News

New study: how the hummingbird performs stunning feats of aerobatics

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Hummingbird in flight
Hummingbird in flight

New study reported by Science Daily.

Excerpt:

The sight of a tiny hummingbird hovering in front of a flower and then darting to another with lightning speed amazes and delights. But it also leaves watchers with a persistent question: How do they do it?

Now, the most detailed, three-dimensional aerodynamic simulation of hummingbird flight conducted to date has definitively demonstrated that the hummingbird achieves its nimble aerobatic abilities through a unique set of aerodynamic forces that are more closely aligned to those found in flying insects than to other birds.

The new supercomputer simulation was produced by a pair of mechanical engineers at Vanderbilt University who teamed up with a biologist at the University of North Carolina at Chapel Hill. It is described in the article “Three-dimensional flow and lift characteristics of a hovering ruby-throated hummingbird” published this fall in the Journal of the Royal Society Interface.

For some time researchers have been aware of the similarities between hummingbird and insect flight, but some experts have supported an alternate model which proposed that hummingbird’s wings have aerodynamic properties similar to helicopter blades. However, the new realistic simulation demonstrates that the tiny birds make use of unsteady airflow mechanisms, generating invisible vortices of air that produce the lift they need to hover and flit from flower to flower.

You might think that if the hummingbird simply beats its wings fast enough and hard enough it can push enough air downward to keep its small body afloat. But, according to the simulation, lift production is much trickier than that.

For example, as the bird pulls its wings forward and down, tiny vortices form over the leading and trailing edges and then merge into a single large vortex, forming a low-pressure area that provides lift. In addition, the tiny birds further enhance the amount of lift they produce by pitching up their wings (rotate them along the long axis) as they flap.

Hummingbirds perform another neat aerodynamic trick — one that sets them apart from their larger feathered relatives. They not only generate positive lift on the downstroke, but they also generate lift on the upstroke by inverting their wings. As the leading edge begins moving backwards, the wing beneath it rotates around so the top of the wing becomes the bottom and bottom becomes the top. This allows the wing to form a leading edge vortex as it moves backward generating positive lift.

According to the simulation, the downstroke produces most of the thrust but that is only because the hummingbird puts more energy into it. The upstroke produces only 30 percent as much lift but it takes only 30 percent as much energy, making the upstroke equally as aerodynamically efficient as the more powerful downstroke.

Large birds, by contrast, generate almost all of their lift on the downstroke. They pull in their wings toward their bodies to reduce the amount of negative lift they produce while flapping upward.

Awesome design in nature!

So the question I have from reading the article is this. Do birds and flying insects have a recent common ancestor? I don’t have too many friends who can answer this for me, but I asked one of them and they both said there is no recent common ancestor for hummingbirds and flying insects. So this looks like another example of convergence – common design in two animals that don’t share a recent common ancestor.

Commentary

What’s stopping young adults from getting married?

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Before we get to the study, I wanted to share something that a Christian male friend shared with me about yesterday’s post on the crazy feminist mommy porn author.

He writes:

I saw your post about the woman who “fell in love” with her fantasy character she created. I’m a victim of this.

My ex-wife is a succeeding indie author. She jets off and hangs with NYT best-selling authors, rubs elbows with a lot of fantasy romance and erotica authors. She reads, oh, roughly 200 +/- smut books per year.

This area is the flip side of the porn coin, and it’s not getting the attention it should. If I told my story and part of the reason for the marriage destruction, it would be an “easy sell” to those who understand that women who fantasize about these fictional characters (even the images on the covers) are doing the exact thing men are doing when they fantasize over airbrushed skin images and other skin porn.

Many will argue it’s not the same thing, but that is preposterous. Husbands are competing with fantasy novel cover art and fantasy characters. It’s every bit the same as wives competing with unreal images or even real ones where they compete with younger, more fit, kinkier, etc., etc.

Men get cheated on all the time. Through this stuff. My ex developed an online romance through it all. Exchanged erotic pictures, emails, texts, Skype, on and on and on.

I discovered travel plans, fake email accounts, it was awful.

This is the third time that I have been sent divorce stories like this by conservative, Christian male apologists on Facebook.

The first time, the wife hit a certain age then just went nuts and started working out a ton and trying to look younger and younger. Then as she got success as a personal trainer and attention for all the photos she posted, she just divorced her husband outright to focus on her business and more glamorous photos. And they had children. The second time, the wife just went nuts into new age beliefs and yoga and divorced her husband, and they had children too. So we are talking real destructive craziness here.

This is why I put so much emphasis on building up a woman first by leading her to learn apologetics, conservative politics and economics, and so on. If she is not willing to learn and grow in things that are good for her and that help her to be a better wife and mother, then you know that her heart is not in the difficult realities of married life and the roles of wife and mother. She will be one of these women who wants to be happy and thinks that happiness means getting rid of family obligations and responsibilities to her man and her kids. Men should ensure that their prospective mates reject the Disney princess perception that relationships should be all about them and their needs – living happily ever after with no hard work or effort. Helping a woman to think logically and argue using evidence is one way to insulate her from the foolish, emotion-driven culture that threatens marriage.

Anyway, with that said, here is the new article from Family Studies.

Here’s the introduction:

In interviews we conducted with working-class young adults, my wife and I were surprised by the strength of their desires to have a long-lasting marriage and stable family life. But many of them were far from realizing those aspirations. Why?  The wide-ranging challenges that frustrate their aspirations, which we must understand in order to find effective solutions, fall into four rough categories: family-of-origin, philosophical, psychological, and financial.

[…]Conflicted about marriage. This crisis of trust, in turn, informs young adults’ conflicted thinking about marriage. As Amber and I described in a previous post, their experiences of family fragmentation sharpen their desire to get and stay married, on the one hand, but on the other hand it also shakes their confidence in the durability of marriage. As a result, many young adults find themselves in tenuous cohabiting relationships, wanting to say “I do” eventually but too uncertain to do so now.

[…]The fixed love mindset. As Amber discussed here, the philosophy of love that young adults inherit from cultural scripts, like Hollywood chick flicks, works against their own aspirations for committed, permanent love. Instead of a “growth mindset” about love that focuses on working through possible differences, these stories about love transmit a “fixed mindset” that focuses on immediate and perpetual compatibility—the absence of which probably indicates that a couple is no longer meant for each other. Young adults with a fixed mindset about love tend to say things like “love is effortless,” or, as one separated spouse put it, “I love him, but I’m not in love with him. I love him as a friend, as the father, but I don’t feel that connection as I used to.”

[…]Extreme individualism. Despite the common challenges that confront working-class young adults, the idea that “my relationship is no one else’s business” prevents them from thinking about marriage and family life as a public issue that demands our common efforts.

For instance, Anthony knows first-hand the painful effects of divorce—his parents divorced when he was ten—and he speaks eloquently about how divorce imposed burdens on him and his other friends from divorced families. So what does he believe we can do about the rising number of children raised in fragmented families?

“I don’t think there’s a thing we can do about it,” Anthony told us. “And that’s kind of the American way—this is a free country, and free this and free that. But it’s your life, and not too many people care about other people’s lives. As long as it’s not theirs, they don’t care.” The result of that attitude, however, is loneliness and helplessness in the face of an urgent social problem.

One of the questions I sometimes discuss with my male friends is “what is the female equivalent of pornography”? It has to be something that teaches women to have unrealistic expectations of men. My answer is that it is this culture that praises irrationality, thrill-seeking, travel and emotionalism over planning, morality and hard work.  Many women today seem to really believe that men are there to provide them with fun, thrills and dreams, instead of with long-term achievements that take planning, sacrifice, problem-solving and hard work. The mommy-porn novels that so many women find attractive just feeds these marriage-destroying delusions. There is even a Christian version of the emotional craziness where women are urged to follow their hearts, and somehow, God will make their bad choices and risky plans work out.

As the story above from my friend shows, mommy porn is also an affair-creator and a marriage-killer. About 70% of divorces are initiated by women, and lesbian couples have the highest rates of relationship breakdown. Feministy women need to be taught (hopefully by their fathers) that entering into a relationship means an opportunity to commit to serve the other person self-sacrificially in order to build something that lasts – it’s not about getting your own way and feeling good. Many women today seem to enjoy choosing the wrong men in their teens and 20s, and then when the right man comes along later, they want to back away from the demands of a serious relationship with him and go on their merry way.

This is why I tell everyone to stay away from premarital sex and cohabitation – it has a huge impact on a person’s willingness to commit. Many women today seem to think that they can choose any man based on superficial criteria (he is fun and handsome and funny) and then make him commit by giving him sex. WRONG. You have to choose the right man by carefully evaluating him for marriage-related responsibilities. A man who can do husband tasks, (e.g. – providing, loving over the long-term, teaching others to defend their faith), is a man who is capable of marriage commitment. The experience of investing in the wrong men and then failing ruins a woman’s ability to trust and commit. They mentally and emotionally check out of subsequent relationships and start looking for excuses to get away from commitment. It creates an attitude of wanting to sabotage the relationship. They focus on scanning for the exits instead of on investing, communicating and problem solving.

UPDATE: The friend who wrote me had this in response to the post:

I carried her physically after her surgery, disciplined her children effectively, managed academics (got one through high school who wouldn’t have made it without me), was at her side for weeks praying for her son who nearly died in an accident, supported her in her accounting career and her writing, served all of her physical needs (yeah, THAT way!), sacrificed rural life and property for the castle she wanted . . .

You get the idea. None of it mattered. What mattered in the end was her chasing a dream.

I’m left with the castle I don’t want or need, and kids I love have been spirited off to a new life.

Sad.

Commentary

Where is the outrage in the black community for black-on-black crimes?

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Walter Williams
Walter Williams

A recent editorial by George Mason University professor of economics Walter Williams.

Excerpt:

Each year, roughly 7,000 blacks are murdered. Ninety-four percent of the time, the murderer is another black person.

According to the Bureau of Justice Statistics, between 1976 and 2011, there were 279,384 black murder victims. Using the 94-percent figure means that 262,621 were murdered by other blacks.

Though blacks are 13 percent of the nation’s population, they account for more than 50 percent of homicide victims. Nationally, the black homicide victimization rate is six times that of whites, and in some cities, it’s 22 times that of whites.

Coupled with being most of the nation’s homicide victims, blacks are most of the victims of violent personal crimes, such as assault and robbery.

The magnitude of this tragic mayhem can be viewed in another light. According to a Tuskegee Institute study, between 1882 and 1968, 3,446 blacks were lynched at the hands of whites. Black fatalities during the Korean War (3,075), Vietnam War (7,243) and all wars since 1980 (8,197) come to 18,515, a number that pales in comparison with black loss of life at home.

It’s a tragic commentary to be able to say that young black males have a greater chance of reaching maturity on the battlefields of Iraq and Afghanistan than on the streets of Philadelphia, Chicago, Detroit, Oakland, Newark and other cities.

This is not even to mention abortion, which disproportionately affects blacks. Yet it is overwhelmingly supported by blacks who vote more than 90% Democrat. Maybe we should be more focused on black-on-black crime and black genocide, since these are bigger problems.