frog vs newt
students always ask, "can we incorporate chloroplasts into our cells and not have to eat?" besides being green here is a answer to that question:
In a way, they already do. A field of grass sits there all day soaking up energy from the sun and storing it chemically. A grazing animal can then come along and absorb weeks of accumulated energy in a matter of minutes.
A Jersey cow presents in the neighborhood of nearly two square meters of usable space to the sun if it stands right. (Cows would have to be trained to stand optimally, but we might not have too far to go; research suggeststhey already align themselves north-south.
Chlorophyll photosynthesis extracts 3%-6% of the total energy from sunlight. If we figure on any given day the cow gets the equivalent of about six hours of peak sunlight, it works out to less than two million joules of usable energy each day.
Is that a lot? Well, a 450-kilogram cow just wandering around in a field might eat about 10 kilograms of dry matter a day, extracting on the order of 50 million joules of metabolic energy. So photosynthesis could only make up about 4% of the required intake—saving only a few handfuls of grain.
If we could equip cows with solar panels, which can be several times more energy-efficient than photosynthesis, we could improve that number—but not by much.
The basic problem facing cows is the same one facing solar cars—they're too small. If you saw the world's cattle population in silhouette, they'd have an overall cross-sectional area of about two thousand square kilometers. This means that if they were migrating through the air over Rhode Island (biology is not my strong suit), they'd blot out the sun over barely half the state. They'd only catch enough sunlight to produce a daily average of about 40 gigawatts of power.
By contrast, about 3% of the world's surface area is cultivated, which means that (given rough estimates of geographic distribution of farmland) our crops easily intercept over a thousand times more sunlight than our cattle—which is why grazing is a good strategy.
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how does yeast "work"?
The tiny, rounded, colorless one-celled plant called yeast floats through the air everywhere, but it is responsible for making all our cakes and breads rise to a nice, fluffy texture. This happens because yeast creates chemical reactions on the starch and sugar in the cake or bread batter. Here’s how it works.
Yeast cells reproduce very rapidly no matter where they are. This reproduction goes on through a process called budding. In budding, each tiny cell swells, and soon the swollen part separates from the main cell. The new tiny cell then goes on to grow to full size on its own and the budding process continues to repeat itself.
During this growth process, the yeast cells produce substances called enzymes. So when the yeast is added to cake or bread dough, one enzyme goes to work on the flour, changing the starch in it into sugar.
Another enzyme then takes over and changes the sugar into alcohol and a gas called carbon dioxide. This gas spreads through the dough in the form of bubbles.
As the dough bakes into bread and cake, the heat causes the alcohol to evaporate and the bubbles to break. This leaves the tiny air pockets in the final bread or cake, making it light and fluffy.
Before yeast was manufactured commercially, women did their baking by mixing flour, salt, sugar, and potato water, and letting yeast cells in the air supply the enzymes!
WHy we age
This is a follow up to the previous post and explains why we age.
Many time we watch shows on TV that float around the idea of "immortality", aside from the supernatural idea of not being able to be killed, what if we didn't age or have to worry about dying of old age, what would our lives be like?
The 2nd law of thermodynamics states that in any closed system entropy will increase over time. The exact rate at which entropy increases is situation dependent (e.g., being on fire or not).
As a quick aside, one of my favorite Creationist (pardon, “Intelligent Design”) arguments uses the second law. That is, a living Human body has far less entropy than an equivalent amount of (most) inorganic matter, so how could living things have come from non-living things? Well, that’s a stunningly hard question, and we’re working on it. Patience. However, entropy isn’t a problem here, because the system of the biosphere is not closed. We get a constant supply of low-entropy visible light from the Sun, and the Earth in turn sprays out a lot of high-entropy infra-red light. For every one photon we get from the Sun we re-emit about twenty randomly into space. That huge entropy sink is more than enough to offset all life, and a lot more.
The Bowhead Whale and the Galápagos Tortoise: two species lucky enough to live for a couple hundred years.
Back to the point. Is the long, grinding, inevitable decay of the body inevitable in theory as well as in practice? Nope.
Nothing survives the heat death of the universe of course, but there’s strong evidence that, if the environment stayed more or less the way it is today, then something “Human-ish” could live (maybe) indefinitely. Single-celled organisms never die of old age, they either die for environmental reasons or tiny murder. Instead of dying when they get old, they split in half and each half then grows to full size and repeats the process. In a very literal sense, we’re all just different parts of the same, still-living, ancient primordial life form (much love, Chopra).
Single celled organisms: kinda immortal.
There are (very) living examples of creatures today that just don’t die on their own, such as the Turritopsis Nutricula jellyfish (which has been shown to indefinitely cycle between it’s adult and adolescent forms) and maybe (but probably not), the Hydra genus. The point is; dying of old age is not a written-in-stone requirement for life.
The hydra which might be immortal, and the Turritopsis nutricula jellyfish which almost certainly is.
So, things don’t grow old and die due to entropy (strictly). The effect of entropy seems to take the form of the accumulation of injuries, toxins, parasites, mutations, and general wear and tear. The “choice” that a species has to make is between fixing bodies as they accrue damage, or shitcanning them and starting over. By “shitcan and start over” I mean put a lot of energy into perfectly maintaining a few hundred cells (the “germ line“) and fixing most of the damage throughout the rest of the body. New creatures that grow out of the germ line (babies) start with a damage-free blank slate.
Also; bonus! Dying of old age helps clear the way for evolution to do it’s thing. The young (and slightly different) merely have to compete with each other, instead of well established and ancient creatures. Without natural death Earth might be home to nothing more interesting than mold (which is boring).
Now consider this: the statement that “entropy always increases” is just a fancy way of saying that “the world tends toward the most likely/stable end” or “the world tends to be in a state that has the most ways of happening”. In this case, there are a lot more ways to be dead than alive. As a result, you may have noticed that there are plenty of ways to accidentally die, but really just the one way to accidentally come to life. Statisticians (being weird and morbid) have figured out that if Humans were biologically immortal the average lifespan would be around 600-700 years. It takes about that long to slip in the shower or something (statistically).
Let’s face the cold truth. A lot of guys have patchy beards. Beards that they are not exactly pleased with. Beards they wouldn’t write home about. Now, I have a deep love for all beards, thick and thin, but having a patchy beard is a huge deterrent to growing one for a lot of guys.
In an effort to find biological reasons for your patchy beard, and hopefully a nice natural fix, I researched many scientific articles that frankly were a bit over my head. But I’m a pretty smart guy, and I was able to take away some info and distill it down to the essential reasons why your beard is lackluster compared to the norm. Hopefully you will take away a better understanding of your frustrating situation and also some hope that the rapid progress in genetic research will someday create a solution.
To the science!
Beard hair growth, unlike the growth of head hair or other facial hair, like eyelashes, depends on compounds called androgens. Androgens are responsible for what are considered masculine features. The most famous androgen is our old friend we learned about in middle-school health class, testosterone.
Testosterone fueled your conversion from a boy to a man and took you through those hellish emotional changes and awkward physical changes we all had to suffer through. Now that you are an adult, your manly hormone keeps your muscles firm and useful and keeps your sex drive at a normal level. It is also beard food.
Inside each of your follicles is a structure called the dermal papilla. The dermal papillae are kind of like the “brains” of your hair follicles. The ones in your beard follicles respond to the messages that your androgens send and cause the surrounding parts of the hair follicles (called the hair matrix) to do their thing and make some damn beard hair. Guess what androgen tells the beard hair follicles to activate the hair matrix? Yep, testosterone.
So why not simply partake in some extra testosterone? Number one, it’s a controlled substance in the United States. Number two, there are other factors at work here that are sabotaging your beard growth.
When the dermal papillae of your beard follicles utilize testosterone, they actually metabolize it and create another androgen as a byproduct called dihydrotestosterone. This substance is like the bigger, stronger brother to testosterone. It contributes to male characteristics, just like wimpy old regular testosterone, just a lot more. It didn’t just kick start your pubescent transition to an adult male, it is pretty much the reason that you developed as a male in the womb.
To utilize testosterone and create dihydrotestosterone, your beard follicles need yet another substance, an enzyme called 5-alpha-reductase. This enzyme is necessary for this conversion, and if you have low levels of it, then you have low levels of dihydrotestosterone. More importantly to the topic at hand, if you don’t have enough 5-alpha-reductase, the dermal papillae of your beard follicles can’t properly use testosterone to tell your hair matrices to make hair. And if your beard hair matrices aren’t making hair, you aren’t growing a beard.
In case you got a bit lost in the science back there, let me summarize.
Each beard hair is like a little plant whose “seed” is buried within each follicle. Your beard seeds need testosterone and an enzyme to grow. The testosterone is like the water and the enzyme is like the germ inside the seed that takes the water and uses it to grow. Too little water means too little growth, but more importantly, if there’s no germ inside the seed, there’s no way anything is sprouting.
So what’s a guy with too little 5-alpha-reductase to do? The good news is that it is already the subject of much pharmacological effort. The bad news is that those efforts are currently working toward the goal of reducing the 5-alpha-reductase levels in normal men. Why in the world would they do that? Because of the dihydrotestosterone that it helps produce. You see, in the crazy mixed-up world of hair, too much dihydrotestosterone causes male pattern baldness! Yes, the more likely a man can grow a beard, the more likely he will eventually go bald. Elevated dihydrotestosterone levels may also contribute to an enlarged prostate and even prostate cancer. Hence the current 5-alpha-reductase inhibitors on the market today.
But take heart, you patchy-bearded soul. If a medicine can reduce the level of an enzyme, then there’s no reason one couldn’t be created to increase the levels instead. Maybe an intrepid reader of The Beard Coach will one day start a foundation to fund the development of such a drug. Until then, don’t fret. Your patchy beard doesn’t make you less of a man. You lack no testosterone man fuel. You simply suffer from a medical condition that one day in the glorious future may be cured. Then you can gladly take your beard pills and finally grow a one you can take home to Mom.
You probably already know that most science fiction movies feature terrible science, and especially awful physics. But some movies feature scientific mistakes so basic and so terrible, they give you what can only be described as a "logic coronary."
Here are seven movies with scientific flaws so bad, whenever someone rents one of these flicks Neil deGrasse Tyson gets a migraine.
See the 7 facts here
A man fell to earth, from space
Yesterday, a man jumped out of space for an energy drink. This is what it looked like, from the point of view of the man.
That's the first footage from the camera mounted on the helmet of Felix Baumgartner, the Austrian skydiver who broke two intense world records yesterday after casually stepping out of a tiny capsule at the edge of the atmosphere: the fastest free fall of all time — 833.9 miles per hour — and highest-ever free fall, at 128,100 feet. Baumgartner also became the first person to break the sound barrier without being in, like, a plane, or a car, or whatever.
And he did it all for that symbol of science and achievement — that beacon of excellence and progress — that eternal emblem of greatness: Red Bull.
The term 'Cobra effect' stems from an anecdote set at the time of British rule of colonial India. The British government was concerned about the number of venomous cobra snakes. The Government therefore offered a reward for every dead snake. Initially this was a successful strategy as large numbers of snakes were killed for the reward. Eventually however the Indians began to breed cobras for the income.
When this was realized the reward was canceled, but the cobra breeders set the snakes free and the wild cobras consequently multiplied. The apparent solution for the problem made the situation even worse.
A similar incident occurred in Hanoi, under French colonial rule, where a program paying people a bounty for each rat pelt handed in was intended to exterminate rats. Instead, it led to the farming of rats.
According to a Wall Street Journal study of four recent broadcasts, and similar estimates by researchers, the average amount of time the ball is in play on the field during an NFL game is about 11 minutes.
In other words, if you tally up everything that happens between the time the ball is snapped and the play is whistled dead by the officials, there's barely enough time to prepare a hard-boiled egg. In fact, the average telecast devotes 56% more time to showing replays.
read the article here
This is a collection of interesting facts collected from the internet.