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Is the classical calculation of the sun bending light wrong?


Lazarus

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If you would be satisfied that there is a correct solution to the bending of light by the sun from these assumptions which does not require the Relativistic assumptions, I will construct an equation even though I can’t even remember how to spell kaculus much less how to use it. Most of the posters on this forum could do it with these assumptions over a hot beer.

 

Roughly speaking, the predictions of Newtonian gravity are equivalent to a theory with "bent time" but flat space. General Relativity includes "bent time" and "bent space." Newtonian gravity cannot and does not predict what GR predicts for this reason. They are not equivalent theories. The Newtonian calculation, no matter how you do it, will always be off by a factor of two. Any calculation that doesn't include relativistic effects is going to be wrong.

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Roughly speaking, the predictions of Newtonian gravity are equivalent to a theory with "bent time" but flat space. General Relativity includes "bent time" and "bent space." Newtonian gravity cannot and does not predict what GR predicts for this reason. They are not equivalent theories. The Newtonian calculation, no matter how you do it, will always be off by a factor of two. Any calculation that doesn't include relativistic effects is going to be wrong.

 

The slowing of light should be equivalent to changing time itself.

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Even if that were true, what does it have to do with anything I just said?

 

Since the Newtonian laws do not address the nuances of light, it is fair to apply the knowledge from modern experiments to the calculation, such as the Shapiro Delay of light.

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Since the Newtonian laws do not address the nuances of light, it is fair to apply the knowledge from modern experiments to the calculation, such as the Shapiro Delay of light.

If you include relativistic effects, this is an admission that a Newtonian calculation gives the wrong answer. Wasn't that the question to be answered?

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If you include relativistic effects, this is an admission that a Newtonian calculation gives the wrong answer. Wasn't that the question to be answered?

 

The slowing of light is not a Relativitic effect. No time dilation, no space shrinkage or expansion,

no curvature of space.

 

The point of the question was, is there a correct calculation that does not require Relativity.

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The slowing of light is not a Relativitic effect. No time dilation, no space shrinkage or expansion,

no curvature of space.

 

The point of the question was, is there a correct calculation that does not require Relativity.

 

Shapiro delay is a relativistic effect.

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I beg to differ. The Shapiro Delay is an experamentally observed effect. It is compatible

with Reliativity but also compatible with the slowing of light.

 

It's considered to be one of the main tests of GR, i.e. the experiment agrees with the theoretical prediction.

http://en.wikipedia.org/wiki/Shapiro_delay

 

Does your slowed-light model make a prediction? If yes, let's see it. If no, then you can't claim compatibility.

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I beg to differ. The Shapiro Delay is an experamentally observed effect. It is compatible

with Reliativity but also compatible with the slowing of light.

 

Now you're just making things up. This is getting increasingly frustrating, and I'm not sure what else we can say to cure you of this strange compulsion to get rid of relativity.

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  • 2 weeks later...

It is very well agreed that the equations of Relativity have an excellent match to observed phenomena. Also agreed is that the Newtonian gravitational laws without adjustment for the behavior of light do not match the bending of the path of light passing the sun.

 

It probably can be agreed that by introducing and adjustment for the behavior of light a correct equation can be constructed for the bending of light’s path since almost any concept can be turned into an equation.

 

The ramifications of these concepts are where the disagreements seem to be.

 

The excellent explanations from this forum have enabled me to visualize some of the current concepts of physics.

 

Visualizing the 4 dimensional space-time continuum is somewhat like looking at a partial derivative. The underlying formula is v=d/t. We hold the v constant and that forces d and t to change.

 

It is easier to think about it using a blue Ford Bronco traveling from Los Angeles to New York City and requiring the velocity of the Bronco be constant. The time and distance are forced to change to keep the v=d/t correct. The solutions in the 4 dimensional space-time arena as the Bronco moves along the road forms a bumpy surface which keeps changing as the Bronco goes along. Each point on the road is a “Frame”. For an observer in Seattle the “Frames” also change but the surface is shaped differently.

 

An equation can be constructed by holding time constant and letting distance and velocity change with quite different results.

 

Now for the predictions that were requested.

 

  1. The photon will be found to consist of interacting physical particles.
  2. All nuclei will be found to have a rotating magnetic field with the time of rotation related to the charge of the nucleus.
  3. Clocks slowing is related to the changing paths of electrons in atoms caused by gravity and speed of the nucleus along with the speed limit of matter.

 

As annoying as I can be, I am not in any way saying the accomplishments of physics are less than amazing. I am in awe of those on this forum that demonstrate a complete understanding of the complexities of modern physics. I have been dissatisfied with the explanations of basic phenomena since the first atomic bombs were detonated and more unhappy with them as time went by. Thanks for all the patience with me.

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Now for the predictions that were requested.

 

  1. The photon will be found to consist of interacting physical particles.
  2. All nuclei will be found to have a rotating magnetic field with the time of rotation related to the charge of the nucleus.
  3. Clocks slowing is related to the changing paths of electrons in atoms caused by gravity and speed of the nucleus along with the speed limit of matter.

 

None of these are useful in comparing with an experiment. I don't understand what you mean in the first, and for 2 & 3, you need a model to quantify the size of the effect. For 2, why wouldn't the nucleus radiate? What frequency should we be looking for? For 3, what path are you talking about? You need to solve for the energy shift so it can be compared with experiment.

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  • 1 year later...

What am I missing?

 

I wrote a computer program to simulate the Sun’s Gravity. The program says that a light ray passing close to the Sun’s surface will be bent an order of magnitude more than the observed 1.75 arc seconds.

 

So I manually calculated what happens to a light ray skimming the Sun’s surface for 1 second after leaving the closest point to the Sun. That bending was much greater than 1.75 arc seconds.

 

The calculation goes like this: The x distance that the light travels is 300,000,000 meters. The acceleration of gravity at the Sun’s surface is about 274 meters per second per second. The distance traveled in the y direction is about 137 meters. The tangent of the angle is about 137/300,000,000. The arc tangent of it is 34 arc seconds and that is only one half of the total curvature.

 

The values that the program uses are G=6.7e-11, M=1.988e30, c=3e8 and R (Sun radius)=6,957e8.

 

The program says that the light ray that bends 1.75 arc seconds passed the sun at a distance of 5.88e10 meters or 34,000,000 miles from the center of the Sun. That is equal to about one third of the distance to earth.

 

The arithmetic is so simple I must be applying something wrong.

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http://www.wolframalpha.com/input/?i=.875arc+seconds+in+radians

 

=4.242e-6 radians

 

http://www.wolframalpha.com/input/?i=(2(6.67e-11*1.989e30)%2F(3e8%5E2*6.96e8)

 

=4.236e-6 radians

 

 

The old Newtonian calc (this is an approximation but damned close) looks to be misfunctioning just as it is meant to :) what calculation were you using?

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http://www.wolframalpha.com/input/?i=.875arc+seconds+in+radians

 

=4.242e-6 radians

 

http://www.wolframalpha.com/input/?i=(2(6.67e-11*1.989e30)%2F(3e8%5E2*6.96e8)

 

=4.236e-6 radians

 

 

The old Newtonian calc (this is an approximation but damned close) looks to be misfunctioning just as it is meant to :) what calculation were you using?

 

Thank you very much. That got me to the correct solution.

 

My error was in the manual calculation of arc seconds to degrees to radians. Now

everything matches the 8,75 almost exactly.

 

 

My error

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Thank you very much. That got me to the correct solution.

 

My error was in the manual calculation of arc seconds to degrees to radians. Now

everything matches the 8,75 almost exactly.

 

 

My error

 

 

You aren't the first and won't be the last to be let down by the simple units conversion after lots of complex maths - it's why we like SI and why I use Google and Wolfram Alpha to check any conversions I do no matter how trivially easy they appear on the face

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