3 ms·
Seems like it could be cool, but too little information; I reallywant to know several more things to start. How does its shape actually behave under pressure?
by toss1 5y ago
Seems like it could be cool, but too little information; I reallywant to know several more things to start.
How does its shape actually behave under pressure? They say "acts like an ultra-hard, shatterproof glass when compressed", so is it really changing state that hard? - I'm not seeing an crisp edge imprint of the rectangle in the top metal sheet that I'd expect from the same setup running a car over something like a wood/metal block of the same shape. If it really stays hard and firm as glass under a certain amount of pressure, that could be actually bad as a cartilage replacement. OTOH, if it just squishes and regains it's form, seems like a lot of other plastics.
How much energy does it absorb? If it really absorbs and redistributes a lot of energy both spatially and temporally, it could be really good shock protection. But I can't tell from this announcement.
What is the real stress level it can handle? They talk about an elephant, but the reality is that it is about 300kg (25% of a 1200kg car assuming roughly wheel weight allocation) over a aprox 3"x3" piece, which amounts to less than 75psi, or about 5x atmospheric pressure. As it turns out, if they are talking about the actual pressure under an elephant's step, it is in the same ballpark [1]. However, the way it is phrased is the entire weight of an elephant, which would be 3000kg on that square, which would be 730+psi.
All in all, disappointingly vague announcement from a crew that should have some expertise readily available in physics and mechanics...
- mschuster91 5y ago> All in all, disappointingly vague announcement from a crew that should have some expertise readily available in physics and mechanics... It's a press release that should be somewhat understandable for non-scientists.
- toss1 5y agoI fully expect that a press release would be fully understandable by non-scientsts. I'm not asking for a scientific paper, just to reduce the huge ambiguities. They could have answered all three of my questions more clearly with no scientific jargon whatsoever. E.g. (assuming these examples are true for the sake of discussion): Instead of "acts like an ultra-hard, shatterproof glass when compressed", "with a bit more pressure than a soup can sitting on it becomes like an ultra hard shatterproof glass and retains it's shape" Instead of "withstand the equivalent of an elephant standing on it", how about "can support the weight of a full elephant across a 3" square" or "can support the weight of an elephant stepping on it". Both are very different, use no jargon, and at least if we can assume that the author was intentionally accurate will let us know the properties within a half an order of magnitude, instead of being so uncertain that we really have no clue as to it's actual utility.
- dekhn 5y agoThe link to the article is in the press release https://www.nature.com/articles/s41563-021-01124-x https://www.nature.com/articles/s41563-021-01124-x however, it's paywalled (you could pay $9 to maybe answer your questions).