published work in the scientific literature on this topic that doesn't involve alternate timelines. Surely they're going to get to that science stuff, right? Wrong.

"I'm showing this as a linear series of events but really it’s two entangled histories happening in parallel." (1:02)

I don't know what it means for two histories to be "entangled" or to happen in "parallel". Here the video shows a Mobius strip with a timeline drawn on it, following the plight of our time traveler.

Mobius strip following actions to their logical consequences.

This shows a chain of causality which loops back on itself. This is a clever way of depicting the paradox but it doesn't "resolve" anything. It merely shows the circular reasoning which caused us to call this a paradox in the first place. This particular type of circular reasoning is called an infinite regress, and is generally considered illogical in science and philosophy.

This mistake is able to slip by due to selective inattention. Viewers are easily distracted by the pleasant visual stimulation (myself included, on first watching). As we try to follow along the Mobius strip with our eyes, we don't notice the false conclusion. This "argument from cool shapes" is something I'd expect from Spirit Science, but not from Minute Physics, which I've always taken as a serious science channel.

Next, to make this glaring fallacy more palatable, we're served a steaming pile of quantum woo-woo. Would you like physics jargon on the word salad? Just say when...

"Subatomic particles regularly do multiple different things in parallel – it’s called quantum superposition ... if the universe were to exist in a superposition of two states – your grandfather is alive and your grandfather is dead – then the natural result is a superposition of two states: you’re born and able to go back in time to kill your grandfather, and you’re not born. And the natural result of these is a superposition of two states – your grandfather is dead and your grandfather is alive – and so, at least from a logical perspective, this looping timeline is entirely consistent and there’s no paradox." (1:11)

When! When!

Let's notice the equivocation between the "parallel" lengths of paper in the Mobius strip and the use of the word with regard to subatomic particles being in different states at the same time. The implication is that what's true about the quantum world applies to our time traveler. This does not logically follow because people are macroscopic objects relatively unaffected by quantum effects like superposition due to decoherence.

Don't get me wrong. I'm cool with describing the quantum state of large objects, even the entire universe as in the Many Worlds interpretation of quantum mechanics. The problem is the superposition shown in the video makes no sense at all and doesn't show what it's claimed to show.

Sure it's science, see the math symbols? That makes it science!

We're told these states represent a model of the entire universe. I'll call this left-most state where your grandfather is alive |A>. We know this state has some representation of your grandfather being born. We can evolve it into the future to see him grow up, put on a bowler hat, marry, have son or daughter, etc. Keep evolving the model forward and eventually our time traveler is born, puts on a red hat, travels through a wormhole or whatever, and emerges on the other side to kill his own grandfather.

See the problem? We can't fully describe |A> without also including |B> in there, too. Because they aren't different possible states of the universe. They're all events in one and the same history! A history that's self-contradictory. Using math symbols from quantum mechanics doesn't make this problem go away.

Now, there's nothing wrong with trying to use the idea of superposition to solve the Grandfather Paradox. But to prematurely claim victory having done no work and having explained nothing is inexcusably poor physics. Which is sad, because many fascinating papers have been published on this topic. The three million Minute Physics subscribers could have learned about the foundational work done by David Deutsch, Seth Lloyd, and others.

Next the viewer is presented with a very telling tease.

"And a similar paradox-free solution can be obtained by viewing the problem as a steady-state solution to a Markov chain ..." (1:48)

When! When! Aside from the obvious attempt to stupefy the audience with big words, Minute Physics seems to have misinterpreted a quantum computing exercise for theoretical physics. In the comments section they cite a lecture and paper by Scott Aaronson. The lecture includes discussion of the Grandfather Paradox "in a computational form" which indeed uses a Markov chain.

This is not a resolution of the paradox per se, but a computer model which satisfies some of its properties. It's not part of any an actual scientific theory. It's just a toy model to teach computer science. Aaronson imposes upon this model the requirement that Deutsch calls "causal consistency". But that's boring because it just avoids the paradox! And it has nothing to do with quantum superposition. Because, as we've seen, quantum superposition can't solve the paradox.

So, having mentioned real science only once, teasingly, the video concludes with this moral lesson.

"The main point is sometimes we think a situation creates a paradox when it doesn’t, and really the only paradox is how our thinking can be twisted enough to dream up time-traveling murderous grandsons, but not twisted enough to think about twisting time." (2:09)

That's ironic because the only paradox is how such a terrible script got on Minute Physics.

Star Trek transporters aren't suicide machines

I really like the YouTube channel CGP Grey. But his latest video The Trouble with Transporters contains some rather serious philosophical and metaphysical mistakes.

The thesis of the video is that the Star Trek transporter technology is a silent holocaust (1:45).

"...your experience of stepping into the transporter will be a funny sound, a bright light, then nothingness eternal, while down on the planet a brand new life complete with all your memories up to the moment before your death popped into existence..." (1:20)

This description is some combination of scientifically false and philosophically bankrupt.

The video seems to be asking us to accept metaphysical Dualism in which consciousness cannot be fully explained as the result of processes in the body and in particular the brain. There is not one shred of scientific evidence to support metaphysical Dualism. There is a mountain of evidence to the contrary. That mountain is called "neurology".

Dualism comes from a pre-scientific time and originates in the religious idea of an immortal soul. It's falsehood is the consensus view in all relevant sciences (neurology, psychology, philosophy, etc.). It is a supernatural proposition and so by definition irreconcilable with the scientific method.

The video grants that the transported body experiences no discontinuity in biological activity. Not in any tissue or organ. Since the brain is an organ, it too experiences no discontinuity in its function. Since consciousness is nothing more than a description of part of the the function of the human brain, the transported person experiences no discontinuity in consciousness.

It's really that simple.

And we don't even need fictional technology to see this in action. Our body is made of cells, which in turn are made of atoms, and on down until you get to the particles from the Standard Model. In particular, the matter particles i.e. quarks and leptons. (Yes, here comes the requisite physics.)

Even these fundamental particles aren't permanent objects.

Matter is not made of permanent objects having unique identities.

For example, there's no unique history of a particular electron. Electrons are fungible excitation in the electron field. In Quantum Mechanics, we predict the behavior of particles according to laws which include consideration for an infinite number of interactions which would create and destroy the particle in question from one moment to the next.

There is quite simply no philosophical justification for the absolute persistence of any physical object given appreciation for this lesson from the study of matter at the smallest scale. So there is no justification to say that I am absolutely persistent as a physical entity, just sitting in my chair.

The Star Trek transporter is an unnecessary addition to the thought experiment because modern physics already forces us to confront the exact problem this video raises.

But the video brings up the "problem of consciousness" and insists there's something "unmeasurably different" between the pre-transport and post-transport copies of a person (3:46). Now, there is something importantly different. Location in space! But that's entirely measurable. And it suffices to describe everything different about the histories of the pre-transport and post-transport person as physical objects. The problem of consciousness never enters into it.

The video even goes so far as to call the transporter a "suicide box" (3:33) which it obviously is not. Suicide is the act of intentionally causing one's own death. Death is the end of the life of a person. The life of someone who goes through the transporter does not end. Sure, transporter errors can cause their life to end. So can car rides.

Star Trek transporter errors can also apparently duplicate a person. This raises interesting questions, like which is the "real" person, but even then nobody dies. So no one committed suicide. So it's not a suicide box. Tom Riker wasn't forced to commit suicide.

Finally, and most ridiculously, the video claims it's "impossible to know" whether you are the same person as the person who you were when you went to bed least night (5:00). This is some combination of false and bullshit because all healthy people act as if they are the same person day to day, and treat others the same way. Any definition of personhood that claims otherwise is inconsistent with reality and therefore a complete and total bullshit.

Redefining words to fit an otherwise comically false narrative is classic pseudophilosophy. I never expected such poor content from this otherwise great channel.

No, Zika wasn't patented by the Rockefeller Foundation

Conspiracy theorists have been buzzing since a possible link between the mosquito-spread Zika virus and microcephaly became big news.

One particularly laughable conspiracy theory is that the virus has spread in Brazil due to GM mosquito testing in the same area.

First of all, there's no plausible mechanism by which GM mosquito experiments could have caused the Zika outbreak. On the contrary, both GM mosquito testing and mosquito-borne viral outbreak probably share the same underlying cause: the plague of mosquitoes endemic to the general region! The whole point of the GM mosquito program is to combat mosquito-borne contagious diseases like malaria, dengue, and now also Zika. To accuse it of spreading the virus is a particularly dangerous and ugly irony.

Second, the claim that Zika spread from the area where GM mosquitoes had been tested is false. True, both events happened in Brazil, but it's untrue to say they share an epicenter.

Another vicious conspiracy theory is that the virus was patented by The Rockefeller Foundation. This is, if you'll pardon the pun, patently false. Instead of the actual patent application readers are shown a screenshot from a website that sells research samples of the isolated virus online. Under the product's history, we see:

"Name of Depositor: J. Casals, Rockefeller Foundation"

All this means is that the sample was provided by the famous virologist Jordi Casals-Ariet. He discovered the Lassa virus. And he's exactly the person we'd expect to be studying the Zika virus, which is known as an "arboviruses" because it's spread by mosquitoes. Here is a quote from an interview.

"So by the mid 40s you had applied the compliment fixation test to arboviruses, and you had applied the suckling mouse to replication of arboviruses. So you were preparing really, without knowing it, to do a large amount of work in terms of growing viruses, making antigens, and preparing viruses."

The man's a hero. Thanks to work by people like him we have vaccines for many deadly viruses.

What about the Rockefeller Foundation? In 1952 Casals joined the Rockefeller Foundation and worked in a lab where he helped identify viruses sent in from research stations all around the world. Here's another clip from the same interview with Casals.

"We were in New York at the time, at the Rockefeller Institute of Medical Research where our laboratories, the Rockefeller Foundation, was located. We were the reference, or the clearing house, for all the field laboratories. We were supposed to help them, both by doing tests for them, and at the same time, developing better procedures if necessary, so they could use them."

The "Rockefeller Foundation" is literally the name he called the lab where he worked! The only conspiracy here is doctors and researchers around the world conspiring to learn about deadly viruses in order to better treat human epidemics.

Two of the authors on the paper reporting discovery of the Zika virus have "The Rockefeller Foundation" as their author affiliation. Private funding of basic science has played a vital role in human health.

But why are Zika virus samples sold online? It's common practice for medical research supplies to be sold online. Importantly, the sale is regulated by the CDC. Zika, for example, is Biosafety level 2. Unless you work for a lab that meets these regulations, you won't be able to complete your purchase of Zika.

Agricultural Soil Loss

Yesterday I posted about a demonstrably false claim is currently circulating in the news media.

This started when the University of Sheffield’s Grantham Centre for Sustainable Futures put out a press release saying:

"...nearly 33 per cent of the world’s arable land has been lost to erosion or pollution in the last 40 years ..."

So I contacted Mark Sinclair, the author of the press release asking how they reached this conclusion.

He let me know the intention here was to highlight soil loss, rather than land loss per se as I addressed in my post yesterday. He acknowledged that this distinction has "perhaps been lost in the drafting". I'll say.

He also shared with me the conclusion above comes from a book called Dirt by David Montgomery.

"So far in the agricultural era, nearly a third of the world's potentially farmable land has been lost to erosion, most of it in the past forty years."

As we shall see this is a fantastical exaggeration!

The book cites something call the GLASOD project which in 1991 surveyed 250 scientists across the world and found that about 15% of agricultural land was degraded. This was a map of subjective perceptions, not an objective measure of land degradation. It's now out-of-date and its qualitative judgments have proven inconsistent and hardly reproducible.

Since this was a snapshot in time it can't be used to assess the rate of soil degradation. So how did Montgomery come up with 40 years? In reference to a paper (full text) by Bruce Wilkinson which again reports only the rate of loss.

"...mean soil losses are therefore equal to 885 m/m.y. in the areas under cultivation ..."

That indeed equals about 1.39 inches per 40 years. But that's a rate of erosion today. Not an historical account of the past 40 years.

Even if we ignore this, GLASOD reports 1.96 billion hectares or 15% agricultural land was degraded which is not "nearly a third".

But agricultural land is a small subset of arable land. So only 0.246% of arable land was degraded.

Furthermore, most of the land classified by GLASOD as degraded was only degraded by amounts "light" to "moderate". The book claims land was "lost" as in "could no longer support crops" which corresponds only to the most severe categories "strong" and "extreme".

This brings the total down to 305 million hectares or 0.0381% of worldwide arable land.

That's 866 lower than reported by Montgomery and thereby the Grantham Centre press release!

Soil erosion is a real problem. To address it and make positive change we start with the truth.

Arable Land Loss

Soil degradation is a serious problem. I care very much about environmental protection and the long-term sustainability of agriculture around the world.

This is why it upsets me that a demonstrably false claim is currently circulating in the news media.

"...nearly 33 per cent of the world's arable land has been lost to erosion or pollution in the last 40 years ..." (phys.org, sciencealert.com)

"... nearly 33% of the world’s adequate or high-quality food-producing land has been lost ..." (theguardian.come, rt.com)

experts from the University of Sheffield's Grantham Centre for Sustainable Futures revealed that nearly 33 per cent of the world's arable land has been lost to erosion or pollution in the last 40 years

Read more at: http://phys.org/news/2015-12-soil-lossan-unfolding-global-disaster.html#jCp

This claim was delivered to the news media by the The University of Sheffield's Grantham Centre for Sustainable Futures which is a political research and advocacy organization. They've circulated a pamphlet and press release which both repeat the "33%" statistic without any indication how the number was calculated.

I suspect they got the number from the FAO website which says:

"... 33 percent of the global arable land used to producing feed for livestock ..."

Or perhaps they misunderstood this description of FAO data:

"Agricultural land covers 33% of the world's land area, with arable land representing less than one-third of agricultural land (9.3% of the world's land area)."

Whatever their mistake, we can use the FAO data to find out for ourselves how world-wide arable land area has changed over time. By multiplying the fraction of arable land by the total land area of each country we get the graph below.

Arable land is not being lost. Click here for the raw data.

But changes in "arable land" over time isn't even useful for measuring soil erosion and degradation. At least, not according to the FAO.

"Data for Arable land are not meant to indicate the amount of land that is potentially cultivable."

The three main causes of soil degradation are overgrazing, deforestation, and mismanagement of arable land. We can do something about all three. Spreading demonstrably false claims about about catastrophic loss of arable land does nothing help. By spreading misinformation, the Grantham Centre for Sustainable Futures only fosters distrust by people who aren't fooled by their doomsday warnings.

If we want people to listen, a good place to start is with the truth. Not demonstrably false claims.

UPDATE: I heard back from a representative of the Grantham Centre, but I still have no idea where the number "33%" comes from.

Power your home with only 150 Indurains!

Today I saw an hilarious news article (more like covert advertisement, but whatever) with the fantastically bullshit headline Pedaling For A Hour Can Power Your Home For Twenty-Four Hours. This may be true if your home has only one dim light bulb. But for modern homes in the USA, it's demonstrably false.

The article advertises a bicycle that's hooked up to generator and battery. You can store charge from exercise and run your home on this power. Well, partially run your home on this power. Don't get me wrong. It's an awesome bike! I want one!

But the average American rural household consumes 93.6 million Btu of electric energy per year.

(93.6 million Btu per year) / (365 days) = 75 kWh per day

The most bad-ass professional cyclists in the world can output at most 0.5 kWh per hour.

So how many Miguel Indurains would you need to invite over to your American rural household each morning to spend an hour peddling in order to supply the average day's power consumption?

(75 kWh) / (0.5 kWh) =  150 Indurains

"We're here to power your home. Don't worry, this will only take an hour. Got any food, by the way...?"

Environmental costs are important so stop lying about them

Many people don't read past the headline of a news story. Headline writers have immense and in my opinion unearned power to influence public opinion. Their objective is to capture attention. To this end they often exaggerate or misrepresent to the point of abject falsehood the contents of the article. When the subject is important the results of poor headline writing can be disastrous.

Here's an example.

New UN report finds almost no industry profitable if environmental costs were included

This is a doubly false headline.

First of all, this isn't a "UN report" but a report conducted on behalf of TEEB, a group which aims to draw attention to the global economic benefits of biodiversity. The TEEB is "hosted by" United Nations Environmental Program. This is one of the dirty tricks of headline writers. They fictionalize authority to artificially inflate the headline's credibility.

The big lie is about environmental costs. On page 28 of the report Table 5 shows 62 of the top 100 "greatest impact" region-sectors are still "profitable" when you subtract the natural capital costs from their revenue. That's a majority, even after cherry-picking the most polluting sectors from the NAICS list (page 63) and world regions (page 77).

This report does illustrate that some industries can't afford to pay for their external costs. Many of these industries like water supply and cereal farming are crucial to human survival and we all must share the cost. Nobody is suggesting all industries incorporate all externalities.

Other industries, notably cattle ranching and coal power generation should probably be reduced. Eating less meat and building solar panels will help the environment. Neither of those lessons are news to me. I find this report supports what we already know. If you take the time to read it.

External costs are real and represent a terrible price paid by the environment. Exaggerating them doesn't help protect biodiversity. It only serves to alienate would-be allies.

I would like to see more regulation put in place to factor in external costs. These regulations can force industry to mitigate and repair damage to the environment.

Planned Parenthood doesn't sell fetal tissue

First, a warning. This is not a typical lighthearted post exposing innumeracy in the media. This is the debunking of a shock-video about abortions.

A group of citizen journalists who call themselves "The Center for Medical Progress" have put out a video in which they claim Planned Parenthood uses partial-birth abortions to sell baby parts.

The video shows undercover footage of Deborah Nucatola, the Senior Director of Medical Services for Planned Parenthood, discussing how fetal tissue is procured and donated for research. There's nothing unethical or illegal about that.

Mothers give informed consent for this use just as some people donate their bodies to science in the event of death. Some people put organ donor stickers on their driver's license. Some people visit the blood bank regularly.

The video uses out-of-context editing to imply Planned Parenthood is making money from donated fetal tissue. In the full video Deborah Nucatola explains how Planned Parenthood receive compensation for the extra cost of handling and shipping samples. She later explains how this compensation allows them to give patients the option without impacting the bottom line.

The video attempts to confuse illegal "partial-birth abortions" with breech (feet-first) abortion which are in no way illegal. She clearly says the calvarium (head) is evacuated (removed) intact, which is not the case for partial-birth abortions. In the full video she explains how fetal demise is chemically induced before delivery.

The video claims the sale or purchase of human fetal tissue is a federal felony citing 42 U.S.C. 289g-2 which only applies to fetal tissue used "for the purpose of transplantation".

The video claims buying or selling human body parts is a federal felony citing 42 U.S. Code § 274e which also applies only to human organs used "for use in human transplantation".

This blatant misinterpretation of the law shows gross negligence on the part of the filmmakers and suggests intentional deception.

Planned Parenthood respects mothers who make the difficult decision to abort a pregnancy. Once the decision is made, one can only hope some good may come of it. If not for oneself, then for others. For some, knowing that the cell lines derived from their aborted fetal tissue may help cure disease, even if this possibility is remote, provides a small but desperate comfort. They should not be denied this comfort.

Abortions are horrible. This thinly-veiled pro-life slander of Planned Parenthood is even more so for its callous disregard for the suffering of would-be mothers.

Jurassic Park and the Half-Life of DNA

With the release of the Jurassic World I am reminded of the fictional science behind the cloning technique in the original movie.

I see nothing implausible about extracting DNA from blood cells found in a mosquito's gut. Although mammalian red blood cells and platelets both lack nuclei, bird blood cells have nuclear DNA one could theoretically recover.

Mr. DNA comes from non-mammalian blood

Unfortunately, the half-life of DNA is only about 521 years even under ideal conditions. The quantity of any substance with this half-life left over since the extinction of the dinosaurs during the KT extinction event is pretty easy to calculate.

(1/2)^(66 million / 521) = 4.81*10^-38135

Though it's hard to make sense of a number this small.

I think we can all agree there were fewer base pairs of dinosaur DNA on the Earth 65 million years ago than there are atoms in the universe. Since there are only about 10⁸⁰ atoms in the observable universe we can immediately conclude that the expected number of base pairs of dinosaur DNA remaining intact today is zero.

So the the fictional cloning technique in Jurassic Park can't work.

Looks like we're stuck with the dinosaurs we've got.

A soda jetpack is physically impossible

Today I saw this funny viral video.

We see a young man appear to lift off the ground propelled by 6 1-liter name brand soda bottles strapped to his feet. We are presumed to believe the carbon dioxide pressure in the bottle produces sufficient thrust to lift an adult human. Most people will intuitively decide the video is fake. After all, he's probably being lifted by a hidden wire.

I'll use some rocket science to show it must be a fake, not just to debunk this silly video, but to provide an example application of physics.

The force to lift a person off the ground must exceed the force of gravity pulling them toward the ground. If we assume the fit young man is 70kg we can calculate this force.

F = m * a = (70kg) * (9.8m/s^2) = 686 newtons

The six 1-liter bottles mass 1 kilogram each for a total of 6 kilograms. You can see on the second attempt they empty in about 3 seconds. Using the ideal thrust equation we can find the minimum exit velocity needed to lift the person.

V = F / ṁ = (686 N) / (6 kg / 3 s) = 343 m/s

That's faster than the speed of sound (340 m/s)!

Since soda bottles don't make sonic booms upon opening, we can conclude this video is fake.

Himalayan salt is a poor source of magnesium

I've seen claims that you should cook with Himalayan salt because, among many other dubious claims, it's a good dietary source of trace minerals like magnesium. Let's put this claim to the test.

An often-repeated claim by the promoters of Himalayan salt is that it contains 0.16 g/kg magnesium. The dietary recommendation is not to exceed 3750 mg of salt per day. The daily recommended intake of magnesium is 400 mg for adults.

To get your dietary intake of magnesium from Himalayan salt, you'd need to consume 667 times the safe amount of sodium! This is not advised.

Instead, you could eat the following foods. All have a higher concentration of magnesium than Himalayan salt. Even better, you can eat enough of these foods to easily achieve the recommended daily value of magnesium.

Food	Magnesium (g/kg)	Times more magnesium than Himalayan salt
Almonds	2.821919258	17.63699536
Spinach	0.687842819	4.299017619
Cashews	2.610275313	16.31422071
Peanuts	1.111130708	6.944566924
Soy milk	0.268964179	1.68102612
Black beans	0.529109861	3.30693663
Edamame	0.440924884	2.755780525
Peanut butter	1.731448763	10.82155477
Bread	0.821428571	5.133928571
Avocado	0.194006949	1.212543431
Potato	0.433365953	2.708537208
Rice	0.370376903	2.314855641
Yogurt	0.185188451	1.157427821
Oatmeal	1.285714286	8.035714286
Kidney beans	0.308647419	1.929046368
Banana	0.271186441	1.694915254
Salmon	0.30570756	1.910672251
Raisins	0.202825447	1.267659042
Chicken	0.258675628	1.616722674
Beef	0.235159662	1.469747885

Red Wine Is Not Exercise

Some online rag called the Elite Daily, which claims to be the premier online news platform for and by millennials, has this article titled A Glass Of Red Wine May Be Equivalent To An Hour At The Gym.

According to a study on the health benefits of resveratrol, a compound found in red wine, your body could receive some of the benefits of hitting the gym without sweat-inducing exercise.

The two-year-old paper they're referencing studied the effects of high doses of resveratrol on rats. They found that rats built more muscle on a 12-weeks progressive treadmill running program when 4 g/kg of resveratrol was added to their diet.

It's important to understand that this study did not compare resveratrol against exercise. It compared resveratrol plus exercise against exercise alone. In other words, says nothing about taking resveratrol instead of sweat-inducing exercise. It should be obvious that resveratrol is no substitute for exercise. Exercise has many benefits. Increasing skeletal muscle is only one of them.

Despite not being comparable to an hour at the gym, just how much red wine would you have to drink to achieve the studied dose of resveratrol?

Red wine can contain as much as 12.59 mg/L resveratrol. Assuming a person eats about 5 lbs of food per day, we can calculate the volume of wine you'd need to drink.

(5 lbs) * (4 g/kg) / (12.59 mg/L) = 720.56 L

That's 4,873 glasses of red wine. Per day.

Drink up!

Of course, no human can drink that much in one day. Since wine contains at least 9% alcohol by volume, all that drinking earns you a daily dose of 50.7 kg alcohol. The LD50 of alcohol is 5 g/kg. Assuming an 80 kg human, we can calculate how many times the lethal dose you'd receive on the Elite Daily's red wine diet.

(50.7 kg / 80 kg) / (5 g/kg) = 126.75

Not doctor recommended.

Michael Greger on Flavonoids

Michael Greger posted a YouTube video titled Cancer, Interrupted: Garlic & Flavonoids in which he offers a dubious summary of a paper from 2012 on the protective effect of the flavonoids.

This paper studied two phytochemicals, quercetin and rutin, at doses from 100μM. Greger presents the results as if they're relevant for humans eating diets rich in these chemicals. While the study is interesting, it's preliminary and the dosages studied are not in the least environmentally relevant.

We can use the molar mass of the two flavonoids studied to understand this dose in parts per million:

(302.236 g/mol) * (100μM) = 30 ppm quercetin
(610.520 g/mol) * (100μM) = 61 ppm rutin

Notice these concentrations are similar to the doses found in the foods high in these phytonutrients.
Red onions contain 32 ppm quercetin and buckwheat contains 100 ppm rutin.

How much of each food would a 70kg human need to consume to match the doses in this study?

(70 kg) * (30 ppm) / (32 ppm) = 144 pounds of red onions
(70 kg) * (61 ppm) / (100 ppm) = 94 pounds buckwheat

That's a lot of red onions and buckwheat! It's clear that these doses aren't achievable through diet.

The lesson here is not to mistake food for medicine. Eating a varied diet containing lots of fruits and vegetables is a good idea for many reasons. The effects of high doses of phytochemicals are not among those reasons.

Chugging Triclosan Soap

A paper was published last week in the Proceedings of the National Academy of Sciences demonstrating that the commonly used antimicrobial additive triclosan is a liver tumor promoter. That's actually the title of the paper! Hilda Bastian at Scientific American wrote a good article on the study, calling out its authors on their hype and fear-mongering. She also points out the study's small sample size and that the positive results came at very high dosages.

... mice received less than 28.6 mg/kg TCS daily through water ... [1]

So, how much triclosan liquid soap would I have to drink daily in order to achieve this dose?

First, we need to know the concentration of triclosan in your average bottle of hand soap:

... most of the popular liquid hand soap brands contain between 0.1% and 0.45% weight/volume ... [2]

I'll be generous and assume that all of the 0.45% triclosan in our liquid soap is absorbed.

For your average 70 kg human the daily dose can now be calculated!

(70 kg) * (28.6 mg/kg) / (0.45%) = 445 g

Just shy of 16 oz. That's a lot of hand soap to use, much less drink. Daily.

You can't even bring that much on an airplane!

Unless you're actually drinking the stuff (don't), environmentally relevant doses from normal are measured in parts per billion [3, page 13], i.e. orders of magnitude lower concentrations than in this mouse liver study. In particular, absorption through the skin is very low, maybe 6.3% [3, page 11]. It's biological half-life is measured in hours [3, page 13].

Preventing antibacterial resistance is reason enough to avoid products with triclosan.

Argument from chemophobia isn't how we get people to use antimicrobial products responsibly.

1. http://www.ncbi.nlm.nih.gov/pubmed/25404284
2. http://www.ncbi.nlm.nih.gov/pubmed/17683018
3. http://ntp.niehs.nih.gov/ntp/htdocs/chem_background/exsumpdf/triclosan_508.pdf

Measles Vaccine Efficacy in China

For whatever sick reasons, anti-vaccine activists try to use fear to dissuade parents from vaccinating their children. Make no mistake. This is an act of pure evil. Not only does it leave unvaccinated children at a higher risk of catching serious, sometimes fatal contagious diseases, but it puts everyone around them at increased risk of catching these diseases too. This is what drives many people to fight against the misinformation, myself included.

The name of the game is science denial for the anti-vaccine activist. They have their work cut out for them. Concocting a worldview where a health measure that prevents between 2 and 3 million deaths every year is a bad thing takes a lot of work.

Thankfully, sometimes all we need to do is give them enough metaphorical rope to hang themselves.

Here's an example!

Earlier this year, a study was published to the Bulletin of the World Health Organization on the progress towards the elimination of measles in China.

Sayer Ji, infamous for misrepresentation of scientific articles, in a blog post about the study, says:

China has one of the most vaccination compliant populations in the world. In fact, measles vaccine is mandatory. So why have they had over 700 measles outbreaks from 2009 and 2012 alone? The obvious answer is the the measles vaccines are simply NOT effective.

While the study's conclusion states unequivocally that:

In 2013, most of the resurgence seen in measles cases was the result of the susceptibility of unvaccinated or incompletely vaccinated children...

Which directly contradicts the central claim of Ji's blog post. This is typical of Ji. He consistently references scientific studies in an attempt to lend credibility to his argument despite the fact that the contents utterly refute his argument. He relies on the laziness and lack of education among his readers. If any of them simply read the study, they'd notice that it says the opposite of what he claims.

His biggest mistake was using the word "effective" which, in the study of vaccines, has a rigorous mathematical meaning. The efficacy of a vaccine is defined as:

E = 1 - (V / U)

Where U and V are the "attack rates" in the unvaccinated and vaccinated population, respectively. We calculate these attack rates by dividing the number of sick people divided by the population size. So the first question is, who got sick? The cited study shows 53% of measles sufferers were unvaccinated, while 47% were fully vaccinated.

The anti-vaccine activist might say, "but those percentages are almost the same! It looks like the vaccine hardly made a difference. You've got almost a 50% chance of getting sick either way, right?"

Wrong. And we just need one more piece of information to prove it.

According to the title of Ji's own blog post, "99% are vaccinated." Now we can calculate attack rates:

V = 0.47 / 0.99 = 0.475
U = 0.53 / 0.01 = 53

Which means the efficacy of the measles vaccine in China is:

E = 1 - (0.475 / 53) = 0.991

Or, 99.1% effective, consistent with efficacy noted on the CDC website.

So why is the anti-vaccine activist wrong to suppose you've got a 50% chance of getting sick either way? I like to think of it from the point of view of the measles virus. If I spread randomly from person to person, it will be hard for me to find that one unvaccinated person in a crowd of 100 people. If I do manage to find that person more than 1% of the time, I've done better than chance. That means it was easier for me to infect this person than the other 99 vaccinated people.

It only takes grade school math to expose the likes of Sayer Ji.

Solar Power and Birds

The Ivanpah Solar Power Facility is a "thermal tower" solar plat in the Mojave Desert, California. Rather than converting sunlight directly into electricity as do photovoltaic solar panels, thousands of mirrors reflect sunlight at a central tower. Water in the tower is heated to 1,000 degrees Fahrenheit. The resulting steam runs an electric turbine. Storing solar energy in the form of heat allows the plant to generate electricity 24 hours a day. Latent heat used overnight is replenishing the next day.

This feature allows the plant to avoid the major drawback of other renewable energy production systems, like wind farms and photovoltaic arrays, which only output energy when the wind is blowing, and the Sun is shining, respectively.

Ivanpah Solar Power Facility (No, it's not Burning Man.)

Criticisms of this pilot plant include the cost, and environmental impact. As for the cost, pilot plants are always expensive. Huge savings are typically seen when a technology is scaled up. The facility cost about $5,561 per kW, only one and a half times the cost of building a new coal facility which runs about $3,500 per kW. Anyway, cost is a concern for the economists. I'm interested in the environmental impact, because I'm an environmentalist.

Unforeseen in the Environmental Impact Statement and prior to construction, some birds were found to have been burnt by when they flew into the area of focused sunlight. US Fish and Wildlife Service (FWS) began an investigation in July, 2012.

Shortly after the plant formally opened in February, 2014 the Wall Street Journal ran an attack piece by Cassandra Sweet with accompanying correspondent interview.

A giant solar-power project officially opening this week in the California desert is the first of its kind, and may be among the last, in part because of growing evidence that the technology it uses is killing birds.

This WSJ article leaves out the fact that all buildings with windows kill some birds, and that all methods of generating power harm the environment. The question is, how many birds are killed by this facility due to heat damage from fling into the focal range? And, how does the environmental impact of this facility compare to other types of facilities?

By the time the FWS published a preliminary report of their investigation in April, 2014, the news story was long forgotten. The report got little attention until August, when Ellen Knickmeyer and John Locher published an egregiously misleading article in the Associated Press.

Federal wildlife investigators who visited the BrightSource Energy plant last year and watched as birds burned and fell, reporting an average of one "streamer" every two minutes, are urging California officials to halt the operator's application to build a still-bigger version.

Here's what report actually says about the "streamers":

... these events represent the combustion of loose debris, or insects.

In reality, the report investigation found only 47 birds injured by solar flux in the 1-year study period. So, at least 47 of the "streamers" might have, in fact, been birds. But not all of them. The article attempts to fool its readers by knowingly conflating the streamers with bird deaths. I trust my readers know better than to fall for such an obvious syllogistic fallacy.

Credulous readers of the AP article would walk away thinking that the report showed 5,591 times more bird fatalities than were actually reported. That's misleading by 3.7 orders of magnitude!

How does this compare to some other anthropogenic sources of avian mortality?

• An estimated 1.4-3.7 billion birds are killed each year by cats.
• As many as 980 million birds crash into buildings annually.
• 174 million birds die from power lines every year.
• Up to 340 million birds perish from vehicles/roads.
• Approximately 6.8 million birds die flying into communications towers.

And how does this compare to other types of power generation?

Avian Mortality from different types of power generation.

One study compares estimates of the number of avian fatalities per GWh by energy sector.

• 0.27 for Wind
• 0.60 for Nuclear
• 9.40 for Fossil Fuel

Whereas I calculate the total (solar flux + other causes) fatalities per Gigawatt-hour:

• (141 birds per year) / (1000 Gigawatt-hours per year) = 0.141 for Ivanpah

That's right. The Ivanpah plant costs the least number of bird's lives per Gigawatt-hour. It's terrible to measure electric power in terms of dead birds. But if you really care about protecting birds, you must question whether the benefits outweigh the risks, not to your own political ideology or world-view, but to the birds.

Moral and environmental consideration of a technology must include the cost of the alternatives!

Solar thermal towers help protect birds by replacing more hazardous means to generate power.

Sugar in a Caesarean Section

Last Week Tonight with John Oliver is plagued by the same problem as other comedy news shows like The Daily Show and The Colbert Report. They sometimes get things wrong because the writers are comedians trying to be funny, not skeptics trying to think critically.

In this week's episode, while discussing our broken prison system, John brought up the story of Regan Clarine. While an inmate in Perryville State Prison inmate underwent a C-section operation. Her mother Lori was interviewed for Al Jazeera.

Lori said the medical staff didn't stitch the wound shut. Instead, they dressed it with butterfly bandages.

It sounds like Clarine was treated with BioWeld, a new way to seal wounds without staples or stitches. The machine uses plasma to bind skin to a biological film based on a naturally occurring sugar.

Clarine developed an infection in the wound site, and sent to the prison hospital. According to Lori:

... they decided that the best thing to do for this would be to pack it with kitchen sugar … we're talking sugar that you get from, because they donate it from McDonald's from Burger King, you know? They're standing there ripping open these little packs of sugar and filling that wound.

It sounds like Clarine was treated with Multidex powder, a moist wound filler useful for reducing purulent exudate (or "oozing" as described in the Al Jazeera article). Some of these powder packets do sort of resemble McDonald's sugar packets in shape and size. The mistake is easy to make, especially for an anesthetized person, but they aren't from a fast food joint. They're medicine.

Multidex powder packets.

This medicine approved for use in 1997. It's main ingredient isn't "kitchen sugar" (sucrose) but a different polysaccharide called maltodextrin.

Even Lori's brother, who's a doctor, said:

It's probably just a nickname of something. Nobody would pour sugar in a wound. So don't worry about it.

But the article says:

Sugar was used to treat wounds before the advent of antibiotics in the early 1900s, but it's no longer accepted medical practice.

Which is false! As we've seen, sugar is used in modern medicine to both seal and pack wounds.

I don't question that this poor inmate was mistreated. It seems likely she developed these complications as a result of inadequate care. Neither do I blame anyone for misunderstanding their doctors bedside explanation of the treatment they receive.

I blame Abigail Leonard and Adam May, authors of the article, for not checking their facts, and for printing the opinion of the mother of an inmate as fact despite all common sense, and without the least bit of skepticism. America Tonight is not supposed to be a comedy show, right?

The claim that privatization of the penal system leads to poor inmate treatment is a serious one, and needs to be backed up with evidence. In this case, the sugar is not evidence. The wound re-opening and subsequent infection is evidence.

Another issue is that a 18-year-old woman was sentenced to 2.5 years for intent to sell prescription painkillers. We can argue for reform of drug laws without exaggerating the problems that face inmates. We already knew prison is terrible before this story. Drug offenders belong in rehab, not prison.

I think John Oliver (and his writers) really care about the topics they talk about on the show. I want them to know that they can better serve their audience with the truth than with half-truths and lies. This can only be accomplished by checking facts and applying critical thinking, which is hard work.

I leave you with this quote by John Oliver from 2009:

... Someone came up to me and asked me a question about a news story, and I didn't know anything about it so I just lied and they listened to me and believed me. The feeling of power that I got from that lie infecting their head made me think, "Yes, this is what I want to do for a living." (1:40)

I know this was said with irony. Let's not make it double-irony.