So tell us why a moving radar system needs two guns while an ordinary stationary handheld radar only needs one?

Remember, I know the answer, having worked on mobile radar systems...

As early as the ancient Greeks, scientists and philosophers supposed that space was not truly empty. Instead, a mysterious substance filled the cosmos like a vast ocean, suspending the stars and serving as the medium through which light traveled.

After all, physicists have long known that light moved, either as a beam or a wave. And if light traveled as a wave, like sound, then surely it needed to travel through something. The greatest minds in history thought it to be true, so surely it must have been. Even physics great James Clerk Maxwell, whose equations reveal the speed of light, considered these ethereal ideas.

You were a sensical theory, luminiferous ether. And physicists love when things make sense. But science need not make sense—the universe doesn’t give a damn what human beings think.

Science is a tool to get at the truth, but it is not the truth itself. And though you’re gone, we do not despair. Finding the truth requires new ideas, and it requires luminiferous ethers to disprove. We’ll never know what’s right unless we know everything that’s wrong.

Rest in peace... maybe. Perhaps someday we’ll find that you’ve been hiding in existing theory all along.

All that matters TO THE [RADAR] GUN is the speed of the reflector RELATIVE TO THE GUN, because that is all it can measure (know). This is proven daily by police that use radar guns -- a gun in a car traveling down the highway at 60 MPH will measure a tree to have a speed of 60 MPH.

A whole second radar just to subtract zero? And why don’t we just leave that out?

Because the radar gun compares photon frequencies.  It needs TWO photons to make a comparison.

In a standard radar gun, the gun compares the frequency of the photons it emits to the frequency of the photons it gets back from the target.

In the "two reflections" type of radar gun, the gun compares the frequency of photons returned from the ground to the frequency of photons returned from the target vehicle.

You and your policeman do not know what you are talking about!!!

You see, Edward, radars only "see" metalic stuff, like cars, trains, airplanes and missiles. A tree is made of wood and not of metal, do you understand that?

You are way too dumb to understand any of this....

Is a lidar a radar?

Do you even think before writing your daily nonsense?

As you can see, they are from Chapter 1 (the Introduction), pages 14 and 15, so it will be easy to find them again in the book if I need to do so.  I can use them when people claim that I'm the only one who believes that light consists of photons, not waves.

Since there is no new physics here, I suggest that further comments be mailed to the original poster.

I'm the "original poster."  So, the guy who had responded sent me an email explaining his view in greater detail.  I agreed with him and said I'd modify the illustration.  Here are the before (incorrect) and after (correct) versions:

The complaint was the stone dropped by the observer on the train (OT) would not bounce in the direction of the engine the way I had shown it.  That version implied that the stone was somehow moving faster than OT and the train.  As you can see, the modified version is better, since the stone never moves past OT.  It is still not totally satisfactory, since the stone would be slowing down and wouldn't actually be directly below OT after it had bounced a few times.  But I don't know how to illustrate that without getting another complaint that the stone didn't fall straight down from OT's hand.

But what really interested me in that response was that there was evidently no disagreement with the physics in my paper.  The guy who suggested the change evidently agreed with the paper, and the moderator felt the paper contained nothing new.  That made me really wonder if the scientists and physicists who share my understanding of Relativity try to avoid "social media" because they do not want to endlessly argue with mathematicians as I've been doing.

If there are lots of scientists out there who agree with me, why aren't they protesting against what the colleges and universities are teaching?  Is it because as soon as they open their mouths a hoard of mathematicians will start attacking them and insulting them?  I'm thinking more and more that that is the case.

Meanwhile, I have registered at imgur.com.  It's a place where I can store images and use them on this web site or in posts to various social media forums.  The image above was placed there instead of on my own web site.  Using an image placed on imgur.com instead of on my own site makes things a bit simpler, and it means I'll be using a lot more illustrations here in the future.  

Yesterday, my arguments with the mathematicians really hit one particularly fascinating area.  We were talking mostly about how police radar guns work.  It's an area where I can find a lot of on-line references which totally disagree with the beliefs of the mathematicians.  But, more than that, the discussions seem to have provided me with undeniable arguments to use against the mathematicians.  I just need to do some more research, and I may even try to contact my local police department to ask them some questions - if I can't find the answers on-line.

We all know that if I am in a police car on the side of the road and I aim a radar gun at a car coming toward me at 90 mph, the radar gun will show that car is traveling at 90 mph.  The question then becomes:  If I am in a moving police car traveling at 60 mph and I aim the radar gun at a traffic sign on the side of the road, what speed will the radar gun register for the sign: zero or 60 mph?

The unanimous answer from the mathematicians is 60 mph.  But, as I see it, that can only happen if the speed of light (c) emitted from the radar gun is added to the speed of the police car (v) I'm in.  That way, the outgoing light travels at c+v, it bounces off the stationary highway sign and returns at c.  The gun subtracts c from c+v and gets v, the speed of the police car (or highway sign).  But the speed of the emitter cannot be added to the speed of light.   I.e., a moving emitter cannot send out light that travels at c+v.  Light cannot go faster than c, the local speed of light.  That is a basic rule in Einsteinian physics and has been confirmed in countless experiments. 

Here's an image I created and put on imgur.com in about 10 minutes to illustrate this situation:

But I haven't been able to find a source that says if you are in a moving car and aim a radar gun at a sign next to the road, the speed of the sign will register as zero velocity.  (That is what you would get if the radar gun sends out light at c instead of c+v and gets back a signal traveling at c.  c-c=zero.)  It isn't that the sources say that is wrong, it's that the sources say nothing at all about that situation.  Or they don't spell things out.  For example, one source I found says,

Radar guns measure the relative velocity between the radar gun and the target. If the radar gun is moving, that has to be accounted for in some way. Most modern guns do this by detecting both the return from the target vehicle and the return from the ground or terrain in the vicinity of the target vehicle, and comparing the two to determine the velocity of the target relative to the ground or terrain.

There will be a number of returns in the radar gun’s received signal. The road, terrain, signs, trees, etc. will all be moving at one speed relative to the gun, and will return a signal Doppler-shifted by an amount corresponding to that velocity. Each vehicle that intercepts the beam will have a return with a Doppler shift that reflects its velocity relative to the gun. Most radar guns today will assume that the single largest return is the (presumably stationary) ground and the second largest return is the target vehicle, or vice versa, and report the difference in velocity between the two as the target vehicle speed relative to the ground.

So it is now concluded that YOU LIE, that you intentionally misquote and change the quotes to serve your needs. Totally fraudulent and disgraceful behavior. I will report this to your publishers and the author of that new book (anthrax/fbi thing on your site). We dont need liars like you.

1. Kennedy-Thorndike
2. Michelson-1913
3. Babcock-Bergman
4. Alvager et al
5. Beckman-Mandics
6. Filippas-Fox
7. Bretcher

Cheers, but given your track record, I’ll just read what Einstein himself wrote, have a look at the actual mathematics, and if I need to look elsewhere I’ll trust people like Bertotti who actually worked on the theories with him.

I’ve already seen your work, and I know what quality I can expect from people trying to seek attention with “independent papers”.

... it is essentially useless since the train/bank Gedanken is well understood and has never been misinterpreted by actual scientists. The only people who don't understand it are folks who do not have the math-physics background necessary to do so... like, for example, YOU, Ed...

 

The Earth as it exists today is at the center of the above illustration.  The outer edge of the disk is the universe as it existed 13.8 billion years ago.  The Cosmic Microwave Background (CMB) is the spider-web yellow and pink stuff just inside of the outer edge of the disk.  So, the CMB surrounds us on all sides.

The problem is reconciling the above image to an image of the Big Bang Universe timeline as shown in the image below:


  
In the second image we are located in one of the "present day" galaxies at the far right.  The Cosmic Microwave Background is the green stuff on the left, between "The Dark Age"which is in dark blue, and the pink and yellow stuff that represents the "Age of Inflation," the period when the material from the Big Bang expanded at a much faster rate than today's rate of expansion.

So, the disk version is like sticking a pin in our galaxy on the right in the second image and then spinning the second image around to create the disk version. 

The problem is that an idiot like Ed posts something up like this, and people who don’t know but want to learn think “wow, that’s amazing! They blew my mind!” giving them a completely false idea about cosmology and astrophysics.
And when someone corrects them, instead of listening, they double down after making lots of genuinely interested people think they’ve said something profound instead of profoundly stupid.

The problem with the center of the universe idea is that it derives from the phrasing of the Big Bang's singularity, or the word, "point" in the description, but that phrasing and wording can be a bit misleading to how we are familiar with thinking. It also relies on dispersion to remain static in momentum and growth. The latter of these we know at this point to not be the case, as there has been enough time for a variety of interactions to have taken place to cause asymmetrical formation in some interesting ways throughout the observable universe, and by derivative relationship, the whole universe model; less highly successful models such as general relativity be grossly wrong, for which we have no evidence to support that position.

The best way I can explain the problem is to imagine a single firework inside of a huge pressure chamber. It explodes, and from it millions of constituent parts fling out. Milliseconds after it explodes, for some reason, the pressure in the chamber changes, and all of the constituent parts push outward in equal direction and rate consequent of the pressure change. Many of the constituents, which flung from the first firework, themselves are highly volatile and when they touch, they create secondary explosions themselves, and from these even more constituent parts fling outward. These secondary explosions do not occur in uniform timing, inherently, therefore, there is an asymmetry embedded here. From here, constituents continue to explode when they interact. Imagine 6 million secondary explosions, and each of those leads to 6 million explosions, and repeat this process to the power of 10. All the while, the momentum of everything previously has been retained until acted upon by a new force giving new momentum.

since we know that the universe is expanding, if what you drew was true, the edge closest to the big bang point would be going slower the edge further would be going faster and the sides wouldn't appear to be moving at all.

We see equal movement in all directions.

Laura Herzog, thanks for your response, but, as I see it, you are viewing things from the Big Bang universe perspective. There it would be clear that the edge closest to the Big Bang point would be going slower, etc., because everything is moving away from the center, and the farther from the center you are, the faster you are moving.

From the perspective of someone on Earth in the center of the OBSERVABLE universe, however, you would NOT see that.

Think of the universe expanding like a released spring. The bottom of the spring is fixed to the point where the Big Bang occurred. A spring doesn't expand like an accordion where you pull on it to draw one side away from the other. A spring expands all along its length. The space between each coil increases. So, if you are on one coil, you will see the coil ahead of you moving away FROM YOU just as fast as the coil behind you moves away FROM YOU. You have no way of detecting your motion away from the point of the Big Bang because you cannot see that point.

So, as everyone here seems to agree, the space between galaxies is increasing just like the space between coils of a spring increases.

If you view things from the Big Bang perspective, everything is moving away from the center.

If you view things from the center of the OBSERVABLE universe, everything is moving away from YOU. 

To my pleasant surprise, today's featured image on NASA's Astronomy Picture of the Day web site is this depiction of the visible/observable universe:



The text that explains the image says:

How far can you see? Everything you can see, and everything you could possibly see, right now, assuming your eyes could detect all types of radiations around you -- is the observable universe. In visible light, the farthest we can see comes from the cosmic microwave background, a time 13.8 billion years ago when the universe was opaque like thick fog. Some neutrinos and gravitational waves that surround us come from even farther out, but humanity does not yet have the technology to detect them. The featured image illustrates the observable universe on an increasingly compact scale, with the Earth and Sun at the center surrounded by our Solar System, nearby stars, nearby galaxies, distant galaxies, filaments of early matter, and the cosmic microwave background. Cosmologists typically assume that our observable universe is just the nearby part of a greater entity known as "the universe" where the same physics applies.

The observable universe is a spherical region of the universe comprising all matter that can be observed from Earth at the present time, because electromagnetic radiation from these objects has had time to reach Earth since the beginning of the cosmological expansion. There are at least 2 trillion galaxies in the observable universe.^[7][8] Assuming the universe is isotropic, the distance to the edge of the observable universe is roughly the same in each direction. That is, the observable universe is a spherical volume (a ball) centered on the observer. Every location in the universe has its own observable universe, which may or may not overlap with the one centered on Earth.

Some parts of the universe are too far away for the light emitted since the Big Bang to have had enough time to reach Earth, so these portions of the universe lie outside the observable universe.

“Thanks to the third dimension of space, all the images making up the past and future are … not laid out with respect to one another like frames on a roll of film … But let us not forget that all motion is reciprocal or relative: if we perceive them coming towards us, it is also true to say that we are going towards them” (Bergson 142).

Time dilation is reciprocal.  If Δt is the proper time for a clock in S, then the two observers in S' would measure Δt' = γΔt.  If this effect were not reciprocal, there would be a way to distinguish between inertial frames.

It is a meaningless question in relativity to ask whether you are moving relative to me or whether I am moving relative to you, it doesn't matter.  All that matters in Special Relativity is the relative motion.  So, you can always think of yourself as standing still and make the source of electromagnetic radiation move to you or away from you, relative to you.

  

If physics wants to make use of time, it first has to define it. In an effort to do this, it becomes clear that a reference body is needed for this definition, and that the definition only makes sense relative to this reference body. It turns out that one can define time in relation to this reference body in such a way that, relative to it, the laws governing light’s velocity are valid. This definition of time can be made for reference bodies in any state of velocity. However, it so happens that the times of differently moving reference bodies do not coincide. There is a more detailed proof of this matter in my popular book about the theory of relativity. If two events happen simultaneously in two different locations judged from a reference body, they are not simultaneous if judged from another reference body moving relative to the first.

Based upon many experiments, physicists became convinced that light propagates through empty space at a speed of c = 300,000 kilometers per second, entirely independent of the velocity of the body that emits this light. Imagine a ray of light sent by the sun in a distinct direction. According to the law just stated, this ray travels a distance of c per second. Now imagine the sun later hurls a body into space such that it flies with a velocity of 1,000 kilometers per second in the same direction as the ray of light. This is easy to imagine. We now can similarly imagine this projected body as an alternative body of reference and ask ourselves: what is the propagation velocity of light in the judgment of an observer who does not sit on the sun but rather on the projected body? The answer seems simple. When the hurled body runs after the light at 1,000 kilometers per second, the ray of light advances against it by only 299,000 kilometers per second. The same situation would prevail if the ray of light were not sent by the sun but rather by the projected body, because we know that the velocity of light does not depend upon the state of motion of the light source.

Therefore, the considerations given above must have contained an error. The law of light propagation is the same, whether the sun or the projected body is chosen as the body of reference. The same ray of light travels at 300,000 kilometers per second relative to the sun and also relative to the body projected at 1,000 kilometers per second. If this appears impossible, the reason is that the hypothesis of the absolute character of time is false. One second of time as judged from the sun is not equal to one second of time as seen from the projected body.

Einstein’s general theory of relativity indicates that time dilation in response to gravity is directional in that an object in high gravity will have slower time than an object in low gravity. In contrast, Einstein’s theory of special relativity describes reciprocal time dilation between two moving objects, such that both moving objects’ times appear to be slowed down relative to each other.

The new paper makes the case that instead of being reciprocal, time dilation in response to movement is directional, with only the moving object undergoing time dilation.

The study, “Implication of an Absolute Simultaneity Theory for Cosmology and Universe Acceleration,” was published Dec. 23 in the journal PLOS ONE.

“Special relativity is supposed to be reciprocal, where both parties will experience the same time dilation, but all the examples that we have right now can be interpreted as directional time dilation,”[University of Georgia professor Edward] Kipreos said.

Time dilation is reciprocal.  If Δt is the proper time for a clock in S, then the two observers in S' would measure Δt' = γΔt.  If this effect were not reciprocal, there would be a way to distinguish between inertial frames.

So what is the number 1 dumbest belief in physics?

That has to be the view of the aether deniers.

Their view is that electomagnetic waves do not need a medium. To sum up their religion, it is that light, heat, radio etc. are all produced by "probability waves in nothing at all"! By denying aether they make the bold assertion that nothing at all can have properties. That the
"nothing" of space can have properties. When it comes to electromagnetic phenomena, they suggest that behavior can exist without anything which possesses the behavior. It's clearly an insane view.

Take the case of waves. Waves by definition are stresses in SOMETHING that can propagate outward from one point to another. Can one stress "nothing at all"? The question makes no sense at all. Hence if radio energy is waves then it is stresses of some kind in space that propagate outward. If space is "nothing at all" then WHAT is being stressed?

The whole aether denier theory has sunk into a morass where only blind religious belief can save it from the mental hospital. It clearly is NOT science, so what is it doing there?

Einstein wrote in his 1905 paper on Special Relativity:   

The introduction of a “luminiferous ether” will prove to be superfluous inasmuch as the view here to be developed will not require an “absolutely stationary space” provided with special properties, nor assign a velocity-vector to a point of the empty space in which electromagnetic processes take place.

He’s saying that his train-embankment experiments show that it can be determined by experiment that one object is moving relative to another (or moving faster than another) without any requirement for any “luminiferous ether,” and without all motion being reciprocal. 

A thought experiment (German: Gedankenexperiment,^[1] Gedanken-Experiment^[2] or Gedankenerfahrung^[3]) considers some hypothesis, theory,^[4] or principle for the purpose of thinking through its consequences. Given the structure of the experiment, it may not be possible to perform it, and even if it could be performed, there need not be an intention to perform it.

The introduction of a “luminiferous ether” will prove to be superfluous inasmuch as the view here to be developed will not require an “absolutely stationary space” provided with special properties, nor assign a velocity-vector to a point of the empty space in which electromagnetic processes take place.

Geometry sets out form certain conceptions such as "plane," "point," and "straight line," with which we are able to associate more or less definite ideas, and from certain simple propositions (axioms) which, in virtue of these ideas, we are inclined to accept as "true." Then, on the basis of a logical process, the justification of which we feel ourselves compelled to admit, all remaining propositions are shown to follow from those axioms, i.e. they are proven. A proposition is then correct ("true") when it has been derived in the recognised manner from the axioms. The question of "truth" of the individual geometrical propositions is thus reduced to one of the "truth" of the axioms. Now it has long been known that the last question is not only unanswerable by the methods of geometry, but that it is in itself entirely without meaning. We cannot ask whether it is true that only one straight line goes through two points. We can only say that Euclidean geometry deals with things called "straight lines," to each of which is ascribed the property of being uniquely determined by two points situated on it. The concept "true" does not tally with the assertions of pure geometry, because by the word "true" we are eventually in the habit of designating always the correspondence with a "real" object; geometry, however, is not concerned with the relation of the ideas involved in it to objects of experience, but only with the logical connection of these ideas among themselves.

It is not difficult to understand why, in spite of this, we feel constrained to call the propositions of geometry "true."

Something is "true" if it agrees with the laws of physics and has been demonstrated to be "true" by experiments. 

An observer is anyone who casts a mathematical net over time and space, establishing conventions to describe locations in space and points in time.

All in all, there is a plethora of different possible observers - each with a specific way of imposing mathematical order onto the world. The differences lie not only in the different location of the observers, or their different motions, but in the infinity of variations that is possible for conventions of how to choose space and time coordinates. In fact, in our definition, the term "observer" is equivalent to that of "space-time-coordinate system", or just "coordinate system".