> Seattle is probably my favorite city in the USA, but the dreary weather kills it for me.
I beg to differ -- a pioneering 1949 Seattle solar energy project offers a different view, and as soon as the sun comes out, they're going to release their final report.
A voice in the wilderness, but weren't PDFs originally meant to be read-only? Yes, nearly everyone now has a PDF editor, but this seems to undermine the original intent behind the format. As things stand, we may need to invent a portable document format that remains read-only, that fills the purpose PDF was meant to fill.
The article's thesis relies on the idea that a genuinely primitive traversal action exists, in the way that a for-loop is primitive and widely applicable, or adding two floats is common enough to justify building it into the language (or processor).
But tree traversal doesn't have this universal property. There are too many methods and purposes for traversing a tree, sufficient that IMHO no single primitive embodiment could materially improve a language. Also, modern compilers efficiently break down high-level traversal code so well that expressing the idea at a high level incurs no serious penalty compared to having a primitive for that purpose, or a series of them.
The article's title, in particular use of the word "first," isn't supported by the content. The title suggests a change or improvement in the technical status quo ante, but the article itself only describes a quantitative scaling up of existing technology, which is Perovskite panels, nothing new. No change is presented, only its scale of deployment.
I don't think a scientist assumes a theory is false until it is proven true. I think a scientist thinks about how to capture data, and enough of it, to position evidence to a theory. By necessity that means the scientist must be open to the theory being either true or false before testing. But they must be willing to pre-register what the experiment would say. And, of course, healthy skepticism is required.
The scientific method requires replication, and there are events in the universe that are inherently long-tailed and leave little trace evidence. That doesn't make their observers crazy or pseudo-scientists. There are some weird things out in this wide universe of ours that happen on the tails of observability.
> There are some weird things out in this wide universe of ours that happen on the tails of observability.
Yes, that is true. And in science, we assume such things are not real until positive evidence leads us to a different conclusion. Consider the ether theory, the idea that an evanescent substance filled all of space and was responsible for the propagation of light. But because it had not been directly observed, scientists invoked the null hypothesis to assume it wasn't real. Tests then confirmed that it wasn't real, and this led to relativity theory.
> It's called the "null hypothesis." It's the gold standard of scientific experimental design.
I think this definition is tying too much epistemic certainty on the part of the scientist towards the null hypothesis versus the alternative hypothesis being tested, hence my disagreement to what I consider a view lacking nuance. In short, if the scientist has no reason to doubt the null hypothesis then there is no reason to test. So the scientist must first be willing to allow the null to be proven unlikely / rejected.
I don't think we're going to see any further agreement this deep in the semantics, so let's move forward understanding each other to be in general agreement on the metaphysical construction of the scientific method.
> And in science, we assume such things are not real until positive evidence leads us to a different conclusion
We assume them to be untestable, not necessarily false. Just unable to be tested. The scientific method only has three states: untested, agrees with available evidence, or rejected by available evidence. If no evidence, then untested.
String theory is a great example of this. Wonderfully mathematical and logical, but we haven't figured out how to test major components of it specifically yet that would distinguish it from alternative theories.
> In short, if the scientist has no reason to doubt the null hypothesis then there is no reason to test.
On the contrary, that's the point at which positive evidence may contradict the null hypothesis, assuming it exists. But the null hypothesis must be the default initial assumption.
My point is that if the scientist assumes anything but the null hypothesis a priori, it's not science, it's marketing. This is why the null hypothesis is the default initial position in any legitimate scientific investigation.
The alternative is to assume the truth of a theory and seek falsifying evidence. But this may require proof of a negative, which is frequently impossible. I can't prove Bigfoot's nonexistence, but this failure doesn't support Bigfoot's existence.
> I'm not sure why these would be just getting release by National Archives now, perhaps as a distraction?
Maybe, or maybe they wanted to avoid giving the content unearned credibility through concealment. The easiest way to turn a mystery into a nothingburger is to release it to the public.
> ... there's a lot of discussion that these photos may have been a hoax.
Yes, or sightings by people constitutionally unable to distinguish Venus from a UFO.
Legitimate content aside, this article is a perfect example of modern public relations writing, of flash over substance. Each paragraph is larded with PR buzzwords like "breakthrough," "cutting-edge," "groundbreaking," etc. to the degree that the topic is nearly lost in the lexical shrubbery.
And it's clear the article's author doesn't understand scientific writing. Each participant is identified as having a PhD (when true), contrary to accepted academic practice. Imagine a scientific article by Albert Einstein, tagged with "PhD" -- except that in 1905, any relevance aside, Einstein didn't have one. My point is that the participants' academic degrees are irrelevant to the science. As Richard Feynman said, "Science is the organized skepticism in the reliability of expert opinion". Oh -- wait -- did I mention that Feynman had a PhD?
My favorite phrase from an article that tries to raise empty PR prose to an art form: "... Lehigh is the only university in the Lehigh Valley to have this designation ..." Noted. But this is like saying, "We're tops in our ZIP code!"
Books
- take up a lot of space
- are not free & not necessarily cheap
- are not searchable
- take a lot of effort to index
- are heavy, prone to damage & loss
- cannot be accessed by multiple users simultaneously
- need physical copy to back up
Most of these points are true for computer media as well if separated from some degree of computer power, especially "not necessarily cheap".
> ... need physical copy to back up
Certainly true for computer storage, which, if left to the whims of nature and given time, will self-destruct.
Years ago I got a call from Tom Clancy, who was writing "Hunt for Red October" using my word processor "Apple Writer." He said a diskette had become unreadable and asked how to recover its contents. I delivered the bad news and recommended that he use his backup diskette. I'm sure you can guess how that turned out.
Having sailed solo around the world, I know this well-intentioned idea won't work. Modern large ships can't change course quickly enough to avoid collisions with objects close enough to be detectable.
Any number of times, a large-ship captain would radio me saying, "Whatever you do, don't change course or speed -- we can get past you as long as you don't change anything."
And I was a distant sailboat with a radar reflector, not a subtle biological target at close range.
Was thinking the same. The ships (large commercial vessels) as shown on the website’s header image use special navigation routes and have difficulty changing course.
Question for you as a sailor in a lighter boat. If alerted, would you be able to change direction fast enough?
Also, I’m guessing at some point the collision is extremely dangerous for the boat not the whale.
Meaning the technology, if feasible, might have a market but just to a different buyer than large commercial vessels) (sail boats, yachts, speed boats).
Not the person you're asking, but I sail a 7 ton, 10 metre yacht. I can change course by 90 degrees in under 10 seconds if I need to (probably far less, depends how hard of a crash tack I do).
people do need to sleep if they're soloing offshore, so the warning would need to be at least a minute to be able to wake up, then there's putting on the safety equipment to go out on deck etc. So make that multiple minutes of warning for it to be useful..
Im not aware (which is not to say it doesn't happen) of that many incidents with sailing vessels and whales. However, you've prompted me to look, and it's more than I thought.
> Question for you as a sailor in a lighter boat. If alerted, would you be able to change direction fast enough?
That would depend. While under sail (i.e. 99% of the time during ocean crossings), no, not really -- not enough speed and limited heading change options in the prevailing wind. But this is balanced by the fact that, during a typical ocean crossing, I might see another vessel every 20 days or so.
Notwithstanding those facts, I ran my mast-head navigation light, all night, every night, because I was alone on the boat, therefore ... asleep for eight hours every night. If I hit something, it was likely to be something smaller than another boat. Like a waterlogged container or a sleeping whale, both rare but dramatic events.
> Also, I’m guessing at some point the collision is extremely dangerous for the boat not the whale.
Not normally. I've hit whales several times during my time as a sailor. I could tell it was a whale because the boat "thumped" the obstacle instead of loudly banging as with a floating log. I hated the thought of colliding with a whale and did all I could to avoid it, but after dark, such things can't be avoided.
In the case of a big vessel, it's all reversed -- the risk is to the whale, not the ship.
Not the topic of most comments, but instead of a 22 ohm resistor that burns up the majority of the battery power to protect the LED from overcurrent, a switching power supply would allow the light to run more than twice as long for the same available battery energy.
And I agree with other comments that linking products to their manufacturers is deplorable -- you don't own a modern product, it owns you.
Oh that's a great point/addition, thanks! The voltage already seems to be good. Everything seemed to work without even the resistor, just added the smaller resistor I had just in case and because I understand an LED in series with a power supply is a very bad idea, even if "it works" (wanted to be on the safe side). So is there something like a purely current protector that doesn't change the voltage much?
> So is there something like a purely current protector that doesn't change the voltage much?
First, in a regulated power supply, you control the current by (a) monitoring current, and (b) adjusting voltage.
Second, a switching power supply can easily be designed to regulate load current, which is what you want for an LED load, because the voltage across the LED changes with both current and temperature. The point of a switching design is that very little power is dissipated by anything except the load.
In your present circuit, the 22 ohm resistor is dissipating at least half the available power, all to protect the LED from overcurrent. I should add that, in any LED driving circuit, a way must be provided to limit the LED's current, or it may experience thermal runaway and failure. A switching power supply is an ideal way to do this, but only if it senses current in the load, not voltage.
Apropos, I designed switching power supplies for the NASA Space Shuttle. They were about 90% efficient, in spite of the fact that they had to deliver widely varying voltages and currents.
I beg to differ -- a pioneering 1949 Seattle solar energy project offers a different view, and as soon as the sun comes out, they're going to release their final report.