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Law 20: A good design with a bad presentation is doomed immediately I definitely struggle with this. I run a math education site and I usually focus heavily on technical accuracy but underestimate the presentation. Hard lesson that being "right" isn't enough if the delivery is clunky.
Law 20 seems to express the state of most startups these days: > "A bad design with a good presentation is doomed eventually. A good design with a bad presentation is doomed immediately."
Imagine that you're a highly intellectual, highly technical, and highly responsible person in control of large sums of governmental or corporate money. You don't want to waste the money, you want stellar results (in spacecraft industry, maybe literally so). Would you assign a large sum of money to a group that cannot present their design clearly, neatly, and concisely? If they are struggling even with that, would you…
I have found that my best designs, few and far between, enter a period where they get simpler as they are completed. And my worst or failed designs keep getting more complex as I go on.
"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius — and a lot of courage to move in the opposite direction."
https://www.goodreads.com/quotes/14789-any-intelligent-fool-...
> "Trellis coded modulation got this rate up to 50 kilobaud by the 1990s" Not quite, and an interesting story that fits these engineering maxims better than you might think. An analog channel with the bandwidth and SNR characteristics of a landline phone line has (IIRC) a Shannon capacity of 30-something kbit/s, which was closely approached with V.34, which used trellis coded modulation plus basically every other cod…
But why is it higher? It's still an analog channel (the last mile from the ISP to your house), right? Doesn't it get filtered? So isn't it still subject to the Shannon-Nyquist limit?
Here's an ASCII drawing of which parts are digital vs analog as I understood your explanation:
Rest of worldTelcoISPmodemHomeModem
I hope you can clear up my confusion.
Earlier quoted context omitted.
That's what happens when the likely success scenario is selling out to an existing company rather than growing to be a genuinely large and long lived company.
There are beef companies and milk companies, depending on the way they plan to use their cash cow. (Most VC funding is used to quickly produce a beefy market share, and sell it to those who think they can milk it, or to profitably butcher it.)
https://en.wikipedia.org/wiki/Wikipedia:Akin%27s_Laws_of_Art...
> "Trellis coded modulation got this rate up to 50 kilobaud by the 1990s" Not quite, and an interesting story that fits these engineering maxims better than you might think. An analog channel with the bandwidth and SNR characteristics of a landline phone line has (IIRC) a Shannon capacity of 30-something kbit/s, which was closely approached with V.34, which used trellis coded modulation plus basically every other cod…
> if your ISP-side modem directly outputs digital audio, the downstream channel capacity is significantly higher But why is it higher? It's still an analog channel (the last mile from the ISP to your house), right? Doesn't it get filtered? So isn't it still subject to the Shannon-Nyquist limit? Here's an ASCII drawing of which parts are digital vs analog as I understood your explanation: Rest of world Telco ISPmodem…
> Couldn't you send data at megabits per seconds over a mile long copper wire without using modems at all (using just UARTs?).
No. The exchange is sampling the analog signal coming in over your phone line at 8kHz and 8 bits per sample. They just designed modems that sent digital data over that analog link, in a way that would line up exactly with the way the exchange will sample it.
The propellant storage shall be designed and located such that a catastrophic failure of propellant storage will not damage the passenger compartment.
The propulsion system shall be designed and located such that a catastrophic failure of the propulsion system will not damage the propellant storage or the passenger compartment.
The launch system shall be designed to ensure a minimum of two survivable abort alternatives at each phase of the flight. Each abort scenario shall be validated by a flight test before certifying the system for general use.
The re-entry system shall be designed so there are no single points of failure. If single points of failure are unavoidable, a method pf inspection or surveillance shall be developed to detect the failure prior to de-orbit.
In-orbit repair procedures for foreseeable types of damage shall be developed and validated prior to certifying the system for general use.
Yeah, this is all 20/20 hindsight. But we really need to avoid developing ANYTHING similar to the STS in the future. I truly believe it set us back by 50 years.
Earlier quoted context omitted.
> if your ISP-side modem directly outputs digital audio, the downstream channel capacity is significantly higher But why is it higher? It's still an analog channel (the last mile from the ISP to your house), right? Doesn't it get filtered? So isn't it still subject to the Shannon-Nyquist limit? Here's an ASCII drawing of which parts are digital vs analog as I understood your explanation: Rest of world Telco ISPmodem…
No, it’s more like HomeModem ←A→ Exchange1 ←D→ Exchange2 ←A→ ISPModem. The digital parts were all inside the telco’s networks that connect the exchanges to each other. > Couldn't you send data at megabits per seconds over a mile long copper wire without using modems at all (using just UARTs?). No. The exchange is sampling the analog signal coming in over your phone line at 8kHz and 8 bits per sample. They just design…
4kHz/2*log2(1+10^(31dB/10)) ~ 60.3kBps
[0] https://www.ecfr.gov/current/title-7/subtitle-B/chapter-XVII...