Active noise cancelling headphones do not filter out all sounds. In fact, many loud tools are not going to be affected at all.

And there in lies the crux of the matter. Active noise cancelling doesn't stop all noise. They also have limits in terms of how much sound and what types of sound they can cancel out.

It is hard to make a claim that they protect your hearing when they don't protect your hearing consistently.

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Yes I can confirm this. I haven’t made a cent off any of my publications. The papers that are available for free are from “open access” programs, where the researchers probably paid a fee to make the work available for free instead of having it behind the standard pay wall. It os becoming more common for funding agencies to require that you make the work freely available.

That said, your public library probably either has or can get any paper you want, it just might take a bit to do an inter library “loan” of the article. Or email the corresponding author. Many (not all) are willing to send you a copy.

In the land of chemistry and physics, ArXiv is a popular way to accomplish satisfying funding agency open access requirements without having to pay the journals extra.

Source: am also in academia

Saying that something offers hearing protection is a claim that it has been tested and shown to be effective at protecting the user's ears. Most earbud/headphone makers won't make such a claim because testing is expensive and anyway, that's not what the product is for. It's for listening to media. What is to prevent a user from cranking the music volume up too loud, damaging their hearing, and suing the device manufacturer because they claimed it was hearing "protection"?

They werent all dead and they were specifically told they werent because one of the victims still called after they were in the stand off and told them they were still alive and had injured kids.

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Note that the people doing the research and the people doing the peer review are not the ones who pocket all the money made by these scientific journals.

The companies operating the journals make the profits.

This made more sense in the days when everything was still on paper.

One of the people who turned scientific journals into what they are today was Robert Maxwell. He is dead, but his legacy lives on.

You may have heard of his daughter Ghislaine who apparently takes after her father when it comes to ethics and morals.

Two things

First, humans are simply much larger and heavier, and have much more mass per surface area to try and oxygenate - and it must travel much farther to reach the critical organs. It’s not a very efficient system so most amphibians are very small and many supplement with lungs, gills, and/or tricks to increase surface area.

Second, if you’ve ever met a frog you may have noticed that they spend 99% of their time motionless staring into the abyss. They’re cold blooded and have poor oxygenation capacity, and so have very little metabolic energy reserve to spend. They move infrequently and tire quickly. Humans are tireless hyper-endurance athletes by comparison. We can move all day and burn oxygen at a much faster rate - but need much more food to do so.

That’s one of our evolutionary advantages, even by warm blooded mammal standards humans are tireless athletes. We’re not the fastest or the strongest, but we can pursue for hours like a horror movie slasher until any prey is absolutely gassed.

I used to think they were all more or less the same until I started buying my own and stopped using the ones they were giving away for free at college or the doctor's office. I am still grateful for the free condoms, but in hindsight, they weren't the nicest ones.

I would encourage you or anyone else using condoms to try different ones and see what you like. Be open minded and try the different sizes, thicknesses, and materials. For example, my favorite so far are the skyn elite, which is a non-latex. Neither me or my partner have a latex allergy, so it would have seemed unnecessary to use non-latex, but I just ended up liking them more.

I also second u/Trivial_specter 's advice, it's a good explanation.

I assume the word you wanted was "create".

Inventing a new form of math usually means starting with some new idea for how to think about things, seeing if that idea produces interesting consequences, and then trying to convert that idea into fully mathematical language.

In the case of calculus, we can follow some steps to "invent" it.

So. Let's imagine that you're in a car that is initially moving at 5 meters per second, and smoothly accelerates over 10 seconds to 25 meters per second. (That is, it has a speed given by v(t) = 5 + 2t.) We want to know how far you actually move in those 10 seconds.

Without a formula or some existing math, this isn't an obvious answer. We know how fast you're moving at any given time, but the distance you move is your speed times the amount of time you're at that speed. In this case, you're only "at" each speed for an instant as you speed up, so that idea won't work, at least without modification.

Okay, well, let's try a different approach. Instead of modeling the way you move continuously, let's imagine you're moving at a constant speed for each second, and use that to get an approximate answer. That way, we can compute distances for each second. So we approximate that you're moving at v(0) = 5 m/s for the first second, v(1) = 7 m/s for the second second, and so on. Since you're traveling at each speed for 1 second in this approximation, the distance you travel is 5 m/s times 1 second = 5 meters in the first second, 7 meters in the second second, and so on. That gets us an approximation of 5 + 7 + 9 + ... + 23 (we don't get a 25 here because we only reach that speed at the end), or 140 meters.

Now, we know that during each second, we're traveling faster than we were at the beginning of that second. So the approximation we just did was always underestimating our speed, so that 140 meters is a lower bound. We know we went at least 140 meters. That's a nice thing to know! But it's not a complete answer: exactly how far do we move in those 10 seconds?

Well. The error in our estimate comes from imagining that our speed is constant for a whole second. What if we didn't do that? What if we just imagined our speed was constant for half a second, instead? That is, we travel at v(0) = 5 m/s for the first half second, v(0.5) = 6 m/s for the second half second, v(1) = 7 m/s for the third half second, and so on. That should be closer to the real answer, because the approximate speed we're using is tracking more closely with our real speed. That gets us 2.5 meters of travel in the first half second, 3 in the second half second, 3.5 in the third, and so on, for a total of 145 meters.

For the same reason as before, we know this 145 meters is a lower bound. We must be going more than 145 meters. But we're still not exact.

Okay, what if we made those time windows really, really short - only, say, (1/100) of a second? Then we travel at v(0) = 5 m/s for the first hundredth of a second, v(0.01) = 5.02 m/s for the second hundredth of a second, and so on. We have a lot more adding up to do this time (because we now have 1,000 time windows to add up), but if we do add it up, we now get 149.9 meters.

Hmm, okay, what about 1/100000 of a second? Now we have to add up a million little steps, but we get 149.999 meters.

We might, at this point, suspect that the true answer is probably 150 meters. After all, we know it has to be more than 149.999, and we know that 149.999 is probably really close.

We don't know that 150 is the correct answer. But we've developed a technique that suggests that it might be. Can we make that technique better?

Well, one thing we can do is get an upper bound on the true distance using the same technique, by using the speed at the end of each window, instead of the beginning. That is, if we're using one-second-long time windows, we could assume we're going 7 m/s for the first window rather than 5 m/s. That way, we're always estimating a faster speed than the real one.

It turns out that if we do this, and use really short time windows, we end up with 150.001. So we know our true distance is between 149.999 and 150.001. We should really suspect it's probably exactly 150 at this point, particularly since the window between the lower and upper bounds is shrinking the shorter we make our time steps.

Once we put this idea into formal mathematical language, we can show that both the lower and upper bounds get as close to 150 as you could ever want, and the only number that fits between them is exactly 150 - the true answer. But that formal mathematical language turns out to generalize to a lot of other situations, and it's that idea that leads you to start really developing calculus.

Calculus was "invented" roughly at the same time by two different people, using it for two different purposes.

Isaac Newton used it as a solution to physics problems, and Leibniz (not sure his first name) used it for more pure math problems.

At its heart they were both concerned with being able to calculate the slope of a line at possible point on the line (if you imagine a straight line that's easy, but a constantly changing wiggly curvy line is hard).

Both people realized that a slope on a line is just rise over run or change in Y divided change in X on a graph. And both people created a math process to make the "change" values infinitely small giving a new equation, this process is called a "transformation" (derivation in this case).

Where they differed is that Newton was more concerned real world physics, he was mostly interested with changes in a system by time very specifically where as Leibniz was more pure-math focused and just wanted to discover what are essentially "tangents" (point-slopes) on curves.

From Leibniz we get the dY/dX notations and from Newton we get the y' and x' notation which (In my engineering school at least) specifically refers to time-based derivates.

Most of your total vasculature is in the peripheries / not in the great vessels.

Widespread vasoconstriction therefore preferentially forces blood away from the peripheries and towards the heart.

This results in increased preload.

Calculus has been developed over the course of two centuries, from about 1700 till about 1900. First the overall concept and useful results were discovered without a firm foundation, then people worked for a long time on refining the details. Nowadays it’s usually taught the other way round - from the basics like the definition of real numbers to the results like the derivative and the integral. But historically those things have been usefully employed with enormous success in math and physics much earlier than being defined in the modern way.

>Weren't most of, if not all, the kids dead within seconds of the shooter
entering the classroom?

No they were not. It is a known fact that that ISN'T true. You can hear children screaming and crying on the Videos where the cops are standing around doing fuck all. One kid was killed after a cop told him during a 911 call to yell something, after which the shooter found the kid and shot him.

Most public libraries by now should participate in interlibrary programs that give them access to just about anything, as long as you're willing to spend a few days waiting. At least in more populous states. You'll definitely need a library card though.

I dont think so. Schools arent prisons, or shouldnt have to be. The more oppressive the school grounds are the less likely kids will actually embrace learning.

People are mad because in the Uvalde shooting the police arrived, locked down the scene, put up a perimeter and then stood around for 20 minutes while the shooting continued. The police were on scene and spent more time and resources stopping parents from entering the school grounds then engaging the shooter.

These are the people we give our tax dollars to with the understanding theyre there to protect the community. Now that we are beginning to understand that police only protect themselves, eachother, and the political elite that let them get away with their crime - theyre simply a gang. And they helped the Uvalde shooter kill more kids by blocking access to the school and stopping people from saving their kids.

Those cops are pieces of shit and shouldnt be allowed to serve in any capacity as a public servant.

>"breathe through my skin" thing that frogs do

Huh. So Kojima didn't make it up entirely out of his imagination, that's interesting. I assume there is something that would stop it working with a human though, right?

Welcome to capitalism, where profits of a few are more important that scientific improvement.

Publishers don't give a s%it if the articles aren't available to everyone, they want to make profit from subscriptions. Authors are kinda forced to publish their papers on the mainstream vehicles, so they don't have a choice.

It has nothing to do with research costs like some people here are saying. Neither the authors and universities get a penny of the subscription money.
However, if you email any author asking for .pdf of a paper/article that he wrote, he'll gladly send you for free, also there are people fighting this, like Alexandra Elbakyan, with scihub (If you don't know her, look it up, here's the transcript of her presentation "Why Science is Better with Communism? The Case of Sci-Hub." https://openaccess.unt.edu/symposium/2016/info/transcript-and-translation-sci-hub-presentation).

This was kind of the case before. Emperors and kings would sponsor large libraries where research were made public to anyone visiting. And this would attract a lot of scholars to these cities where they would be learning and then even teach others. The purpose of this was to gain cultural influence, technological supremacy and military tactical advantages. I am not just talking about the ancient Greek and the Library at Alexandria here but these programs were also heavily funded by people like Louis XXIV of France, Cathrine the Great of Russia and is how institutions like the Royal Society of London for Improving Natural Knowledge were founded and operated.

The cost of gaining this knowledge was that you had to travel to the library and even ask for permission to read the research. But this started to change when printing took off and papers could be printed and mailed to whoever wanted it. But this did of course have fees associated with it. Printing was fairly cheap but still cost money and the postal dues also cost some. So you were expected to pay these costs. Eventually as the peer review process were better established and regular journals were published with the best papers the costs of administration were included as well as the printing and mailing. These made sense and you could usually go to the university library of the authors to read the paper for free.

The issue was when computers and the Internet came about. Most of the administrative and practical aspects of running a scientific journal were gone over night. But the fees still remained as they were. There have been much less focus on reducing these fees then there should be. And the owners of these journals knows this and provides excellent service to the libraries that pay these fees to prevent them from arguing over price. It is just considered the cost of research.

There are quite a bit of push towards open access journals, mostly from political and individual academics rather then from the academic institutions themselves. So we are slowly getting there but it is a very slow process.

Running a journal is expensive. There are production staff, editorial staff, IT demands (organisation and publishing software), and other office costs. There are also reviewing costs - while the main subject matter is often done by volunteer reviewers, ceraint parts of the review may require paid specialists (eg. A medical journal may need to hire a mathematician to check the statistical analysis).

Traditionally, the way journals were funded was by selling subscriptions to individual scientists or universities and libraries. This is still the case, but there are now so many journals that it is inpossible, even for top universities to keep up. I teach at a med school and while some of the most famous med journals are subscribed to and the library has a login, minor or specialist journals often are not available, and while the library can get a copy it usually costs $20-30 for the request to be sent out to a partner library who does have a subscription and get the article back.

Increasingly, many journals now offer an option where the authors pay to have their article published. So, if yoi write a scientific article, send it to a journal and their reviewers and editor accept it, then you can pay the cost of publication (usually around $1000) and the publisher will make the article "open access (free to anyone).

As $1000 is very cheap compared to a new scientific experiment or study, this is easily affordable by anyone who had the money to do the study. Indeed, many charities and governments which give out money for scientific work, now specifically include a publication fee in the donation, and make it a requirement that any articles published come out "open access".

It wasn’t that long ago (1990s) that scientists themselves would have to go to the library and photocopy their own journal articles (or I guess if you were a prof, you probably had an assistant do it).

I don’t understand the current business model of journals existing as PDF files mailed around. The purchase price of $35 per article is absurd and no one ever pays that. Big schools do subscribe to the journals their research teams publish in. So that’s how scientists get themselves get access.

If they don’t have to actually print as many physical copies of the journal, it should be cheaper than it was before, but it can’t be free. There are still administrative costs. I don’t know how much the senior editors get paid.

/u/Mastodon996 and /u/Expert-Hurry655, both wrong. If only it were like that.

>Some research articles are free, and others are behind paywalls. Why? Because it costs money to operate. If you see a research paper you'd like to read that's behind a paywall, any public or university library should be able to get you a copy, because most of them have subscriptions.

>But research is expensive and scientists need to bring food to the table too. Someone needs do pay for all that and whoever pays can decide where the results go, if an aerospace industry company is researching on a new material, they do that because they hope to make proffit in the future.

Research is expensive, and researchers do need to make a living (most in academia don't earn particularly much relative to the time/education investment needed to get to their positions).

But the paywalls you're seeing do not fund these researchers and their projects. It is an entirely for-profit middle-man business run by the journal publishers, a model that persists only because they have the power of establishment on their side. Scientists must publish to stay relevant and stay funded, and publishing is controlled by these journals who extract fees from the scientists to publish their work, too. And the peer review process, where impartial experts judge the quality of submitted work before publication, playing a major part in the editorial role for journals? Those scientists aren't paid for their time either. Journals take and take, and make everyone else pay for things they didn't create, with minimal operating costs -- all they have to do is host the research papers, and print some paper copies. The profit margins on this business are ludicrous.

Some countries are attempting to break up this model. I believe in the US, regulations are being put in place currently that force academic work funded by taxpayer money (a huge share of research funding!) to be made available free of charge to the public within a year.

There are also certain fields, mostly around computer science, that are breaking free of this themselves by launching open publication platforms and collectively trusting/supporting them, taking away traditional journals' prestige factor.

Source: am in academia.

Im not talking about the paper but the actual research, the money the scientists needs to pay to the publisher is normaly covered by the employer.

yes that's what i heard as well, and also apart from that authors need to pay for their papers to get published in the first place

University libraries, yes, but generally only for students or staff. Public libraries rarely have subscriptions to scientific journals, AFAIK (I've never seen this).