If the size of the hole is significantly greater than the wavelength of the light then the lines on ray diagrams are reasonable approximations of the behaviour of light waves coming from a point source.Steve if you use an example in an attempt to clarify your argument it has to perform. The pin hole camera does the complete opposite to what you intended. You can only explain the image created by using straight lines. The inverted image and size of the opening indicates atom to atom contact. I have never seen an explanation nor diagram that uses complex 3 dimensional waves.
The speed of gravity is instant
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Re: The speed of gravity is instant
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Re: The speed of gravity is instant
I can appreciate that a linear wave function has to be less than the aperture but these proposed waves are not linear. I have never seen a complex 3D diagram of light entering and forming an image with a pin hole obscurer.Steve3007 wrote:Xris:I can appreciate that wave frequency has to be less than the size of the apSteve if you use an example in an attempt to clarify your argument it has to perform. The pin hole camera does the complete opposite to what you intended. You can only explain the image created by using straight lines. The inverted image and size of the opening indicates atom to atom contact. I have never seen an explanation nor diagram that uses complex 3 dimensional waves.
If the size of the hole is significantly greater than the wavelength of the light then the lines on ray diagrams are reasonable approximations of the behaviour of light waves coming from a point source.
As for the laser moon experiment. Could you explain if the proposed wave front is a convex in shape? Would the movement of the moon create an even wider angle of reception? Im sorry Steve the concept of waves capable of returning an accurate calculation is very hard for me to accept. Yes light could be said to have speed, so might be said to travel. But is it travel in a conventional sense? If light is relative to the speed of the object it emits from then our understanding of light has to be a considered as a direct relationship and not this strange concept of waves without a medium.
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Re: The speed of gravity is instant
You will see a LASER BEAM if you're in the path of the beam, which is a problem aircraft pilots have experienced. However, if you're not in the path of the beam, you will see light at the source and destination but nothing in between, UNLESS the beam passes through a medium that gives rise to fluorescence when photons in the beam collide with particles in the medium, thus emitting light in the direction of an observer.Steve3007 wrote:enegue said:
Gravity can't have speed because speed implies motion. Gravity doesn't move from one location to another, but CAUSES bodies to move from one location to another. This is true regardless of whether you adhere to the ideas of gravitons or EM ropes or curved space.
Both you and Xris (and possibly others) have also made this same point about light. i.e. we don't see it travelling, we only perceive its arrival. We see its' effect on an object at the destination.
Only light that travels FROM A SOURCE TO AN OBSERVER is seen by the observer. The nature of human vision is a limiting factor in our capacity for observation, which has particular implications for objects in motion. In regard to moving objects, what we observe may be distorted by the motion, which has led some to the erroneous notions of time dilation and length contraction.
You don't need such an elaborate set up. A simple laser pointer will confirm what I have said above about laser beams.Steve3007 wrote:Nevertheless, in the case of light, what we can do is observe a set of events separated by a period of time which we attribute to the same bunch of light. For example, we can observe one event: the firing of a laser pulse towards the moon, and about 2.5 seconds later observe another event: the reception of a light pulse from the direction of the moon. You can still argue that there is no sense in which we could possibly "see" a light pulse travelling to the moon and back, and that therefore the light doesn't do so. But the idea that this is what has happened is a very useful model to describe the events that we do see. And we know that, if we wanted to, we could place a detector at any point along that path to the Moon and confirm this model.
"Pulses" of gravity are a legacy of mathematical models of the Universe that depend on the existence of particles called "gravitons" for the model to make sense.Steve3007 wrote:The same applies to gravity, except that current technology doesn't allow us to create "pulses" of gravity. But is it not possible to see, in principle, how the details of the gravitational influence by one body on another might lead us to conclude that there is a delay in that influence and that therefore it's useful, for at least some purposes, to think of that influence as "travelling" from one body to the other?
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enegue
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Re: The speed of gravity is instant
As demonstrated in previous conversations, your rejection of the conclusions of Special Relativity are based on a fundamental lack of understanding of the basics of what that theory says. As you have pointed out to critics of the Bible, it is wise to criticize only when you know what it is that you are criticizing. Apply those standards to yourself....In regard to moving objects, what we observe may be distorted by the motion, which has led some to the erroneous notions of time dilation and length contraction.
I wasn't attempting to confirm what you have said about laser beams. I was demonstrating the utility of regarding light as something that travels at finite speed.You don't need such an elaborate set up. A simple laser pointer will confirm what I have said above about laser beams.
I take it from this comment that you regard the concept of gravitons as outdated and having been superseded by more accurate models. On the basis of what knowledge do you do this?"Pulses" of gravity are a legacy of mathematical models of the Universe that depend on the existence of particles called "gravitons" for the model to make sense.
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Re: The speed of gravity is instant
No. My conclusions are based on what Professor George Smoot has published in regard to his thought experiments. Your rejection of my conclusions is based on a religious belief that mathematical models should override notions such as anomalies associated with human vision.Steve3007 wrote:enegue said:
In regard to moving objects, what we observe may be distorted by the motion, which has led some to the erroneous notions of time dilation and length contraction.
As demonstrated in previous conversations, your rejection of the conclusions of Special Relativity are based on a fundamental lack of understanding of the basics of what that theory says.
I do apply those standards. The problem is, you seem to have a religious attachment to particular physical models that when challenged, cause you discontent.Steve3007 wrote:As you have pointed out to critics of the Bible, it is wise to criticize only when you know what it is that you are criticizing. Apply those standards to yourself.
LOL. I'm saying this because, "In physics, the graviton is a hypothetical elementary particle that mediates the force of gravitation in the framework of quantum field theory." (emphasis mine).Steve3007 wrote:enegue said:
"Pulses" of gravity are a legacy of mathematical models of the Universe that depend on the existence of particles called "gravitons" for the model to make sense.
I take it from this comment that you regard the concept of gravitions as outdated and having been superseded by more accurate models. On the basis of what knowledge do you do this?
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enegue
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Re: The speed of gravity is instant
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Re: The speed of gravity is instant
Steve, YOU have brought religion into this discussion. I have just shared with you my understanding of the nature of gravity and light.Steve3007 wrote:Yes. I was pretty sure that the next move would be to accuse me of a religious attachment to science. You're so predictable!
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enegue
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Re: The speed of gravity is instant
...I didn't mention religion. I mentioned the obvious importance of criticizing a body of knowledge from a position of knowing something about what that body of knowledge actually says. A point with which you have claimed in the past to agree, but only, it seems, when people have criticized a particular body of knowledge in which you are interested.As you have pointed out to critics of the Bible, it is wise to criticize only when you know what it is that you are criticizing. Apply those standards to yourself.
There are many, many good introductory non-technical texts on the theory of relativity. As I said before, I think Bertrand Russell's "ABC Of Relativity" is still one of the best.
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Re: The speed of gravity is instant
Your mention of the Bible is irrelevant to this discussion. If you or anyone raises an issue with the Bible, I address it in the appropriate place.Steve3007 wrote:...I didn't mention religion. I mentioned the obvious importance of criticizing a body of knowledge from a position of knowing something about what that body of knowledge actually says. A point with which you have claimed in the past to agree, but only, it seems, when people have criticized a particular body of knowledge in which you are interested.
Just as a side issue, since we've taken a timeout, the use of "next move" in your previous post betrays an attitude of competition I believe is causing you unnecessary grief. As far as I'm concerned everyone is a HEDONIST, everyone is RIGHT, and everyone is RELIGIOUS. Within in that framework grief is minimised.
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enegue
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Re: The speed of gravity is instant
Also, while I'm about it: ignore all emoticons. To tell the truth, I don't really like using them anyway, although I grudgingly accept their utility in a written forum (as I grudgingly accept things like LOL. I prefer the more accurate: YWHCMMAWIANSEEFAFS, which stands for: "Your words have caused me momentary amusement which I am not showing externally except for a fleeting smile.")
There. Sorry for the terminological clarification interlude (TCI).
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Re: The speed of gravity is instant
Cheers,
enegue
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Re: The speed of gravity is instant
I'm guessing that what you mean by the HEDONIST part is:As far as I'm concerned everyone is a HEDONIST, everyone is RIGHT, and everyone is RELIGIOUS. Within in that framework grief is minimised.
Everyone, by definition, tends to say and do the things that they want to say and do. We've discussed this before and I agree that it's possible to characterize all acts, whether "altruistic" or "selfish", as hedonistic. I just question the utility of doing so.
I'm not sure about the RIGHT, and RELIGIOUS parts, but I guess it's the same general kind of argument. Again, I question the usefulness of saying "everyone is X" because I think words are at their most useful when they distinguish between things.
(By the way, when I said that, I didn't mean "everyone is Bible". This is a different X. Perhaps I should have used Y!)
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Re: The speed of gravity is instant
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Re: The speed of gravity is instant
One interesting thing I did find in my brief search was the equation that somebody or other worked out for calculating the optimal size of the hole in a pinhole camera. It was (in words) this:
diameter of hole = square-root of ( 2 X focal-length X wavelength ).
So, for example, in a camera which is 5 cm long, the diameter is about a 1/4 of a millimetre. About 500 times the wavelength. If you drew a diagram of waves going through a hole which is 500 times bigger than the wavelength I think that would show that they act very much like the idealized straight-line rays of geometrical optics, as opposed to the diffracting, spreading-out waves shown above.
Anyway, after all this, what I thought would be fun to do would be to actually create a computer simulation of these kind of multiple wave sources creating something analagous to an image on a screen behind a pinhole. I've created a simulation similar to this before as part of my work writing educational physics software. So it would be relatively quick to do. But I still haven't done it yet!
When I get a bit of time free I think I'll give it a try and, if you like, could post some screenshots of the resulting waves on this forum? Whatever the result turns out to be, I think it will be interesting.
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Re: The speed of gravity is instant
2023/2024 Philosophy Books of the Month
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