FERMI'S QUESTION ... WHERE ARE THEY?

WHERE ARE THEY?

As the story goes, at lunch one day in 1950, physicist Enrico Fermi and colleagues were discussing the possibilities for life in the universe. It was noted that the chances for the existence of extraterrestrial civilizations are very high.   Our understanding of the origin of life on Earth, and the chemistry of life, and the abundance of planets throughout the galaxy, and the abundance of time itself dictates a near certainty of not just another, but a huge number of other technological civilizations.  Given a "technological" lifetime of merely a few hundred thousand years any one of these groups should have diffused through the entire galaxy.  Given that we have at least a billion year window for such a scenario one can imagine the stunning silence which must have greeted Fermi when he is said to have asked "Where are they?"

 In just three words Fermi got to the core of a very troubling thought. Certainly very few scientists believe the Earth is the unique location of life in the universe. Yet where are the probes, visits, messages from the ET’s that we might have received over the millenia?  Where is the tiniest bit of evidence, anywhere in our Solar System, of such contact that might have occurred over the last several million years?

THE SEARCH FOR INTELLIGENT LIFE ELSEWHERE (SETI, OSETI)

The Search for Extraterrestrial Intelligence (SETI) involving the attempt to detect extraterrestrial radio transmissions has been going on in some form or another since the 1960’s. A number of radio telescopes, including the Arecibo Radio Teslscope, have been part of the effort. The belief is that there is a chance that we may have been targeted by ET’s radio signals, or that there is a chance that we might luckily detect accidental leakage of radio waves used for communication on some distant planet.  This approach seems unreasonable on the face of it.  It seems from our own experience that the use of radio, in other than highly directed beams, will have a very limited lifetime in our technology. Thus leakage would be very slight. Directed radio beams are hardly a smart choice for interstellar communication due to lack of sufficient directivity and therefore signal gain.

The most reasonable approach for a search project would be based on a search for optical signals, frequently referred to as OSETI  ...   optical SETI.   We can speculate on what might be the very least approach ET's might use by considering, at the least, what would be leading edge for us today.

A feasible approach would be to drive a laser transmitter with megawatts of average power compressed into single nanosecond pulses at repetition rates under one such pulse per second. Such a laser pulse would then be focussed by a mirror of perhaps 10 meters diameter.  This would result in a transmission lasting a nanosecond which could be detected at a distance of thousands of light years.  That signal would exceed the intensity of the ET’s local star for one nanosecond as seen from the Earth.  An early serious attempt to detect such signals is being pioneered by Stuart Kingsley, an amateur astronomer in Columbus Ohio. He employs a sensitive high bandwidth optical detector at the eyepiece end of a ten inch telescope. There are currently at least two additional attempts in progress at observatories at Harvard University and Princeton University.  These two observatories are operating telescopes which are doing coordinated searches to allow positive confirmation of signals.

Thus far the optical searches have not succeeded in finding ET’s. This is not greatly surprising as we are not yet "watching" a large enough fraction of stars, planets to be precise, within say 20,000 or so light-years. To conduct a serious optical survey, we would need perhaps a hundred times the present effort. Considering the awesome nature of a positive result, the cost of such an effort does not seem excessive when compared to other leading edge scientific research areas. The longer range searches would need to be done at infra-red to improve signal detection through galactic dust.

While negative results from the searches is not extremely surprising yet, what is extremely surprising is the absence of any evidence of visits over the past millions of years, by either ET’s or their probes.

Is the problem due to the fact that communication and travel are limited in speed to c, the speed of light?  If indeed that is so, it is depressing indeed because while c seems to be fast, on an interstellar scale, it is extremely slow. If the closest interstellar civilization is say, 10,000 light years away, it will be at least 10,000 years before they can detect that we have reached our current technological level. Then, assuming they are interested in chatting, it would be another 10,000 years before we hear from them.

This is, to say the least, disheartening  ...  even more so now than in the past because we know now what space is whereas we had a very different view of the cosmos a few hundred years ago.  If indeed, we are stuck here, at this spot in our galaxy, unable to hear or be heard by any neighbors, it is a distressing, depressing situation we’ve been handed.  It’s kind of a mean trick by the designer, if there was one.

The big question is "is there really a universal speed limit?" How can this be? So light speed is limited … but why should that apply to everything else?  Let’s look a little more closely at the speed of light and it’s ramifications.

THE LORENTZ TRANSFORMATIONS

Our usual real world activities preclude our becoming aware of the consequences of relativity. Our daily velocities are much too slow. At very high velocities, high fractions of the speed of light, the behavior of clocks and rulers are completely anti-intuitive.  To understand this we must we must look at some very simple basics of the special theory of relativity. The general relativity theory includes the effects of acceleration and gravitation which are beyond the scope of this discussion.

If you wish, you can skip some simple math here and move on to the next page.

In special relativity, we can compute, using very simple equations, how clocks and distances appear when they are viewed in a frame of reference other than the one they are in. We consider a frame of reference to be a three dimensional set of length coordinates, X, Y, and Z which has in addition a fourth dimension, time, measured by clocks distributed throughout.  All clocks within a frame may be synchronized by having a master clock at the origin send a radio synch-signal (for example, at t=0) to all the clocks. Then at all clock locations, clocks are set by the synch-signal not to time=0, but to a time slightly later equal to the delay in time due to the time it took the synch-signal to reach the clocks. Simple enough.

We can simplify things considerably. Let’s consider two frames of reference in motion relative to each other. One frame is the O frame (X, Y, Z with O referring to the origin), and the other the O’ frame (X’, Y’, and Z’). By convention we are in the O frame. To simplify things, we’ll have the two frames each moving along their X and X’ directions.  In addition, the X and X’ axes are part of the same straight line. The equations which allow us to make the transformations between the frames are known as the Lorentz Transformations and in a simplified form are expressed as:

  t’ =   b(t – vx/cc) and x’ = b( x – vt )      where  b  = 1/sqrt( 1 – vv/cc)

  vv is v times v and cc is c times c where c is the velocity of light.

Since motions are only in the X direction, we can ignore transformations in the Y and Z directions to keep the equations simple.

Next, for further simplification, let the velocity of light, c, be considered to be 1, a dimensionless unit. It is a natural constant with the same "speed" property in any frame of reference. We can then define speed in general as a simple dimensionless ratio of the speed of some object to the speed of light.

Next we define the unit of time. Let us, for example, choose seconds. We may then define the unit of distance as the distance light moves in one second. In this case we thus call the distance unit a light-second. Thereby distance is also expressed using the unit of time e.g. a distance of 1.2 sec means the distance light travels in 1.2 seconds, or about 223,000 miles.

To summarize the units:

(Assuming our time unit is seconds)

Time                           seconds

Distance                     seconds
Velocity                     dimensionless
Velocity of light        dimensionless

For example, assuming the time unit is years: An object goes a distance of 0.5 years (1/2 light year) in 2 years, it’s velocity is 0.5 years/2 years = 0.25.

The Lorentz transformation equations as a result of normalizing the velocity of light to unity, now become:

   t’ =  b( t – vx )  and  x’ = b(x – vt)

For example, if we are in the O frame, and the O’ frame is zipping by us at say, 0.6 of the speed of light, then what is the value of x’ directly opposite to x where x=50 and our time (in the O frame) is t = 30 seconds?

   If v = 0.6    then    b = 1.25
     Then: x’ = 1.25(50 - 0.6 * 30) = 40
     Then: t’ = 1.25(30 - 0.6*50) = 0

Thus, as our two frames zip by each other, if we look across the way from our point at x=50 when our clock reads 30 seconds, we observe that directly opposite us at x = 50 is x’ = 40 and the clock there reads t’ = 0.

Remember, we have normalized our distance units to the speed of light so that the unit distance is always, for example, one light-second, or one light-week, or one light-year whatever your choice of time unit is.  In the above example, we used seconds, so x was 50 light-seconds, and x’ was 40 light seconds.

One light-second is 186,000 miles. One light-nanosecond (light-ns) is about a foot. So in the above example, if we used nanoseconds in place of seconds, then x would be 50 feet and x’ would be 40 feet.

THE RELATIVITY WINDOW

We can provide a nice visual representation of how special relativity makes the world look. See Fig. 1. Ignoring the scroll bars at the right side of the figure, the upper half represents the O’ frame, and the lower half the O frame. The view here is at the initial rest position. The primed frame, O’, is not in motion in this figure and its origin (shown at x’=0) at this time coincides with the origin of the O frame at x=0. The circles represent clocks; 11 clocks are shown for the O’ frame, and 15 for the O frame. One rotation of the hand on the clocks is 100 units of time, whatever time unit you choose. The clocks are separated by ten distance units, as perhaps ten light-seconds, or ten light-years as mentioned earlier --- in general as light-TU’s --- light-timeunits. The O’ clocks have their face readings shown next to the clocks. In the initial rest position, all clocks read zero, and x’=0 is directly opposite x=0.

When O’ is in motion, the assumption is made that at the instant when x’=0 is opposite x=0, the clock located at x’=0 will read t’=0. All clocks in the stationary frame, O, will also at that moment read zero. See for example, Fig. 2, showing a velocity of 0.4 and time t=0. Remember, velocity here is defined as a fraction of the speed of light so v=0.4 means the velocity is four tenths of the speed of light.

We will adopt the convention that in referring to the O frame, we will call it "our" frame, or the stationary frame. We might call the O’ frame the "other" frame or the adjoining frame or the moving frame or something else which should be clear from the context. Note that there are shown ten divisions between each of the clocks. Thus in the moving frame, at the clock reading t’=-8, the value of x’ is 20. If we were using years as the time unit, then that would be 20 light-years.

Notice in Fig. 2 the relativistic effect of such speed. Note the readings on the clocks at the various values of x’, and note the fact that x’ distances are now shorter than the x distances as viewed, of course, from our frame, the O frame.

Fig. 3 shows the situation for the values used earlier in the numerical example. The velocity is 0.6 and the time in the stationary frame is 30. The point, x = 50 light-TU’s is directly opposite x’ = 40 light-TU’s and the clock there shows t’=0. Note that distances in the moving frame are shorter than corresponding distances in the stationary frame as seen from the stationary frame. Note particularly the time on the other clocks. Some are earlier and some later than the time in our frame. Note that the clocks in the moving frame were set in the same manner as the clocks in our frame --- they all have the same reading simultaneously when viewed in the other frame --- yet no two of the moving clocks read the same as seen from our frame. The observance of simultaneity does not transfer between relatively moving frames.

The picture of time and distance between two moving frames of reference, as seen through our "Relativity Window", looks very unfamiliar in terms of everyday life. It seems hard to believe. The results in these pictures are based on two very simple first-year algebra equations, the simplified Lorentz Transformations shown earlier. You can check the numbers in the figures in minutes with a calculator. The only question at this point would be: are the equations themselves actually correct? The Lorentz transformation equations have been around for over a century and are basic to the Special Theory of Relativity. They have withstood the test of time including many very precise experiments. It should be noted that the transformations apply not just to light, but to all matter, anything, which can be defined by distance and time.

A question might be raised as to the validity of a "picture" of the scene as depicted in the figures. A picture, after all, uses light itself and that light takes time to reach the lens of a camera. We can overcome this objection by locating our camera somewhere along the Z axis, (coming out of the page) and far enough distant that there is negligible difference in distance from the camera to either side of the x axis within the view.

SIMULATING SIGNALS

We know of no particles or waves which go between two points at a speed which exceeds the speed of light. Entangled quantum particles do not exactly violate this speed limit because they cannot be used to send information between two points faster than light. Does this speed limit for electromagnetic waves exist for anything else we can imagine.  It seems to. Why should this be? How can we even analyze this or even imagine it when material particles cannot actually reach the speed of light and we know of nothing faster. Well, there is a way to actually imagine and simulate particles at speeds faster than light, FTL.  By simulation, I mean a nearly real, physical simulation.

On occasion I have been in an airplane, sitting at a window seat, and noticed the airport, at night from a distance while the airplane turns into line with the runway. At some point, the control tower switches on their strobing runway lights. These are a string of several dozen powerful strobe lights, set in a straight line for a distance of several miles leading directly to the leading edge of the runway. The lights are programmed to strobe in such a manner that they create the appearance of a moving ball of intense light travelling along the ground right up to the runway. This technique does fine job of creating very strong visual cues defining the edge of the runway.

How fast does that ball of light travel?  It’s not really a thing, but it does have a velocity. It can be easily programmed to have any value. It can move at a mile per second, or a hundred miles per second. If the distance between the first and last light is say 3 miles, and the time between the first and last strobe is approximately 16 microseconds, the ball of light is moving at the speed of light. Of course, to an observer, it will look just like all the strobes went off together and we see a single line of light. We can make the ball of light go even faster. We can make it go at any speed even infinitely fast. We can imagine a real experiment in which we have such lights, not necessarily stretching for miles, but a much shorter distance, which are programmed to fire at times to provide various selectable speeds from sublumic to superlumic velocities. The strobe lights can be placed alongside clocks and the clocks can read the time of the firing of the associated strobes. That arrangement can be placed on some platform which will then be our moving axis. That platform will then be given a relativistic (a high fraction of the speed of light) velocity past our stationary X axis. Our stationary frame contains cameras and clocks to record the corresponding values in the moving frame.

The reason for placing our "moving lightball" signal on a moving frame is because some very interesting things happen when such signals are viewed in different frames.

FASTER THAN LIGHT (FTL) SIGNALS

If you were to ask someone interested in technology or science or research what one scientific achievement would they like to see in their lifetimes,  it would probably be success in obtaining evidence of intelligent life elsewhere.  There are obstacles and the biggest one is the speed of light --- the same speed limit on any signal method we know of. 

Our fastest signal would take about 75,000 years to make a one way trip from Earth to the most distant part of our galaxy, the Milky Way Galaxy. The nearest fully developed galaxy, Andromeda, is two million light years away so a round trip for a light speed signal is four million years.

Is light fast? It certainly seems it is. A light or radio signal can go coast to coast (U.S.) in about one and a half hundredths of a second! That’s considerably faster than the blink of an eye. Despite such mind boggling speed, it takes about three years to get to the nearest star. When we think of communication with ET’s (extra-terrestrials) it is depressingly slow. Why can’t we do better? What is there about the velocity of light that is not only a speed limit for light and radio, but for any conceivable signal? Is it really a speed limit?

Let’s at least pretend we can ignore the speed limit by simulating FTL signals using our strobe lights and doing the analysis using the relativity window to help us visualize the results. If we’re going to simulate something that we hope some day to really do, should we start with an FTL signal or with an infinitely fast signal, an I-sig? One might reasonably guess that an I-sig is probably harder to generate than an FTL signal. Let me cut to the chase here. I found that if we produce an FTL signal in one frame, there is another frame in which it is an I-sig! This surprising fact is really well known but in a somewhat different context.

An I-sig is a signal which is simultaneously detected everywhere within the frame it is observed in.  Remember Einstein’s train which gets struck by lightning at both ends? A person in the middle of the train notes that light from both strikes reach him at the same time, and so he concludes the strikes were simultaneous. That is indeed the correct conclusion for his frame of reference. But for that to be so, since the train is moving, someone on the station platform sees the bolt striking the rear of the train first. Thus events which are successive in one frame might be simultaneous in another.

Thus a faster than light signal, with some measurable velocity in one frame may appear in another frame to be infinitely fast. Infinitely fast means, as mentioned earlier, that it gets detected simultaneously everywhere.  Consider Fig. 4. The moving frame is moving to the left at a velocity of 0.2 of the speed of light (-0.2c). We see here a picture of the situation at the moment of t=0, but this does not mean the action just started. In these pictures, the action has been going on and will go on before and after t=0. The picture is simply a snapshot at the moment of t=0. Next imagine that strobe lights are placed alongside each of the clocks (which read 0 or higher) in the moving, frame. Also, imagine that each strobe light fires at precisely the time, t’ showing on the clocks, which happen to be the very values of time recorded in this snapshot.  Notice that the t’ clock at each light, when each light fires, is approximately opposite a clock in the stationary frame which has exactly the same reading as every other clock in the stationary frame, in this case, zero. Thus when viewed from the stationary frame the simulated strobe-light signal is an I-sig because it is observed everywhere in our frame at the same time.

The strobe lights in the moving frame in Fig. 4, when viewed by the travelers in the moving frame, see something very different. They see a strobe firing at x’= 0 at the time t’ = 0.  Then, 2 TU’s later, they see a strobe at x’ = 10. And so on. At t’ = 10 TU’s they observe a strobe at x’ = 50. In the moving frame, they have a signal going right and that signal is observed in the our frame as going at infinite speed!  Next, let’s calculate the speed of the signal within the moving frame.  It is seen to move 50 distance units (light-TU’s) in a time of 10 TU’s. The velocity is thus, distance / time, 5 times the speed of light. So if our friends in the adjoining frame transmit an FTL signal at a special velocity, we in our frame enjoy an I-sig!  Note however, and this is important, for this to happen the signal in the adjoining frame must be an FTL signal. It can be shown that the FTL velocity must be equal to the negative reciprocal of v, the velocity of one frame relative to the other.  So we have achieved an I-sig by making something that might be easier to do, an FTL signal.

Why can we believe this simulation?  We believe it because we are defining the signal in the moving frame as a distinct set of space-time points each of which is viewed in the stationary frame.  The view in the stationary frame is computed in a straight-forward manner using the transformation equations for each point in the sequence.

SENDING MESSAGES - TACHYONS

Tachyon is a name that has been used for particles that go faster than light. Using Fig. 4 again, let’s consider that a tachyon is transmitted in the moving frame, to the right, at t’ = 0 with the velocity, as before, of 5 times the speed of light, 5c. That tachyon will move past each clock to the right of x’=0 at the same instant that the strobe lights referred to above fire. Thus we would expect any analysis of the motion of the tachyon to be identical with the analysis of the strobe lights. This is an important idea because tachyons have never been produced and perhaps can’t be produced, so how can we deal analytically with them?  If their motion, in time and position, can be equated to something that’s real, like the strobe lights, we can have faith in the analysis using the strobes. The use of the strobe lights represents an experiment that could really be performed.  Then we must trust the Lorentz equations.

At a very brief interval before t=0, we send a message from our location at x=0 to a space ship, the X’ frame. That message then gets encoded by our friends in the space ship into the tachyon and the tachyon goes on it’s way. That message then reaches our position at x=50 in zero time where the message is detected and read.  For this exercise, let us use units of time as hours.  Thus the message is read by our associates, in our frame, at x=50 light-hours, (about 33,500,000,000 miles) out at the edges of our solar system.  Actually there was nothing special about the choice of the velocity of the space ship that helped us send that I-sig message by generating an FTL signal in their frame.  A single requirement is that their direction is along our negative x axis since we require an FTL signal along the positive x axis.  An I-sig would result for any velocity of the other frame if the FTL velocity chosen were the negative reciprocal of the velocity of the space-ship.

We wish next to reply, or return a signal from that point located at x=50 light-hours.

Consider Fig. 5. Let us now use the same stationary frame as before, but now we consider that the origin is located, for computational simplification, at that distant point 50 light-hours away to the right.  We will now, however, use a different adjoining frame, this one going to the right. We are therefor now out in space and the Earth is at x= -50 light-hours. The velocity of the adjoining frame is +0.2, and a tachyon velocity is assumed to be -5.  Thus an FTL particle is launched to the left in the moving frame. With a velocity of -5, that tachyon will hit each of the clocks to the left of x'=0 at exactly the times shown on the clocks so once again that will appear as an I-sig in our frame. We can once again transmit some information to the space ship which will be encoded onto the tachyon, That message will arrive back at the Earth in zero time and the total message delay will therefor be only the time it took to compose the reply message.

CUSTOMIZING THE I-SIG

In order to help us visualize the tachyon’s position and movement we include in Fig. 6 a short vertical red line. That line represents the position of the tachyon at the time of the snapshot. In Fig. 6 we assign a value of -4.99 to the velocity of the tachyon. The tachyon is seen at the origin in both systems, x'=0 and x=0 at our time t=0. The tachyon time is also t’=0 at this moment. Fig. 7 shows the scene for time at 0.01 time-units, or 0.01 hours in our frame. The tachyon has moved to the left and appears at x’=25 light-hours and at a time value of about t’ = 5.01 hours.  (time = dist / vel = 25 / 4.99 = 5.01).   In Fig. 8 we advance the time in our frame to 0.02 hours and we see the tachyon at approximately x = -50 light-hours or approximately back at Earth. Thus this message time took about 0.02 hours for a round trip by using an I-sig from the Earth out to the x=0 point in Fig. 8. Earlier, using Fig. 5 we found that a tachyon in the moving frame, with a velocity of 5 going to the left, would produce infinitely fast message reply.

We have been using a conveniently established frame to zip by at the right time to receive our signal and to rebroadcast it as a left going FTL signal. But there is no size requirement imposed on that frame. It could be a very tiny device traveling at a high speed along a small racetrack shaped path fully contained within our laboratory. The device has a tiny receiver which receives our signal and then with a tiny on-board FTL transmitter sends the FTL signal.

Now for something interesting:   In Fig. 9 we launch a slightly faster tachyon in the moving frame at a velocity of -5.01, going left. In Fig. 10 we see the picture at t=.01 hours. The tachyon is not to be seen! At this moment of time as seen from our frame, there is no clock which together with the x’ value of its position satisfies the velocity, -5.01, of the tachyon. For example, the moving frame clock at x’ = -10 reads 2.01. But for a tachyon moving at a velocity -5.01 it would have arrived at that clock at 10.07. Similarly with each position along the negative x’ axis. The times shown at the corresponding distances at no point correspond to a possible position of the tachyon at that time. In a sense, the tachyon is beyond infinity to the left and is an imaginary quantity for this value of time (t = +.01) in our frame. As it turns out, this is true for any value of time greater than zero in our frame.

Next, in Fig. 11, using the same conditions as before, we change the time in our frame to t = -.01 hours. The tachyon appears! The tachyon appears, in our frame at least, seemingly before it was launched. Tachyons are questionable, but we made the case that strobe lights provided a realistic simulation. Let’s go back to strobe lights --- how would that look? It would look exactly the same. The explanation is that the strobe lights were programmed. Each strobe would fire at a programmed time regardless of what it’s neighbor strobe does. Seeing a strobe firing before t=0 has no significance because it did not depend on a strobe firing at t=0. With a tachyon, however, this is strange because we are seeing the SAME tachyon at a time before it was launched!

Next, in Fig. 12 we move the clock to t = -0.02. The tachyon is now at about x = -49, or back approximately to Earth. We had to set our clock to -0.02 hours in order to locate the tachyon back near Earth. The tachyon is moving backward in time! ( See: "A Closer Look At The FTL Signal").

We now could have, as we showed earlier, sent a message to a point 50 light-hours away in zero time, and then received a reply 0.02 hours earlier --- before we sent it! Imagine --- we could send the price of a stock to an associate 50 light-hours away and then he would send us back that same price and we would receive it earlier in time. Sounds like a great get-rich-quick scheme.

Well, one indisputable truth of life is that there is no guaranteed way of beating the stock market. Thus this stock market observation highlights a fatal flaw in our assumptions about tachyons. This is most disappointing.

 IS THERE A WAY OUT?

If the speed of light imposes a speed limit on communication then we have good reason to be very pessimistic about ever communicating with ET’s. As fast as the speed of light seems to us, it is snail speed in terms of the scale of just our own galaxy. The problem, however, seems to hinge on just one fact: FTL signals lead to I-sigs which lead to time reversed signals and violations of cause and effect. Setting aside over-imaginative ideas such as dimension branches leading to multi-universes which hide those violations, there just might be a way out. If a signal can be found which, despite having super-lumic speed does not cause such violations, then perhaps there is hope.

 What follows here is pure speculation and not meant to be taken too seriously --- but on the other hand --- not to be entirely dismissed either.

Consider the possibility that there is a single, special frame of reference. The velocity of this frame, because it is special, is zero. We will discuss presently What the special frame of reference might be.  Let’s hypothesize the existence of some fort of disturbance to the spacetime framework of the universe which propagates at intinite speed …  an infinitely fast signal, the I-signal.  On important restriction, however, is that this signal is clocked at intinite speed only in the special frame.  In all other frames it shows up as an FTL signal.  The I-sig energy might diminish with distance according to some power law but that’s not important.

Having thus defined a single special frame, and a signal of infinite speed only in this frame it becomes obvious that this will not result in any cause-and-effect violations. This is because in the special reference frame there is no possibility that the receipt of an I-sig somewhere can produce another I-sig which arrives anywhere earlier than the original signal. There is no way to defeat this in any other frame because it is well established that a sequence of two space-time points at the same location in one frame can not be reversed in any other frame of reference.

We certainly might consider the possibility of a medium, an aether, to support the I-sig.   Haven’t we outruled the possibility of an aether? Actually the Michelson-Morley interferometer experiments disproved the existence of a luminiferous aether … a light bearing aether.  We hypothesize here an aether which supports the propagation of the I-sig, an I-aether. 

Every frame of reference, other than the special one, does not measure infinity as the speed of an I-sig as defined above.  This is easy to see from the figures shown earlier because if there is an I-sig in one frame, the other frame’s clocks have different readings along the X axis. A consequence of this is that any frame in motion relative to the special frame can measure a non infinite value of an I-sig, and thus, in effect, has on board an absolute speedometer.

We have become very used to rejecting any notion of an absolute frame, or absolute velocities. The question that immediately comes to mind is --- what can possibly be a reference for the absolute frame? Actually, there is a reference. Every point in the universe is equal to any other point in the sense that regardless where one is positioned, all galaxies appear to be receding and the same Hubble constant holds true everywhere. The universe appears isotropic. If enough galaxies are observed and their velocities relative to ourselves were summed as vectors, the result should be close to zero. If it is not, that indicates we have a motion relative to the universe. Consider the analogy of the expanding balloon and ants on the surface. If all ants are still the vector average of all the recession speeds should approach zero. This "stillness" on the surface, analogous to a stillness in space-time is referred to as having a co-moving velocity. If all galaxies are exactly co-moving, including ours, we would measure precisely the theoretical Hubble velocity for each. Let us consider that at any point in the universe, the co-moving velocity is the special velocity and a frame moving with that velocity is the special frame. Thus all special frames are precisely co-moving. The I-aether will have to be considered to be expanding in the same manner as space-time is. If not the aether will have differing "velocities" everywhere with respect to co-moving objects and we will assume it does not.          

    
To summarize, we suggest an I-sig has in infinite velocity and its medium is the I-aether. Thus non co-moving objects have a velocity with respect to the aether at their location. Quite different from the luminiferous aether.  The I-aether causes the measured velocity of the I-sig to be non-infinite if the object is non co-moving and permits the non co-moving velocity to be measured within the frame itself.  The idea of measuring an absolute velocity is a serious departure from special or general relativity.

 CONCLUSION

It is depressing to accept that the speed of light is a limit to communication as well as travel. If that were true we are alone and will probably be alone for millions of years if not forever. An important reason for the speed limit is a violation of cause and effect that comes with FTL signals. As we have seen above, there is perhaps no violation for a unique infinitely fast signal which has the same infinite speed at every co-moving point in the universe. Perhaps the absence of violations of fundamental requirements of science makes it possible. Believing it possible should make it easier to be discovered.

SO … WHERE ARE THEY?

Perhaps the answer to the question is found by turning the question around. Perhaps they are the ones asking this question and are waiting for us, or any others to discover I-sig communication in order to start a conversation.

---        APPENDIX     --

A CLOSER LOOK AT THE FTL SIGNAL

 We will look at some simple math to analyze the FTL signal. Once again, a possible objection might be that there might not even be such a thing so what validity does this analysis have. We should remember that we can simulate an FTL signal with our runway strobe lights analogy and that is a real experiment and the Lorentz equations would correctly describe situations such as that.  The Lorentz equations lead to an expression which allows us to add 2 velocities.  Given the case where we have an object which has a velocity u' in another frame when the other frame has a velocity v relative to ours, the velocity, u, which we observe is given by:

 u = (u’ + v) / (1 + u’ v)    where, once again, the speed of light is equal to 1.  Intuition says we might simply add the two velocities but that is not the case.

 Notice that if the velocity of the signal in the other frame is equal to the speed of light, u'=1, then

 u = (1 + v) / (1 + v)  =  1   thus the speed of light is observed to have the same value in any frame of reference.

 As another example:  If the moving frame has a velocity of 0.9, and a signal in it has a velocity of 0.9, we in the stationary frame observe the signal to be moving at

u = 1.8 / 1.81 = .994 ,  and with normal signals this result never exceeds the speed of light. 

 Next, we'll allow ourselves to imagine the signal velocity, u', to exceed 1 thus exceeding the speed of light.

 Note then, in the equation above, that as the product u’ v approaches -1 the value of u approaches infinity.

 This happens when u’ = -(1/v) as we have noticed, for example, in Fig. 7.

Consider, a frame velocity v = 0.2 and a tachyon velocity u’ = -4.9. Substituting in the above equation we get  

u = -235 !

For a tachyon velocity of -4.99 the velocity observed in our frame is: u = (-4.99 + 0.2) / (1-4.99*0.2) = -2395!  In Fig. 7, the position of the tachyon, given by the vertical red line, is approximately x= -2.4. Since the time of Fig. 7 is .01, the velocity, u, based on Fig. 7 is approximately -2.4 / .01 = -2400.

 Now, here’s something curious. Consider a tachyon velocity u’ of -5.01 for the same case as above with v = 0.2. Now the above equation gives us:

u = +2405 .

The problem here is that this result indicates a velocity to the right whereas the tachyon was launched to he left. If we look at Fig. 9 we see that movement to the right corresponds to negative time values in the moving frame! We can thus ignore any solutions which give us positive values of x as being unrealizable. Clearly, since the tachyon is launched to the left, it must go to the left. Next, in Fig. 11 we set our clock to t = -.01 and the tachyon appears! We have a result which has consistent motion in the moving frame but goes backward in time in our frame!  This result is realizable and would be confirmed by an experiment with strobe lights.  There is nothing "improper" with time reversals between frames provided only that they CANNOT be used for communication to send messages back in time.  Furthermore, time reversal cannot be observed at a single point when viewing another frame.