Thin Gruel

Chaos Manor View, Wednesday, March 25, 2015

Most of the day was devoured by medical appointments, and the rest was pleasurably enjoyed in lunch and dinner with Roberta two of our sons. Frank, who lives in Texas, came out for the day and actually joined us going out to Kaiser in Panorama City, and when we had lunch on the way back we were joined by Alex, who lives in the Valley. Then we all four went out to dinner.

In other words I didn’t write much, for this journal, for the SFWA Bulletin, on my novels, or anything else. Tomorrow Larry Niven and I will go out to JPL to have lunch with Richard, my youngest son, who lives in DC but operates out of Houston a good part of the time; after which he has a presentation at JPL, doubtless about NanoRacks and the satellite launching business. And after that my old friend Harlan Ellison will come to a LASFS meeting, and Niven and I can’t miss that, and ==

So it’s thin gruel today and probably less tomorrow. Ah well.

A little more on reactionless drives:

OK, this is most likely my last on this subject, having foolishly gotten myself into it…
Housekeeping first:
1) No, I did not dig more for further information than the popular science bits that were first presented. My research time these days is used for other things (mostly economic and social evolution, military history, and one rather nasty astrometric project.) I would submit, though, that this is precisely why the Doctor invites many different people to the Manor.
2) I stand by my opinion of Chinese research. When all things are subordinated to the State, there is a far steeper cliff of verification needed. There are Chinese researchers that I have on the trust but verify list (a very few), ones that I’ll take a look at but approach with a great deal of skepticism (the majority), and ones that I automatically dismiss (once again, a very few). By the way, I hope that nobody confuses the institution at which these researchers work with the American university – Northwestern PolytechnicAL Institute is in Xi’an, Shaanxi, China; *not* Fremont, California, USA. This paper fell under the majority rule – but on checking, looks like a fairly reliable description of a beginning research effort.
The preceding being out of the way – now to the meat…
Reviewing the links for all three published pieces (sorry, not the YouTube clips – time, again) *not* one of them is claiming a reactionless drive. (See page 2 of the Shawyer IAC presentation, abstract of the Chinese paper – NASA does not say it so simply, but “momentum transfer” is action/reaction, whether momentum is being transferred by “normal” kinetic processes or through the virtual quantum plasma.) Sorry, no breaking of the current “laws” of physics here…
Probably the best way to (vastly) simplify the Shawyer and Chinese work is to describe it as putting a nozzle on your “traditional” engine’s combustion chamber, thus turning a relatively low thrust into a far higher one. Shawyer describes a NASA test device that is quite like his own, and that of the Chinese. All of them apparently produce thrusts at a rough order of magnitude of 0.2 Newtons / kilowatt. (That’s one kilogram, accelerated at 1 meter/second/second with an input of 5 kilowatts of power – which is *extremely* good).
Where Shawyer and the Chinese part company is in what they see as the *potential* of the technology. Shawyer is, in the best Western tradition, looking at the speculative endpoint of a huge amount of further research and engineering advancement – it is a long way from 1 Newton for 5 kilowatts to a SSTO lifting large masses against a 1G field. Note that there is nothing *wrong* with that, and everything *right* with it – how does anyone think the West gained its preeminence in the first place? In any case, this is the very long view.
The Chinese, on the other hand, are seeing this technology as solving in the near term a very practical, but important problem. That is the problem with the fact that any kind of “traditional” thruster that throws mass is certain to cause interference with delicate instrumentation on your spacecraft – or, even worse, deposit that mass onto things like camera lenses, communication antennas, solar cells, etc. To them, this is a way to get small thrusts without the inevitable “pollution” of the immediate environment. It would not surprise me to see this showing up in PRC surveillance satellites, planetary probes, and the like in the near future.
The NASA link is to an engineering paper. You might think it is simply a more sophisticated version of the Shawyer/Chinese devices – but the apparatus described is *very* different, as is their description of the physical principles involved. They also measured the thrust of their apparatus at a mean of 40 *micro* Newtons – which, unless someone did something very wrong, is not in the same region as the other two, not by a very long shot. I think that, despite the superficial similarities (no propellant mass and involving microwaves), the NASA paper is describing a completely different line of approach to achieving thrust. (Apparently not an overly efficient one, either, which does not surprise if the momentum transfer is through the virtual particle plasma – it is called the “vacuum energy” for a very good reason.)

Richard Skinner

I don’t have time to analyze that. I can only repeat, any reactionless drive – any thrust without a propellant – is impossible under the Standard Theory. It blows up Relativity so far as I can tell; certainly makes it complex beyond understanding. It requires serious adjustment to Newton, much more than Beckmann’s postulating a finite speed of propagation to gravity. It makes the quantum structure more important, and certainly changes what we think we know about it. Magnitude isn’t important here. Any propellantless thrust changes our understanding of the universe.

And that’s wonderful. It’s also unlikely. Sagan was fond of Descartes’ dictum, “extraordinary claims require extraordinary proof.” Existence of a device that can produce thrust without a propellant is a very extraordinary claim.

Jerry,

For whatever it’s worth, coming from one who consistently flunked high school math, but, having looked at the number of stars in our galaxy, and the number of galaxies in “our” known portion of the universe — and said to himself, “wow, that’s a lot of stars…” I have to ask: If a reactionless drive is indeed possible, then it would seem to my mathematically challenged mind that the upper limit of velocity, given sufficient time, would approach an impressive fraction of the speed of light.

If so, then, given the equally impressive number of stars in the sky, how unlikely is it for us to be “visited” by others?

The more I ponder the questions, the more important the warnings from Hawking et al seem — and the more idiotic any form of “active” SETI (AKA “Here we are, come and get us!”) seem.

Anon

Many years ago Freeman Dyson pointed out the mathematics point strongly to there being but one intelligent species per galaxy. The logic summarizes thus: assume a thousand years in transit in a generation ship to get to the next inhabitable planet. Assume a thousand years for the resulting colony to achieve an industrial technology to build two more star ships. How many millions of years does it take to fill the galaxy? But we have billions. The only variable is how long it takes to evolve the first star crossing industrial civilization…

I have drastically summarized a brilliant analysis, but you may now play with the assumptions, and you will find the conclusion compelling. One per galaxy.

One way or another.

Gulf conveyor slowing

From (admittedly alarmist) articles and television programs I saw at least a decade ago, I know that interruptions of the Gulf stream are likely to have played a part in historic periods of cooling in the Northern Hemisphere. Now comes this:
-Gulf Stream system: Atlantic Ocean overturning, responsible for mild climate in northwestern Europe, is slowing
http://www.sciencedaily.com/releases/2015/03/150323132746.htm
This seems to match some of your speculation.
-d

http://www.ft.com/intl/cms/s/0/9edfa07c-ceaa-11e4-900c-00144feab7de.html?siteedition=intl#axzz3VFLx03DX

Apple puts clinical research tool in your pocket

Bloomberg

Tapping an iPhone’s touchscreen to take a photograph or make a phone call is as familiar as the traditional cameras and mobile phones that it displaced. Medical researchers hope to use the same simple interactions to study diseases from Parkinson’s to asthma.

Apple began its move into the digital health industry last summer when it unveiled Healthkit, a software platform that developers can use to pool data about workouts, caloric intake and weight. Apple touted its potential to alert doctors about changes to the user’s wellbeing, and several US hospitals have begun to pilot the system.

Less than a year later, almost 1,000 fitness apps are plugging in to Healthkit, giving Apple a strong base upon which to launch its health-centric Watch device.

Apple’s longer-term plans became clearer with the launch earlier this month of ResearchKit, a way for medical researchers to transform the iPhone into a tool for conducting clinical research.

“All you have to do is stick the iPhone in your pocket, walk out 20 steps and back, and the iPhone’s accelerometer and gyroscope precisely measure gait,” said Jeff Williams, senior vice-president for operations, of an app studying Parkinson’s, at this month’s launch.

Apple is not planning to make money directly from these apps, which also track diabetes and cardiovascular health. But ReserachKit is building goodwill with the medical community that could help to sell more iPhones or Watches.

“Having a common platform is a godsend to researchers at the university, hospital, clinical and government level,” says Richard Doherty, research director at Envisioneering, a technology consultancy.

Guaranteeing users’ data security and privacy will be essential. Mr Williams has said that customers will opt into any ReserachKit programmes and promised that Apple “will not see your data”.

“Apple has always believed that amazing things can happen when you put technology in the hands of the many,” Mr Williams concluded.

Force fields could be the next big battlefield innovation (WP)

By Dominic Basulto March 25 at 7:00 AM

America’s military-industrial complex keeps coming up with innovative ideas for how to win asymmetric wars in far-flung locations around the world. As if insect-like drones and Terminator bots were not enough, Boeing recently filed a patent that describes how to create a “force field” capable of shielding soldiers and military vehicles – including tanks and armored personnel carriers – from the shockwaves of IEDs.

While Boeing doesn’t actually call it a “force field patent,” that’s essentially what it is. You can see how Boeing’s “method and system for shockwave attenuation via electromagnetic arc” works in the figure below. Here, a sensor (10A) mounted on the top of a military humvee would detect an explosion and its resulting shockwave (24) in the immediate area. The sensor system would then almost instantaneously send a signal to a power source (38) to superheat the surrounding ambient atmosphere (26) around the vehicle, producing a heated, plasma-like medium (30) between the target and the explosion that would act as a buffer and shield from any shockwave.

Although some have referred to this innovation as a Star Wars or Star Trek-like shield for repelling enemy attacks, that’s not exactly the purpose of the patent. As Boeing points out in patent no. 8981261, such a system would act to “attenuate” any shockwave by a combination of means that might include “reflection, refraction, dispersion, absorption and momentum transfer.” The goal, then, is not to knock down an incoming projectile or missile, but to deploy an intermediate medium that would reduce the collateral damage from such an attack.

Unlike previous attempts at creating a similar type of shield, this Boeing patent – if it ever gets commercialized — would be a dynamic system, rather than a stationary system, relying on sensors to activate a shield in real-time. This would differentiate it from previous patents, which focused more on how a specific substance – such as an aqueous foam, gas emulsion or gel – could somehow absorb the blow of an incoming object when placed inside a barrier. In other words, the force field would be highly mobile and be capable of activating at a moment’s notice, rather than being erected in front of a structure hours, days, or months ahead of time.

Given the nature of modern asymmetric warfare, such a dynamic “force field” is greatly needed. Over the past decade, the “roadside bomb” has fundamentally changed the way the military operates as well as how it innovates. Consider the number of IED attacks in a war zone such as Iraq or Afghanistan, where over 3,100 deaths and 33,000 injuries have been sustained over the past decade. Clearly, the U.S. military needs some way to counter the ability of a terrorist or insurgent group to inflict maximum damage on unsuspecting U.S. soldiers with minimal risk.

As researchers are now finding out, even the shockwave from a detonated IED can cause internal injuries that may not be detected for years afterwards. Unlike the Hollywood movies, where heroes walk away from impressive-looking detonations and blasts as if they were nothing, researchers now say that IED shockwaves are tantamount to being hit multiple times by a ferocious NFL middle linebacker, resulting in potential head concussions each time.

There’s a huge potential market for this type of technology and that means it’s not just the U.S. military that could become buyers of such a battlefield innovation. The British Army is also working on the creation of supercharged electromagnetic fields to deflect anything up to the size of a small missile. And the Israeli Army is also working on a system to knock down incoming projectiles.