-
-
----------------- - 1827 - Gravity Waves discovered using the LIGO telescopes.
-
- The ripples in space-time were gravitational waves generated 1.3 billion lightyears away by two orbiting Blackholes. The Blackholes were 29 and 36 Solar Mass each
6 miles in diameter spiraling into each other and merging into a single Blackhole. That massive collision generated gravity waves felt a billion lightyears away.
-
- As the Blackholes spiral into each other they are loosing energy by generating gravitational waves like a star looses energy emitting light waves. These waves left the Blackholes when the Earth had only multi-cellar life 1,300,000,000 years ago. The Blackholes merger lasted only a few milliseconds but the collision released 50 times more energy than all the power output of all the stars put together.
-
- The gravity waves were detected by two identical interferometers. One in Louisiana and the other in Washington state. Two separate detections at the same time in these separate locations were needed to confirm results.
-
- At each location a laser beam is split so it travels down a pair of perpendicular arms each a 2 ½ mile vacuum tube. The beam bounces off a mirror and returns to the origin. When the interferometer is set up the distances are identical and the light waves cancel each other. ( See Review on LIGO for more details).
-
- A passing gravity wave will stretch space-time in one direction and compress it in the other perpendicular direction. When the arms are no longer identical an interference signal is generated at the origin. This interference is so sensitive it can detect a change of 1/10,000th the width of a proton.
-
- In addition to confirming gravity waves truly exist the results are proof binary Blackholes also exist. Future detections are expected to locate orbiting Neutron stars, and Blackholes devouring a Neutron star, and even relic gravity waves produced by the Big Bang.
-
- We now have a new way looking at the Universe Our vision started with visible light. Technology has expanded it to radio waves, microwaves, Gamma Rays, Neutrinos and now to Gravity Waves. New ways of seeing.
-
- Even more amazing to me was that Albert Einstein predicted these Gravity Waves existed 100 years ago, all just using his brain. His discovery was not from technologies latest telescopes but through his imagination scratched out on paper. He envisioned the physical process governing matter-energy and space-time while formulating abstract mathematical expressions corresponding to this new reality. He died in 1955, I was a freshman in high school, I still remember the news and impact it had on the school.
-
- It all started in 1915. Before then space was featureless and changeless with the math defined by Isaac Newton. Einstein’s 4 papers merged matter and energy with E=mc^2. Then he merged matter and space-time with gravity acting along curved paths of space-time. Mass was seen to curve space-time while space-time was seen telling mass how to move.
-
- General Relativity was a new mathematical vision for the entire fabric of the Cosmos. It required that the laws of nature to appear the same to all observers regardless of their relative motion. The speed of light was everywhere constant at 186,282 miles per second for all observers.
-
- In 1919 his theory that gravity curves space was confirmed by a solar eclipse. The light beam from a distant star behind the Sun changed positions as the beam passed closest to the massive Sun.
-
- Anything moving through a gravitational field follows a curved path in space-time. To visualize this imagine two observers leaving the equator on Earth walking the shortest path to the North Pole. The paths would correspond to the meridians. The two would start out separated by some distance following different curved meridians. As they approach the Pole they would grow closer together. Their travel northward would appear to the observers as gravity pulling them together while simply following the shortest paths on the meridians.
-
- Today astronomers are using Gravitational Lensing to detect unseen mass. To discover Dark Matter that envelops every galaxy. Einstein proposed this phenomenon in 1912. It was first observed in 1979.
-
- In 1915 Einstein calculated the orbit of the planet Mercury. Using Newton’s math astronomers could not explain why the perihelion of Mercury’s orbit shifted forward by a slight amount ( less that 2 degrees of arc per 100 years.) 43 arc seconds could not be explained being due to gravity effects exerted by other planets. Using Einstein’s math in General Relativity the math exactly corrected for the 43 arc-seconds.
-
- General Relativity also explained the expanding Universe and space-time’s bottomless pits, Blackholes. General Relativity is even used to correct GPS measurements. The Global Positioning Satellites calculated positions on Earth by simple triangulation . But, the answers have to also be corrected for satellite motion while being in less gravity. Without GR corrections locations would be off by miles. With corrections GPS can be within a few feet.
-
- Einstein’s imagination showed that acceleration and gravity had to be two sides of the same coin. In an accelerating rocket ship with no windows astronauts could not detect the difference. Inertia and gravitational mass are equivalent. For these proposals to be true the math required space and time to be different for different observers. Every event had a location due to be specified in both time and space to yield a mathematical description that two observers could agree on.
-
- To derive the math Einstein needed to us “ new “ math. He had to abandon Euclidean Geometry. Gravity distorted straight lines and angles. Mass and energy distort the shape of space-time. The new math instead used “tensors” to describe space and time. Tensors are a type of vector that could describe a gravitational field. Like velocity is a vector described by both speed and direction, example: 60 miles per hour due north.
-
- General Relativity tensors describe geometry of space-time. The equations show matter and energy density as the source of the gravitational field. But, the equation is unstable. It says the Universe must by expanding or collapsing. It would be like a pencil balanced on its point. The slightest disturbance and the pencil would fall in one direction. To stabilize the equation Einstein added the Cosmological Constant term.
-
- Decades later the Cosmological Constant is interpreted as the Dark Energy responsible for the Universe’s accelerating expansion.
-
- Karl Schwarzschild used Einstein’s equations to define a “ critical radius” , a limit in which mass could be compressed to where the gravity ( space-time) would fold back on itself. Even light would not have the escape velocity needed to get out of the gravity of the Blackhole.
-
- Headlines, February 12, 2016, “ Einstein’s was right about gravity ripples” Scientists capture audio proof of gravitational waves, ripples in space-time , created by massive disturbance of mass-energy in the Universe.
-
- LIGO detected gravity waves generated by the collision of two Blackholes 1.3 billion lightyears away. The waves were detected in two locations simultaneously. The chirp of sound waves were incredibly tiny, equivalent to a thumb width wavelength compared to the diameter of the Milky Way Galaxy.
-
- General Relativity has brought us these concepts by shortening space and slowing time as velocity increases approach the speed of light. Then, time slows down for clocks in GPS satellites. Traveling at light speed, time stops all together.
-
---------------------------------------------------------------------------------------
- Request these Reviews to learn more:
-
- #1754 - How gravity affects the Earth and the Moon, the galaxies and Blackholes.
-
- #1751 - All bodies accelerate the same in a gravitational field regardless of mass or composition.
-
- #1456 - Our Moon is 1/4th the size of the Earth but only weighs 1% as much.
-
- #43 - Studying gravity waves will allow us to peer far back into the beginning of space-time, to the birth of the Universe.
-
- #1534 - Gravity lensing. The math involved.
-
- #1470 - Loop quantum gravity. Are there atoms of space-time?
-
- #588 - Gravity Probe B. The experiment to prove the frame dragging effect of a rotating mass, like the Earth.
-
- #1728 - Gravity waves. Measuring the size of the Universe.
-
- #1686 - Using Baryon Oscillations to measure Cosmic distances.
-
- --------------------------------------------------------------------------------------
----------------- RSVP, Pass it on to whomever is interested. ----------------
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email comments, corrections, request for copies or Index of all reviews
- to: ------- jamesdetrick@comcast.net ------ “Jim Detrick” -----------
- https://plus.google.com/u/0/ -- www.facebook.com -- www.twitter.com
----- 707-536-3272 ---------------------- Monday, February 15, 2016 -----
------------------------------------------------------------------------------------------
No comments:
Post a Comment