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How to start a rocket engine

everydayastronaut.com

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Re: How to start a rocket engine

#61

Post by chriswarbo »

sbradford26 wrote: post #43
chriswarbo wrote: post #31

Earlier quoted context omitted.

> You might have one thing measuring fuel burn rate in grams/second and another in kg/second This sort of redundancy is a big problem with metric (e.g. hours, litres, tonnes, etc.); and why it's better to stick to the SI subset. http://www.chriswarbo.net/projects/units/improving_our_units... In particular, SI is "coherent" https://en.wikipedia.org/wiki/Coherence_(units_of_measuremen... - There is only one unit for ea…

When designing new systems it is best to clearly define the expected units for everything clearly at the start. SI units are great but sometimes they are not great for the specific use case. When measuring high power systems like power plants or EVs kW/MW/GW are a more appropriate unit versus Watts. In embedded systems you have limited bandwidth having to have large variables just to store values in SI units is a was…

> SI units are great but sometimes they are not great for the specific use case. When measuring high power systems like power plants or EVs kW/MW/GW are a more appropriate unit versus Watts.

Those are all SI units. In fact, they're all the same unit: the Watt (almost http://www.chriswarbo.net/projects/units/metric_red_herring.... )

A non-SI example would be e.g. kilowatthours (kWH); since 'hour' is not an SI unit. The SI equivalent would be 3.6 MegaJoules.

> In embedded systems you have limited bandwidth having to have large variables just to store values in SI units is a waste versus using an appropriately scaled unit and saving bandwidth.

This seems like a non-issue to me:

- Integer arithmetic can be "appropriately scaled"; we call it https://en.wikipedia.org/wiki/Fixed-point_arithmetic

- Floats are designed to be scaled, by adjusting their exponents. In the happy case, our algorithms don't care; so why not stick with standard units? In the unhappy case (imprecision, numeric instability) we may need a mixture of entirely bespoke representations, even within a single algorithm. Ideally we'd still use standard units at the "boundaries".

Re: How to start a rocket engine

#62

Post by LargeTomato »

ghostpepper wrote: post #52
LargeTomato wrote: post #50

I'm surprised at the amount of people who enjoy EDA. I find him very irritating. Most people at my small space company find him extremely irritating. He is not a rocket scientist. He parrots silly buzzwords like "biomimickry" like a fanboy, not an engineer. He suggests things to Elon for how to do rockets that are just pants-on-head dumb. His blind fanboyism and arrogance irritate so many people who work in space. I'…

Didn't he suggest something to Elon that Elon immediately decided to alter on an upcoming rocket? Doesn't sound like he knows nothing..

I forget exactly what he suggested but I remember is being like kind of dumb. Elon was humoring him. This guy is absolutely not a rocket scientist. He's not even an engineer.

Re: How to start a rocket engine

#63

Post by sho_hn »

LargeTomato wrote: post #49
samwillis wrote: post #3

Earlier quoted context omitted.

> His interviews with Musk are a treasure trove as well, whatever you think of Musk. My main take away from those interviews is just how knowledgable Tim is, he's able to engage in low level and in depth conversations about how these engines work. It's not just superficial high level knowledge from making videos, he is thinking himself how to optimise and improve these things, and leading that conversation. The passi…

To be honest he's regurgitating a lot of information. He has large gaps in his knowledge but presents himself as extremely knowledgeable. Understanding a rocket engine as a layman is easier than understanding a diesel engine. EDA acts like he's a genius but he is not. I work in space. Some of my coworkers have met EDA. He is insufferable and extremely arrogant. A very difficult person to be around.

> but presents himself as extremely knowledgeable

I don't get this sense at all. I've been watching his channel for a couple of years, and I've consistently found him to portray himself as a fan/enthusiast trying his best to understand and summarize complex information he doesn't have first-hand knowledge of. He's never pretended to be an engineer.

I think the value is in getting inspired to dig deeper when he shows you something interesting.

Re: How to start a rocket engine

#64

Post by martythemaniak »

LargeTomato wrote: post #50

I'm surprised at the amount of people who enjoy EDA. I find him very irritating. Most people at my small space company find him extremely irritating. He is not a rocket scientist. He parrots silly buzzwords like "biomimickry" like a fanboy, not an engineer. He suggests things to Elon for how to do rockets that are just pants-on-head dumb. His blind fanboyism and arrogance irritate so many people who work in space. I'…

No, he's not an engineer and he cannot build anything, he has no special insights or novel ideas. He is an educator that popularizes niche and inaccessible knowledge to a large audience and that large audience really appreciates his efforts. His work in popularizing space tech is a net benefit to your industry and thus your company.

Re: How to start a rocket engine

#65

Post by sho_hn »

LargeTomato wrote: post #50

I'm surprised at the amount of people who enjoy EDA. I find him very irritating. Most people at my small space company find him extremely irritating. He is not a rocket scientist. He parrots silly buzzwords like "biomimickry" like a fanboy, not an engineer. He suggests things to Elon for how to do rockets that are just pants-on-head dumb. His blind fanboyism and arrogance irritate so many people who work in space. I'…

Could you give me an example of his 'arrogance'? I've been watching his content for some time, and I'd say he's always been very upfront and transparent about being an enthusiast/fanboy and not an engineer. His concept is to be an audience insert and ask the stuff his non-professional audience would ask, as a sort of avatar. I would expect no more expertise from him than from myself.

If the people he interviews are humoring or correcting him, that's exactly what I would expect and is part of the value of the content really. He's giving them a platform and enthusiastic laymen a chance to ask dumb questions.

Re: How to start a rocket engine

#66

Post by LargeTomato »

peterfirefly wrote: post #60
LargeTomato wrote: post #49

Earlier quoted context omitted.

To be honest he's regurgitating a lot of information. He has large gaps in his knowledge but presents himself as extremely knowledgeable. Understanding a rocket engine as a layman is easier than understanding a diesel engine. EDA acts like he's a genius but he is not. I work in space. Some of my coworkers have met EDA. He is insufferable and extremely arrogant. A very difficult person to be around.

> He has large gaps in his knowledge Yes. > but presents himself as extremely knowledgeable. No.

Yeah he has an extreme level of confidence. Tweeting Elon about how to architect the landing fins to use "fish scale biomimickry"? That's ridiculous.

Re: How to start a rocket engine

#67

Post by punnerud »

The more I learn about different types of rockets and all the engineering behind SpaceX, the more I am impressed by what they have accomplished.

Huge thanks to ‘Every Day Astronaut‘ for this YouTube channel, so many good videos.

Re: How to start a rocket engine

#68

Post by lb4r »

LargeTomato wrote: post #50

I'm surprised at the amount of people who enjoy EDA. I find him very irritating. Most people at my small space company find him extremely irritating. He is not a rocket scientist. He parrots silly buzzwords like "biomimickry" like a fanboy, not an engineer. He suggests things to Elon for how to do rockets that are just pants-on-head dumb. His blind fanboyism and arrogance irritate so many people who work in space. I'…

Regardless of you think of him and his 'dumb' ideas, with 1.4 million subscribers he will probably inspire more people than work at your 'small space company' to become real rocket scientists themselves. I wouldn't be surprised if he does more for the future of space industry than most of those who currently work in it individually do.

With that said, if you find him irritating, then you find him irritating. Hard to argue with that.

Re: How to start a rocket engine

#69

Post by twic »

LargeTomato wrote: post #50

I'm surprised at the amount of people who enjoy EDA. I find him very irritating. Most people at my small space company find him extremely irritating. He is not a rocket scientist. He parrots silly buzzwords like "biomimickry" like a fanboy, not an engineer. He suggests things to Elon for how to do rockets that are just pants-on-head dumb. His blind fanboyism and arrogance irritate so many people who work in space. I'…

I'm comparably bemused by the enthusiasm shown here towards some life sciences stuff. HN users are perhaps not the discerning polymaths you imagine.

Re: How to start a rocket engine

#70

Post by jaywalk »

Retric wrote: post #26
somenameforme wrote: post #24

Earlier quoted context omitted.

I'd also add this standard. Another amazing YouTuber is Veritasium. He went from [1] to [2]. The production quality is more than slightly improved, but the "spirit" remains identical. And I think that spirit is what drives success or failure. The production quality is just icing. [1] - https://www.youtube.com/watch?v=JUJPyQtoB5E [2] - https://www.youtube.com/watch?v=5eW6Eagr9XA

Veritasium videos are often subtly misleading which really annoys me. It’s great for views, but terrible for science education.

Whenever he drops a new video, I just look for the "Here's how Veritasium was wrong" videos to get the real story.
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