• 0 Posts
  • 15 Comments
Joined 1 year ago
cake
Cake day: June 17th, 2023

help-circle
  • A reasonable length survey will never “paint a full picture”. Maybe what they’re trying to show is that there are a lot more people who value walkability more than is currently assumed. In most of the US you can either chose a super high density walkable area in a condo tower or a house in a car based suburb. It’s possible to design neighborhoods that are walkable and can provide a reasonable amount of private outdoor space, and what this shows is people would be willing to pay for it!





  • Having multiple, semisolated compartments in a Hyperloop train is entirely reasonable. There’s definitely room in a traincar for the occupants of a compartment that’s on fire to move to another compartment for emergency purposes.

    Evacuation points would be defined every so often (say every few miles) such that the train could come to an emergency stop within one, seal doors on each side and let air in. This would take a few minutes, but so does landing a plane or stopping a high speed train.

    Bottom line is that fire safety is, to me at least, an entirely solvable problem. The biggest problem with Hyperloop, I think, is that given the materials for the vacuum sealed tube and the energy required to hold that vacuum, it is just so unlikely to be more efficient than a maglev. For medium distance travel, even standard high speed rail is good enough to replace planes, so we don’t need the extra speed for ~500 mile distances. For longer distances where high speed rail is super slow or impossible, such as across continents and oceans the cost of building the vacuum tube will be so costly that it would take something like a complete ban of non-renewable fuels in aircraft for it to be a consideration. Even then, I think it could end up being cheaper to develop and use renewable fuels for aircraft.


  • It is much harder for fire to exist without air. There are some self oxidizing fires, but it should be relatively easy to avoid those materials. For fires inside the vehicle, there are some existing fire protection protocols that could be followed. There have been fires on the International Space Station and they couldn’t exactly run outside either.



  • I agree there’s a lot of interesting things to discuss about this topic. It can hardly be contained in a short survey like this.

    For the additional thoughts I put:
    Positive: Selfish human thinking restricts most people to considering only how their actions will impact the world within their lifetime. The potential for living hundreds or thousands of years could allow people to think more long term about their actions. Very few things are persued in the 50-year time span, let alone planning for something that could take 200 years.
    Negative: People may be much less willing to take risks. If the only things that can kill you are possible to avoid entirely, wouldn’t you?

    I hadn’t considered how bad the unequal access could be in the way that you talked about. I was thinking it would be one of those things like advanced cancer treatments, for example, that the mega-rich get access to when it is first developed and then within a few years to decades it becomes the standard of care. What I didn’t consider is that whatever the breakthrough is that allows immortality may need to be near-constantly applied for it to work. Almost like a potion of immortality that lasts only weeks. Even if the cost of the treatment is lowered very quickly it’s not likely it will be something as simple as insulin for treating diabetes or aspirin for treating blood pressure. It could take decades for it to become affordable for the upper class and may never become economical to give to everyone. Having a class of people who die of old age and a class who doesn’t is some super dystopian cyberpunk type shit.



  • I’m seeing a lot of misconceptions in the replies. You have it mainly right from a very high level.

    The reason why prepreg “expires” is simply that the resin system is mixed before being impregnated into the fibers, so it starts the curing reaction immediately. These resin systems are usually designed to cure properly at high temperatures, typically 250-400F depending on end-use, but they’ll still slowly react at lower temperatures. To further slow the reaction, prepreg is kept frozen. Prepreg also has two types of expirations: “shelf life” and “out life”. Shelf life is how long it can last frozen. Out life is how long it can last at room temp.

    Theres a few issues that can happen when using expired prepreg. It can be harder to laminate since it will be too stiff and not as sticky. It won’t cure correctly causing failures in the resin.

    Expired prepreg can be recertified by testing the material for those types of failures. Check if the prepreg can fold over a certain radius and stick to a certain angle without sliding off. Cure a sample and test it to see if cured properly.




  • PocketCasts was pretty much perfect for me for a long time and recently (past couple years maybe?) they did a big update which made it noticeably worse. I tried a few other apps and they had even bigger issues. I’m still using PocketCasts and they’ve fixed some of what they messed up but it isn’t perfect.

    They have a good library of podcasts built in but also allow you to add custom rss feeds for any smaller shows they don’t have or if you have private feeds from patreon or elsewhere.