The Very Many Questions-Not-Worth-Their-Own-Thread Thread XXXII

[hobbsyoyo]

What's SpaceX's carbon footprint? Explained in some way that would put the numbers in a context my sick mind could comprehend, if possible

Pretty bad.

Aluminum takes a ton of electricity to produce and that's what you build rockets and capsules out of. The BFR/BFS they are planning will use carbon fiber but it doesn't exist yet. I also don't know what the environmental impact of composite production is but I assume it's not great. I also have no idea where their aluminum is sourced, so it could be relative benign if it is processed with hydro, solar or nuclear power but it could also come from very dirty coal plants.

The RP-1 used as the fuel in the Falcon 9/Falcon Heavy is essentially ultra-refined jet fuel (kerosene). It is bad for the atmosphere by itself but the quantity of exhaust is only equivalent to say a few thousand, maybe tens of thousands of cars. That's bad but not godawful by itself. Because it is so pure and burned at extreme temperatures, the exhaust products will also overwhelmingly be CO2 and water vapor which again, are not the worst thing at the quantities we're talking. Obviously not good, but not Chinese power plant bad.

The real problem is the high-altitude injection of exhaust and it's extreme concentration. High altitude, highly concentrated injections of even water vapor at those altitudes is bad for the natural balance of the atmosphere, much less all the other byproducts from the engine exhaust. They also dump a fair quantity of nitrogen (harmless) and helium (also harmless for different reasons) at altitude as well.

The fuels used in Dragon are extremely poisonous but are so reactive that they are not a huge environmental concern. They break down into mostly harmless water and nitrogen compounds relative quickly in the environement because of their reactivity.

The rest of their environmental impact comes from running a medium sized factory in a heavily congested urban zone and from burning copious amounts of fuel in tests in Texas, California and Florida.

But hey they have free electric car charging and a giant "X" in solar panels on the roof so there's that.


Edit:
Sorry I don't have numbers, I can qualify the problem but not accurately quantify it. I could find the information if I wanted to but I don't.

 

[Chukchi Husky]

Why would it do that? As I recall, aluminium has an extremely high melting point.

It was something that I was told.

The boosters did, the shuttle engine where Hydrogen burners.

I was told that it was the booster rockets that used aluminium.

So I take that they were right? I remember watching a BBC documentary about the space shuttle but I don't remember it mentioning that aluminium was used as a fuel, but I always seem to get the wrong message from documentaries.

 

[Michkov]

I was told that it was the booster rockets that used aluminium.

So I take that they were right? I remember watching a BBC documentary about the space shuttle but I don't remember it mentioning that aluminium was used as a fuel, but I always seem to get the wrong message from documentaries.

No that's quite right. The boosters react ammonium perchlorate (oxidizer) with aluminium powder (fuel). Plus a bit of iron oxide as catalyst all held together by a binding agent which are then cast into large rings. Essentially you are making highly explosive cake.

 

[hobbsyoyo]

Yes @Chukchi Husky, your friends were right for the first time ever.

 

[hobbsyoyo]

So when people go to other countries and get very sick, how often is it from genuine food poisoning (i.e. under cooked food or untreated water) versus just normal background bugs in the area that our bodies just aren't used to?

 

[warpus]

Pretty bad.

Interesting, thanks for the details! Are there any plans moving forward to make SpaceX more planet/green friendly? Or is that just not possible with today's technology?

 

[hobbsyoyo]

Interesting, thanks for the details! Are there any plans moving forward to make SpaceX more planet/green friendly? Or is that just not possible with today's technology?

The company does what it can to mitigate climate change with solar power and charging for EVs. When the BFR launches it will use cleaner methane as a fuel. However it will also be much bigger and so will produce much more exhaust, offsetting the cleaner emissions by higher volume.

Truth be told, rocketry is just terrible for the environment and there isn't much that can be done to change that. Maybe one day they will be able to run the factories purely off solar power but that depends entirely on the grid itself being updated and of course does nothing to fix high altitude GHG injections from launches.

I have no idea what their green initiatives look like though and even if I did know I couldn't tell you. Everything I have posted is public information.

 

[Lexicus]

ruth be told, rocketry is just terrible for the environment and there isn't much that can be done to change that.

Tfw combustion

 

[The_J]

So when people go to other countries and get very sick, how often is it from genuine food poisoning (i.e. under cooked food or untreated water) versus just normal background bugs in the area that our bodies just aren't used to?

Two things here:
#1 I don't think there'd be any possiblity to get real data for this
#2 It needs to be distinguished between the types of food poising. Because food poisoning comes #A either from food gone bad, and the poisoning is caused by by-products of the bacteria growing on the food (e.g. botulinum toxin from Clostridium botulinum; you could not fix this by cooking anymore, the toxin is in there), or #B by not properly treating still good food (resulting in e.g. Salmonellosis caused by the actuall Salmonella bacteria from undercooked chicken).
For the latter part...uh... as said, hard to discriminate. If you drink uncooked water in a tropical country, you might get diarrhea. But who tells us that a native person from there might not get diarrhea too? This might be especially caused by a pathogenic bacterium in the water, or could be that your intestine does not have enough colonization resistance against this one bacterium, can not defend against it, and then you fall for it. Colonization resistance can depend on if a similar bug is already inhabiting that niche in your gut, so might depend on the exposure to (and colonization of) similar (non-pathogenic or less virulent) bacteria before, which might be more native in that area.
But it doesn't have to. For some, just a big enough dose is enough (like Salmonella), and you'll get sick.
To actually discriminate that (to come back to #1), we'd have to sequence/culture everything what you get in contact before you travel somewhere, and afterwards. And even then it might not be possible to see it.

Although there's at least one case where it was noticable, although not disriminatable. I don't know the researchers anymore (might remember if I googe some candidates), but there were 2 guys, who profiled their gut microbiota for roughly a year, for each day. You could then see, that one guy got diarrhea when he travelled to south eastern asia. This at the same time corresponded to the appareance of Clostridium difficle (commonly causes diarrhea) in his gut microbiota. He must have gotten this during the trip, because it was not visible before. Even there, it is not exactly possible to say if that C. difficile was background population in this area (that can absolutely be; you can have it (or your cat/dog, whatever), and not be sick), or if he was exposed to a specific one from one of the food sources (pigs also have it, without symptoms often). It would be possibe to say if we sample everything...but that's a ton of work and not worth the effort (although potentially interesting).
So lots of info, and no answer, sorry :/ ^^.

 

[civvver]

Random question: How much fiber do you usually eat per day and how much should you eat?

I read something online that men should aim for around 40 grams. That seems like a ton unless you pound beans, oats or berries. For example yesterday I ate a lot of vegetables, high in fiber right? Breakfast I had white toast without much like 2 grams, but lunch I had beef vegetable soup however it still only has around 8, I had a salad that apparently has around 7, for dinner I had chicken and vegetable stew with potatoes, carrots, celery, peas in it so you would think that's a lot but it's probably only a cup and a half of vegetables plus one potato, somewhere around 10-15 grams. I basically ate vegetables with every meal except breakfast and only got to ~30.

 

[Arakhor]

High-fibre cereal is my go-to breakfast (particularly good if you have nether issues). I've had Weetabix or Shreddies most mornings every week for years now.

 

[Broken_Erika]

High-fibre cereal is my go-to breakfast (particularly good if you have nether issues). I've had Weetabix or Shreddies most mornings every week for years now.

If i ever meet you remind me not to ride in an elevator with you.

 

[Arakhor]

Your lift journeys with me would be safe - those cereals make you more regular, not noisier.

 

[Synobun]

Your lift journeys with me would be safe - those cereals make you more regular, not noisier.

I only take the lift with irregular folks.

 

[civvver]

I don’t have regularity issues my poops are great actually, always same time of day. I just want to eat a lot of fiber and good fats to combat cholesterol. But it’s teally hard. I like cooked vegetables, salads are fine but you can’t usually just snack on salad. I don’t really like snacking on raw veggies ala cart. And I don’t like fruit much.

 

[shadowplay]

Should a man avoid boarding an elevator behind a lone woman? So I don't make her afraid? This is something I wonder about a lot. I'm especially interested in the perspective of female posters

 

[hobbsyoyo]

Thanks @The_J !

Should a man avoid boarding an elevator behind a lone woman? So I don't make her afraid? This is something I wonder about a lot. I'm especially interested in the perspective of female posters

I'd be interested to know this too. I can't avoid getting in the elevator with lone women because I have to take one multiple times a day but the parking garage is another thing altogether. To get my mail, I have to take a byzantine path through the lower garage level and more than once I've found myself inadvertently following a lone woman through the maze at night, by ourselves. I always feel bad, mostly because I'm a massive guy and I know I can be intimidating.

 

[CKS]

Should a man avoid boarding an elevator behind a lone woman? So I don't make her afraid? This is something I wonder about a lot. I'm especially interested in the perspective of female posters

I don't think this is necessary. However, follow basic elevator rules - stand as far apart as is reasonably achievable, look at the floor level indicator instead of the other person, don't talk to people you don't know, give people space to enter and exit. A man breaking the rules wouldn't scare me, but he would annoy me if I noticed. (I can be pretty oblivious sometimes.)

I'm not easily intimidated, so maybe others feel differently, but none of my friends or acquaintances have ever mentioned this to me as a concern.

Being followed by someone through the garage at night is a different story, and this would bother a lot of people I know. If the number of people you might end up following is fairly small, I'd suggest introducing yourself to them at a different time of day (ideally in the company of your wife) and then saying hi when you find yourself following them - "Hey, Susie, it's just me" - but not starting a conversation or getting to close.

 

[Synobun]

Should a man avoid boarding an elevator behind a lone woman? So I don't make her afraid? This is something I wonder about a lot. I'm especially interested in the perspective of female posters

This is a really odd question and I've never worried about this myself. It's an elevator, they're usually located in public buildings that are well-lit. I don't think I've even talked to another human being in an elevator.

Hobbs' concern is a little more reasonable since both genders can identify with that fear. My go-to in those instances is to simply make a lot of noise. I'll walk louder and perhaps cough a couple times. People who are up to no good are generally less eager to call attention to themselves and it'll alert them to your presence long before your proximity can even be a threat. Anyone who's ever tried anything with me in a dark area/alley/garage/wherever were intentionally quiet and didn't draw attention to themselves.

 

[hobbsyoyo]

I did make noise haha. Great minds think a like. I also walked very, very slowly. She was much shorter than I and it was hard for me not to overtake her but I hung back as far as I could. I was relieved when she turned on a different path.

People in my building (male, female, young and old) are super friendly. In elevators I almost always get a 'hello' and usually a 'have a nice day'. It's also common for strangers to strike up conversation. It actually makes me feel really welcome in this building.