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Tightening the Beam: Correspondence on PROCSIMA

Yesterday’s post on PROCSIMA (Photon-paRticle Optically Coupled Soliton Interstellar Mission Accelerator) has been drawing a good deal of comment, and I wanted to dig deeper into the concept this morning by presenting some correspondence between plasma physicist Jim Benford, a familiar face on Centauri Dreams, and PROCSIMA’s creator, Chris Limbach (Texas A&M Engineering Experiment Station). As we saw yesterday, PROCSIMA goes to work on the problem of beam spread in both laser and particle beam propulsion concepts.

In my own email exchange with Dr. Limbach, he took note of the comments to yesterday’s Centauri Dreams article, with a useful nod to a concept called ‘optical tweezers’ that may be helpful. So let me start with his message of April 4, excerpting directly from the text:

I took a quick glance at the comments, and I see that the laser guiding (i.e. waveguide) effect is fairly well understood, but the guiding of the particles is less clear. I admit this is the less intuitive aspect and the weak interaction requires special consideration in the combined beam design. But to give a general sense, we are taking advantage of the same effect as optical tweezers (https://en.wikipedia.org/wiki/Optical_tweezers) except applied on the level of atoms instead of nanoparticles. That is, the atoms in our neutral beam are drawn to the high intensity region because they can be polarized.

I hope your readers are as excited about this project as I am!

Personally, I do find the project exciting because I’ve been writing about the problems of keeping a laser beam collimated for an interstellar mission ever since I began digging into Robert Forward’s papers back around the turn of this century. You may remember the vast Fresnel lens that Forward proposed in the outer Solar System as a way of collimating the laser beam for interstellar use. Avoiding such colossal feats of engineering would be a welcome outcome!

We’ve examined the pros and cons of particle beams in these pages as well, learning that there is controversy over the question of whether neutral particle beams would not likewise be subject to beam spread. Geoff Landis has argued that “…beam spread due to diffraction is not a problem,” while Jim Benford has offered a strong disagreement. See yesterday’s post, as well as Beaming to a Magnetic Sail.

The PROCSIMA idea combines a neutral particle beam and a laser beam to eliminate beam spread and diffraction in both. If it can be made to work, it seems to offer long periods of acceleration for beamed interstellar sails and high delta-V. An Alpha Centauri mission with a flight time of about 40 years becomes possible with a spacecraft reaching 10 percent of the speed of light. Dr. Limbach had been discussing the idea with plasma physicist Benford before the NIAC Phase I award was granted, and they engaged in further correspondence about the idea shortly after.

Here is an excerpt of a Benford message from last August with regard to PROCSIMA. The paper he refers to is a fleshed out and much more detailed version of Jim’s Sails Driven by Diverging Neutral Particle Beams, which ran in these pages in 2014. It has been accepted at the Journal of the British Interplanetary Society, where publication is expected this fall:

Chris: I made more revisions on my paper than I had expected, and submitted it to JBIS last night. It is attached.

On your laser tweezers idea, I assume the wavelength of the laser will be much much larger than the size of the atoms. So you will treat their interaction as electric dipoles in the electric field of the laser. What intensities of laser would you need in order to defeat the divergence of such a beam? The beams themselves will probably be on the order of 10 cm-1 m in diameter and so the laser beam will be of comparable size, I suppose.

Of course, the introduction of a powerful laser adds a complexity to the overall system, but the remarkable focus that you are expecting would be very interesting to see.

I will keep your idea to myself, but I’m sure that the community, in particular Gerry Nordley, Adam Crowl and Geoff Landis, would be very interested to hear about it.

By the way, there is at a meeting that’s entirely relevant to this, in October in Huntsville Alabama. It’s the Tennessee Valley Interstellar Workshop, which expects to have about 200 people attending. I attach their newsletter. Unfortunately, they don’t do streaming, so one has to attend to hear the talks!

Image: Beamed propulsion leaves propellant behind, a key advantage. Coupled with very small probes, it could provide a path for flyby missions to the nearest stars. PROCSIMA studies the possibility that the problem of beam spread can be resolved. Credit: Adrian Mann.

Chris Limbach was unable to attend the TVIW meeting, but he replied to Benford in a message on August 15:

Thank you for your quick reply. My timing was fortuitous! Also, thank you for offering to send an updated version of your forthcoming paper.

I would like to hold this concept closely until I submit the full proposal, but I will describe the general outline. I only ask that you do not share with anyone in the near-term.

Essentially, I have discovered that a neutral particle beam and high intensity laser beam can be combined in such a way as to simultaneously eliminate the problems of diffraction and beam divergence. This is possible because of physical mechanisms that 1) attract atoms into regions of high optical intensity (i.e. toward the center of the laser beam) and 2) provide an optical focusing effect in regions of high atom density (i.e. toward the center of the neutral beam). If these two effects can be balanced then both the neutral beam and laser beam will propagate, together, without any divergence. After running the numbers, I believe a spot size of 5 meters could be maintained over several astronomical units (!).

I am still concerned that higher-order effects will cause problems, but I believe the basic numbers work out and the concept warrants further investigation/optimization. I am interested in your paper because the neutral beam divergence will place fundamental constraints on certain parameters (e.g. particle density, laser beam intensity, …) for this concept.

After the August messages, the correspondence ended until news of the recent NIAC funding, about which Dr. Limbach informed Jim Benford, leading to my own conversation with Jim and agreement with both scientists that this correspondence could be reproduced to help clarify aspects of the PROCSIMA project. As I mentioned yesterday, there are two levels of funding at NIAC, with PROCSIMA currently receiving Phase I funding. After Phase I’s initial definition and analysis, a Phase II grant can be applied for to develop the concept further.

We’ll await the completion of the Phase I study with great interest, given that a successful PROCSIMA would deliver the best of both the laser and neutral particle beam ideas, while removing one of their biggest problems. If it works, this idea should be readily scalable, pointing to its uses in fast missions throughout the Solar System and interstellar precursors far beyond the heliosphere. The idea has to be shaken out through this initial NIAC work, but it is certainly gaining the attention of the beamed propulsion community.

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{ 44 comments… add one }
  • ljk April 5, 2018, 9:51

    Quoting from the main article:

    “By the way, there is at a meeting that’s entirely relevant to this, in October in Huntsville Alabama. It’s the Tennessee Valley Interstellar Workshop, which expects to have about 200 people attending. I attach their newsletter. Unfortunately, they don’t do streaming, so one has to attend to hear the talks!”

    Perhaps they should start doing this, or at least make the lecture videos available ASAP. They should also seriously consider putting these lectures into book form for wide dissemination.

  • Isaac Kuo April 5, 2018, 10:40

    Interesting. So, that helps explain how the particles are attracted to the center of the beam. I’ll admit I don’t truly comprehend the optical tweezers effect for dipoles.

    The discussed beam size of around 5m in diameter and multi-AU range are in the same ballpark as my ideas for X-ray FEL focused by zone plate, but without the annoyingly large ~100m-1km diameter zone plate spaced annoyingly ~1 light second away from the beam engine. (And annoyingly, the target needs to be a swarm of sailbots for a sail-beam like scheme, or the target needs to have a lengthy “ribbon” sail in order to catch all of the X-ray photons.)

    • Brett Bellmore April 5, 2018, 15:17

      It’s pretty simple. When the atom or molecule is exposed to an electrical field, the positive charges get pushed in one direction, the negative charges in the opposite direction. It develops a “dipole”. If the field is uniform, that’s all that happens.

      But if the electrical field varies in strength, the one side of the atom is in a stronger field than the other side. So it’s attracted towards the higher field strength direction more than the other side is repelled, and a net force results.

      The same goes on with magnetic fields, by the way.

      Since electromagnetic radiation involves electrical and magnetic fields, stronger areas of EM radiation attract dipoles for the same reason static fields do. But not as much, because the dipole doesn’t have time to fully polarize before the field flips. The higher the frequency, the weaker the effect gets, for that reason.

      So, I wonder how the proposal would work if you used microwaves?

      • Isaac Kuo April 5, 2018, 16:57

        Thanks, Brett Bellmore! Sounds like this effect is going to require some really powerful lasers to work.

        • Matterbeam April 5, 2018, 21:49

          It will depend on the temperature of particles. Higher temperature means higher lateral velocity, meaning a stronger laser field is needed to prevent their spread.

  • Charley April 5, 2018, 11:07

    “What intensities of laser would you need in order to defeat the divergence of such a beam? ”
    what causes divergence of such a beam (within this context)?

    • Brett Bellmore April 5, 2018, 15:25

      Just the fact that there’s no mechanism to produce a particle beam where the particles have no sideways momentum at all. It would be equivalent to the beam having a temperature of absolute zero, physically impossible to achieve.

      But in principle you could you Doppler cooling to get that sideways momentum down to the point where it was practically negligible. (An inch every 30 seconds, perhaps.) That’s one of the arguments here, whether it’s possible to do that in practice, not just in principle.

      • Michael April 5, 2018, 17:58

        Once we get into the high relativistic range time dilation slows everything down in the moving frame including atoms movements.

  • Alex Tolley April 5, 2018, 11:42

    As the particles must travel more slowly than the laser light, I take it that beyond the front of the particles, the laser light will diverge again.

    The forces collimating the beam must be far stronger than the effect of gravitation on the particles, otherwise, I would expect the particle and light beams to diverge in a gravitational field. However, is there any guarantee that the beam’s path will not be influenced by gravity, which would make it difficult to ensure that the beam hits its target accurately?

    • Ron S. April 5, 2018, 14:15

      “As the particles must travel more slowly than the laser light”

      I keep seeing this said but it isn’t really true. In every reference frame, including that of the beamed particles, the photon speed will be measured as c. What changes is that the energy of the photons will be reduced (wavelength increased) from that emitted by the laser.

      Presumably that’s accounted for, but I don’t know, and the rest of the science here seems to be outside my own knowledge.

      • Michael April 5, 2018, 18:00

        The laser light will pass the atoms at the speed of light it is their wavelength that the atoms see that will change.

        • Alex Tolley April 6, 2018, 12:12

          To clarify. From the particles’ POV, the laser light will be passing them at c due to the time dilation effect. To an external observer, the laser light will move faster than the particles based on their velocity differential. If the particles are relativistic, traveling at 0.9999… c, then the laser beam front will appear to slowly move ahead of the particle beam front.

          • Ron S. April 6, 2018, 16:40

            With regard to beam operation more useful (and pertinent) is what the photons and the particles “see” from their perspectives. Using Earth’s reference frame makes the calculations more difficult and carries the risk of making conceptual errors about how they interact. That was my point.

  • Matterbeam April 5, 2018, 13:54

    Hi!

    Me and my Discord folks are fascinated by this concept, but the consensus right now is that the intensity of the laser scales with the velocity of the particles, requiring potentially tens of gigawatts to hold together a 0.1C beam.

    Could we get an idea of the scales this concept works on? Is is practical to use relativistic particle beams?

    Thanks.

  • Antonio April 5, 2018, 17:53

    I still don’t know whether they will do lab work or not.

    • Andrew Palfreyman April 5, 2018, 22:50

      Almost certainly at least in Phase II, I would have thought. But $500,000 isn’t enough to fund space-based experiments of the type required here.

      • J. Jason Wentworth April 7, 2018, 8:43

        I’m not sure about that; an experiment that could fit aboard a sounding rocket could fly quite cheaply, because these suborbital rockets–except the Black Brant and Oriole vehicles–use surplus military guided missile rocket motors, with machine shop-fabricated payload housings, interstage adapters, and–in some cases–fins. (When I was the volunteer range historian at the Poker Flat Research Range, I helped the range acquire 232 surplus HYDRA-70 (2.75″ [70 mm] diameter FFARs–Folding-Fin Aircraft Rockets–and several dozen HYDRA-70 warhead casings from the Toelle Army Depot. The cost of the rocket hardware was basically just the shipping cost.)

        • Brett Bellmore April 8, 2018, 18:51

          No, he’s right: The power levels necessary to actually test this effect would be quite high, you’re not going to test it with anything cheap.

          What’s first required, though, are very detailed simulations.

  • Rob Flores April 6, 2018, 1:06

    I am greatly exited by the Idea of sending micro payloads
    to nearby star systems. I’ve always thought it a tough
    sell politically however both in the halls of congress and academia, if the mission arrival is over 20-25 years. Other than the Centauri system, No G or K type stars are close enough to meet this political need.
    But if you put infrastructure out it may turn out that advances in micro payloads mass reduction over time will allow us to push interstellar probes to double or triple the speeds of older payloads using the same beamed power hardware. So maybe the beamed power infrastructure can be viewed as a permanent capability gained, rather than a handful of launches into deep space. That would sell better politically

    • J. Jason Wentworth April 9, 2018, 5:48

      I agree. Such beam projectors would also be–like an airport with its runways (or a rocket launch complex)–capital equipment items; literally, they would be investments, because they could be used over and over and could be upgraded over time. If we ended up sending later, faster, micro-payloads that overtook some earlier ones, so what? We would get multiple looks at the star systems in question, which would be a “win-win” situation.

  • Bynaus April 6, 2018, 2:53

    Its an exciting idea, but wouldn’t pointing such a tight beam be a problem?

    There could be other interesting applications, which do not depend as much on pointing: such a powerful and concentrated beam could be aimed at the icy surfaces of atmosphere-free bodies (like comets, outer solar system satellites and KBOs) to heat them and create ejecta plumes, which can then in turn be analyzed for their composition.

  • Anton M. April 6, 2018, 6:52

    OK, the guys are going to make it a neutral beam, basically a gas stream. Bad news: when you have a high-intensity beam propagating in transparent media, all it takes to make a KABOOM is a single optical imperfection, e.g. a dust particle or maybe an ionization track from a particle crossing the stream, or maybe even a density fluctuation. Then you have a process not much unlike detonation except the energy goes from one direction rather than stored in the volume. If it grows faster than acoustic relaxation disperses it, you get problems. This is why pulsed lasers make such terrible weapons BTW, but I digress. The interesting question is if the beams will mend themselves after the (inevitable) optical spark, or just break apart.

  • Adam Crowl April 6, 2018, 7:02

    I’m going to have to ask Jim more since he’s invoked my name.

    • Michael April 6, 2018, 15:59

      Awkward…but do tell us how it work out.

  • Harry R Ray April 6, 2018, 11:00

    Talking about “beams”: Michael Hippke has a very interesting paper out stating that the beam(s)used to propel the “Breakthrough Starshot” spacecraft to Proxima Centauri would appear as NAKED EYE “stars” out to kiloparsec distances in the very distant future. Star of Bethlehem anybody?

    • J. Jason Wentworth April 9, 2018, 5:53
      • Harry R Ray April 9, 2018, 9:32

        While we are on the subject of naked-eye stars. The much ballyhooed March 24,2017 superflare on Proxima Centauri was a PIKER compared to the one detected by the Evryscope a year earlier! THAT ONE would have been able to be seen UNAIDED for a few minutes by anyone who was looking at the right part of the sky at exactly the right time, just like the Clarke Blast would have!

        • Michael C. Fidler April 9, 2018, 22:36

          THE FIRST NAKED-EYE SUPERFLARE DETECTED FROM PROXIMA CENTAURI.

          “Proxima b is a terrestrial-mass planet in the habitable-zone of Proxima Centauri. Proxima Centauri’s high stellar activity however casts doubt on the habitability of Proxima b: sufficiently bright and frequent flares and any associated proton events may destroy the planet’s ozone layer, allowing lethal
          levels of UV flux to reach its surface. In March 2016, the Evryscope observed the first naked-eye visible superflare detected from Proxima Centauri. Proxima increased in brightness by a factor of ∼68 during the superflare and released a bolometric energy of 1033.5 erg, ∼10× larger than any
          previously-detected flare from Proxima. Over the last two years the Evryscope has recorded 23 other large Proxima flares ranging in bolometric energy from 1030.6 erg to 1032.4 erg; coupling those rates with the single superflare detection, we predict at least five superflares occur each year. Simultaneous
          high-resolution HARPS spectroscopy during the Evryscope superflare constrains the superflare’s UV spectrum and any associated coronal mass ejections. We use these results and the Evryscope flare rates to model the photochemical effects of NOx atmospheric species generated by particle events from this extreme stellar activity, and show that the repeated flaring is sufficient to reduce the ozone of an Earth-like atmosphere by 90% within five years. We estimate complete depletion occurs within several hundred kyr. The UV light produced by the Evryscope superflare therefore reached the surface with ∼100× the intensity required to kill simple UV-hardy microorganisms, suggesting that life would struggle to survive in the areas of Proxima b exposed to these flares.”

          https://arxiv.org/pdf/1804.02001.pdf

          PROXIMA CENTAURI the Death Star.

          Three interesting details in the light curve from the Evryscope camera shown in figure 1: After the flare peaks they are showing three weaker flares at about 8 (d), 27 and 55 minutes, could these be reflections of the original flare from planets orbiting further out from Proxima Centauri. If a planet at the 8 minutes mark was at its greatest elongation that would be about 100 million miles or around 1 AU from Proxima Centauri. They also mention another Evryscope camera simultaneously observing the event showed a very similar light curve offset by 2.2 seconds. Could that be a reflection from Proxima b?

          • Michael C. Fidler April 10, 2018, 1:52

            Could this be reflections from the dust rings?

            ALMA DISCOVERY OF DUST BELTS AROUND PROXIMA CENTAURI.

            https://astrobites.org/wp-content/uploads/2017/11/Screen-Shot-2017-11-13-at-21.27.12.png

            “Proxima Centauri, the star closest to our Sun, is known to host at least one terrestrial planet candidate in a temperate
            orbit. Here we report the ALMA detection of the star at 1.3 mm wavelength and the discovery of a belt of dust orbiting
            around it at distances ranging between 1 and 4 au, approximately. Given the low luminosity of the Proxima Centauri star, we estimate a characteristic temperature of about 40 K for this dust, which might constitute the dust component of a small-scale analog to our solar system Kuiper belt. The estimated total mass, including dust and bodies up to 50 km in size, is of the order of 0.01 Earth masses, which is similar to that of the solar Kuiper belt. Our data also show a hint of warmer dust closer to the star. We also find signs of two additional features that might be associated with the Proxima Centauri system, which, however, still require further observations to be confirmed: an outer extremely cold (about 10 K) belt around the star at about 30 au, whose orbital plane is tilted about 45 degrees with respect to the plane of the sky; and additionally, we marginally detect a compact 1.3 mm emission source at a projected distance of about 1.2 arcsec from the star, whose nature is still unknown.

            https://arxiv.org/pdf/1711.00578.pdf

            I had not noticed the e marked at 80 minutes in figure 1, that could be sheperd planet or ring at 10 AU.

            http://francis.naukas.com/files/2018/04/Dibujo20180409-naked-eye-brightness-superflare-from-Proxima-arxiv-1804-02001.png

            The outer cometary belt at 30 AU would of brighten about 240 minutes or 4 hours after the flare.

            The light curve offset by 2.2 seconds could not be Proxima b, it would be brightening about 24 seconds after the flare at its orbit of o.o5 AU. Not sure what this could be, if it was a 2.2 second delayed effect or just data binning?

            • Harry R Ray April 10, 2018, 9:37

              Could a K2 civilization use a giant mirror situated at 0.005 AU to DEFLECT a flare of this type AWAY from their homeworld? One problem with this comjecture would OBVIOUSLY be the LACK of a TRANSIT SIGNATURE, but; if the mirror was a COMPACT STRUCTURE that UNFURLS to its maximum size JUST BEFORE a flare occurs, its transit signature may not be detectable.

              • Michael C. Fidler April 10, 2018, 11:54

                It depends on the orbit of the homeworld. What I find interesting is that no one is even suggesting this may be the way station to our planet and these flares are signals or spacecraft launches. After all we may be the most entertaining planet in the galaxy right now, so a ring side seat would be what all the rest of the galactic civilizations would want! Entertainment may be the most valuable commodity, and I’m sure we would love to watch a civilization that still thinks they are at the center of the universe! ;-}

                • Harry R Ray April 11, 2018, 9:16

                  So, could THAT explain the 2.2 second offset?

              • Michael C. Fidler April 11, 2018, 19:45

                Or you could just turn it sideways.

  • Isaac Kuo April 6, 2018, 16:15

    I have a thought – what if we don’t worry about preventing particle beam bloom, and instead just use the particle beam as a lens? If this can work, then we can have a large aperture without constructing a large solid lens (or mirror) in space. The particle beam doesn’t need to have a long range. It just needs enough range to provide the desired aperture.

    We could test this concept with a weak particle beam and a weak laser, and use the resulting data to confidently predict the performance of a system with a far more powerful laser.

    I think it may be desirable to have the laser generator located far away from the particle beam generator, because it’s easier to make a tight laser beam and such a laser beam would need less refraction in order to be focused.

  • Michael C. Fidler April 6, 2018, 20:11

    Little digging and found some buried treasures.

    Fast beam of neutral atoms created using lasers and plasma.
    1/29/2013

    “A new experiment has achieved neutral particle energies on the order of a billion times greater than prior efforts. R. Rajeev and colleagues managed this by accelerating particles while they were charged, and then transferring in electrons to neutralize the charge. This method has the advantage of being compact.
    Laser acceleration works by bombarding atoms with light pulses to strip electrons off, creating a plasma—a neutral gas of ions and electrons. Since the electrons are a lot less massive than the ions, you can tune the laser pulses in a precise way that separates them. The electrons shoot off, leaving behind a gas of positively charged atoms moving in coherent waves.”

    https://arstechnica.com/science/2013/01/acceleration-of-neutral-atoms-using-lasers-and-collisions/

    Particle Refraction, Reflection and Channeling by Laser Beams.

    “It is shown that the charged particles are refracted and reflected on the boundary of field free and laser field regions in vacuum. Simple and transparent estimates are given which show the possibility of channeling of charged and neutral particles having polarizability by strong electromagnetic field of certain laser bunches just as by the field of orientated crystalline planes and axes. These processes can be applied for production of femtosecond sliced electron bunches, for
    measurement their length and particle distribution as well as for production of femtosecond X-ray and terahertz pulses using transition, channeling and other types of radiation.”

    https://arxiv.org/pdf/0707.0148.pdf

    Is Tesla’s particle beam weapon practical?

    “During the later part of his life, Tesla made grandiose claims about having invented a “death ray” or “teleforce” weapon, the plans for which were discovered in 1983. In more prosaic terms what Tesla designed is a neutral particle beam weapon.’

    http://moreisdifferent.com/2015/01/13/is-teslas-particle-beam-weapon-practical/

    Laser and Particle Beams (Laser Part Beams)

    https://www.researchgate.net/journal/0263-0346_Laser_and_Particle_Beams

    “The possibility of channeling of charged and neutral particles having polarizability by strong electromagnetic field of certain laser bunches just as by the field of orientated crystalline planes and axes.”

    • Andrew Palfreyman April 6, 2018, 21:50

      Wow. Thanks for the weekend reading! This field is really popping. How timely for StarShot!

  • Michael C. Fidler April 7, 2018, 6:52

    Getting back before you left! :-o

    Relativistic solitons and superluminal signals.

    “Envelope solitons in the weakly nonlinear Klein–Gordon equation in 1 + 1 dimensions are investigated by the asymptotic perturbation (AP) method. Two different types of solitons are possible according to the properties of the dispersion relation. In the first case, solitons propagate with the group velocity (less than the light speed) of the carrier wave, on the contrary in the second case solitons always move with the group velocity of the carrier wave, but now this velocity is greater than the light speed. Superluminal signals are then possible in classical relativistic nonlinear field equations.”

    https://docslide.com.br/download/link/relativistic-solitons-and-superluminal-signals

  • Michael C. Fidler April 7, 2018, 7:38

    Slepian’s Faster-Than-Light Wave.

    http://www.hep.princeton.edu/~mcdonald/examples/ftl.pdf

    Spontaneous multidimensional wave localization in self-focusing and
    filamentation of ultrashort light pulses.

    https://pdfs.semanticscholar.org/48ab/3780dc4230734dc43974890f19fe856d822e.pdf

    NON-DIFFRACTING WAVES: A NEW INTRODUCTION.

    https://arxiv.org/pdf/1408.6503.pdf

    LOCALIZED WAVES: A HISTORICAL AND SCIENTIFIC
    INTRODUCTION.

    https://arxiv.org/pdf/0708.1655.pdf

    NON-DIFFRACTING WAVES, AND “FROZEN WAVES”:
    An Introduction.

    https://websites.pmc.ucsc.edu/~acti/sanya/SanyaRecamiTalk.pdf

  • Michael C. Fidler April 7, 2018, 7:49

    Self-Similar Scaling of Solitons and Compactons in Relativistic Jets.

    https://docslide.com.br/download/link/self-similar-scaling-of-solitons-and-compactons-in-relativistic-jets

    Superluminal Motion and Relativistic Beaming in Blazar Jets.

    “High resolution radio observations remain the most direct
    way to study the formation and evolution of radio jets associated with
    the accretion onto massive black holes. We report preliminary results of
    our seven year VLBA observational program to understand the nature
    of relativistic beaming in blazars and the surrounding environment of
    massive black holes.
    Most blazars show an apparent outward flow away from an active
    core. However, in a few sources the motion appears inward, most likely
    the result of projection of a curved trajectory which bends back toward
    along the line of sight. The apparent motion of jet features is not always
    oriented along the direction separating the feature from the core, and in
    a few cases we have observed a clear change in the direction and velocity of a feature as it flows along the jet. In other sources, the motion appears to follow a simple ballistic trajectory. We find no simple relation between the time scales of flux density changes and apparent component velocities.

    https://arxiv.org/pdf/astro-ph/0211398.pdf

    DISCOVERY OF SUB- TO SUPERLUMINAL MOTIONS IN THE M87 JET: AN IMPLICATION OF THE ACCELERATION FROM SUB-RELATIVISTIC TO RELATIVISTIC SPEEDS.

    https://arxiv.org/pdf/1311.5709.pdf

    Doppler Boosting, Superluminal Motion, and the
    Kinematics of AGN Jets.

    https://arxiv.org/pdf/0708.3219.pdf

  • Michael April 7, 2018, 13:02

    If we had a balloon with mirrors or both, say an incomplete torus we could reflect/bend the laser light from a ground based starshot laser system for much longer than a few minutes to hours. A geostationary satellite could reflect/bend a laser beam with no time limit. No need for a massive space based laser array yet, save that for the moon.

    • Michael C. Fidler April 8, 2018, 3:26

      Well, I know of a place that Alpha Centauri stays 50 degrees or more above the horizon all the time! Ross Island, Antarctica with altitudes as high as 12,000 feet. Nearby is McMurdo Dry Valleys, the place closest to Mars on Earth, but with elevations of only 5,ooo feet. This would work great for cooling and pulling energy out of the active volcano, Mount Erebus (Named for the HMS Erebus) to to power the Laser and Neutral Particle Beam. The nearby neighbor, Mount Terror is 10,720 feet and inactive, would be the best location, with easy access from the sea. Mt. Terror was named in 1841 by Sir James Clark Ross for his second ship, HMS Terror. This is the same ship that is in the “The Terror” TV Series (2018– ) (Drama, Horror) and was actually lost with the ship HMS Erebus! The Franklin’s lost expedition in 1845 was trying to find the northwest passage thru the Canadian arctic for a British shortcut to China and India.
      Something very fascinating to me and a bizarre coincidences is that my great, great, great grandfather is Peter Fidler of the Hudson Bay Company, surveyed and map large parts of central, western and northern Canada, was also looking for the Northwest Passage. His grandsons, John Fidler was on the 1850-51 expedition of Dr. RAE to find the fate of the Franklin’s lost expedition and found pieces of wood that were probably parts of Sir John Franklin’s vessels.
      In 1853 Henry Fidler was part of the another RAE expedition, again sailed to Repulse Bay. This trip enabled RAE to return to London with the first solid evidence, from Inuit sources, of the fate of Franklin and his crew. This same voyage also enabled RAE to find the last unknown link in the much-sought-after North West Passage.

  • Michael April 7, 2018, 15:47

    Perhaps a free electron/proton laser could be used to control the particles. Free electron lasers can alter their wavelength over an order of magnitude allowing very tight frequency control suited to the atoms used.

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