A bowling ball is a better example than you think. A black hole is not a "hole" in space.A black hole is a former star. Stars with enough mass(many, many times larger than our sun), upon reaching the end of their life span,instead of going nova they collapse in upon themselves.They have so much mass that when they collapse they are the densest substance known, a cubic inch can weigh yhousands of tons. It is this mass that causes the tremendous gravity well that lets nothing escape, even light.

My understanding is that the solar wind is entirely charged particles, not photons.  The solar sail is based on radiation pressure, just photons, not the solar wind (despite the name).  The magnetic sail would use the solar wind, if I am understanding everything correctly.  See the link in my post above.

There are two variations on the solar sail theme. One is the positively charged sail being repelled by the positively charged "solar wind", the other uses light pressure. I think it was Ray Bradbury who did a story on solar racers using the second type. Both would take advantage of newtonian forces striking the sail as well as the other forces described acting on the sail.

Silence-Gravity is indeed a warping of spacetime, and from the photon's point of view it does indeed seem to always be moving straight ahead. The only way they could be subject to the disturbance in spacetime caused by a massive body is if they themselves have mass. Massless bodies, such as neutrinos, are not subject to warps and just keep right on plowing through spacetime, massive bodies in their path or not. Masses affect one another, massless objects affect nothing. The curvature of light peripheral to a massive object shows light has mass. Do a search or ask a physics instructor. I believe they will agree with me.

One other note-Remember in Bill and Ted's Excellent Adventure when they went to the 7-11 to get history research? Not so absurd an idea now is it?

This is an interesting thread.  I was talking with my Brother-in-law last summer and we were discussing this very same thing.  One interesting thing that he mentioned was that the world's physicists are working on sub-atomic theories and such, but are all but ignoring gravity.  It would seem to me that to come up with a valid unification theory, someone should be looking at how gravity works, rather than just assuming that it does so.

My BIL is a pretty sharp guy.  Phd in Astrophysics and works for NCAR, and he is working on some theories....they are very interesting.

I am surprised the Radiometer has not come up in conversation. [%|]

I will say it again:  Light does not have mass.  This is proven fact.  Gravitational lensing is not because of massive light.

Gravity is a 400 pound gorilla at a WASP cocktail party. Nobody wants to acknowledge it except when they have to. The reason is this, gravity seems to violate the speed of light. When doing calculations of orbits and space travel you have to treat gravity as instantaneous, so it may be a quantum level effect writ very large. It may also be the negative energy  that was briefly touched on earlier.

Please give me a link or a book reference I can go to. Periodicals are good too.

Zonan is again correct.

“Gravitational lensing” as you call it is due to characteristic changes (density, permittivity ?) in the Ether due to gravity. One could assume that at near infinite gravity the Ether becomes opaque (black-hole). Light propagation is effected by density (as pointed out above) as shown by simple refraction.

Edited to simplify: The media (the Ether) around light is effected by gravity, NOT light itself.

Don’t let those bigheaded science fools fool you!

Think about how electrons would share simular mathematics with the dielectric constant.

Think about a vacuum. It has a characteristic impedance, permeability, permittivity, etc. Quite a number of defined physical characteristics for “nothingness”.

S_G-

Neutrinos probably have mass, or at least it is a better chance that they are 'massive' than photons.  

And the force of the 'solar wind' (the charged/ionized particles) is 1% or LESS the pressure of the EM radiation force (photons).

Oh oh. I smell a Stichin fan here.

I know that interstellar space and interplanetary space is as close to a vacuum as you can get, so yes the force of the particles on a sail would be small. Where were you going with this?
Also, neutrinos have never been shown to have mass in any detectors. In fact we have had to reassess our understanding of solar physics because we have trapped so many fewer than predicted.

Who? ZECHARIA SITCHIN? Not at all! I did a search, Sounds like some kind of comic coo-coo.

The "Don’t let those bigheaded science fools fool you!" was not meant to down play what I just proposed.

Actually the vast majority of physicists seem to disagree with you, although admittedly there is no solid evidence either way.

Then I humbly withdraw my statement and beg your forgiveness. It was a combination of the term "Ether" and the big headed remark that made me suspect you might be one of his many Manson cult-like followers who seem to have no grasp whatsoever of any of the principles of science.

Since photons don't have mass, why are they bound to a "speed limit"?  Game rule?  Or are they not waves or particles at all and just some sort of information packets that we can't really explain?  Would this explain how 2 particles that make contact are always in contact, even if they're at opposite ends of the galaxy?  Some sort of subluminal information transfer without a carrier?  So maybe the imposed speed limit on photons is a way for us to perceive things in our environment but not a universal constant.

I have a decent grasp of science although I am no physicist.
The notion of a Ether has been around a long time and has in fact never left (just changed names). RT in fact supports the entrained Ether. Given that history, I thought I throw that in to offer a different view. I usually get involved more jealiously in these physics discussions. Zonan supports sRT and i sometimes like to rib him on that.

You are right in positing that what we see may be nothing more than our consenual perception of a reality that we can't really comprehend. It certainly seems to be that way with regards to my dating situation. The subluminal data stream leads to support of a "subspace" connection where everything is fundamentally connected, which might be nothing more than an extension of the Big bang theory wherein it is posited than the zero point singularity that everything sprung from had only 30-40 Kg total mass, so we are really and truly all the same stuff. It also supprots the holographic universe theory. Take your pick.

Hehe, I read those books once...it even seemed reasonable at first...till he got to the part about how the Annunaki were mining gold so they could use it as an atmospheric shield (!) to keep their planet warm (!) during its long journey through the solar system.
What a nutball.

Mustangman,
When you are forced to interpret this in mathematics, light simple being observed at c and bound to c become two very different edicts. There is many a theory that are bound by either of these two ideas.

Note that the wave/particle duality, because of it's contradictions, can be more perceived as a model and less of a fundamental. The wave notion certainly has no room for light to have mass. There is reading available which tries to assign mass to photons.

You touched on "Action in a Distance". Another confusing observation much like quantum tunneling. Both ignore time and distance, which works well for SRT since those two once solid constants are now variables.

Back to my Ether theory........
If you want to gauge gravitation lensing and do not support this theory, you might ask why we do not experience this diference between earthbound TX/RX and sats. Take a tiny-tiny divertion of light and notice the difference in course when compared to a few 100,000 miles against a few light-years. :P
Much of modern science now-a-days is bound by resolution of measurement.

I searched around briefly and found one site that said this.  There reasoning was that obviously light has energy, and E = mc^2, therefore light has mass m = E/c^2.  This is incorrect reasoning.  Light has energy, yes.  It [b]is[/b] energy.  Now, if this energy were completely converted to mass (requiring the light to be converted to matter, meaning it is no longer light), then the amount of mass you should end up with is m = E/c^2.  But light, existing completely as energy, does not have mass.  Does that make sense?

Here's one article about this:
[url]http://math.ucr.edu/home/baez/physics/Relativity/SR/light_mass.html[/url]


Yes, in the classical sense you are exactly correct.  Momentum is proportional to mass.  p = mv

Things get more complicated when you consider Maxwell's equations.  the momentum of an em wave can be found to be E/c.

So p = E/c, but we know that the energy of an em wave is given by E = hf, where h is planck's constant and f is the frequency.  So p = hf/c => light has momentum despite having no rest mass.


Not if photons have mass.  Special relativity tell us that anything with mass travelling at the speed of light appears to have infinite mass.

You are correct in another way, however:  From SRT, which Boomholzer would be quick to remind us, is far from gospel [:D], any mass that is moving less than the speed of light cannot be accelerated to the speed of light because this would require infinite energy.  But this does not theoretically prevent something from already moving [b]faster[/b] than c.  The only problem is we don't know how to detect anything like that.


That isn't exactly true.  The rate of change of momentum (the force) is proportional to the acceleration, but the momentum itself isn't related to it (other than the fact that zero acceleration implies constant momentum).  I don't know if you have much calculus, but this is where it is useful.


You made perfect sense, and hopefully I did too.  As a physics wannabe (student), it is always useful to attempt to explain things to others.  At worst it solidifies my ideas, and at best I help others understand (or someone else can correct my incorrect ideas to help me better understand).


I hope to write more later

I found the first line of this kinda interesting...

Quote from Einstein:


Energy and mass being the same thing and all...

Speak on it bros...

Another question:
"IF" light and other spectrums, in this case radar, are the same. Can someone explain "heat inversion" partaining to radar seen on particularly hot days?
For more background, if the radar dish is pointing just above the horizon as in the picture:
[img]http://www.imagestation.com/picture/sraid36/p7a35b5edb9dd892eb45f3b62c844ab3f/fd2215bc.jpg[/img]

Would this not mean that the light photons are bouncing off the photons of the "heat wave"???

If the different freqs are "bouncing off" of one another, could this be particles  bouncing off one another?????

Particles being "massive" physical "stuff"???
Whatchall think???

As to where we are goin witht the charged wind vs Radiation Force, just letting you know that AFAIK noone is designing a realworld sail to use the 'wind', they are all designing sails to use 'photons'.

As to neutrino mass check here, seems there are some scientists that disagree with massless neutrinos.


[url]http://www.slac.stanford.edu/slac/announce/9806-japan-neutrino/more.html[/url]

Or here:

[url]http://www.phys.hawaii.edu/~jgl/neutrino_news.html[/url]

Maybe here:

[url]http://www.lbl.gov/Science-Articles/Archive/neutrino-mass-announcement.html[/url]

Seems pretty definite to those people that neutrinos have mass.

fixed my broke pic link...

is there a imagve hosting place out there that doesn't resize my hard worked on pics[pissed]

Erm I dunno much about radar, but the way I always understood it was that it is the disturbances in the air by the ground heat that cause 'heat inversions'.  Sorta like a mirage,  the sudden changes of temp and density of the air causes it reflect the EM radiation in odd ways.

I had a conversation with a friend who is a physics major just a few weeks ago about this topic. He said that this phenomenon is not particularly well understood currently. Because if when photons do indeed transfer momentum to whatever it is hitting, then it would lose energy, however, if light were to lose energy, it can only lose energy in discrete quantities. Doing so would mean that the light reflected would not be of the same energy as the light that you started with, and since energy is directly related to wavelength, that would mean the reflected light would be of a different color than the original light. This predicted phenonmena has never been experiementally observed, since if you shine a light at a mirror the light reflected back is the same color.

What you are seeing there is light passing through rapidly varying densities of heated and non or less heated air leading to rapidly changing indexes of refraction. So no, it isn't photons smacking photons. Remember the machingunner's maxim, "There is always more air than meat." Collisions between photons outside of an artificially induced clustering of photons are rare. Their wavelengths could certainly interfer with one another however. How is that for a quandry?

I do not agree with that last statement.  I maintain that general relativity is just as "complete" as quantum mechanics, it is just that they are valid on mutually exclusive domains.  Neither QM nor GRT can explain everything--if I understand you correctly, you believe that QM can be modified to encompass everything.  I would suggest that it would be equally likely that GRT could be modified to explain everything--that is, neither is very likely.  I believe it will take a more generalized theory than either to encompass both domains.  String theory maybe, but I am not familiar with that yet.

By the way I was confused when I mentioned "quantum gravitation."  That is unrelated.  It is simply quantized gravity, which has been experimentally observed (and from my limited understanding, lends a lot of support to the idea that the force of gravity arises from something like gravitons).


You are referring to the correspondence principle, which in terms of quantum mechanics states that as one looks at ever higher numbers of particles, the observed behavior of the system approaches that predicted by classical physics.  If this were not true, QM would be worthless.  You are confusing this with general relativity, however, which is most certainly not in the domain of classical physics.  QM can account for the Newtonian laws of mechanics, but not for the warping of space-time etc. predicted by general relativity.

Disclaimer, that is the way I understand things from my brief introductions to the material.  I have by no means yet undergone a rigorous course devoted to either QM or GRT.


And this undergraduate physics student will have to defer to the particle physics researchers.  The graviton is purely theoretical at this point.

From my understanding of observed quantized gravity, the idea of the graviton is gaining support...but I could be wrong.  Here is a link about the experimental observations:
[url]http://jove.eng.yale.edu/pipermail/eas-info/2002/000405.html[/url]

[:D]  Thanks

There's plenty of room for you to post!  By reading others' posts I am forced to reexamine my own understanding and to hopefully clear up any misconceptions that I may have.

Some areas I have very little study in so far (like QM and general relativity).  I don't know how familiar you are with the formal physics training sequence that most schools seem to follow:  the first two years consists of introductory classes on just about every classical aspect of physics--mechanics, eloctromagnetism, oscillations and waves, a little thermodynamics, and a dose of quantum physics.  Then you sort of start over again for the last two years, which is interesting.  I am currently a junior taking a classical analytical mechanics course--mechanics, just like my very first semester except more mathematically intensive.  Instead of ignoring friction, etc., we are forced to look into the more complex cases--projectile motion, accounting for air resistance, the variation of gravity with height, the spin of the earth, etc.  Very interesting, but very mathematical.

Anyway, the point of my babbling was that next semester and the semester after I will get a whole lot of quantum mechanics, electrodynamics, thermodynamics, etc.  Hopefully then I'll be more comfortable with some of these things.

That is a good observation, and I think that has been the case in the last few decades.  It seems that there is a significant faction growing that is working on the gravitational aspects, though.

You are right, an understanding of gravity is necessary for a unification.

One interesting link regarding gravity:
[url]http://www.business2.com/articles/mag/0,1640,43531,FF.html[/url]