Saturday, February 13, 2016

Gravitational Waves -- Understanding the Impact of Einstein For a Simple Human

I love science, and I also like to consider space, time, and all of the mysteries in the universe. Right now everyone is extremely excited about the confirmation of gravitational waves, something I read that Albert Einstein first mentioned in 1916 in his General Theory of Relativity.

I know scientists have been racking their brains over this concept since then. However, I admit my stupidity about the subject, and I thought I might try to understand it myself by writing today what I consider to be the Dummy's Guide to Gravitational Wave blog entry.

First of all, I want to acknowledge Einstein. How intelligent was this man? His theories solved centuries-old problems in physics and rocked even non-physicists' view of the world. Time and again, the question is posed about his I.Q. Although he was not measured for I.Q., I have heard estimates that he would have easily scored 160-180 on Intelligence Quotient.

However, Einstein was much more than a genius; he was one of the most influential people who ever walked the planet, a true visionary. Robert Oppenheimer summarized his impression of him as a person: "He was almost wholly without sophistication and wholly without worldliness... There was always with him a wonderful purity at once childlike and profoundly stubborn."

"The true sign of intelligence is not knowledge but imagination." --Albert Einstein

Gravitational Waves

I am taking this explanation very slowly because, to be honest with you, my simple mind often fails to comprehend detailed scientific theory about space and time. I often get lost in the translation. But, here goes.

Albert Einstein predicted over a century ago that something called “gravitational waves” wouls enable mankind to listen to the stars, and not just see them, but he also calculated that they would be extremely feeble, so much so that he thought they would never be detected.

It seems up until now, gravitational waves were only “thought to exist,” and this recent discovery is so important since it proves with the most convincing evidence, short of direct detection, that a key part of Einstein's theory of general relativity was right 100 years ago.

The Discovery

When did scientists confirm the existence of gravitational waves?

They were detected on September 14, 2015, at 5.51 a.m. by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana; and Hanford, Washington. The signal they observed came from the collision of two black holes about 400 megaparsecs (1.3 billion light years) from Earth.

Researchers believe this revolutionizes our understanding of the most violent events in the universe. Analysis of the waves suggests they originated from a system of two black holes, each with the mass of about 30 Suns, that gravitationally drew closer to each other.

The dense objects whipped up to nearly the speed of light before colliding, sending out a stupendous release of gravitational wave energy that eventually reached the Earth, 1.5 billion light years away. As the gravitational waves warped space-time within LIGO's gargantuan twin detectors, its exquisitely sensitive instruments registered vibrations on the order of thousands of the diameter of a proton

(“Space-time ripples could bring stars within earshot.” Times Syndication Service. February 13, 2016.)

Understanding the Discovery

OK, here is the big news explained in very elementary form.

In his theory of special relativity, Einstein determined that the laws of physics are the same for all non-accelerating observers, and he showed that the speed of light within a vacuum is the same no matter the speed at which an observer travels.

As a result, Einstein found that space and time were interwoven into a single continuum known as space-time. Events that occur at the same time for one observer could occur at different times for another.

As he worked out the equations for his general theory of relativity, Einstein realized that massive objects caused a distortion in space-time.

Try to use this model for better understanding ...

    1. I am told to imagine setting a large body like a bowling ball in the center of a trampoline (or some other elasticated cloth).
    2. The bowling ball would press down into the fabric, causing it to dimple.
    3. Then, if I rolled a marble around the edge of the same trampoline that held the bowling ball, it would spiral inward (be drawn towards the bowling ball) as the Earth is to the Sun.
    4. However, the marble would not fall into the bowling ball as long as it kept moving at sufficient speed. Gravity, argued Einstein, was not an attractive force between bodies as had been previously thought.
    5. It was not a force, as Sir Isaac Newton had supposed, but a consequence of the distortion of space and time, conceived together in his theory as “space-time.” Gravity is simply the motion of objects following the curvaceous lines of the dimple. Any object distorts the fabric of space-time and the bigger it is, the greater the effect.
    6. Note – the fabric of the trampoline would undulate and oscillate, like ripples on a pond. The marble would tend to lose energy as a result of causing these oscillations, and the bowling ball and the marble would ultimately come closer and closer to each other and finally collide.
    7. If I could watch a gravitational wave head-on as it moves toward me, I would see it alternately stretching and compressing space, in the up–down and left–right directions.
It is believed gravitational waves can travel in empty space -- and they do so at the speed of light. The payoff for understanding the universe … Just as a bowling ball placed on a trampoline stretches the fabric and causes it to sag, so planets and stars warp space-time - a phenomenon known as the “geodetic effect.”

Thus, the planets orbiting the Sun are not being pulled by the Sun; they are following the curved space-time deformation caused by the Sun. The reason the planets never fall into the Sun is because of the speed at which they are traveling. Of course, the Earth is not stationary – the planet spins, and the spin slightly twists the dimple, pulling it around into a 4-dimensional swirl So, according to the theory, matter and energy distort space-time, curving it around themselves.

The rest of the theory is that “frame dragging” theoretically occurs when the rotation of a large body “twists” nearby space and time. Frame-dragging states that as the world spins, it drags the fabric of the universe behind it.

      (Anushka Asthana and David Smith. “Last Einstein was right: space and time bend.” The Guardian. April 14, 2007.)

      Relating to Black Holes and the Big Bang

      The strongest waves are caused by the most cataclysmic processes in the Universe - black holes coalescing, massive stars exploding, or the very birth of the universe some 13.8 billion years ago. Scientists believe detecting gravitational waves is important because they may hold the answer to the origins of the universe.
      One of the consequences of Einstein’s general theory of relativity was a solution in which space-time curved so much that even a beam of light became trapped. These solutions became called black holes. Black holes are believed to form when stars die and their massive bulk collapses inward, creating intense gravitational fields. They are objects of extreme density, with such strong gravitational attraction that even light cannot escape from their grasp if it comes near enough.
      Because general relativity says that the curvature of space-time is equivalent to the force of gravity, the singularity of a black hole has infinite gravity. Any matter going into a black hole would be ripped apart by this intense gravitational energy as it neared the singularity. According to this theory, all of the matter that we know today may have came out of such a point.

      Apparently, these miniscule gravitational waves the researchers now detect were “born” during what is considered the Big Bang. The theory is that the Bang occurred as two black holes, one 36 times the mass of the Sun and the other 29 times the mass of the Sun, lost energy through their emission of gravitational waves and were drawn closer to each other. As they came closer, the spinning became faster and they emitted even more gravitational waves and lost even more energy. By the end of 20 millisecond of data, they were whirling so fast that each orbit lasted just a few milliseconds; the black holes had whipped up to nearly the speed of light before they collided and merging into one huge black hole 62 times the mass of the Sun. This is believed to have happened 1.3 billion light-years away from Earth.

      “The total power output of gravitational waves during the brief collision was 50 times greater than all of the power put out by all the of the stars in the universe put together,” Kip Thorne of Caltech, one of LIGO’s founders, told New Scientist.

    (R. Prasad. ”Listening to the chirps of gravitational waves.” The Hindi. February 13, 2016.)

    Before this latest discover, no one knew for sure if black holes actually merged together to create even more-massive black holes, but now there's physical proof. An entirely new realm of information is available to spur further investigation.

    Nature reports interesting news:

      “The waves are the confirmation of a cornerstone theory of the standard picture of cosmology. This theory, called inflation, says that during the first moments of its existence, the Universe underwent a brief period of exponential expansion.

     “During inflation, the Universe's temperature — and thus the energies reached by elementary particles — were trillions of times higher than can be achieved in any laboratory, even in particle accelerators such as the Large Hadron Collider at CERN, near Geneva, Switzerland.

    Because inflation is a quantum phenomenon and gravitational waves are part of classical physics, gravitational waves establish a link between the two, and could be the first evidence that gravity has a quantum nature just like the other forces of nature.”
    (“All you need to know about gravitational waves.” Nature. March 17, 2014.)

    LIGO team member Vassiliki Kalogera said, "It's like Galileo pointing the telescope for the first time at the sky. You're opening your eyes — in this case, our ears — to a new set of signals from the universe that our previous technologies did not allow us to receive, study and learn from."
      (Calla Cofield. “Gravitational Waves: What Their Discovery Means for Science and Humanity.” Yahoo News. February 13, 2016)
    The significance? Everything we know about the universe comes from observations made through telescopes and particles of light. But unlike light, gravitational waves can pass through the universe unobstructed, so they carry information that we cannot obtain otherwise.
    According to Nature, the “Earth should be awash with such waves — but by the time they reach us, the disturbances that they produce are minute and cannot be detected.”
    LIGO is particularly sensitive to gravitational waves that come from violent cosmic events, such as two massive objects colliding or a star exploding. The observatory has the potential to locate these objects or events before light-based telescopes can do so, and in some cases, gravitational-wave observations could be the only way to find and study such events.
    As LIGO's sensitivity continues to improve, the instrument could be sensitive to black holes that are 100, 200 or even 50 times the mass of the sun that are further away from Earth. "There could be a really nice discovery space that opens up once we get out there," he said. The findings can open up new research on things like supernovas and neutron stars.

    My Take

    The search for proof of gravitational waves is upon us. The new discovery by LIGO seems to confirm some very old knowledge acquired from one of history's greatest minds. It is always a little frightening to find confirmation that the human race is clinging to a planet that is merely a speck in time and space. We better understand that our fragile existence is part of an infinite creation.
    To me, curiosity and knowledge will always make us look to the heavens in wonder of what it all means. Since science involves the minds of man speculating about answers of creation, new discoveries will continue – some will remain and some will be disproved in the future.

    Even Albert Einstein begged for answers, so who am I to understand brilliant theory? I try, and I partly succeed. In other words, I understand to the best of my very limited ability. I do keep an open mind even though most deep science befuddles me. Yet, in my limited human condition, I am still in awe of creation and very much humbled by being a part of God's plan – a part of it that exists with a questioning brain and a submissive heart.

    "The most beautiful and most profound experience is the sensation of the mystical. It is the sower of all true science. He to whom this emotion is a stranger, who can no longer wonder and stand rapt in awe, is as good as dead. To know that what is impenetrable to us really exists, manifesting itself as the highest wisdom and the most radiant beauty which our dull faculties can comprehend only in their primitive forms - this knowledge, this feeling is at the center of true religiousness.”

    --Albert Einstein 


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