Posted on 12/20/2016 7:24:12 PM PST by MtnClimber
The discovery of gravitational waves, announced earlier this year, marked the ultimate test of Einstein’s general theory of relativity. Einstein published his theory in the form of 10 abstract equations 101 years ago. The equations did away with Newton’s theory of gravity and replaced it with curved space and warped time.
Within weeks, Karl Schwarzschild found a solution to Einstein’s equations. His conclusion was astonishing and almost unbelievable: it told us that time depends on altitude and that matter can create holes where space and time come to an end.
A few months later, Einstein himself found a solution to his own equations. This solution described waves in the curvature of spacetime that would ripple out at the speed of light whenever masses accelerated around each other.
For its first half-century, Einstein’s theory was controversial. Were the waves real or mere mathematical artefacts? Do gravitational waves deposit energy? Are the black holes hypothesised by astronomers the same black holes that Schwarszchild predicted, or are they some other very dense agglomerations of matter?
Over the past 40 years the evidence has mounted that gravitational waves actually exist and that black holes are the real thing. Thousands of physicists believed the theory well enough to devote years inventing technology for making the exquisitely sensitive detectors required to prove the theory.
Yet when the waves were finally discovered, it still came as a shock. The shock was to suddenly know what for years had been a belief and a hope..........
All shared the vision that we owe it to our children to teach our best understanding of the nature of our universe, rather than the obsolete 19th-century science that still dominates our school curriculum.
We heard about three countries that are pioneering Einsteinian physics in the classroom: South Korea, Norway and Scotland.
(Excerpt) Read more at realclearscience.com ...
I was lucky to have really great physics teachers. I wish they had taught relativity too. I knew nothing about it until college.
We quit teaching cursive writing to our kids. many can’t balance a checkbook.
Science is the pedestal of knowledge.
I study as much as I can about all things physics and science related, unfortunately so much of it in the form of podcasts and written material is by dumb as rocks “I have a PhD therefore I AM smarter than you, harumph” types that believe in global warming, that you really need to study all angles of a particular subject and as far back as writings on the subject go to get a good understanding of the topic.
Since General Relativity is a college post-graduate level course, and the average high school graduate reads at a 4th grade level, its not clear to me what they’re proposing.
many can’t balance a checkbook. We call them CONGRESS.
I had a prof in college that, during an electromagnetics lecture, proceeded to derive Einstein’s E=MC^2 from Maxwell’s equations.
As I was never worth spit at vector calculus, I was more that a bit impressed.
I’m all for teaching (some) kids Einsteinian physics.
But the article seems to imply that Newtonian physics is no longer worth teaching and I would have to disagree. It works to explain the observable world that the vast majority of us experience and is pretty easy to understand.
Of course, where Newtonian physics is lacking, Relativity should be discussed. But how often does 99.5% of the population experience the cases where Newtonian and Einsteinian physics diverge? It’s like saying every cashier at Walmart needs to learn calculus.
Just MHO. If those in the know believe I’m wrong, I’d surely appreciate being enlightened.
As an electrical engineer by training I had courses in general relativity and quantum physics as an undergrad and a graduate. However, I am stumped by this assertion. Could someone elaborate on what is meant by this?
It seems odd on the surface since altitude is an attribute of a body in its relationship to the surface of another body. I don't understand how that can be related to time unless it is related to the curvature of space related to gravitational fields.
I think you’re on thhe right track. What would have worked well for me is more independent study mini-classes that would allow a student to pursue specific interests without the complete professional-track of courses. This example is perfect as I was fascinated to know more about General Relativity but couldn’t get into the class(es) without having done all the prerequisites as I was not on the Physics major track. In the end I self-taught enough to satisfy my curiousity and still try to keep up a bit.
Of course we’d be lucky if every cashier at Wal-Mart just knew how to make change without looking at the machine ;-)
I agree that Newtonian physics is very important. I wish my high school senior physics class had some discussion of relativity without the heavy mathematics.
I agree. I’ve often wondered why “learned professors” are unable to explain modern physics in plain English. I do understand that “mathematics is the language of Physics”, but are there no “multilingual” physicists?
It seems that many theories in higher physics which have been derived solely through the equations appear antithetical to basic logic. Multiverse theory seems to be nothing more than a desperate attempt to avoid facing the full implication of the Anthropic Principle and contrary to Occam’s Razor.
String Theory with 11 Dimensions, or Bosonic String Theory with 26...
Seriously? Similar to Einstein’s Cosmological Constant?
So 59% still believe what they see on the tube and in the papers? That is way too much gullibility.
Sounds like a great way to have even more people believe physics to be an intellectual exercise rather than an experimental science.
Our two semester course in GR was only taught every other year. The combined class size of two years worth of PhD candidates was 23; only 4 people took the class in GR. It would have been 3: my advisor was pissed off at me that I took it, said it took time from my research and was useless for it (he was right ... but ... )
Unlike The Special Theory, which you can explain clearly and even thoroughly with not much more than right-triangle geometry, The General Theory requires tensor calculus on manifolds. Except for a basic introduction, with a lot of hand-waving, I'm not sure how accessible it would be even to senior undergrads.
While you can have a discussion of general relativity without the heavy mathematics, it is near impossible to advance the topic without years of post-doc Physics/Mathematics. By the time a person attains the knowledge base to be “current”, one’s most creative years are in the rearview mirror.
Fortunately, just like you don’t have to understand Particle Physics to benefit from scanning technology, the uninitiated can have Fun with Physics without immersing in complex Math.
As for Newtonian Physics, Newton made it possible for man to make better stuff that rolls, flies, provides shelter or helps get stuff from point A to point B. It is still the base of almost all Engineering.
Ding ding ding! We have a winner.
Satellite clocks at altitude experience time dilation which is smaller than at the surface because gsurface > gorbit (weaker gravity.) This effect is about -45 μsec/day -- the satellite clocks run faster.
They also experience a time dilation effect which is caused by the fact that they are accelerating in orbit. Unlike the time dilation of Special Relativity, where each observer in comoving Lorentz frames sees the other guy's clock running slower, in this case, the effect is not symmetrical because of circular motion (they are not comoving reference frames.) This accounts for about +7 μsec/day.
The net effect is that without corrections to their clocks, GPS satellites would be significantly off in their distance, altitude, and velocity pingbacks to the ground. The effect is large: on the order of kilometers.
See here, among many other places (including basic formulae): http://physics.stackexchange.com/questions/1061/why-does-gps-depend-on-relativity
Gravity is the major, but not the only, GR effect. See previous post.
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