Earth's Magnetic Field Declining. Results...? - Page 2 - PeachParts Mercedes-Benz Forum

sixto · #16 12-17-2012, 07:20 PM

The worst thing I can do is keep thinking about it. Now I have to accept that light follows a path? I always thought light paved the way.

This is how I understand it - think of a shaft of light as a series of drinking straws. Working from the origin, stack straws end to end such that all you see looking through the stack of straws from the far end is the point of origin. As far as you know, what you've created is as straight as straight gets. But oddly, someone watching you from a distance, way out in the distance, will see your stack of straws bend towards black holes and other massive objects. You say it's straight, he says it's not. Who's right?

Sixto
87 300D

barry12345 · #17 12-17-2012, 07:39 PM

Quote:

Originally Posted by pj67coll

Einsteins theory of gravity has not been discredited to my knowledge? Where did you hear this?

- Peter.

Read it from two sources over the last few years. His theory I believe was bending light or a stream of photons creates gravity. Why his theory stood for so long was he said he had proved it I imagine. Combined with no alternate solution offered up perhaps.

Botnst · #18 12-17-2012, 08:50 PM

Mass deforms space.

Light follows the shortest geodesic through space.

sixto · #19 12-17-2012, 09:03 PM

It's ironic that geodesics make space a headache.

Sixto
87 300D

Air&Road · #20 12-18-2012, 08:10 AM

On aviation charts you will find lines that indicate magnetic variation. At different points on the Earth, a compass varies from true North by different magnitudes. The lines of variation are ever changing and have changed significantly throughout the history of aviation charts.

Although the magnetic variation lines are changing, I don't think we have to worry about them going away anytime soon.

pj67coll · #21 12-18-2012, 12:08 PM

Quote:

Originally Posted by Air&Road

On aviation charts you will find lines that indicate magnetic variation. At different points on the Earth, a compass varies from true North by different magnitudes. The lines of variation are ever changing and have changed significantly throughout the history of aviation charts.

Although the magnetic variation lines are changing, I don't think we have to worry about them going away anytime soon.

Not any time soon perhaps, but according to some geophysicists the earth is due for another pole reversal some time in the future. How soon? Well that's the million dollar question.

- Peter.

pj67coll · #22 12-18-2012, 04:05 PM

I asked a Physicist friend of mine about Einsteins gravitational theories being rejected and this was his response...

"Pure nonsense. Photons indeed have no mass and are indeed subject to gravitational
lensing, but thats one of the original observations that led to the adoption of
General Relativity.

The discovery of "dark energy" from the universe expansion is something we don't
understand, but it doesn't overthrow GR"

- Peter.

Dudesky · #23 12-18-2012, 04:22 PM

Quote:

Originally Posted by barry12345

Einsteins theory of gravity that was accepted as fact for decades.. The bending of light creates it I believe was the one . Has been discredited not that long ago.

Einstien said light should respond to gravity. So Arthur Eddington proved it during a solar eclipse in 1919 as light was bent around the sun, during eclipse you could see the near stars light behind the sun due to bending.

The stuff about earth losing its gravitational/magnetic attraction is merely a pre-mayan calender variation that should end sometime Friday.

barry12345 · #24 12-18-2012, 06:48 PM

Light may respond to gravity is not the issue. The issue is does the light bending or being deflected create the gravity itself. I thought that was the basic premise of the original einstein origin of gravity work.

I always asumed gravity could bend light.

Botnst · #25 12-18-2012, 08:46 PM

Quote:

Originally Posted by barry12345

Light may respond to gravity is not the issue. The issue is does the light bending or being deflected create the gravity itself. I thought that was the basic premise of the original einstein origin of gravity work.

I always asumed gravity could bend light.

Your first statement is not what Relativity describes.

Also, at the fundamental level, energy and mass are interchangeable. recall that light is a form of energy. For example, in the various particle accelerators the folks talk about accelerating particles in terms of electron volts, not in terms of mass. Knowing full well that as particles approach lightspeed their mass increases, which means it takes and exponential power increase to continue accelerating the mass.

Going to the deformation of space under acceleration, look up 'lorentz transformation'. Gravity is 3-space deformation in an accelerating field. More mass, more acceleration, more deformation.

Dudesky · #26 12-18-2012, 10:56 PM

Quote:

Originally Posted by barry12345

Light may respond to gravity is not the issue. The issue is does the light bending or being deflected create the gravity itself. I thought that was the basic premise of the original einstein origin of gravity work.

I always asumed gravity could bend light.

Doubt it....didn't Albert also prove gravity also responds in a similar fashion as light? I thought it too, bends and so on.
I think the gravitational force has to do with the objects mass and the attraction it causes.

I still think a proton has to have some type of mass, thus would fall prey to gravitational attraction.

However...I hope you have a big fat doobie to comprehend this postulation:

Quote:

The Question

(Submitted November 02, 1996) This questions has been bugging me and my chemistry class. Does light have mass? Most people would think not but here's why I argue against it. Even though light does not effect anything it its path like a solid object, it is affected by gravity. Anything that has mass is affected by gravity. Why do I say that light has mass? Well, If a black holes gravity field is so strong that light cannot escape itself, light must have mass? Am I right? Everyone argues against it.

The Answer

These are interesting issues that you bring up. Whether or not light (or more accurately photons, the indivisible units in which light can be emitted or absorbed) has mass, and how it is affected by gravity, puzzled scientists for many, many years. Figuring it all out is what made Albert Einstein famous. Bear with me and I'll try to explain both the theory and the observation. Back in the 1700s, scientists were still struggling to understand which theory of light was correct: was it composed of particles or was it made of waves? Under the theory that light is waves, it was not clear how it would respond to gravity. But if light was composed of particles, it would be expected that they would be affected by gravity in the same way apples and planets are. This expectation grew when it was discovered that light did not travel infinitely fast, but with a finite measurable velocity.
Armed with these facts, a paper was published in 1783 by John Michell, in which he pointed out that a sufficiently massive compact star would possess a strong enough gravitational field that light could not escape --- any light emitted from the star's surface would be dragged back by the star's gravity before it could get very far. The French scientist Laplace came to a similar conclusion at roughly the same time.
Not much was done over the next hundred years or so with the ideas of Michell and Laplace. This was mostly true because during that time, the wave theory of light became the more accepted one. And no one understood how light, as a wave, could be affected by gravity.
Enter Albert Einstein. In 1915 he proposed the theory of general relativity. General relativity explained, in a consistent way, how gravity affects light. We now knew that while photons have no mass, they do possess momentum (so your statement about light not affecting matter is incorrect). We also knew that photons are affected by gravitational fields not because photons have mass, but because gravitational fields (in particular, strong gravitational fields) change the shape of space-time. The photons are responding to the curvature in space-time, not directly to the gravitational field. Space-time is the four-dimensional "space" we live in -- there are 3 spatial dimensions (think of X,Y, and Z) and one time dimension.
Let us relate this to light traveling near a star. The strong gravitational field of the star changes the paths of light rays in space-time from what they would have been had the star not been present. Specifically, the path of the light is bent slightly inward toward the surface of the star. We see this effect all the time when we observe distant stars in our Universe. As a star contracts, the gravitational field at its surface gets stronger, thus bending the light more. This makes it more and more difficult for light from the star to escape, thus it appears to us that the star is dimmer. Eventually, if the star shrinks to a certain critical radius, the gravitational field at the surface becomes so strong that the path of the light is bent so severely inward so that it returns to the star itself. The light can no longer escape. According to the theory of relativity, nothing can travel faster than light. Thus, if light cannot escape, neither can anything else. Everything is dragged back by the gravitational field. We call the region of space for which this condition is true a "black hole" (a term first coined by American scientist John Wheeler in 1969).
Now, being scientists, we do not just accept theories like general relativity or conclusions like photons have no mass. We constantly test them, trying to definitively prove or disprove. So far, general relativity has withstood every test. And try as we might, we can measure no mass for the photon. We can just put upper limits on what mass it can have. These upper limits are determined by the sensitivity of the experiment we are using to try to "weigh the photon". The last number I saw was that a photon, if it has any mass at all, must be less than 4 x 10-48 grams. For comparison, the electron has a mass of 9 x 10-28 grams.
Hope this answers the questions that you and your Chemistry class have.
Good luck,
Laura Whitlock.

Botnst · #27 12-19-2012, 07:43 AM

All atomic particles have mass, that's why we call them particles.

TwitchKitty · #28 12-19-2012, 09:19 AM

The magnetic field and gravity are not the same. If you turn a compass through three dimensions it might help get a feel for that. There are variations and deviations in both fields but they do not correspond. Those terms have very specific definitions with regard to the earth's magnetic field.

The magnetic field protects the planet from the solar winds. If the field weakens beyond a point the solar wind will wipe away the atmosphere which is what supports life on the planet. Kinda cool actually, Mars is a model for a planet after loss of the magnetic field/solar wind/atmosphere balance.

Will cel phones hasten the end of life on the planet? Not sure but I suspect this is already becoming apparent for intellligent life.

Dudesky · #29 12-20-2012, 11:11 PM

Quote:

Originally Posted by Botnst

Your first statement is not what Relativity describes.

Also, at the fundamental level, energy and mass are interchangeable. recall that light is a form of energy. For example, in the various particle accelerators the folks talk about accelerating particles in terms of electron volts, not in terms of mass. Knowing full well that as particles approach lightspeed their mass increases, which means it takes and exponential power increase to continue accelerating the mass.

Going to the deformation of space under acceleration, look up 'lorentz transformation'. Gravity is 3-space deformation in an accelerating field. More mass, more acceleration, more deformation.

What he said......