"the BIPM collects time measurements from national timing laboratories around the world"
I'm really interested in how this is done with multiple clocks over a distance. Can anyone explain? It feels like it would be very difficult since asking "what time is it there?" at the timescale of atomic clocks is kind of a bit meaningless? And that's before considering the absolute local nature of time and the impossibility of a general universal time per relativity.
The term of art you want for searchengineering is “time transfer”.
There are a variety of mechanisms:
* fibre links when the labs are close enough
* two-way satellite time transfer, when they are further apart
* in the past, literally carrying an atomic clock from A to B (they had to ask the pilot for precise details of the flight so that they could integrate relativistic effects of the speed and height)
* there’s an example in the talk, of how Essen and Markowitz compared their measurements by using a shared reference, the WWV time signal.
I believe an important aspect is that the actual time offset between the clocks doesn't matter all that much - it is the drift between them you care about.
True UTC is essentially an arbitrary value. Syncing up with multiple clocks is done to account for a single clock being a bit slow or fast. It doesn't matter if the clock you are syncing with is 1.34ms behind, as long as it is always 1.34ms behind. If it's suddenly 1.35ms behind, there's 0.01ms of drift between them and you have to correct for that. And if that 1.34ms-going-to-1.35ms is actually 1.47ms-going-to-1.48ms, the outcome will be exactly the same.
This means you could sync up using a simple long-range radio signal. As long as the time between transmission and reception for each clock stays constant, it is pretty trivial to determine clock drift. Something like the DCF77 and WWVB transmitters seems like a reasonable choice - provided you are able to deal with occasional bounces off the ionosphere.
Of course these days you'd probably just have all the individual clocks somehow reference GPS. It's globally available, after all.
It isn’t just the difference in rate. The main content of Circular T https://www.bipm.org/en/time-ftp/circular-t is the time offset of the various national realisations of UTC. Another important aspect is characterizing the stability of each clock, which determines the weighting of its contribution to UTC.
It's mad that this even needs said. A company's aim should be to be sustainable and profitable, not to be a receptacle for capital. Some companies need external capital to get to that point, particularly hardware or those operating in slow-adopting markets. If you don't need it, don't take it.
A couple of lifetimes ago, a business mentor of mine taught me a truth that has served me very well.
There is a correct amount of money for starting a business, and it's probably less than you think it is. Too much money in a startup tends to gum up the works and can kill a business just as dead as not having enough. If you have too much money, you're not only going to blow it on things that don't matter, but when you do, you're likely to do so in a way that incurs ongoing costs.
Things like leasing fancier offices than you need (or, in some cases, leasing any office space at all), hiring more people than you need, etc.
As he put it, if you're starting a business and aren't worrying about how you're covering your expenses next quarter, you probably have too much money.
To add on, a company who spends a lot of money on frivolous things or over-hires will need to pay the internal cost of downsizing when the time inevitably comes. That means layoffs, fewer employee benefits for those still employed, and general tightening of the belt.
There is a huge cost when you let go of people who would otherwise be kept on payroll if you could continue to pay them. You will get fewer internal referrals to new hires and remaining staff become less engaged in their work. There is additional long lasting damage to your staff as a whole who survived the layoff this time. The culture at the company shifts and never fully recovers.
I don’t think businesses always fully appreciate the long term cost and damage layoffs do to small and medium sized companies, but see headcount reduction as a simple way to reduce its own costs.
Plus you will tend to take committing decisions like hiring, location, or business goals that will limit how much you explore alternative paths.
Having a team to manage forces you to find problems they can solve, which is not necessarily where the money is.
You have a css/js developer? Ok I have to find frontend tasks now. Etc
Yeah sometimes it becomes clear founders forget the purpose of a company is to make money/turn a profit and not just to repeatedly raise money and be famous. I have worked at a company that forgot this. It feels kind of surreal sometimes.
That's one view of what a company should do. Another is that it should become famous enough to attract the attention of a FAANG and get bought out ASAP, making the founders multimillionaires before they turn 30. It's the techbro lottery. Many will play, few will win.
Surreal indeed. It blows my mind to see investors repeatedly try to propel the same business model (like electric scooter sharing) far past the point of reason. The founders can surprisingly turn around, start something else, and get showered with money again.
It feels completely disconnected from reality, a very abstract way of thinking about money and business.
Does that happen sometimes? Surely. But more often than not, founder led companies who have personal attachment to the outcomes deliver far better than some self-interested, career stepping-stone, decision-by-committee corporate blob. See Nvidia, Facebook, Stripe, and Tesla compared to Intel, IBM, GM, and PayPal.
Not arguing that at all. I fully agree. There are a lot of smaller startups that fail to get past the “tribe” level due to founder’s syndrome though, among many other factors. It just reminded me of that right off the bat.
Have you actually watched his video on the Gimbal craft? I thought that was a big piece of evidence myself, went into his video at the recommendation of someone here on HN with heavy skepticism, and came out sufficiently convinced it was not actually a UFO. He's also classy with his debunkings. To me that's a big bonus. Other YouTubers whose niche is debunking things seem to love being snarky, sarcastic, and condescending. Doesn't make his points any more/less valid though.
I'm not generally a fan of Mick West, particularly when he gets into specific debunkings of videos, because his argumentative framework depends on the same flawed approach as those he's debunking: he starts from the conclusion that the aliens are not here, and then claims any evidence offered against this conclusion is insufficient. He depends on the same fallacy as his opponents. The only difference is the conclusion from which he starts. And of course he has an inherent advantage of credibility because his conclusion doesn't require any extraordinary evidence. That's why it feels like he's just taking cheap shots - in many ways he's on the easier side of the debate (but ironically it's become the harder side because it's nearly impossible to deprogram his opponents out of their cult).
However, I did enjoy his recent video [0] on Grusch, where he focuses on the meta arguments against the narrative itself. He does a good job of describing the logical and dialectical flaws in the claims of the so-called "whistleblower" (who needs to get approval to speak publicly), and the reporting of the story itself (which was rushed and published by the same group of people with monetary and reputational incentives to uncritically promote the same narrative for which they've previously lost credibility).
It's called circular reasoning. Conclusion cites the premises, which in turn the premises cite the conclusion. Evidence (or lack of) is used to prove it self. When you start with a false or circular premise, anything that follows is technically true. It's a powerful (bullshitting) tool that can be used to prove or disprove anything.
It's bayesian reasoning. If I tell you that I predict the sun will explode tomorrow, you should consider the sun's track record of not exploding when evaluating my claim.
There's no bayesian reasoning here, just someone assuming something to be proved to be already true. Statements don't become self-evidently true just because someone assigned probabilities on them.
Also, using only past billion occurrences of the sun not blowing up, and then still concluding that the sun will not blow up despite of any recent indications of the sun showing anomalous activity seems a more accurate analogy.
Mick West presents rational reasons for why his assumptions are true, he's not simply asserting his assumptions as correct.
> despite of any recent indications of the sun showing anomalous activity
The whole point is that the videos are not in fact the indications of anomalous activity that they're made out to be. There are mundane explanations for all of them.
This comment makes it seem like the video does not contain rational arguments. It very much does. If you're skeptical about them, why not address them.
As another commenter says, it's actually easier the more generators you have because the rotational inertia of all the spinning masses is larger. This (and the storage problem) is one of the reasons that wind and solar destabalise grids - they are interfaced to the rest of the grid by converters that create ac sources - but there's no real rotating mass there, so the inertia is tiny. The result is that as we add more renewable power to the network, it becomes less able to 'roll with the punches' of loads coming on and off line.
PS One of the answers in the SO thread mentions JET in the UK. I spent a few summers there as an electrical engineering student (it's home to the MAST and JET fusion reactors). When the JET tokamak ignites a plasma, it can't sustain it for very long (we are not yet at the point of extracting enough energy to sustain the reaction). As a result they need to ignite the plasma and keep it hot. They can't do it for more than 1-10 seconds. During that time, they draw massive amounts of power - they're permitted to draw up to 1% of the UK's capacity for a short period, whilst they simultaneously dump all the energy stored in two gigantic flywheel generators housed in a nearby building. I've never been there when the flywheels are running but I've climbed around beneath them. There's nothing quite like massive engineering :)
> This (and the storage problem) is one of the reasons that wind and solar destabalise grids - they are interfaced to the rest of the grid by converters that create ac sources - but there's no real rotating mass there, so the inertia is tiny. The result is that as we add more renewable power to the network, it becomes less able to 'roll with the punches' of loads coming on and off line.
Other problem is that for renewables to be profitable you want to push all the energy out all the time, especially in peak. Even now solar installation users have problem with that when there is too many small solar installations installed on same street the voltage goes too high and the inverters just trip and stop pushing the power to the grid, losing owner money.
We just need to have more cheaper storage solutions. Technically utilities could just put a bunch of batteries near concentration of residential solar and just basically sell the service of "storing the kilowatts" to them (say "you can receive 80% of what you put into it in next 48 hours"), all while having the capacity to use that stored joules in case a peak needs to be handled
If the inertia of turbines helps cover small loads, couldn't that be scaled up with a bunch of flywheels connected to motor/generators? Seems like it would be better able to handle sudden changes in the network than batteries+inverters.
Yes - this is precisely what was trialled in the UK a few years ago. You can basically take old decommissioned generators and just take power to spin them up - thus, you've just (re)created rotational inertia on your grid. It's a bit absurd, but it does work!
