The question to ask is where does that energy come from. Of course "from the sun" is correct, but that is also true for fossil fuels. If that ocean-stream has been fueled by the sun for millennia and now contains 10EJ of energy, then tapping 60GW will deplete that storage in about 6 years. That's not "endless green energy".

The problem (I htink) is that nobody knows how much energy is stored in such ocean currents. And even less about how they are fueled by the sun. For all we know, the current was started by some major event millennia ago and now the sun just fuels the yearly losses.

People expect to be able to search their old EMail. This means that it is unacceptable if they are suddenly lost. Therefore you need to make backups.

IF you have a file sharing setup, the users will "clean up" after themselves. A new version of a big file will overwrite the old one. You back up one or the other, but not both.

With Email you need to backup all versions of the 700Mb file because that's the attachment that was sent with THAT email.

That said my Email-attachment-policy on the servers in my control has not changed in 20 years. Up to 100Mb: Just send it. Don't worry. Up to 1Gb: please let me know in advance, and i'll double check that it's ok. (Because it is always THEIR server that is more restrictive nobody ever takes me up on this.)

The research has already been done. It was done near Eindhoven in The Netherlands. Maybe not with autonomous cars, but with people who agreed to drive the system-recommended speed exactly. (little box in their car).

Right! And counter-intuitively: When done right it will on average reduce travel time. (because you increase throughput at congestion points).

The first thing you need to look at is where does the consumed energy go.

Small losses in the battery. Not much you can do about that.
small losses in the electronic drive circuitry (ESC in model airplane speak). Sure, making that more efficient will gain you a few more percent.
small losses in the motor. Some improvements can be made, but everybody is already doing their best.
small losses in the drive train. (fixed gear ratio gearbox).

And most of the energy is delivered to the wheels. Where does it go from there? Air resistance of the car. So improving that requires: "low Cw" and "low frontal area". Look at a model 3 and you see where that leads to.

So... what does "more efficient" mean? You can gain a few percent here and there. But the big gains are already gone.

What if you could hoist stuff up more than 70m? Wouldn't that be better? How about not 70 but 700 or 1000m? You'd need a mountain of a construction... wait! what? A mountain!
Just make a railway up a mountain, and hoist 35 tonne railway cars up to the flat spot at the top. Then with little effort you can park a lot of the cars at the top (more than on the 70m tower, which has a construction limit) and store WAY more energy.

So this 6 armed tower, can it hoist 6*35 tons or maybe 12x? Assume 12. So a 35 tonne object has .35MN of weight. Times 70m heigt, times 12 equals almost 300MJ of energy. That's .081 MWh of energy. Compare that to a telsa grid level battery of 100MWh....

If instead of rail cars of 35tons, you'd use water.... that's what they've been doing over there (Switzerland, Austria) for decades already.

For flat countries like NL the tower is the only option. But still... 6.8kWh per block is too little to be worth the trouble. Suppose I want to live fully off solar. My daily use is 10kWh, So I'd need 2 blocks for my own home. but then I'd like to be able to bridge say a week of little to no sun. So I'd need about 14 of those blocks. We would need one of those 70m towers PER HOUSEHOLD to store enough energy to be able to last a week without sun.

Not gonna happen. My back-of-the-envelope calculations.

I've designed built a RP2040 board. The first prototype now appears to be working (as of march 23rd 2022). I ported the full application (just a few minor things to add) to it and... 0.27% of flash used.... OK. I did mount the big flash chips because a few dollars on the prototype is not going to kill me.

For apple mounting 64Gb as opposed to say 4 or 8 is not significantly impacting production costs significantly for an already expensive product. So mounting it (like me!) with the attitude: "Who knows what it'll be useful for in the future?" sounds reasonable.

The mentioned 16T drives differ quite a lot with .14% and .91%. With an overall average of 1.01%, the .14% is quite good. Several times better than average.

On the other hand, the .91% is "better than average" but "not by much".

Are filesystems for 16T+ drives (and raids even larger) reliable yet?

I'm pretty sure you've not detected a computer vulnerability yourself. In practice when you detect some vulnerability and stop at "looking at the lock and saying that's a cheap lock you should replace it", the owner will say: "it's plenty safe: I can't pick it!". This is quite universal. It is very rare that owners of computer systems will acknowledge a weakness with your "say-so". (*)

In computer security you HAVE to provide proof that there really is a hole. Just opening the lock and showing: "See I can turn the knob, so I'm in"... is not enough. The system operator will counter with something like: But there is a secondary protection. In the lock analogy that would be one of those chain protections. Unless you have real data to prove that you got access to should-be-protected stuff, your report will be ignored.

The good guys, "white hats" is what they are called in the security business, will gather evidence that there is something wrong and then report the issue. If you start punishing the good guys for reporting issues, those "good guys" will stop reporting the problems they find. You really don't want that: Then the first time you know about an issue will always be when a bad guy gets in and starts to exploit the exposed material.

(*) True story from about 30 years ago. I found a vulnerability. I exploited it once or twice to convince myself of the seriousness. I then scanned the whole university and found about 100 more instances of vulnerable computers. I sent out 100 Emails: "your system is probably vulnerable, it's easy to fix, please do so". That saturday afternoon I got one reply: "Thanks, fixed!". The next monday I got one more: "we're not vulnerable, go away". A year later, about 60 vulnerable computers remained. When you don't have very convincing evidence 90+ percent of the people operating computers will take the easy way out and pretend it doesn't exist.

I run a couple of servers on the internet. I've configured most of them to add a firewall rule to redirect your IP address to a different SSH server once you've entered 5 wrong passwords. That's an original ssh server with the "yup, that password seems correct" taken out. Oh and as you're already on the naughty list it also logs the attempts. So I have such a list of attempted passwords as well.

The thing is... with an online "brute force" attack, you are limited to a few attempts per second. But offline attacks, where the attacker manages to get hold of the encrypted password database are many orders of magnitude faster. So in that case, much longer passwords can and will be attempted. Thing is: by online logging you won't see those.

It's easy to forget just how much higher the moon is compared to the ISS.

There's a graphic on Wikipedia that shows the radius of the earth (blue ball), the ISS orbit (purple circle), and how far out the moon is.

Saying that you can reach the purple line doesn't really mean much in terms of reaching the moon. It's literally 0.1% of the way there. (About 400km to the ISS, vs. 400,000km to the moon, give or take.)

Get your F-ing units straight.

Assuming that "7 megawatts" must be "7 megawatt hours". At 7MWh/month that's only 10kW... You could have that in solar panels on a residential home....

In the seventies (I was told this story in 1980, and they told it as if it happened a while ago) this company was making electronic traction systems for electric trams.

So they wanted to have a realistic load for their motor. So they did the math and made a flywheel. Wel. somehow the flywheel became unbalanced and ended up across the river 1.2km away, No casualties, just a broken roof. (no significant damage where it came down).

Anyway, when this would go wrong... "a couple of miles" is not far enough.

Normal rockets reach max Q at around Mach 1 after one minute of acceleration. That would happen about 10km up where the air pressure is only about 1/3rd of what it is at the surface. From there on, the air density drops faster than the increase of the forces due to going faster.

For normal rockets, this is such a critical event that they accept longer pull of gravity and throttle back to reduce the stresses on the vehicle. (At least Falcon 9 and Space shuttle do this).

So these guys are going to accelerate stuff to 8000m/s at ground level and then throw it up in the air at ground-level-pressure. Air friction is going to be about 3x (pressure) * 25*25 (speed differential squared!) times more of an issue. That's significant.

Oh.... One more thing... If you give something orbital speed at ground level, ignoring air friction, it will go into an orbit with at best the lowest point at the place where you started. In that case you're launching horizontal, meaning you'll encounter about 200km of air instead of the normal 10km of air starting mostly up.

One last back-of-the-envelope calculation. Orbital speed is about 8000m/s. Humans riding to space can handle 3G for a few minutes, but lets assume we're talking satellites, so 10G is acceptable. So 100m/s^2. That means max Omega (rad/sec) is max 80. So your launch facilty will need an 8000m/s / 80/s = 100m radius launch facility. Do you know anybody who can make a 200m diameter vacuum chamber? (that you're going to explosively re-compress at launch?)

Throwing stuff hundreds of feet into the air is not a problem. Throwing stuff into orbit is.

lots and lots of muscles are operated "on automatic" by your brain.

It is just that most people don't practice to operate them that they are not able to do so on demand.

I have a friend who has a lazy eye. He says that he feels the focusing action of his eye, so he can gauge distances that way. Moving ears, breasts or nostrils is something that some people can do. In some cases the muscle is no longer there (evolution didn't find it important) but in most cases it is just that you've never felt the need to control that muscle.

As an example of that you can learn to use muscles that (most of you) haven't really been able to control until today....

Spread out the fingers of one hand. Now group them into a group of three and a single lonely finger. Now move one finger so that there are two groups of two. Now move onre more finger so that you're in the toher 3+1 configuration. Try not to move other fingers while doing this.

It is taxing for the mind to try to do this. The younger you are the easier you'll learn. Practise this for two weeks 5 hours a day and you will be able to do it pretty fluently., Way better than what you did just now.