摘录

“一个人在精神上足够成熟,能够正视和承受人生的苦难,同时心灵依然单纯,对世界仍然怀着儿童般的兴致,他就是一个智慧的人。”

我花了41年的时间明白了一个道理:
“决定孩子成功的最重要因素,不在于我们给孩子灌输了多少知识,而在于我们是否帮助孩子获得了以Grit为首的七项重要的性格特质。

Grit坚毅、Zest激情、Self-control自制力、Optimism乐观态度、Gratitude感恩精神、Social intelligence社交智力、Curiosity 好奇心。

不要在感觉糟糕的时刻结束。在遭遇挫折的那一刻就立即放弃,可能意味着你将错过最棒的时刻-比如最终打进了制胜一球或在演出结束后听到雷鸣般的掌声。”

“世界上只有一种英雄主义,

就是看清生活的真相之后,

依然热爱生活!”

“生活是否永远艰辛?

还是仅仅童年才如此?

里昂回答:总是如此。
生活如山,

有人岁月静好,

有人负重前行。
生活不止眼前的苟且,

还有诗和远方的田野。”

“所谓细节便是,你对达官显贵和保姆乞丐持一样的心,呈一样的笑。不以物喜,不以己悲。你拥有一颗悲悯的情怀于万事万物。你保持品行的高贵却又于高贵处平凡得一如脚下的泥土。”

“此生如若有你,何惧岁月老去?

只要我能时时看着你,

哪怕你的脚步,

如孩子般蹒跚,

我也会像,深海的鱼一样,

幸福、陶醉、沉迷……”

”他令我意识到爱并不是凝固不动的东西。正相反,爱是永无止境的探索和学习,两个人都应该尽力鼓励和引领对方见识更多更美的东西,成长为更加丰富与宽容的人。”

Are Singularities Real? (ZT)

Are Singularities Real?

It’s hard to imagine infinity: something that is, by definition, larger than everything you can imagine. Physicists have to deal with the unimaginable every day, and have the tools to do so. But does their math describe reality?

Mathematicians have found a way to pack infinity into manageable equations and theorems as part of a class of mathematical oddities called “singularities.” To a mathematician, a singularity is simply a point where a function breaks down, as 1/x does when x gets close to zero. The defining property of a singular point is that it’s impossible to predict what happens beyond it. But are the singularities in mathematicians’ equations just an abstract concept? Or do they occur in nature?

spiral_620

Flickr user slightly-less-random, adapted under a Creative Commons license.

The word “singularity” was popularized in a 2005 book by Ray Kurzweil, who uses it to refer to an impending revolution in artificial intelligence (AI). According to Kurzweil, once artificial intelligences become smart enough to improve their own kin, a feedback loop will lead to a runaway process. After that, all bets are off: nobody knows what will happen. But Kurzweil’s technological singularity, if it comes to pass, is not a true singularity. There is no law of nature that limits our ability to predict what might happen once AI evolves past the “singularity” point; we’re confined instead by the limits of the human mind.

Though they sound exotic, mathematical singularities are actually common in solutions to all but the simplest equations in physics. The formation of shock waves and cracks, and even the motion of a billiard ball bouncing off a hard wall, can contain singularities. While these singularities fulfill the mathematical definition, they aren’t physically real either: they arise from idealized assumptions that physicists make to force the messy world of reality into the neat one of mathematics. In reality, no crack is perfectly sharp, no wall is perfectly hard, no shock wave is perfectly localized.

Here is another example: Turn down the water on your kitchen tap until it starts dripping. The hydrodynamical equation describing the surface of the drops has a singularity at the pinching point: you cannot from one drop predict where the next will be. But this singularity, too, can be avoided by applying a more suitable theory. Using atomic physics, you could, in principle, calculate exactly how the water stream breaks apart on the level of single atoms. All these singularities are thus artifacts of using a theory outside its range of applicability, on distances so short that a more precise theory would be needed.

The one type of singularity that might be real—that physicists don’t know how to resolve—is the one that appears in Einstein’s theory of General Relativity when matter collapses under the gravitational pull of its own weight. There is nothing in General Relativity that then stands in the way of this collapse. It will continue until all the matter is located at a single point of infinite matter density and infinite space-time curvature: a singularity.

The singularities that appear inside black holes pose a big problem for physicists. Crossing a black hole’s event horizon is like jumping into a river upstream of a waterfall, at a place where the water flows faster than you can swim. Whatever you do, you’ll end up being pulled down the waterfall. Likewise, whatever falls into a black hole is pulled down into the singularity. And once there, it reaches its end.

At the black hole singularity every particle’s path seems to dead-end. Space-time stops at the singularity, and nobody knows what happens at this point.  Yet we cannot imagine how something can just end. The black hole space-time is for this reason referred to as “incomplete,” but in General Relativity there is no way to complete it. This is the origin of the black hole information loss problem: It is the horizon that makes the information irretrievable, but it is the singularity that ultimately annihilates it. This is a big headache for physicists because such annihilation of information is incompatible with quantum mechanics.

The Big Bang is a singularity, too. If you run the expansion of the universe which we observe today backwards, then the density of matter must have been larger the younger the universe was, all the way back to an initial moment where the density must have been infinitely high: it must have been singular.

Are these singularities real, or just vestiges of the gap between math and reality? Based on their experience with other systems, physicists suspect that the singularities in General Relativity are a warning, a tip-off that we need another theory to describe the physics in the extreme situations when gravity is very strong and its quantum effects are very large. Physicists still don’t know how to describe the quantum effects of gravity, but we hope that by doing so we will one day resolve the singularities.

None of our measuring devices can show an infinite value. Not only have we never observed it, we don’t know how to observe it—we don’t know how to even give meaning to such an observation. Physicists therefore treat singularities as symptoms of an ill theory in need of a cure. It would be possible to mathematically deal with the singularities. But based on past experience and intuition, for all we know so far, nature doesn’t like sudden ends. Does nature make an exception for black holes? Right now, we just don’t know.

Why Is Our Universe Filled With Spirals? (ZT)

Why Is Our Universe Filled With Spirals?

spiral-galaxy

The spiral galaxy M81 as seen through a combination of X-ray, optical, ultraviolet and infrared imaging techniques. 

Can you tell me why a spiral design seems omnipresent in our natural world and in the universe? I see this pattern in plant tendrils, flowers and leaves, pinecones, the unfurling of needles, as well as in astronomy. 

— Dorothea Fox Jakob, Toronto

The short answer is, sadly, we don’t really know. Nature does seem to have quite the affinity for spirals, though. In hurricanes and galaxies, the body rotation spawns spiral shapes: When the center turns faster than the periphery, waves within these phenomena get spun around into spirals.

The florets in a sunflower head also form two spirals, but there’s no rotation here — it’s simply an efficient packing solution for the plant. With 55 florets running clockwise and 34 counterclockwise, the sunflower is an example of a pattern of numbers called the Fibonacci sequence, named after the medieval mathematician who popularized it. It’s a simple pattern with complex results, and it is often found in nature.

The Fibonacci sequence starts with 0 and 1 and increases based on the sum of the previous two numbers: 0, 1, 1, 2, 3, 5, 8, 13, 21 and so on. You’ll notice that both groups of florets in a sunflower match Fibonacci numbers — as do the number of rows in a pinecone, the arrangement of leaves on a stem and many other natural formations. In fact, the spiral shape itself is built upon the rapidly increasing pattern of the Fibonacci sequence.

But since nature’s swirly patterns result from a few different mechanisms, the phenomenon is likely coincidence more than some underlying physical property of the universe. Nevertheless, it is striking that many natural examples follow this number sequence, either broadly in their curling shape or with their actual numerical values.

[This article originally appeared in print as “Ask Discover.”]

Science

NASA released amazing high definition footage of the sun.

What makes the gut microbiome stable?

Outflanking RSV

Vitamin C could target some common cancers

Vitamin C kills tumor cells with hard-to-treat mutation

Microbes aid cancer drugs

World Poverty, Immigration & Gumballs, by Roy Beck

Your Pill Is Printing: FDA Approves First 3-D-Printed Drug

This Is Your Brain on Exercise: Why Physical Exercise (Not Mental Games) Might Be the Best Way to Keep Your Mind Sharp

Climate change can impact what we eat – increasing CO2 leads to ocean acidification, which means we could have 48% less scallops, 45% less oysters and 32% less clams for our grandchildren in 2100.

Einstein’s genius changed science’s perception of gravity

“Lights all askew in the heavens, men of science more or less agog,” proclaimed one of the most famous newspaper headlines in science history, in the Nov. 10 New York Times.
https://www.sciencenews.org/article/einsteins-genius-changed-sciences-perception-gravity

As expressed decades later by the physicist John Archibald Wheeler, mass grips spacetime, telling it how to curve, and spacetime grips mass, telling it how to move.

   
Explaining Mercury’s odd orbit

 
Bending light

The Einstein Field Equation with Lambda

Gμν + Λgμν = = 8πTμν

  
Gravitational collapse

  
Gravity’s pull on time

  
General relativity and GPS

  
Geodesics

Amazing similarities between Celestial Bodies and Microorganism

I am amazed by the comparison between 3 celestial bodies and 3 microorganisms. Can you tell inner space from outer space? The answer is below.

The heavens declare the glory of God; the skies proclaim the work of his hands. — Psalm 19:1

I have a conjecture: Since God made light and separated from darkness on the first day, on the fourth day, he made sun, moon and stars, so if an astrophysicist wants to know the origin of the universe, he should study the light deeply.


inner-outerspace

09/27/2015 Lunar eclipse ended

7:07-11:30pm US CDT , moon returns white and the lunar eclipse ended. See you again in 2033! When I look up to the sky, I am amazed by His creation. The magnificent universe praises His omnipotence.
7:07pm 与11:53pm 09/27/2015 US CDT 的月亮都是那么皎洁。宝宝贝贝在梦乡中不知道大了14%的圆月和血月曾经发生过,不知道月亮与地球亲密接触过(35万多公里),不知道月亮在地球的阴影里呆了3小时20分钟。这里乌云遮着月亮,Murfreesboro ,甚至Knoxville 的我们也看不到什么。可是在天空中它静悄悄的发生了。我用这个app记录了整个过程。12:01am,新的一天开始了。