gridspy

This optimization is important because you can then discard most of the number in question, bounding the integer size required for computation.

For instance you could store the number in question in a 128 bit integer, shift left (double), check for odd digits (a series of modulo & divide operations) and then truncate using a modulo and subtract. You can repeat this process as long as you like. If you find an all evens number than you can do a more expensive indepth check.

Well, more correctly the difference needs to exceed the breakdown voltage of the insulation barrier. Or (depending on the insulator) some current might flow the entire time, but a limited amount.

While you raise some valid points, you need 10kV to jump a 1cm gap. So in a domestic situation at the much lower voltage involved (130V / 250V) I imagine you don't need to worry so much about the air gap.

The care instructions and dust you mention sounds likely to be super important when you're casually touching live stuff while standing on a grounded floor.

In an electrostatic situation, the electrons can flow (almost) freely without the shoes / tyres and so a large differential between body / ground will not build up. With shoes, you'll need a large difference to build up (10kV? 20kV? More?) before it discharges.

Anyway, there is clearly a difference between these situations - even if the shoes don't provide magical protection. But the shoes are not magical, as you correctly describe.

The skin is very resistive, the body itself is not. There is a soldier who "won the darwin award" by taking the probes of a multi-meter and after measuring their skin resistance decided to measure their internal resistance.

After piercing the skin, the test current from the multimeter (9v) was sufficient to electrocute this person. Sadly it (apparently) was a fatal injury. I couldn't find a reference, but the logic makes sense (50V sufficient to kill normally, skin is most of the protection).

When dealing with electricity, having items which reduce the protection your skin offers (metal rings, moisturizer, etc) is a substantial risk.

When someone is talking about insulating shoes their point is that the body is electrically isolated from the floor. Without that isolation charge can travel between the two. Concrete and skin are fairly good conductors by comparison with air or insulators.

Wearing a conducting ring might make it easier for charge from the air to move into your body through your skin - but it will not make it easier for that charge to get to the floor (and then to ground) from your body.

If you change 1,2,3,4 into A,B,C,D - you're still counting. You're just using different symbols to do it.

Take a moment longer to think about it and you realize that 1,2,3,4 are also just symbols - potentially raw counting does not require these symbols at all.

So ABCD is unlikely to make life easier for the subject of this story.

It's great scientific progress, but seems doomed to costing more than actual reuse.

This was our approach too, it worked pretty well. When Covid and the lockdowns hit it all went out the window for us. It was simply to hard to supervise the kids and work as well.

I'm glad that you have made it work for you.

I agree with you that I want a non-magic approach. I want to understand the nitty gritty so I am building my code with solid foundations based on how the actual hardware works.

However, this is not an approach that works for the masses. The vast majority of programmers are quite happy to work at the surface level and they can tackle a huge amount of the work doing things I consider too easy to be interesting. That's good, because I can't motivate myself to do that boring stuff either.

You are right that baby steps is always the way. Especially good when you can get something basic working, then test & iterate.

Organise is the British english spelling. So you're right somewhere!

While mass to orbit costs as much as it does now, sure. However later on it's gonna be great to have humans closer to the working robots to reduce the round-trip latency. They could also perform tasks robots are not suited for.

Consider operators living on Mars and operating drones near their habitat each day. It would be like modern day drone operators and robot assisted surgery. Like remote operators of mega-trucks today.

Those robots could interact with the operators - driving into a "garage" that can be pressurized for maintenance, upgrades or science.

StarShip promises to reduce the cost of mass to orbit, making larger and more complex scientific, industrial and habitat options feasible.

I think it's a really responsible decision by SpaceX to not put their StarShip stage into a full orbit until they have demonstrated the ability to get it back out of orbit.

They should be applauded for this, along with their iterative approach.

Note that this next test will demonstrate re-light of the engine in space at micro-gravity. This is the demonstration needed prior to putting the StarShip in orbit. We'll probably see a full orbital test for the flight after this one.

They could have easily put previous tests into orbit - it's a fairly minor change to their existing regime and they have plenty of fuel to use.

Plus, your payload needs to be gun compatible. Not gonna put people in there.

> But Saturn V's purpose was not getting things to orbit.

The way rocket staging works - each stage delivers the next stage to a predefined orbit / trajectory or energy level. It is not Saturn V that went to the moon, it just lofted a payload (final stage) into orbit that could perform a TLI.

This was the final stage of the Saturn V rocket for TLI (123,000 kg): https://en.wikipedia.org/wiki/S-IVB

In orbit refuelling with StarShip is a major innovation, meaning that we don't need to separate payloads into parts and assemble them on orbit. Instead we can refuel a reusable boost stage.

> Amortized over the number of launches it takes to get a single moonshot.

Saturn V was completely destroyed by each launch with only the payload surviving. It's not exactly an apples to apples comparison when you compare # launches.

Those 10-15 launches of StarShip will be a lot cheaper than a single Saturn V launch because at the end you still have all the StarShips you launched and all you used was some methane and oxygen.

> 5 and 20 Starship launches per mission

That is not actually such a big deal when you realize they are just ferrying fuel on a reusable rocket. They're also doing it well in advance of the mission. There is a massive logistics chain making it possible to buy fuel on your road trip, this is similar.

> That's a clear regression from the Saturn V.

Not exactly, as the fuel provided in orbit by these other missions will allow a much larger payload to reach the Moon's surface and return.

StarShip can already deliver a similar payload to orbit as Saturn V (though a bit less due to reusability) - it is the extra mass to the moon which requires the refuelling.

Each streamer adds a delay to their stream. This means that any stream forwarded to you by another streamer is going to be delayed.

The delay was between SpaceX recording and uploading an event and Everyday astronaut decoding it at their mixing desk. Their own feeds from their cameras and microphones had less delay than the SpaceX stream did. Everyday astronaut then had another delay between when they encoded this result and you saw it.

If you had opened up the SpaceX stream directly you would have found it was ahead of the stream shown inside Everyday Astronaut.

BTW I was also watching EA's stream.

At least in LEO you need to keep expending DeltaV to keep stuff in orbit. Trace atmosphere slows everything down and would eventually clean LEO at 500km of relevant junk in about 25 years depending on altitude.

https://space.stackexchange.com/a/55995

Also, as mass to orbit gets cheaper you can build your payload more cheaply. Many compromises in complexity and material cost are made to minimize payload mass - we'll be able to launch cheap and heavy satellites and probes into orbit instead.

The shuttle boosters required rebuilding / refueling (which is solid rocket goop) and the fuel tank was completely lost and required rebuilding. The head shield tiles were extremely fragile on the shuttle.

It was never a fully reusable design, just more reusable than before.

SpaceX plans to have no parts that are lost each flight and is working to make the tiles mostly standardized and less sensitive to faults.

Especially when each rocket successfully makes it further into the test, beyond the point where the previous iteration failed.

I think there is a disconnect here between the decision makers and the experts in the Police Garage.

The post is fundamentally about all the performance of making stories, assigning points, allocating work and doing standups all the time. None of that is required to actually create software.

If people are judgemental around what stories are left uncompleted or points / week then the situation can become stressful for no benefit to anyone.

- One on Ones to discuss roadblocks and thoughts every week.

- Issue tracking as a common place to describe what needs to be done and thoughts / details on how it is solved. Something lightweight like Trello is ideal

- A Kanban board so people have an organised way to pick up new issues when low on work

- A weekly showoff meeting where there are few 5 minute presentations and a 30 minute "I did something really cool or learned something really cool"

- 6 month task split into 1 month ish deliverables, with a flexible deadline for each. Presentation of finished work each deliverable.

To do this with any DC battery you add a solar battery charger to accept the panels and an inverter to turn the DC into mains 230V you can use.

nmi - Nautical mile (1 nmi/hour mentioned above)

Today the international nautical mile is defined as 1,852 metres (about 6,076 ft; 1.151 mi).

https://en.wikipedia.org/wiki/Nautical_mile

Most technology has a limit like this (for instance CPU transistor size in the past). However once this is a proven technology, money will be invested in solving these issues.

Agent - Something that makes decisions and actions that are not pre-programmed or predictable. Humans are definitely agents. LLM (eg Chat-GPT) are not quite there yet (they don't take action on their own).

Tool - Pretty much everything humanity has made to date. It does a preprogrammed thing or provides mechanical advantage. But it does not act on novel decisions it is making.

The terms come from an AI safety expert that Lex Friedman interviewed recently. [1]

Tesla FSD is almost an agent, though it asks a human to be ready to take over at any time.

[1] https://www.youtube.com/watch?v=NNr6gPelJ3E

One is a failure to act as an agent - to control the car and make decisions. Another is a failure to even be a reliable tool - to do what the operator commands. Very different.

Creating Agents is a lot harder.

The first useful rockets were during the second world war, used for artillery into London. So over 80 years ago. https://en.wikipedia.org/wiki/V-2_rocket