Tabby's Star

I've found the discussion and speculation around Tabby's Star intriguing. This is the one where a near-steady ~ 0.3 - 2% dimming per year is being observed, with intermittent, near instantaneous 1%-22% dips in brightness being observed anywhere from a month to a couple years apart.  Many theories have been posed and many debunked.  My favorite theory / debunk combination is that there is a vessel approaching us from Tabby's star; however the parallax as observed across the span of Earth's orbit would show the "vessel" only intermittently occluding the Tabby's Star's disk as seen from Earth. (Or otherwise we have to imagine an "impossibly" sized vessel, but more realistically perhaps one leaving a very largely expanding trail of exhaust behind it, especially since the effects would be cumulative along a straight-line path towards us . . . )

So I decided to imagine another theory that i've since seen only a little discussion of - that of a large amount of interstellar traffic - e.g. commercial traffic, between two stars whose joining pathway occludes our observation cone to Tabby's star.  Unfortuntely I don't have a map of the stars in our view to Tabby's Star (i e in the constellation Cygnus or its neighbors) to be able to propose which two stars could be playing that role. Or perhaps Tabby's Star itself is one terminus to that path (or even a central, i.e. transhipment, hub to many stars?) .

The traffic could simply be so voluminous in nature (or emit sufficient exhaust as in the "approaching vessel" case) as to measurably occlude the light from Tabby's Star.  The steady increase in dimming could be attributed to the same kind of typically steadily increasing growth rate of economic flows that we see in simple commerce here on Earth.  Intermittent significant dips could be due to whatever the interstellar equivalent is of the odd freight train passing through, as contrasted with the more frequent small truck in this analogy.

What criteria to propose to debunk this theory?

Zipping around the Solar System

So I was researching on another technical musing, related to navigation in the solar system.  And I really enjoyed this map I came across by Reddit user ucarion which shows the delta-v's required to get to different orbits of interest in the solar system.  And its format is very intuitive, being the same as the globally popular subway map style.

What I've been thinking about is a way for a vehicle to be piloted around the solar system with impunity.  i.e. not having to be restricted to the hohmann transfers and planetary momentum captures  commonly used by NASA to get to Mars and other planetary bodies.

Right now, the limiting factor as I see it is the fact that we are very propellant-poor in our current means of pushing ourselves around the solar system.  By contrast, energy (for adding kinetic energy to propellant) is less of a concern, as it can be generated from a variety of sources.

My motivation to get this solved?  Exploration, but I recognize that our economy won't expend real currency at the problem unless there's the potential for financial return.  So to that I suggest asteroid capture e.g. like Planetary Resources advocates for.

What do we do with a big asteroid?  No doubt you can think of your own application from them.  From my perspective, precious metals aside, lets say people living on Earth want to start spreading out across it - e.g. for lower rent or more agricultural area.  Then you can envision massive tropical colonies in the Pacific Ocean's international waters as advocated for by seasteading companies!  Where is the material going to come from to build floating landforms that covers millions of square kilometers?  Most countries aren't going to let you displace from land from theirs, and environmental advocates are going to make it politically difficult for you to dredge up enough material from the sea floor.  How about material harvested from asteroids instead?

But back to the propellant problem.  Where are we going to get all the propellant we need to navigate with impunity around the asteroid belt and bring massive material mined from the asteroids back over and down into Earth's low-earth-orbit (LEO) for eventual transport down to the Earth's surface?

I bring you:

Jupiter! 

Yes, the Jovian monstrosity can be monstrously helpful in our quest to zip around the solar system for economic and exploration gain!  

How?  Simple!  Jupiter's atmosphere is packed with gaseous hydrogen.  We just need to capture *lots* of it on an ongoing basis to fuel our spacefaring adventures!  So how do we get it? 

First, we need to get away from the incumbent paradigm of chemical rocketry.  It's too expensive to bring fuel and oxidizer to orbit. Enter nuclear technology.  Normally I'm bearish on nuclear for terrestrial activity for its hazard potential, but in space, its a wonderful thing.  According to wikipedia (yes I'm citing wikipedia, deal with it) fission-heated hydrogen gas rockets can achieve twice the exhaust velocity (twice the specific impulse for rocket aficionados) than hydrogen in a chemical rocket.  That's basically more bang for our propellant buck.  But even more importantly, we don't have to bring any oxidizer on a fission rocket, we only need fissile rods for replacing every once in a while, (and they are much easier transport for their small size than chemical fuel).  We are just heating the propellant gas to high pressure and then releasing it through a rocket nozzle.  So, we don't need to find and harvest oxidizer somewhere or send up expensively from Earth.

To first order, I advocate for having many such automated fission-powered rockets making round-trips to Jupiter, equipped with a very wide scoop to harvest Jovian hydrogen as propellant for itself and for other vessels it will transfer to.  The scooper craft doesn't need to descend far down into Jupiter stratosphere at all - because the craft is traveling so fast and Jupiter is so vast.  The craft will naturally slow as it gathers gas, but it can still even wildly overshoot Jupiter afterward, because it can use the propellant it just gathered to change to the opposite direction, only to gather more propellant for its return leg for delivering onward.

Then we'll want to set up propellant "coaling stations" at key Lagrange points like Jupiter's L1 as well as in sun-centric orbits that allow for easy interception - effectively a supply chain in space.  Our asteroid-mining craft can then transact at these coaling stations to collect propellant and travel where they may.  No more propellant-hoarding, no more strict Hohmann transfers. Just get to where you need to go and come back whenever you're ready. 

Going back to the Solar System Subway Map image at top, there are three primary phases of travel from one planet to another that apply here.  Surface-to-LEO,  LEO-to-Earth-intercept, and Earth-intercept-to-Jupiter-intercept.  The nuclear (fission) powered gas scoopers lend themselves to Jupiter-intercepting transfers.  Origin: perhaps Earth intercept only initially, but before long one of the coaling stations.

Then what about the other two transit phases?  Maybe I'll save the detail for another technical musing since I have to go, but I advocate for maglev / hyperloop-esque mass drivers to get from the Earth's surface to LEO (massively reduced cost to orbit - no expended propellant required!) and yes, chemical rockets to go from LEO to intercept.  Why chemical rockets and not fissile ones?  Because I don't think people on Earth will stand for having a nuclear reactor in LEO that could come down in the event of an accident and create a Fukushima-like incident.  So there still is a place for the chemical rocket industry (chemical rocket industry lobbyists rejoice!), but luckily now over the long term this industry only has to bring its own oxidizer from Earth, since the hydrogen is already going to be there courtesy of Jupiter. :)

Technical musings - high-speed ocean-traversing craft

(Images above come from here and here)
Somewhat out of character for this blog, I wanted to post an item more technical than nature than anything else.  This is because somewhere, evidently way deep inside this more managerially oriented head, is something still resembling an engineer.

So what I've been thinking about a in the back of my mind a lot is hydrofoil-borne and Wing-In-Ground (often called ekranoplane) sea-cum-aircraft.  I think this is the result of having flown back and forth to Asia so many times, and, frequently missing the place, ponder about how to get there more easily, comfortably, and less expensively.

I believe somewhat bullishly that there is a market opportunity for an alternative to passenger airliners that fly fairly close to the water, at markedly lower speeds for an aircraft, but markedly higher speeds for a watercraft.  So, instead of the ~13 hours it currently takes to get to Shanghai from San Francisco, maybe this would become 24 hours or even 36 hours, but in a much more spacious, and therefore more comfortable setting.  Also, these craft wouldn't require airports, but could take off from a (perhaps purpose-built) pier, so the costs (esp. real estate) of operating an airport largely go away.  Finally, I believe security costs are also reduced, because even if there is a terrorist attack,
1) There are few targets of value that the craft can fly into
2) the craft is so close to the water anyways that should an attack disable it, it simply lands in the water in the same way that it does whenever preparing for routine disembarkation.
Therefore I believe that security-interested national governments / transportation regulatory bodies should have an interest in fostering (or at least facilitating / allowing) such an ecosystem.

With the reduced security and operating requirements, it is my hope that someday itineraries for this craft could be booked in a much more on-demand way than typical commercial air travel - i.e. that schedules could be published by the operator, and people arrive as they need to or book just shortly before without paying excessively for the privilege as happens in traditional air travel.

Capital costs to get to a demonstrable version, and subsequently a commercial grade version, would be substantial (to understate).  But I believe it is possible to fund demonstrators today thanks to crowdfunding and that it is possible to finance the commercial grade version with VC / PE funds  thanks to the already demonstrated market in the form of commercial airline passenger revenue.

So who are some people who could step up to the plate to bring advocacy to such a venture?  Among them I would certainly vote Charles Bombardier, who's already written vividly of unique sea craft, and who is the legacy of a family for whom the development of unique vehicles is their raison-d'etre.

The obstacles (besides funding of course) I see are primarily psychological in nature.  You see, ekranoplanes saw the most development under Russian engineering development (see here).  Because of politics, a technology that owed much to Russian advances (that too especially during the Cold War) will be given short shrift without more open-minded thinking.

As I'm researching just a little for this post, here seems to be this kind of venture in action.  I wish them (and any competitors that spring forward) well.

Goa. 9 years later.

My first Goa post I wrote most of a decade ago.

A lot's changed - for example, the "King of Good Times" Vijay Malia's Kingfisher Villa in Candolim is in lien.  Many, many more local Indians (who the vast majority are male) have arrived for the 2017 New Years' celebration, and relatively few foreigners.

I've also changed.   For example, this time, I haven't arrived alone.  You see, last year, my wife and I married, and this is the beginning of our honeymoon.  So I write as a honeymooner instead of a backpacker.  We've technically been calling this the "pre-honeymoon", as we're intending to arrive in Bhutan for the main deal.

Finally, I couldn't help but see each of the two Goa trips as bookend moments in the expansion of my awareness of the world and my place in it as a person.  So I've also been drawn to thinking about how the world has changed in the past ten years.

World:  China's ascendant.  The BRIC concept would have been more accurately captured with b-r-i-C  .  It's old news by now that the world's nations are turning inward on themselves currently in reaction to globalization.  (I don't need to mention who we elected president).  Canada stands out as having the only recently elected head of state with an outward-looking perspective.  Eyes will slowly turn to France and Germany to see if the conservative wave takes hold there too.

The US notionally has a national healthcare system now.  It's under fire right now, and has built in flaws from the start like lack of single-payer and lack of national uniformity (and the resources / bargaining clout that would go with that).  I pay more for healthcare than I did before but I see it as at least an interim sacrifice if the country's most desperate can get adequate health care now.

The developing world's middle class have swelled, even as the ranks of the developed world's middle class have contracted somewhat.  (Hint: they didn't head toward the rich end of things)

India's working hard to fight corruption. As I write the country is in the midst of "demonetization" which is basically outlawing the largest denominations of currency and requiring them to be replaced with new currency, with the dual intent of flushing out black money, and getting India into a more trackable, more liquid cashless electronic payments society.

Self:  First, I received a diagnosis and got treatment for sleep apnea.  (For anyone in the world who snores, including people I come across hearing you loudly dozing away on airplanes, I have enormous empathy for you).  Second, after a lot of ups and downs, highs and scars, I have a career that faces the world especially it's less fortunate (primarily in Africa) that leverages my technical experience.  Finally, as mentioned, I'm married now, to a woman I met in business school who is sincerely amazing. For all of these I feel truly blessed.

One MBA (and a lot more independent reading) later, I understand economics better than I did before, but there is still so much to learn that is simply not taught in formal curriculae.  The closest I find is "input/output economics", and I am hopeful for what still-nascent economic simulations can teach us about the world we live in.

During these couple days in Goa, my wife complains that I'm being too wistful / nostalgic, which she perceives as depressed, and not being present enough to her.  I try in vain to convince her otherwise, that I'm just a massive introvert.   (My writing this post isn't helping in the immediate term, but I think will help after I'm done and have got the feelings out of my head and onto paper).

I think the key thing is that I need to "put the backpack down", even if my own self-image is the only remaining manifestation of that.  Although she loves travel, this kind of it is definitely not her thing: 4+-star hotels, not guesthouses.  Anyway our near term life plans are incompatible with anything resembling the backpacker lifestyle.  Again I hope this post helps with that.

Our next stop is Bhutan, the "land of happiness".  I sincerely hope it lives up to its intent of being the world's happiest nation, or at least successfully striving to be.  I may or may not write a blog post about it.  For the sake of my honeymoon's happiness, I hope I am not motivated to :) .