• 2 Posts
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Joined 1 年前
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Cake day: 2023年6月17日

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  • The carbon free rock is replacing limestone in the manufacturing process, not the sand. Sand is added to cement, along with rocks and other aggregates, to form concrete.

    From what I can tell, the way this might be bad is that the carbon free rock may not exist in significant quantity. If it does, it will be mined in the same way as limestone, so that’s just a wash not a bad thing. If the rock they need doesn’t really exist they have to buy it from someone else who makes it from readily available materials. In that case, it could be green washing, where the company can claim “our process doesn’t release much carbon compared to the traditional process” but in reality the total carbon released to create the cement - from mining to processing to pouring - could be similar.


  • 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 think the point that is counter to yours is that we are nowhere near the fundamental limits of energy density for batteries. It’s probable we are near a fundamental limit for LiPo, but the point is that battery tech improves by changing technologies/chemistries. BEVs couldn’t exist at all when the best rechargeable battery tech was lead-acid, but were enabled by LiPo. Theres most likely a type of battery you can’t even imagine that has yet to be invented that could store >10x or more energy than current LiPo per unit cost or mass.




  • There’s nothing formal stopping the SC from doing anything, but courts are generally limited to ruling on the controversy in front of them in as narrow a way as practically possible. I haven’t read any analysis on this ruling, but just from the little I have seen, it looks like they ruled that the HEROES Act didn’t grant the federal government the ability to forgive the loans in the way they were attempting.

    Biden could try using an authority from a different law or creating a different set of rules by which the loans may be forgiven.

    My non-lawyer prediction is that if Biden tries again, the SC will find a new reason to stop it and will make a bigger ruling that takes more power away from federal agencies to make decisions. They’ve already been doing this with environmental and health decisions, and I’m sure other agencies have been impacted too.



  • No guarantee they get the edits. Plus every instance can store older versions if they want and provide a ‘edit history’, whether that’s a part of the current protocol or not it is technically possible.

    Just like how someone can archive anything on the internet really.

    People should consider everything they do online to be public and trackable. If anonymity is important, it requires direct planning and effort to achieve. Data processing is so powerful and only getting stronger. Companies can learn more about you than you’d think without ever having access to your “PII”.