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Apollo 11 Guidance Computer vs. USB-C Chargers

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Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#61

Post by vardump »

cnst wrote: post #9
duxup wrote: post #6

I admit I didn't understand much of that but enjoyed reading it none the less. I wonder about the hardware selected for say a charger, is it maybe just that the power (CPU, memory) are just a factor of that being the most cost effective choice and the power (cpu, memory) are far more than a USB charger needs?

I'd guess at one point you simply can't buy anything cheaper than 10MHz? I'm updating my laptop; it'd probably be fully sufficient to have just 16GB DDR4 (I have just 4GB right now, and it ain't that bad), but I can get a 32GB stick for only like 110 USD, so, I might as well go for 32GB to max out the slot and not have to worry about it later on. If the price for 32GB sticks was more like $500, I'd probably not bothe…

I guess – if you don't mind halving your memory bandwidth.

Most laptops have two memory channels, so if both are not populated with same size memory module, at least part of the memory range will provide only 50% bandwidth.

For memory bandwidth sensitive tasks it can halve performance, although I guess for most workloads the effect is way less, perhaps just 15-20% slowdown.

Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#62

Post by segfaultbuserr »

ghaff wrote: post #31
jedberg wrote: post #12

And despite the fact that a wall charger has more compute power than the Saturn V, we can't actually go to the moon today. We've actually lost the ability to go. No one understands how the engines on the Saturn V work anymore. It would take years to tear them apart and analyze them, and most of the original engineers are dead. And the guidance systems would have to be built back up from scratch. Kind of sad if you th…

>No one understands how the engines on the Saturn V work anymore. That's not really true [1]. Although the project is dead AFAIK a fair bit of work went into reviving the F-1 engine in the early 2010s. >And the guidance systems would have to be built back up from scratch. As with many things, you can't easily replicate complex old artifacts because you don't even have the tools to make the tools to make the tools...…

> I doubt you could easily get things like rope core memory or just about any of the components.

"Any of the components" is an exaggeration. For example, bipolar transistors are still here, here's the schematics [0] of the switched-mode power supply in the AGC - still perfectly understandable, rebuilding it can a fun weekend project. Also, discrete NOR gates are still around, although the underlying technology is different.

> As with many things, you can't easily replicate complex old artifacts because you don't even have the tools to make the tools to make the tools... No, we couldn't build an Apollo Guidance Computer today.

I think there's a difference between a 1:1 faithful replication and a replication based on the same architecture and/or principle of operation. While it's difficult to build a 1:1 faithful replication, rebuilding a new one based on the same architecture in general is much easier.

So when the original commenter said, "no one understands how the engines on the Saturn V work anymore", I think the point to be made is whether the ideas from the Space Age, e.g. whether the Saturn V architecture has survived, it is not necessarily meant that rebuilding it makes sense - it probably does not.

> The guidance computer would probably be the least of your challenges

+1.

[0] https://www.righto.com/2019/08/reliable-after-50-years-apoll...

Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#63

Post by jonplackett »

kragen wrote: post #44
jonplackett wrote: post #38

Earlier quoted context omitted.

I think this is the thing we'll be looking back on like this. AI in EVERYTHING. because it'll be so cheap in 20 years. Like maybe those useless automatic taps or hand dryers will finally actually know if hands are under them properly because they'll have the equivalent of a modern day supercomputer of AI power trying to figure it out.

Maybe. 20 years ago Moore's Law was in effect. We've become accustomed to "it'll be so cheap in 20 years" because, from 1947 to 2010, transistors dropped in price by a factor of two every 2 years, while getting faster starting in 1975 due to Dennard scaling. Roughly, for ten thousand transistors or so, the prices (in inflation-adjusted US dollars) and response times varied very roughly as follows: 1950: $1'048'576 (1…

20 years is a long time to work some stuff out though.

I think it’s a bill gates quote (badly paraphrased probably) - “people overestimate what can be achieved in a year and underestimate why can be done in a decade.”

So 2 decades ought to be something well outside our current expectations.

I hope it will be at least!

Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#64

Post by flatiron »

J5892 wrote: post #60
bloopernova wrote: post #50

Earlier quoted context omitted.

Speaking of fun technical rundowns, I've idly wondered: - Approximately which year's average desktop PC is equivalent to a current Raspberry Pi? - What year's worldwide computing power is equivalent to a current Raspberry Pi? I'm sure folks can come up with other comparisons to make. I know it's not very useful to the world, but it's fun to think of just how much astonishing compute power we have these days.

- How many Apollo 11 guidance computers would you need to run Doom?

I believe you require a 32 bit computer and I think those were 15. So no doom :(

Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#66

Post by ufmace »

jedberg wrote: post #12

And despite the fact that a wall charger has more compute power than the Saturn V, we can't actually go to the moon today. We've actually lost the ability to go. No one understands how the engines on the Saturn V work anymore. It would take years to tear them apart and analyze them, and most of the original engineers are dead. And the guidance systems would have to be built back up from scratch. Kind of sad if you th…

I don't believe that's a good portrayal of the situation. I doubt that there's anything all that special about the actual Saturn V engines. Sure, maybe nobody remembers all of the engineering details about those particular engines, and it would be hard to reverse engineer them. But I'm pretty sure we would find it much easier to design and build new engines of similar spec today. SpaceX, Blue Origin, and several other new space companies don't seem to have had all that much trouble designing and manufacturing new, powerful rocket engines.

Ditto guidance systems. Why try to replicate something designed around the constraints of hardware that seems ancient by today's standards? No reason to think we couldn't build something new with equivalent or better features on modern hardware.

Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#67

Post by gowld »

crmrc114 wrote: post #3

This is awesome! The media loves to say your pocketwatch is more powerful than X form $date. This is a fun technical rundown. I think at some point we have to start talking about how far from optimized we are https://en.wikipedia.org/wiki/MenuetOS comes to mind when talking about what can be done in fasm. Are we ever going to get compilers to the point where we can squash things down to that size and efficiency? Is t…

Apollo 11 used a heck of a lot more materials and energy than a USB charger.

Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#68

Post by gowld »

xkemp wrote: post #36
jedberg wrote: post #12

And despite the fact that a wall charger has more compute power than the Saturn V, we can't actually go to the moon today. We've actually lost the ability to go. No one understands how the engines on the Saturn V work anymore. It would take years to tear them apart and analyze them, and most of the original engineers are dead. And the guidance systems would have to be built back up from scratch. Kind of sad if you th…

We could easily go to the moon. It's just a completely useless exercise to do so, unless you can find a way to taunt China into another round of the space race. The scientific case for the moon was always weak, and most anything they could come up with has been done. Just look at the useless lets-grow-salad-in-space-oh-look-its-just-salad timesinks the ISS has been busying themselves with. So, in a way we've become m…

https://www.sciencenews.org/article/china-landed-moon-missio...

Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#69

Post by sterlind »

lopmotr wrote: post #46
jedberg wrote: post #12

And despite the fact that a wall charger has more compute power than the Saturn V, we can't actually go to the moon today. We've actually lost the ability to go. No one understands how the engines on the Saturn V work anymore. It would take years to tear them apart and analyze them, and most of the original engineers are dead. And the guidance systems would have to be built back up from scratch. Kind of sad if you th…

Something requiring human labor doesn't make it impossible! There's no lost scientific knowledge. Engineering details may be lost but we can design a new rocket that works just as well. We send unmanned probes to the moon all the time. There's no loss of resources to do it either. We have more money than ever before. We just can't be bothered. That's all.

Even if we could be bothered, I think we've lost the political technology to organize large government projects and complete them on a sane budget/timetable.

The budget plan for the James Webb Space Telescope was $500m with completion in 2007. We're now at $9.6b with completion predicted in 2021. Some of the cost overruns and delays were caused by the unexpected complexity of fabricating the mirrors and assembling them in space, but that underscores my point. The Apollo mission was orders of magnitude more ambitious at the time.

I'm not pointing any fingers because the causes are complex. NASA is underfunded and relies on unreliable funding from Congress, which itself is a source of inefficiency. Defense/aerospace contractors are greedy, sure, but there's a much bigger pie to be had if past successes encouraged even larger-scale projects like moon colonization they could bid for.

I don't know what's gone wrong, but we are failing on these big projects as a species for some reason.

Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#70

Post by 75central »

bloopernova wrote: post #50
crmrc114 wrote: post #3

This is awesome! The media loves to say your pocketwatch is more powerful than X form $date. This is a fun technical rundown. I think at some point we have to start talking about how far from optimized we are https://en.wikipedia.org/wiki/MenuetOS comes to mind when talking about what can be done in fasm. Are we ever going to get compilers to the point where we can squash things down to that size and efficiency? Is t…

Speaking of fun technical rundowns, I've idly wondered: - Approximately which year's average desktop PC is equivalent to a current Raspberry Pi? - What year's worldwide computing power is equivalent to a current Raspberry Pi? I'm sure folks can come up with other comparisons to make. I know it's not very useful to the world, but it's fun to think of just how much astonishing compute power we have these days.

My idly wondering one day was when in history did the worldwide available compute power (roughly) equal that of my iPhone 11?
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