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标称成绩很好,它到底替我测了哪种用法?

从一只白炽灯的寿命开始,比较洗涤剂、热泵、冬季车道与食品标签。每报一个漂亮数字,先把它对应的工作条件写回来。

本文的问题 · 11
  1. 车位过一夜,该拿多少能量除以功率?
  2. 格式一样,带速一样吗?
  3. 充电停靠多花十分钟,是桩慢还是站满了?
  4. 给灯泡延寿,谁来付电表上的差额?
  5. 说明书给了刻度,比较测试用了哪一格?
  6. 能在低温启动,等于房间暖得起来吗?
  7. 地图上已经有自行车道,下雪后还有一条完整路线吗?
  8. 包装上的「户外」覆盖动物一生中的哪一段?
  9. 书没读够十本,阅读方向偏了吗?
  10. 一盘带能不能装下整场节目?
  11. 你要横穿大陆,还是去趟商店?

车位过一夜,该拿多少能量除以功率?

给定充电功率,算空电池充满的时间很容易。通勤者的车停一晚时,通常只需补回这次出行用掉的电,还要知道实际可用的充电时间。同一个功率等级可以在长途停靠时显得慢,在家用场景却充裕。把使用场景换掉,算式变的是分子和时窗。

原文与时间戳 · 2
60 kilowatt-hours divided by 10 kilowatts is 6 hours
A Complete Beginner's Guide to Electric Vehicles · ▶ 12:33–12:37
charging time also depends on how charged the battery already
A Complete Beginner's Guide to Electric Vehicles · ▶ 12:44–12:50

格式一样,带速一样吗?

同一台录像机可以选择录得久一点或保留更多细节。比较 Beta 与 VHS 的演示具体说明了用了哪些模式,也因此能指出哪个结论只在那一对模式下成立。借来的旧设备若只支持某些带速,还要说明用户能否实际选择被比较的设置。

原文与时间戳 · 2
the linear tape speed on Beta 3 is higher than SLP
Comparing Beta & VHS on Quality: Was Beta Really Better? · ▶ 6:50–6:56
Beta 1 was sharper than VHS SP
Comparing Beta & VHS on Quality: Was Beta Really Better? · ▶ 8:11–8:16

充电停靠多花十分钟,是桩慢还是站满了?

快充的硬件讲解沿导线计算能送到电池的功率。三辆车的路测则从真实停靠开始,连找站和能否看到车位占用都影响到达时间。将插枪到拔枪的时间与偏离路线、排队的时间分栏,才能判断换一个更大数字的充电桩究竟能省下哪几分钟。

原文与时间戳 · 4
can carry more power with the same current
The tech which can charge an electric car in 10 minutes · ▶ 14:10–14:14
deliver 350 kW of power straight into the battery pack
The tech which can charge an electric car in 10 minutes · ▶ 23:21–23:28
how much time charging at these different infrastructures adds to a road trip
Driving 1000 Miles in 3 Cars: Gas vs Electric! · ▶ 2:16–2:21
literally currently being occupied by other cars
Driving 1000 Miles in 3 Cars: Gas vs Electric! · ▶ 16:16–16:21

给灯泡延寿,谁来付电表上的差额?

买白炽灯时把额定寿命翻倍,听起来总能省下一半换灯次数。Watson 的演示还留了一块电表:让灯丝在不同条件下工作,每瓦发出的光也会改变。现在把采购问题写完整:在同一张桌面上,照出同样的亮度,照相同的小时数,需要买几只灯泡、用多少度电?他关于电费通常高过购置成本的判断针对这种灯和他讨论的历史条件。换成另一种灯或电价,要重新算这笔账。

原文与时间戳 · 2
they deliberately traded lifespan for efficiency
Longer-lasting light bulbs: it was complicated · ▶ 26:00–26:03
their operating costs almost always exceeded the purchase cost anyway
Longer-lasting light bulbs: it was complicated · ▶ 26:07–26:17

说明书给了刻度,比较测试用了哪一格?

在 Watson 自己的硬水环境里,只加到洗剂槽第一道刻度就能满足他的要求。他转述的一种比较测试却干脆没有用预洗槽。只写「产品 A 赢了」会把两个决定隐去:程序是否有预洗,洗剂是否在预洗阶段出现。试着把两种洗剂放进同一张记录表,除了产品名,还写下餐具脏污程度、水质、程序和两次投放量。知道测试覆盖了哪种用法,才知道能否把结果带回自己家。

原文与时间戳 · 2
only filling to the first line is sufficient
I messed up. You're using too much detergent. · ▶ 8:07–8:12
they don’t use the pre-wash cup in their testing!
I messed up. You're using too much detergent. · ▶ 16:10–16:13

能在低温启动,等于房间暖得起来吗?

Watson 介绍热泵时先给出一个比值:送入室内的热与用电之比。机组在低温下仍能启动,却可能同时损失输出能力。假设在一次寒潮里观察到它一直运转,先问两个问题:电表走了一格送来多少热?每小时送来的总量赶得上房屋散热吗?对照灯泡再看:每瓦流明和这张桌实际得到的总光量,同样需要分别记录。

原文与时间戳 · 3
how much electrical energy it consumes in the process.
Why Heat Pumps are Immensely Important Right Now · ▶ 2:44–2:48
they won’t attain their full output
Why Heat Pumps are Immensely Important Right Now · ▶ 16:05–16:10
they deliberately traded lifespan for efficiency
Longer-lasting light bulbs: it was complicated · ▶ 26:00–26:03

地图上已经有自行车道,下雪后还有一条完整路线吗?

从起点骑到终点,要通过沿途每一个路段。Not Just Bikes 拿奥卢的优先路线说明这个区别:承诺既写了触发清雪的降雪量,也写了完成时限。地图上的新车道里程可以马上计数,骑行者却要等雪后出门才能检验全程。读一项建设成绩时,试着把某个路口设为未清理,然后再追踪一次完整通勤。

原文与时间戳 · 2
the next most important element is snow removal.
Why Canadians Can't Bike in the Winter (but Finnish people can) · ▶ 4:20–4:25
the priority bicycle routes are all plowed within 3 hours of a 2cm snowfall
Why Canadians Can't Bike in the Winter (but Finnish people can) · ▶ 5:28–5:34

包装上的「户外」覆盖动物一生中的哪一段?

《Dominion》拍摄的是澳大利亚养殖业。片中所说的“bred free range”针对猪出生时的环境,后来被转入棚舍是一条另外的信息。镜头转向蛋鸡,解说提到的规则又采用室外面积上的最大密度。把两条说明并排,你会发现它们分别在衡量一段生命历程和一块可用空间。要判断一只动物实际在室外度过多久,还需要按个体或群体记录使用时间。

原文与时间戳 · 2
pigs are born outside in small huts, but then spend the rest of their lives in sheds
Dominion (2018) - full documentary [Official] · ▶ 12:15–12:22
a maximum outdoor density
Dominion (2018) - full documentary [Official] · ▶ 28:35–28:39

书没读够十本,阅读方向偏了吗?

Grey 的“阅读之年”允许从书转向论文。若最初只记「读完的书」,这种转向会让测得的成绩下降。可以把目标写成一个你期望改变的选择,再给它配两条不同的观察:上车时是否拿起阅读材料,读过以后是否能解释其中一个论证。这样既能保留原先的意图,也能看见一种计数在哪一步失效。

原文与时间戳 · 2
Year of Reading
You Need a Theme, Not a Goal · ▶ 1:06–1:09
The broadness of a theme allows its meaning to change.
You Need a Theme, Not a Goal · ▶ 3:10–3:13

一盘带能不能装下整场节目?

Watson 描述录像制式竞争时,一盘卡带能否录下用户要看的整场节目就是一个明确任务。改变走带速度可让相同带长录更久,所以「支持某种制式」还需追问是哪台机器、在哪个模式下录。与灯泡的标称寿命对照,把一项硬件指标还原成实际任务,比较结论往往就能从争论变成一张可填的表。

原文与时间戳 · 2
a 2 hour recording time
Why Sony's Beta Videotape System Failed--and failed hard (Part 1) · ▶ 10:19–10:23
cut the tape speed in half and thus doubled the recording time.
Why Sony's Beta Videotape System Failed--and failed hard (Part 1) · ▶ 13:05–13:10

你要横穿大陆,还是去趟商店?

Not Just Bikes 区分了国土面积、城际距离与日常行程。给某条路线选择交通工具,最相干的是哪些起终点之间的出行,以及其中有多少能被连贯可用的网络覆盖。即便国家平均密度已知,也还无法据此判定某个居民能否走到商店。把地图放大到一次实际的往返,再重新问一遍。

原文与时间戳 · 2
walking or cycling
The Dumbest Excuse for Bad Cities · ▶ 3:16–3:20
for most trips.
The Dumbest Excuse for Bad Cities · ▶ 3:26–3:32

读完再想一步

拿一张产品规格表,选一个你真打算据此做决定的数字。写下这次使用的工作量、环境和时间,再列出即使该数字完全准确,你仍会付出的一种成本。