Category Archives: Science

Food Irradiation

Posted on by The Old Wolf

I’ve long had in my library a September 1958 National Geographic entitled “You and the Obedient Atom.” It’s an intriguing look at the scientific applications of nuclear radiation, and one of these has always intrigued me.

Ektachromes by Gervase A. Arndt ©1958 N.G.S.

“Bombarded Foods Stay Germ-free as Others Rot

Using gamma rays to destroy micro-organisms that cause decay, the Army Quartermaster Corps preserves foods for weeks and months at room temperatures. When exposures are light, changes in taste are scarcely noticeable; gamma radiation does not linger.

Foods irradiated in Argonne’s pool (illustration not shown – Argonne National Laboratory near Chicago) and elsewhere were first fed to rats, without harmful effect. Later, military volunteers tried samples. Congressmen have eaten entire gamma-sterilized dinners.

Both samples of frankfurters were kept three months in air¬tight plastic wrappers. Irradiated meat on right looks as fresh as ever. A potato sprouts six months after harvesting; in its opposite, sprouting is delayed. Treated oranges stay fresh and juicy. Moldy bread contrasts with a two-month-old treated loaf. The Food and Drug Administration has not yet certified gamma-treated foods for the market.”

National Geographic, September, 1958

Wow. What a way to reduce spoilage. Yet despite the massive consumer push-back against GMO’s or “frankenfoods,” we hear almost nothing about irradiation today. Doing a bit of research, I came across

Apparently foods treated by radiation will display the “radura”

And yet despite the initial approval by the FDA of irradiated foods for certain applications and continuing research showing its safety, I have never once in my life seen the radura on any food label, anywhere.

“Irradiation has not been widely adopted due to an asserted negative public perception, the concerns expressed by some consumer groups and the reluctance of many food producers.[47]

Consumer organizations, environmentalist groups, and opponents to food irradiation refer to some studies suggesting that a large part of the public questions the safety of irradiated foods, and will not buy foods that have been irradiated.[48]

On the other hand, other studies indicate the number of consumers concerned about the safety of irradiated food has decreased in the last 10 years and continues to be less than the number of those concerned about pesticide residues, microbiological contamination, and other food related concerns. Such numbers are comparable to those of people with no concern about food additives and preservatives. Consumers, given a choice and access to irradiated products, appear ready to buy it in considerably large numbers”

Wikipedia, Food Irradiation

Irradiation works by destroying DNA, preventing microorganisms from reproducing or creating toxic byproducts. Obviously people are going to have concerns about consuming modified (destroyed) DNA in the same way as they will about consuming transgenic foods, but that doesn’t mean the issues are the same. Still, given what we know about how prions work and the devastating effects of BSE, people are right to be concerned enough to do their homework.

Given the relative paucity of irradiated foods on the market, it’s probably safe to say you are not likely to encounter any, but I’m going to do a bit more digging. If it is safe, it could go a long way to reducing food waste, which at this point reaches a level of about 40% of all consumables in the US alone.

The Old Wolf has spoken.

 

 

No, it’s *not* a “Blue Moon”

Posted on by The Old Wolf

A blurb today at Newser announces that Friday will be a “Blue Moon.”

No, it won’t.

Summer began on June 20, and has only 3 full moons:

2012
Jul
3
18:52
Tue
2012
Aug
2
03:27
Thu
2012
Aug
31
13:58
Fri

 

The next full moon won’t be until September 30, after the autumnal equinox. The next real Blue Moon will be August 21, 2013. But as Sky and Telescope noted, “With two decades of popular usage behind it, the second-full-Moon-in-a-month (mis)interpretation is like a genie that can’t be forced back into its bottle.”

The Old Wolf (and science) have spoken.

Violet, resistance is futile.

Posted on by The Old Wolf

Science is full of facts and numbers and formulæ and things to remember. Keeping it all straight can be a chore, even for the geniuses. As a result, over time people have developed interesting ways of remembering the order of things in groups and categories.

Cross-stitch reminder of resistor codes, courtesy of Adafruit.

Another way of remembering the color values:

First two (or three) digits: Bad boys rape our good girls, but Violet gives willingly – get some now ->

Black, Brown, Red, Orange, Gold, Green, Blue, Violet, Grey, White (gold, silver and none refer to the tolerance band)

Resistors can be ever more complicated than in the early days when this mnemonic was developed. Six-band resistors have three significant digits, a multiplier, a tolerance band, and a temperature coefficient.

339Ω with a 1% tolerance.

39 kΩ with a 10% tolerance

Mnemonics are a good way of remembering other things as well. Most of us became good friends with Roy G. Biv in school:

Partial rainbow over Utah Lake, Mt. Timpanogos in the background. The order of colors in a rainbow are Red, Orange, Yellow, Green, Blue, Indigo, Violet.

There are numerous mnemonics for remembering the order of the planets in the solar system; my favorite is found in Robert A Heinlein’s Have Space Suit, Will Travel: Mother Very Thoughtfully Made A Jelly Sandwich Under No Protest (he used “T” for Terra, and included the “A” for Asteroids.)

And for what it’s worth, to Hell with the AIU. Pluto may be smaller than some of the other TNU’s and dwarf planets out there, but it was part of the solar system since Tombaugh discovered it, and by the dessicated skull of Mogg’s grandfather, there it stays. Randall Munroe of XKCD fame disagrees, and I give him mad props for being a genius, but as far as I’m concerned,

Huge selection of mnemonics here.

The Old Wolf has spoken.

It’s hot, and getting hotter.

Posted on by The Old Wolf

I’ve never taken a locked-in-concrete stance on the issue of climate change because, simply, I don’t understand all the variables. That said, my gut tells me that the amounts of greenhouse gases we have produced since the beginning of the industrial revolution have got to be taking a toll on our global ecology.

Then along comes an article in The Register, claiming that based on a recent study, temperatures are going down rather than up. So I put the question out into the ether, where I happen to have friends and associates who are far wiser about such matters than I, including career professionals in the field. The responses I got back were enlightening, and I summarize them here.

The chart below comes from the Register’s article.

  1.  The first thing to notice is that the cooling trend line in the above chart is deceptive, and that statistics can be made to say anything you want them to. If you were to begin it at the “Little Ice Age,” it would be trending decidedly upward, with a sharp spike noticeable around the beginning of the 20th century.
  2. The data recorded in Esper’s study (again, see the article linked to above) are of interest, and will doubtless be put through the scientific wringer to see how they add to our overall knowledge of the climate and its behavior. Using a single data set, to draw definitive conclusions about long-term trends is not sound science, however, and Esper’s team does not do so. In this case, either the author of this article misunderstood the paper, or – given the Register’s reputation as a bully pulpit for climate-change skeptics – used the data to support its own pre-conceived conclusions.
  3. Esper’s data focuses exclusively on northern Scandinavia, rather than multiple lines of numbers taken globally. An accurate picture of what is happening planetwide would have to be extrapolated from sources such as ice cores, sediments, tree rings and other empirical data gathered at different time points in varying locations throughout both hemispheres. One such chart attempts to pull together a number of different analyses into a single graphic:

Source and key here.

4.   Well-understood orbital mechanics have satisfactorily explained previous warming periods throughout history.
5.   The Paleocene-Eocene Thermal Maximum, which took place about 55 million years ago, saw the temperature of the world rise 6 °C over a period of 20,000 years, resulting in numerous extinctions but also the rise of other modern mammalian orders. While the cause is not yet clear, it appears that a massive outgassing of carbon from the oceans followed by uncontrolled warming created a planet-wide hothouse that took 150,000 years to cool off. Compare this with the Medieval Warm period, a blip on the grid by comparison, which affected only Europe and the North Atlantic; during the same time other parts of the globe were suffering wet spells or severe drought.

My own experience is that it’s hot, and getting hotter. The past six months have broken numerous local, nationwide and historical heat records since recordkeeping began. If the current trend continues, my grandchildren may experience a world that could be 4.3 °F to 11.5 °F hotter than it is today, and such a heat differential will lead to an increase of the kinds of drought and severe storms we have been seeing in the past year. I have lived in the same area in the west for over 40 years. Over time, our temperatures have risen and our precipitation, particularly in the winter, has decreased. This does not bode well for the future, where our desert state depends on scarce water resources for survival; it’s not the kind of world I want to bequeath to my posterity.

The Battle over Climate Change

A recent article in PopSci lays the battle lines out fairly clearly, and it’s not pretty. When solving a crime, detectives still look at the old standbys of motive, method and opportunity. In the battle over climate change, it helps to ask the single question “Who benefits?” In other words, follow the money. While one could make a case for scientists stirring up public outrage with an eye toward prestige and grant money, or politicians using global warming as a vote-getting strategy, it seems far less an incentive than the prospect of billions in profit lost by industries and corporations which will be impacted by increased restrictions on the amount of carbon they are allowed to pump into our atmosphere.

There are places in the world where people are killed for the price of a meal; small wonder that the amounts of money and power that are at stake result in a firestorm of scientific legerdemain, character assassination and even intimidation and death threats directed at honest scientists who are pursuing nothing but scientific conclusions based on empirical data.

When I distil the admixture of data down to its undiluted essence, I can’t escape the conclusion that we are fouling our nest with exponentially-increasing speed, and those who say it ain’t so have a vested interest in keeping climate change off the table. The good news is that despite adversity (eppure si muove!) scientists have a tendency to keep doing science, and the more time goes on, the clearer the picture will become. In the end (if the science is sound) the only skeptics will be meeting in the room across the hall from the flat earth society.

The Old Wolf has Spoken.

On the internet, urban legends never die

Posted on by The Old Wolf

Stumbling around this morning waiting for a student to show up online (he never did), I came across this:

Now, I had never heard this – but my stepdaughter happens to be insane about hippos, so I thought this might make a cute shirt for her. A bit of searching, however, raised a problem: despite countless hits and re-posts and re-blogs, and entries in things like Yahoo Answers (otherwise known as the blind leading the blind, but don’t get me started), it seems that it’s just not true.

It turns out that hippos produce a natural sunscreen. From Wikipedia: “Their skin secretes a natural sunscreen substance which is red-colored. The secretion is sometimes referred to as “blood sweat,” but is neither blood nor sweat. This secretion is initially colorless and turns red-orange within minutes, eventually becoming brown. Two distinct pigments have been identified in the secretions, one red (hipposudoric acid) and one orange (norhipposudoric acid). The two pigments are highly acidic compounds. Both pigments inhibit the growth of disease-causing bacteria; as well, the light absorption of both pigments peaks in the ultraviolet range, creating a sunscreen effect. All hippos, even those with different diets, secrete the pigments, so it does not appear that food is the source of the pigments. Instead, the animals may synthesize the pigments from precursors such as the amino acid tyrosine.”

Like all mammals, hippos produce white milk; when the milk mixes with these skin secretions, it may acquire a pink color cast. At ASPCA kids, one of the answer-writers produced this with regard to the question:

“You’re right about hippos oozing an awesome red-pink liquid to keep away bugs and germs and avoid sunburn, Finley! But pink milk? Sounds too crazy to be true. But you’re also right that many websites claim hippo babies are drinking pink milk.

I’m sorry to say that I don’t know any hippos personally, so to answer your question I had to turn to the experts—specifically, Dr. Rebecca Lewison, an ecologist and hippo conservationist at San Diego State University. According to Dr. Lewison, the pink milk thing is totally false! She thinks people are confusing hippos’ pink secretion with their milk. I guess you can’t believe everything you read on the Internet—except when at ASPCA Kids, of course.”

I’ll take the word of the experts on this one. Hippo milk is white.

The Old Wolf has spoken.

We are not alone.

Posted on by The Old Wolf

Pure science would say that since there is no evidence of life beyond our own planet, one can neither assume nor rule out life elsewhere.

Our place in the universe. Click to make massive.

Yet a mind open to surprises looks at the above schematic, factors in the existence of 70,000,000,000,000,000,000,000 stars (that’s 70,000 million million million) in the known universe, and that’s as of 2003, and wonders what kind of hubris allows for this incomprehensible vastness and beauty to exist solely to amuse us? As of 2012, Wikipedia reports, “Data from the Habitable Exoplanets Catalog (HEC) suggests that, of the 725 exoplanets which have been confirmed as of 14 January 2012, four potentially habitable planets have been found, and the same source predicts that there may be 27 habitable extrasolar moons around confirmed planets.”

The Hubble Ultra Deep Field image was taken of an area of the sky just a tad over 3 arcminutes across. That’s smaller than a 1 mm by 1 mm square of paper held at 1 meter away, and equal to roughly one thirteen-millionth of the total area of the sky; with the exception of one or two local stars in our neighborhood, every pinprick of light in this image is a galaxy. Every single spot. Add to that the fact that galactic scale is unfathomable; despite the existence of hundreds of billions of stars in a single cluster, when our own celestial home collides with its nearest neighbor, the Andromeda Galaxy, no two stars will ever come close enough to collide. (Watch the video at the link, it’s elegant.)

Using the Drake equation to estimate the number of civilizations with whom we might have communication is an exercise in futility, simply because none of the terms are or can be known, but I don’t need higher math to look out into such mind-bending vastness and see a result higher than zero. For me, life out there is inevitable.

No, I can’t get my head around the idea that we’re the only thing out here, or the best, or the brightest. Unless someone figures out how to void the laws of the universe, it’s unlikely that we’ll ever know, but that doesn’t dampen my certainty: we’re not alone.

The Old Wolf has spoken.