lte678

joined 1 year ago
[–] lte678@feddit.de 9 points 1 year ago

Oh shit looks like you got em'

[–] lte678@feddit.de 12 points 1 year ago (4 children)

Who wouldn't? They are doing some of the most advanced rocket science on the planet. Of course, trusting corporations statements and research is an entire topic of it's own. Taking Elon Musk seriously on the other hand...

[–] lte678@feddit.de 4 points 1 year ago (1 children)

Thanks! Both look like very decent studies so I am not certain where the difference comes from. I suspect that the division into age brackets, or averaging across all of the them may be the cause. Either way, it seems that the effects of being slightly overweight are barely statistically significant. The more you know

[–] lte678@feddit.de 3 points 1 year ago* (last edited 1 year ago) (3 children)

After some cursory research ([1] among other meta-analyses), this does not seem to be true below the age of 80. Could you cite a source?

[1] https://doi.org/10.1016/S0140-6736(16)30175-1

[–] lte678@feddit.de 9 points 1 year ago

Feeling pretty called out, ngl

[–] lte678@feddit.de 3 points 1 year ago (1 children)

Well, the article refers to both :)

I think you'd be right about the "number of diagnoses" statement in the title, but I think the discussion is about the deaths due to cancer, which have also increased and would not have as strong of a correlation for the reasons others mentioned

[–] lte678@feddit.de 2 points 1 year ago

From briefly having worked on a project where this was a relevant issue, and I had to throw good people of foreign nationality off the team due to higher up NASA decisions: ITAR also becomes relevant when you want to access data and hardware that is ITAR regulated for use in your mission. This is the case for all space missions -- even for SpaceX, who likes to do things in-house -- since the advanced electronics, alloys, etc. will come from elsewhere and fall under regulation.

[–] lte678@feddit.de 1 points 1 year ago

Cool, didn't think of that one. But it would still work, since you could consider that a constant in front of the f(x) not raised to the nth power (easier to imagine if we have a constant function, then its just (b-a)). The nth root will then normalise it to 1 for any real factor.

[–] lte678@feddit.de 52 points 1 year ago (2 children)

I don't know a single person who consumes milk because they think they require it. They just like the taste of dairy products.

The subsidization is an issue imo, but I don't think people are as brainwashed regarding milk as you assume.

[–] lte678@feddit.de 9 points 1 year ago

It should be fine for normal use cases when used with error correcting codes without any active scrubbing.

According error rates for ECC RAM (which should be at least by an order of magnitude comparable) of 1 bit error per gigabyte of RAM per 1.8 hours^1^, we would assume ~5000 errors in a year. The average likelyhood of hitting an already affected byte is approx. (5000/2)/1e9=2e-6. So that probability * 5000 errors is about a 1.2 percent chance that two errors occur in one byte after a year. It grows exponentially once you start going a past a year. But in total, I would say that standard error correcting codes should be sufficient to catch all errors, even if in hibernation for a whole year.

[1] https://en.wikipedia.org/wiki/ECC_memory

[–] lte678@feddit.de 10 points 1 year ago

TMR (so the tripilicate method) wouldn't be super suitable for this kind of application since it is a bit overkill in terms of redundancy. Just from an information theory perspective, you should only have enough parity suitable for the amount of corruption you are expecting (in this case, not a lot, maybe a handful of bits after a year or two). TMR is optimal for when you are expecting the whole result to be wrong or right, not just corrupted. ECC and periodic scrubbing should be suitable for this. That is what is done by space-grade processors and RAM.

[–] lte678@feddit.de 5 points 1 year ago

The gold around satellites are actually very thin layers of mylar, aluminum foil and kapton (a type of golden, transparent plastic) which are used to keep heat inside the satellite inside, and heat outside, outside (See Multi-Layer Insulation). Radiation shielding usually comes from the aluminum structural elements of the spacecraft, or is close to the electronics so you do not waste too much mass on shielding material. Basically, shielding efficacy is most determined by its thickness, so it quickly becomes quite heavy.

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