I've always been skeptical of these liquid-air cycles, but this scheme strikes me as especially problematic in that an ejector ramjet would be mechanically simpler and have the same top speed. For the curious, an ejector-ramjet (or ram-rocket or air-augmented rocket or any of a number of other names) is just a ramjet with a small rocket motor behind the center body of the diffuser. The exhaust plume entrains the inlet air, boosting the combustion chamber pressure by cooling the rocket exhaust plume. (It also acts as a fairly, err, robust flameholder.) If you're wed to LH2 as a coolant, just bleed it in along the walls of the rocket combustion chamber, and it will mix with the main mass flow and combust. Et voila! The cooling system is the fuel injection system for the ramjet mode.
Now you just spend all the compressor and heat-exchanger machinery weight that you saved by not going with the Skylon engine by having dedicated thrusters elsewhere on the vehicle for the pure rocket mode.
As someone somewhere else said, Skylon strikes me as a characteristically British solution to the problem, just due to it's sheer over-reliance on plumbing.
I find your comment amusing in light of my particular frustration with the near anonymity of SpaceX in relation to its accomplishments, especially in addition to the nearly universally unfavorable press it gets over at AviationWeek.com. And never mind that Orbital is not "working on the same thing" by any reasonable understanding of the phrase.
Let's get one thing out of the way up front: SpaceX launched, orbited, reentered, and retrieved a fully reusable capsule, one with an ablative heat shield that can be used hundreds, if not thousands, of times over. Disregarding the reusable aspects of the design, they're in the company of 3 nations. Include the reusability aspect and they're in the company only of the United States and the former Soviet Union. I have a degree in engineering. I have engineering friends, some of whom work in aerospace companies. Until this recent PR push, I hadn't found one of them who'd even heard of SpaceX, to say nothing of their groundbreaking and historical flight and recovery of a capsule with private funds. If that's "all the press," then I have "all the press," too. Go ahead. Ask me how it feels to be so famous!
The little press that they do get within the ossified aerospace industry has been terrible. AvWeek recently ran a piece which was focused on how SpaceX had "lost some of its luster" (not a direct quote, but close) with the slip from February to April for the Space Station rendezvous launch, as if any government-run space technology was ever delivered on time. A while ago, they found some blow-hard "space policy expert" to opine about how space was hard and how it was absolutely obvious that SpaceX was over-promising and destined to radically under-deliver. They ran another piece about how congress was unhappy with COTS. Only recently did they have to give some ground with a piece about how commercial space was "already having benefits" now that the launch is so near, and I was overjoyed with schadenfreude when they had to provide neutral coverage of the uninteresting and everyday fact that Space Station astronauts were rehearsing for SpaceX's visit to the station. There's a reason, I'm sure, that SpaceX chose Muse's Uprising as the theme song for their animation about their plans for full reusability. It fits.
Further, Orbital's offering is not even close. Orbital's vehicle is not reusable. It burns up on reentry, and therefore has no capacity to bring cargo back from ISS. And their price point is nowhere near Musk's. In case you're keeping track--and I mean the hypothetical "you", I'm not pissed at you, Metapony--that's less for more. Less than SpaceX for more money. Furthermore, the floor on Orbital's costs is the same trifecta that's always been around in aerospace: expendability, costs of disparate components, and integration costs. I'd love to see a viable competitor to SpaceX, but Orbital isn't even close.
Make no mistake, the battle is not between "government" vehicles and private industry. There are no "government" vehicles: Every vehicle gets built by private contractors. The battle is actually between the established aerospace industry, built around expendables and cost-plus contracting, and SpaceX, an innovative and disruptive aerospace company based around competition, reusables, and fixed-price contracts, with Orbital taking up the rear with the worst aspects of both models.
I know. I come across as a strident cheerleader. I hope that has less to do with any inherent fanboyism in my makeup than it does with my absolute perplexity at and frustration with the bare fact that SpaceX has done unprecedented, amazing, historic things, and hardly anyone knows about them at all.
Item [8] was mentioned in this talk: http://www.youtube.com/watch?v=3kEfedtQVOY by Meredith Patterson. She contends, and it seems sound to me, that the time has passed to be "tolerant when accepting," and that you should instead only accept regular grammars or, at worst, context-free grammars as input languages on the open Web.
We could be saved by the square-cube law, or, The Power of Being Big.
In essence, let's assume you've made your own fully-shielded space capsule for one, and that you need, for example, a pound of material for every square inch of its surface, and that you've made it into a sphere to economize on material. Wise choices, all of them. A 2m diameter capsule would come in at 19,500 lbs, or so, for that many square inches.
Congratulations. You've just found out why we don't shield small spacecraft. Now, however, let's get an estimate of what it would cost to shield 200 people, providing them each with a volume-equivalent of your capsule, or 4.2ish cubic meters per person. Really packing them in. This is a 11.6-meter diameter sphere, with roughly 3,300 pounds of shielding per person. At 2000 people, packed in like sardines, we're at 25.2 meters in diameter and 1550 lbs of shielding per person. A 54-meter sphere packs 20,000 sardines, and requires a mere 717 lbs of shielding per person.
A factor of 10-20 better. Obviously, we want to relax the space constraints a bit. However, the form factor of shielding in the larger craft is going to be much better suited to the reutilization of supplies as shielding. In the limiting case, of course, there is effectively no required shielding per occupant. Long before that, magnetic shielding schemes become a viable option, too.
A more practical limit would be to consider a transport module made up of re-entry craft seating 1-10 persons, with the ablative heat-shields and supplies facing outward. In this case, assume we can get down to 5 times your cross-sectional area in shielding, and guess that that's about 2.5 square meters. That's 4000/lbs per person. So, still a factor of 5 better than the solo case.
Additionally, this is a lot of arithmetic to ask of google and http://www.calculatorsoup.com/calculators/geometry-solids/sp..., so the numbers may be off. Also, the Dragon capsule checks in at 5.8 m^2 of heat shield per astronaut, which may be a practical limit. And I just made up the 1lb/in^2 shielding requirement.
There a couple of things that allow him to make these claims without being "laughed out of the room," as you say, but they don't have to do with his personality in the sense in which I take your meaning.
First, there is the rocket equation. That little gem tells us the amount of fuel it takes to achieve a given change in velocity for a given energy density of fuel. Then there are some results from orbital mechanics and aerodynamics that tell us what that change in velocity is. For the curious, escape velocity is just sqrt(2) times the circular speed at any given altitude.
I've laid this out before, but here it goes again. To put a pound of anything into orbit has a fuel cost of a little over $20. "Incredible!," you say, "It costs $10k/lb on the Space Shuttle! How can that be?!" Like so. Typical mass fractions are on the order of 2%. That is, 2% of the stuff on the pad, fuel, structure, payload, everything, actually ends up in orbit. About 12% of that mass is structure, things like tanks and engines and the like. That leaves 86% of the thing as fuel. 86:2 is 43:1. 43 lbs of fuel for every pound of payload. Assuming that propellant is roughly as dense as water and roughly the price of milk, both easily verified, that's under 6 gallons of propellant for every pound of payload, which will run you $21 at $3.50/gallon.
Multiply sqrt(2) by $21/lb and you have something like $30/lb. If you and your capsule weigh 2,000 lbs, That's $60,000 for a one way ticket. A little over 8 times that price may be a reasonable number. So, what makes up the difference in cost for current launch systems, or even for antiquated and clunky systems like the Shuttle? Low safety margins and their concomitant need for enormous administrative costs for each part, disposable launch systems where that administration cost burns up in the atmosphere or splashes down in the Pacific, and enormous system complexity driven by a lowest-flight-weight-results-in-the-cheapest-vehicle mentality.
We can begin to address, based on SpaceX's design philosophy and planned vehicle, how they may be able to make these claims without deserving to be "laughed out of the room."
First, SpaceX has reduced engineering and integration costs by reusing common components and simplifying designs at every step. they were (and I think, still are) using a pintle injector which is much less susceptible to catastrophic combustion oscillations than the more typical injector-face solution, at a cost of some performance. The tanks for all of their stages are the same diameter, allowing them to engineer and build one capital-intensive jig rather than two or three, and they get more experience with that hardware since all their work is done on it. They're using a pneumatic stage sep mechanism rather than a pyrotechnic one to eliminate material-handling, static, and other safery concerns related to pyrotechnics. Rather than relying on one or a few very large engines to power the first stage, they've chosen to use 9 smaller engines on the first stage and isolate each one in its own cato-proof container, again allowing them to gain more experience with a single system, prove its reliability, and leverage that experience and track record to perform a larger job.
Second, they have plans for full reusability of the launch system based on incremental changes to their existing systems. Yes, there is a fuel and performance penalty for going this route, but the savvy armchair aerospace critic will note that those penalties are expressed in tens of dollars per pound, whereas 100% disposal is measured in thousands to tens of thousands of dollars per pound. That is to say, even if reusability results in a 10-fold increase in fuel cost but allows vehicle cost to be amortized to negligibility, we're still approaching Musk's $500k/flight number. As to his actual plan, the fuel cost to land a booster segment is tiny compared to the cost of launching a vehicle. The first stage will simply reenter without having to retro-burn, and the second stage will need to retro-burn just enough to enter the atmosphere to achieve the rest of the braking. After that, the delta-v required is on the order of 100m/s, hardkly the 10km/s needed for orbit. You seem to know what you're doing, so I leave the derivation of that penalty, using the rocket equation, to you.
tl;dr: You're absolutely wrong in the most irrelevant way, and had you addressed SpaceX's achievements and plans in anything like a rigorous way, you could easily have answered your own question.
EDIT: The fuel cost for escape will not be sqrt(2) times the cost for circular speed. The real factor will be something more like 2 or 3, not 1.414... Still, we're in the range of $60/lb, not $6,000/lb.
I hate Neil DeGrasse Tyson. Not on a personal level, mind you. He's probably a nice guy to have beers with. But he's a shill for NASA. He's a good shill, but he's a shill, nonetheless.
A little background. I'm old enough to have been "inspired" by the Space Shuttle Program near the point of its inception. Imagine a young mkn sitting down with a pencil and paper to work out how much it would cost to buy himself a ticket on the Space Shuttle at the promised $50/lb. I weighed 70 lbs. I knew it would be more than $3500 because I'd have to eat and breathe while I was up there. I wondered if I could go naked to save some cash. But still, it was a nice number. And then, the number changed. The promise went up to $100/lb. Fine. The math was easier. Oh, and the number of launches went from 26/year down to 12/year. Not quite the airline-style operations they had promised, but not bad. And then the price went to $500/lb. 3 or 4 launches per year. And then, the media just stopped talking about the costs and launch frequency, probably because it quit showing up in the press kits.
Tyson complains that we don't dream about the future anymore. He's right. We don't. But he complains without the slightest hint of irony. The promise of NASA was that the costs would come down. The promise was that spaceflight would become routine and affordable. The promise tapped into the then-current emphasis on mobility in the American Dream. Tyson is right that we don't dream about the future anymore. But we don't dream about it because NASA has proven to us what the future is. The future is NASA, and the future is stagnation. We have all been "inspired" by NASA. We don't dream because we don't need to. We know.
Tyson breathlessly opines about all the amazing things NASA could do with twice the budget. Missions to Mars! To those, I have this to say: Big fucking deal. The promise of NASA was never its "missions". The missions were a vehicle for the promise. The promise was ubiquitous space access. I'm going to see my cousin on the Moon. We're taking a year and seeing Mars. Sending some highly-selected and highly-trained spam in a can for some fahrt around a crater is not the promise. Sending you and me there for a fahrt around a crater is. Somehow or other, that part of the promise has slipped out of NASA enthusiasts memory. Long live NASA! All we have to do is pay twice as much!
The imagery of the Shuttle and of the new capsule is especially offensive. It's the easiest thing in the world to verify that the Shuttle was the most expensive launch system ever conceived in the history of manned space flight. It is, as I've hinted above, the primary reason for the complete demoralization of the populace with regards to space flight. And it was promised to be so much better than that. The Orion capsule is all that is left of that disgraced launcher program, the one that retained the disgraced SRBs to placate Morton-Thiokol.
NASA can't. That's my new slogan. Unlike other slogans, which are mainly inspirational, mine is intended to remind me of reality. Take any dream you have about space and phrase it as a question, and the answer is "NASA can't". Will we build orbiting habitats in space on a massive scale? NASA can't. Will we ever colonize the Moon or Mars? NASA can't. Will we ever be able to realistically dream of democratic access to space? NASA can't. Every time you hear Tyson speak, just remember: NASA can't. And it ain't for lack of funds.
I wish Tyson would other shut the hell up or direct his energies and oratorical gifts at making NASA an agency worth supporting. But, he won't. He's a cheap shill, and he's just going to keep doing his shabby job.
After seeing that clip, I wondered how Cernan and Armstrong could have said the things they said and, eventually, how they could even feel qualified to comment. I think the answer to both questions is related.
Armstrong and Cernan are just the Spam in the can. They're glorified pilots. As such, they are extensions of the PR arm of NASA and the entrenched aerospace industries. I've phrased that a little harshly, but not by much. Certainly, as trained monkeys go, they are marvelously trained. And not just any monkey could be trained to perform as they did in their, and I emphasize, highly specialized and limited roles within the space program. But, when we see a well-trained dog, the credit goes to the master.
If Armstrong and Cernan were rocket designers, if they had captained a startup that created a new launch vehicle, then I could take their statements seriously. If they were systems integrators, if they were manufacturing engineers, if they were anything other than good pilots, then they might have something useful to add to the discussion on a national level. Until then, all I want to hear from them is how beautiful the Earth looks from space, how fun it is to play golf on the Moon, and various other fun facts about events that took place 40+ years ago.
I feel awful trying to cut these men down, trying to knock them back into place. However, the truly shameful thing is that they've used their legacy to usurp beyond their areas of expertise. I console myself that the bounds over which they've stepped are generous bounds, the bounds of heroes, and it takes a truly cataclysmic level of folly to behave as they have done. It would take nothing less than the legendary ego of a pilot.
Cernan and Armstrong, rest on your laurels, and get out of the way of people who are doing.
Actually, it turns out that it's neither heinous nor poisonous. You seem to be having an allergic reaction to the contrast between advice about how the actual world functions and how actual productive people function in it, and the flowery advice given in the article.
Basically, each of the 5 points I listed comes down to, "Momma said there'd be days like this, days like this Momma said!"
I guess, at this point, I'd be curious about what, in particular you found "heinous", "poisonous", "horrid", or likely to lead to one becoming a "burnt out husk of a human being" before the remarkably specific age of 40. However, I suspect that you'll find you've imported a bit of your own baggage into your explication.
I can see why people get all fuzzy and romantic about their children and their children's future, but these people are just going to end up crippling their children for lack of realistic ideas about real skills to learn.
Let's set aside questioning the notion of whether or not there even can be one universal set of skills that guarantee success merely through some conformance to a Platonic Ideal of Humanity for a second, and begin to construct a somewhat harsher, but more realistic, list.
1) Shutting up and getting to work--Yes, your mommy thinks you are special, and you think your kids are special, but nobody else does. Whether you're in service of a crappy manager inside some sucky megacorporation or trying to pry cash out of fickle customers, the only thing your gatekeepers care about is what you can do. So, do it. Turn off Facebook. Turn your phone off. Write your damned code or design your damned bridge and deliver it. Or push your resume around. Just turn off the distractions and make yourself go.
2) Conform--Again, Snowflake, you're one among a million lower-case-s snowflakes. Get over it. Go along to get along. If your so stuck on yourself that you can't dress down like a slobby developer when working with slobby devs, or put on banking attire if you code at a bank, then you're going to make people uncomfortable and make things worse for yourself. Go ahead, feel smugly superior about it as you do it, but do it. I'm sure they are all mindless automatons, but you can do it out of a conscious choice. Just remember, they can kill you, but they can't eat you. Snowflake.
3) Perform while depressed or discouraged--You're not a hothouse flower. You are an employee. Or an entrepreneur. You're a name to you and your friends, but your a number to somebody who's between you and a promotion. Or your next paycheck. You're not always going to be happy, and you're still going to have to meet your obligations, still going to have to provide value to someone or make progress to a goal that provides value to someone. Take a pill or drink a beer or cry on a shoulder, but don't stop performing until you can afford it.
4) Recognize bullshit--And recognize that it's everywhere. That's not a moral judgment. It's just the way it is. It's easy to spot in the obvious places, like advertisements, but not so easy in others, like when someone is blogging about the wonderful things they're going to instill in their children that the Bad Old Education System just won't for some reason. Everyone wants to blow smoke up your ass. Especially your parents. Especially parents who want to view themselves as enlightened friend-peer-guides to their crotch spawn. You're special, but not more special than Daddy's ego. Not really.
5) Watch out--Look out for number one. I don't mean to not play on a team. Just recognize that it's play, that it's a thing you do for certain reasons. Everyone else on the team is in the same situation, whether they realize it or not. Are your skills a threat to someone else on the team? Watch them. Be careful around them. Be a little paranoid while maintaining some perspective. It is not at all uncommon for someone of either gender to trump up a harassment claim to neutralize a rival. (Among many other stupid and counterproductive things.) Don't be paranoid, but be aware and smart.
That's a start. You get those things down, and "Problem solving", "Compassion", and "Tackling projects" will seem like the stress-free child's play that they are.
"Human hearing is limited to 20k because frequencies higher than that are perceived as painful? Dont agree with that one."
Yeah, that's a silly one. I disagree with it, too. It's a good thing it appears nowhere in the fine article. Are you actually confused about the difference between frequency and amplitude? Or did you misread the article?
"24 bit doesn't offer any advantages to sound quality? Sheesh."
As brazzy rightly points out, "Sheesh" isn't a reasoned statement. It's an ejaculation. And, it turns out, the author talked about why sound engineers record with 24 bits; It has to do with pragmatic reasons about leaving room for the highest and lowest frequencies in the audio being recorded without clipping, as well as with the author's discussion of Nyquist considerations in the distributed product.
Your post is wrong in so many ways that would have been easily fixed by reading the linked article with even 8th-grade reading skills that the reasonable reader has to wonder if you're being deliberately obtuse. Are you?
I think the entire discussion would be helped by the simple realization that programming is not really all that glamorous nor scientific. It seems like a lot of programmers have math envy, but programming is much more like managing an office staffed with savants than it is like discovering a proof; You tell the workers in the office what to do, using very specific instructions because they can't figure out what you mean, no matter how blindingly obvious it is to you, even though any one of them can add two numbers together in a billionth of a second.
Given that, we can probably look to progress in the "science" of management to get a feel for what progress in the "science" of language design is going to look like. That is to say, we probably can't expect anything at all in the way of progress. It's funny that there's a parallel between the conclusions in William Whytes' "The Organization Man" and "progress" in language design. Whyte concludes, one, that management in the abstract doesn't actually exist and, two, "management" taken as organizational oppressiveness and intrusion is actually a parasitic load on people trying to get work done, and ought be minimized. Look at the success of weakly-typed scripting languages like perl, js, ruby, python, and so on: the fewer strictures they impose on the data, the more work you can get done!
Researchers are just going to have to get over math and physics envy. The "truths" they discover are very unlikely to be anything like nearly as universal as physical truths. Structured programming, OOP, AOP, functional programming, or whatever else aren't ever going to fit into a proposition like "If we adopt ____, we find that blah," where blah is any kind of contingent claim relating to bugs or productivity. All we'll ever get are notions that whatever paradigm worked well in one context and poorly in another. Again, this is parallel to management. You can't manage programmers like auto workers like farm workers like service workers. Outside of algorithmic analysis, computer "science" has as little to say about programmer efficiency as management science has to say about how many weeks of parental leave you should give your employees.
Huh. I really thought the days of the (she-was|they-were)-asking-for-it-I-mean-look-at-how-(she-was-dressed|well-covered-their-market-was) argument were over. Wonders never cease, I guess.
If their patent work left them confident that there were OK, then the courts will see if they're right. If they chose to take a chance... this is what can happen.
The only trouble with that statement is that it's completely incoherent. On the most charitable reading of it, there is no way not to "take a chance." This is, in fact, the very thing that you're obscuring, whether by accident or design. If the patent system is a structural quagmire that stifles innovation, then that is the problem precisely because "due diligence" is impossible.
Incredibly, you continue:
But Nest is no victim here...
Yes. Yes, they are. They may be an affluent victim. An able victim. But a victim nonetheless. And, as long as this kind of victimization is allowed to continue, innovation will continue to carry a market-altering penalty that retards human progress. And, lest you think I'm being grandiose in my assessment of this thermostat as an example of human progress, it saves energy, and energy is one of the more pressing problems facing humanity.
They knew what they were getting into.
"But, ladies and gentlemen of the jury, look at how short that skirt was, and she decided to walk home on a Friday night! Drunk! Who's the real victim here? My client couldn't resist!"
The cost per kg currently around $10k, about half what it cost on the shuttle. If you assume a payload mass fraction of 2% and a vehicle mass fraction of 10%, you have a fuel-to-weight ratio of 44:1. So, it takes--switching to English units because milk is in gallons--44 pounds of fuel to launch 1 pound into orbit on current launch vehicles. Fuel is roughly as dense as water and roughly the same cost as milk. So, about 6 gallons of fuel at $3.50/gallon. $21 in fuel for 1 lb of payload, then.
How do you solve this problem? You work on the difference in engineering cost between $21/lb and $5k/lb, say by simplifying systems, building them more robustly so the $30k paper trail that guarantees that the otherwise $700 part will perform exactly as advertised goes away, or aiming for reusability.
Of course, if you did that on a large enough scale, you'd be Elon Musk.
The stupidity of ideas like this is they are counterproductive. If your employees are 'shopping around' or seriously entertaining recruitment offers it likely means they are unhappy in your employ. In this case it is best for everyone for them to go elsewhere. You know how you retain good employees? By giving them challenging work, minimizing stupid bureaucratic taxes, avoiding silly office politics, paying them fairly and treating them with basic dignity and respect. What a concept.
It's probably not insightful to frame this problem, as you seem to have done, in terms of the naive "markets are always best" argument, especially when that model seems to imply that employees should always be "shopping around," by definition. You say that "it is best for everyone for [dissatisfied employees] to go elsewhere." Where to begin? Specific persons in your employ aren't fungible. They've accumulated training and product knowledge that you might direly need in order to meet a deadline or bring a product to market before a competitor, to cite the most obvious objection. In other words, the cost/benefit ratio of retaining a given employee is dominated by factors external to the labor market.
I'd also be interested to hear, in detail, how your particular arrangement of challenging work, bureaucracy, office politics, fair pay, and dignity and respect programs both reaches a maximum of employee satisfaction and functions in even one competitive company. And then I'd like to hear how that generalizes, from first principles, to all technology companies everywhere. For example, how are you going to stop office politics from coming in to play during the distribution of challenging work, say in one of the "schlep" companies that pg wants to fund, all while minimizing "stupid bureaucratic taxes." And, which of bureaucracy or politics is going to be more generally erosive of "basic dignity and respect," if you have to choose between them?
I mean, it sounds nice, from an employee's or prospective employee's perspective, to just say, "Employers should just do only amazing things to me, or I'm within my rights to throw a fit and leave to go work for an obviously smarter employer," but that doesn't mean you've actually got a workable hypothesis.
This is a hi-fidelity recapitulation of one of the main pop theories of negotiation, that good bargaining is always hard bargaining, especially if it's brainless. However, I think it's completely wrongheaded.
There's a great book called Getting To Yes that I recommend everybody read. Here are the main points in a nutshell:
1. Focus on interests, not positions.
2. Separate the people from the problem.
3. Invent options for mutual gain.
4. Insist on objective criteria.
How might that work in a salary negotiation? On the first point, the employer has interests in retention and morale, as well as in the value they can extract from an employee. (Or, maybe not. This is good information to have.) They want to minimize disruption so that they don't have to retrain. The employee has this interest, too, as it's stressful to change jobs. Neither party is going to be served by a wage that is out of balance either way.
On the second point, one important thing not to do is to treat them as someone whom you'd use petty tactics on, as someone to whom you would use something "towards your advantage as bait." You're always having a meta-negotiation about the terms of the negotiation that carries over into your employment environment. Are you going to be cutting each other's throat all the time? Or, during your working relationship, are you going to want to be reaching understandings about how best and most fairly to proceed?
On the third point, you might find that there is a non-obvious imbalance between your demonstrated skills, for example, and your potential in a job that looks to be an amazing fit. What to do then? Do we shift the risk onto the employer, forcing them to pay for potential? Do we shift it onto the employee, insisting on pay for experience only? Well, to "invent an option," what about a probationary period long enough to see whether the potential is going to materialize? The pay would be, say, slightly above pay for experience only, but well below potential. And then you revisit, agreeing in advance that either party can walk if the fit is poor. That's one option, there may be more. Like contracting at a higher rate with an option to be brought on as an employee. Or so on.
Finally, on objective criteria: "Market rate" is not the only criteria. Market rate is just an average, anyhow. What's more objective would be anticipated value from the unique relationship between this employee and that company. How much can you increase sales? What's the likely perceived differential in reputation of your employer if you, the crack tester, continually find nasty bugs before they're discovered outside, so that they can be patched before they become problems? What if you're the amazing architect who can design a robust system that is easy to program in, increasing developer productivity across the board? These things are measurable, even if Bayesian, criteria, if we can look at your history of providing these goods.
I just bristle at this simplistic view of bargaining as mere power plays, and marvel at its persistence in the face of so many better options, not to mention the enormity of value left on the table by both sides of negotiations everywhere.
What you've all just witnessed is power talk masquerading as service talk.
What cdata has actually said is, "Sorry, you're not our customer. The websites that use us are our customers. Your feedback isn't really wanted. Fuck off."
The "fuck off" meta-message is aimed at the rest of us as much as it is aimed at jerrya. It emphasizes two things. One, cdata is going to pursue a strategy of nitpickery, mockery, and isolation to dis-empower dissatisfied victims of his company's software, under the guise of smoothing ruffled feathers. The strategy is containment, not satisfaction. Think of what satisfaction would have looked like, then compare it to cdata's post. Two, it emphasizes that we can participate in the game of isolating jerrya, and doing so will shield us from his treatment, as well as the harsh treatment of any who join in. Additionally, as soon as the first toady chimes in, the apparent perception of an emergent group dynamic aimed at belittling jerrya, bolstering the perceived value in siding with the group or staying away altogether.
Now, I am using the same tactics, I assure you. The difference is that I believe that you can see that I have a good warrant for using it, namely that it is precisely the surreptitious use of the tactic that must be discouraged.
Don't let cdata get away with it. It's not polite and it harms the process by which we can provide feedback about our distaste to people who want to wreck the Internet for personal gain.
"The Internet is the first technology since the printing press, which could lower the cost of a great education and, in doing so, make that cost-benefit analysis much easier for most students."
Perhaps it will bring the cost of an education down to the point where even a TechCrunch writer can afford to learn basic grammar as it pertains to the uses of subordinate clauses and commas.
It turns out that "relative efficiencies" from an energy standpoint is not the relevant consideration, by two or three orders of magnitude.
Fuel costs for launch vehicles are a negligible fraction of the total cost to fly. Musk is working the rest of the problem by simplifying the design, designing for manufacturability, using off-optimum technologies, building everything under one roof, and so on.
Human languages are far more complex and verbose than is required for talking to computers.
This is mostly a quibble, but human languages are not more verbose than computer languages, generally. I can generally rely on you to allocate all the variables and present the result in a context-aware way when I ask you, "What is 3 + 5?" I'd generally have to allocate variables and tell the computer where to put the result if I were to ask it the same question.
What was, and still is, sort of magical about Perl is the degree to which it is aware of context and can use it to sort out meaning. If anything, the chief complaints against Perl, which stems from its similarity to natural languages (!), is its terseness and expressive power, these complaints being that it's indistinguishable from line noise and is a write-only language.
In U.S. dollars in the year 2000, it came to about $16 of fuel per pound of payload launched. We had a homework assignment to figure out that number in our propulsion class at the University of Washington.
Shocking. The rest of that $10k per pound is amortized launcher costs and operations. (If you include the initial R&D, it goes up to something like $50k per pound.)
Now you just spend all the compressor and heat-exchanger machinery weight that you saved by not going with the Skylon engine by having dedicated thrusters elsewhere on the vehicle for the pure rocket mode.
As someone somewhere else said, Skylon strikes me as a characteristically British solution to the problem, just due to it's sheer over-reliance on plumbing.