andlier

Fun fact, there are databases of the exact frequency vs. time and it can be used to accurately time stamp audio/video recordings by correlating the ~50/60hz noise in the recording with the database. Good writeup on the technique and how it has been used in court cases: https://robertheaton.com/enf/

A political bet, with enough funding it might make it so… https://www.washingtonpost.com/climate-solutions/japan-hydro...

This reminded me of the extended range with reversed ski box for tesla. https://electrek.co/2020/03/24/tesla-model-3-roof-rack-box-r...

No sure how these guys (https://www.xethru.com/) are doing financially, but they sell development kits for respiration sensors etc.

Microplastics from car tyres seems to be a big source as well: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5664766/

Protactinium

After a quick napkin calculation+google it seems the sun has around 20kW of power per square centimeter. So not entirely unfeasible that a cooler star, or a nuclear reactor is closer to the typical 10-100W/cm2 of a modern cpu/gpu. Still some orders of magnitude off from our closest star. (Hope calculation is correct)

The issue with the «chopping» is noise level. Counter rotating propellers are more efficient than a single propeller. «Contra-rotating propellers have been found to be between 6% and 16% more efficient than normal propellers.» https://en.m.wikipedia.org/wiki/Contra-rotating_propellers

“Simply put, unleaded fuel burns less smoothly than leaded and the toluene and benzene, which is added to the fuel to act as a lead substitute, burns to form what are called peroxides. Unfortunately peroxides are inherently unstable and explode, forming shock waves that cause detonation. This explains why engines designed to run on unleaded from the outset feature sophisticated knock sensors, which retard the ignition setting at the onset of harmful detonation.”

https://www.classiccars4sale.net/classic-car-how-to-guides/r...

Zero Kelvin is still a different league of special scientifically speaking.

Resistive power losses in the battery pack, drive inverter, motor, and associated wiring are proportional to the square of the current. Doubling the motor current doubles the torque but quadruples the losses.

Actually most new (<5 year old) petrol cars use direct injection which emits much more fine soot particles than diesel with particle filter. In EU particle filter for petrol cars is only mandatory from 2017. Also worrysome that most of the particles are of the ultrafine type which is the most dangerous in terms of cancer-risk etc. https://www.transportenvironment.org/press/new-petrol-engine...

Apparently this discussion has been on here before: https://news.ycombinator.com/item?id=11896883

ehh, muddy.ashes.pardon maps to US Holocaust Memorial Museum... (https://www.ushmm.org/) insensitive for sure, is that just a coincidence?

Even if we covered the earth in windmills, we'd still only affect the lowest 100-200m of the atmosphere. And windmills can only extract 50% of the winds energy. I'm thinking a forest full of trees might even reduce the windspeed more than a field of mills.

Me five. This isn't the first time I've had this happen.

I'm happy with my Yaesu VX-6R, bought it 11 years ago, same day I got my license. Incredibly sturdy and amazing build quality, submersible to 1 meter, die-cast aluminium and O-ring sealed ear-plug/antenna connections. There are some new models now with more digital features. https://www.yaesu.com

If each cell is connected to the bus bars with fuse wire (like in the Tesla battery pack for instance) this connection diagram seems valid. Same way it is connected in the car/powerwall packs that tesla makes at least.

I'm a bit tired of all these CO2 comparisons regarding electric vehicles. If we put the CO2 emissions aside, there are so many other benefits moving to EV's. Especially reduced local pollution in cities such as NOx, VOC and particulate emissions. Even if we just look at noise and easy maintenance, electric cars are clear winners. All this focus on CO2 just leads to a lot of inaccurate napkin calculations on one part of the issue, taking focus away from the bigger picture.

That being said, for cities, cars in general are problematic since the consume so much space. I'd say electric bicycles and public transportation is the way to go for cities.

[0] Estimate about half of the particulate emissions comes from non-combustion sources (brake wear, tire/road wear, dust re-suspension). Interestingly 16-55% of these particle emissions in city-areas comes from brake wear, which should be significantly lower for EV's since they mostly slow down by regenerating. This might offset the weight-related increase for EV's.

[0] http://publications.jrc.ec.europa.eu/repository/bitstream/JR...

I'm trying https://www.jottacloud.com now, they have an unlimited plan for ~$70/year.

Funny story; They previously had a clause in the terms about restricting storage space for users with abnormal usage patterns. A friend of mine sent a complaint to the norwegian consumer ombudsman about this based on the fact that if you advertise with unlimited, all users should get unlimited. Half year later they've changed the terms to be less suggestive on possible restrictions (https://blog.jottacloud.com/updated-terms-conditions-63f4ba2...).

Just be sure to read the datasheet carefully. That particular capacitor is only ~120uF at typical 3.3V DC voltage. At 5V DC (which isn't really advisable for a 6.3V rated cap) it is only 88uF.

This: https://www.lhup.edu/~dsimanek/museum/DDWFTTW.htm

There is a fascinating BBC-documentary about chemical warfare history and the british Porton Down military research facility, hosted by Michael Mosley [0]. There is a part where the researcher actually makes sarin and VX right in front of Michael in a fume-hood. They literally watch the VX-liquid condense out of the vacuum distillation apparatus right in front of Mosley and the camera team. [0] http://www.bbc.co.uk/programmes/b07hx40t

Edit: Program available here until mid March: https://tv.nrk.no/program/KOID23002916/mosley-og-de-kjemiske... If you can VPN to Norway.

The headline and article are a bit misleading, the share of completely electric cars (no internal combustion engine) is actually dropping compared to last year as there are some newly introduced tax-reductions and benefits for hybrid plug-in vehicles as well. Many of the top-selling cars on the list that is counted as electric are actually cars with a small battery and electric motor along with a traditional ICE. [0] The topsellers of "electric" cars are actually big cars like the VW Passat GTE and Volvo XC90, both of which will probably produce more emissions than smaller ICE-only vehicles through their lifetime (unless the owner is very concious about charging the battery all the time.) [0] http://ev-sales.blogspot.no/2017/02/norway-january-2017.html

You are correct, the link to powertechsystems.eu has those erroneous percentage calculations.

40kg for lead acid equals 13.6kg for lithium so that's 66% lighter.

Here in Norway we had this publicly funded mushroom control staff located strategically near the forest to allow people to get their mushroom-forage checked by an expert. They would literally go through all the mushrooms in your basket and throw out any mushrooms they couldn't positively identify as edible. Unfortunately the money "ran" out. I guess we'll take the hit as an increased spending on public healthcare instead. http://www.newsinenglish.no/2015/08/10/money-ran-out-for-mus... edit: here's a better link with pictures, but in norwegian: http://www.nrk.no/norge/savner-stotte-til-soppkontroll-1.119...

There is Minikeepass, supports keepass files on iOS. (http://minikeepass.github.io/)