The STEM thread

TipRoast

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Almout four years ago, I started a thread in the P&R forum named "Gravitational Waves Detected" - I don't know why I put it there, but it seemed to be well-received and generated a lot of activity.

It might have done even better if it had been placed in the main forum - there are a number of people on the board that never venture into the P&R forum, and they may have enjoyed reading through the many thoughtful posts that populated that thread, and perhaps would have contributed.

So this thread is a follow-up to that one, but with a wider scope: anything in the STEM fields (science, technology, engineering, and mathematics).

I'll kick things off with this article on quintessence, a form of dark energy that may explain why the universe is expanding faster than all the current models predict.
 
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RoadNasty

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A new physics, with 99.2% confidence level, which violates parity symmetry.

 

johnlocke

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I have a small handle on theory here, but I don't understand half of what you guys are talking about in these 2 threads.

That said, a physicist friend who shares my reason and reality based, objective philosophy sent me this:

Purely Mathematical? Not a full answer, but on the right track.

"At the frontiers of theoretical physics, many of the most popular ideas have one thing in common: they begin from a mathematical framework that seeks to explain more things than our currently prevailing theories do. Our current frameworks for General Relativity and Quantum Field Theory are great for what they do, but they don’t do everything. They’re fundamentally incompatible with one another, and cannot sufficiently explain dark matter, dark energy, or the reason why our Universe is filled with matter and not antimatter, among other puzzles.

It’s true that mathematics enables us to quantitatively describe the Universe, it’s an incredibly useful tool when applied properly. But the Universe is a physical, not mathematical entity, and there’s a big difference between the two. Here’s why mathematics alone will always be insufficient to reach a fundamental theory of everything."

And: "This was a revolutionary moment in the history of science. Mathematics wasn’t at the root of the physical laws governing nature; it was a tool that described how the physical laws of nature manifested themselves. The key advance that happened is that science needed to be based in observables and measurables, and that any theory needed to confront itself with those notions. Without it, progress would be impossible."
And: "But in reality, there’s only one object. It only follows one trajectory, landing in one location at one specific time. Which answer corresponds to reality? Mathematics won’t tell you. For that, you need to understand the particulars of the physics problem in question, as only that will tell you which answer has a physical meaning behind it. Mathematics will get you very far in this world, but it won’t get you everything. Without a confrontation with reality, you cannot hope to understand the physical Universe."

View: https://medium.com/starts-with-a-bang/no-the-universe-is-not-purely-mathematical-in-nature-d202e2d7f03e
 

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I know it's just a fun sitcom but Sheldon on The Big Bang Theory just about only worked with math, rarely observing the real world to forumlate his ideas. That kinda doesn't seem OK.

Science is based on observation and the such is it not? What can math describe without observation?
 
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TipRoast

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I know it's just a fun sitcom but Sheldon on The Big Bang Theory just about only worked with math, rarely observing the real world to forumlate his his ideas. That kinda doesn't seem OK.

Science is based on observation and the such is it not? What can can math describe without observation?
That's certainly true in my own field (satellite tracking). Tycho Brahe collected a lot of great data on the planets, and Kepler took it and used it to derive his laws. Later mathematicians (Gauss, Laplace, et alia) took the field of orbital dynamics even further. But it all started with the data collection - the mathematics followed the data.

But that's not the only way science is done - sometimes we use math/physics to make predictions, and then go looking for observations that support those predictions. Einstein's relativity theories made many predictions (gravitational waves, for example) that weren't confirmed by observations until decades later.
 

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That's certainly true in my own field (satellite tracking). Tycho Brahe collected a lot of great data on the planets, and Kepler took it and used it to derive his laws. Later mathematicians (Gauss, Laplace, et alia) took the field of orbital dynamics even further. But it all started with the data collection - the mathematics followed the data.

But that's not the only way science is done - sometimes we use math/physics to make predictions, and then go looking for observations that support those predictions. Einstein's relativity theories made many predictions (gravitational waves, for example) that weren't confirmed by observations until decades later.

Oh, very cool Thank you. Like I said this by far not my area of expertise. :)
 
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Interesting article on an advance in computer science with direct relevance to medical research.

It's a NY Times article, but I don't think it's behind their paywall.

And there's a nice video that provides some insight into the development process and the people that did the work.

 
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O_P_T

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And- for the first time - neutrinos have been observed:


Not exactly.

Neutrino's from the "proton-proton" fusion reaction (i.e., two hydrogen atoms becoming a helium atom) in the Sun, have been detected for decades in these detectors.

This was the first time neutrino's from the CNO fusion reaction were detected.

In both cases, they are electron neutrinos, they simply have a different energy signature (i. e., spectra)
 

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OK, I posted this in the political humor thread with my normal Saturday binge, but it deserves to be here as well.



This is perhaps the best ever representation of the Copenhagen Interpretation (CI) of Quantum Mechanics I've ever seen.

That is one way to interpret what the Schrodinger Equation "means".

Now I'm not going to bog this down with the math, because if you haven't taken advanced calculus, it will be like I'm speaking a foreign language to you.

The thing one has to understand is that the Schrodinger Equation is really nothing other than a Hamiltonian with a probability applied to it.

Now, I'll bet most of you have no idea what a Hamiltonian is, and that's OK.

It is something used in classical mechanics (e.g., Newton's Laws) to "simplify" the calculations.

OK, it's simpler if you know advanced calculus, but it has the advantage that you can capture all types of things that classical mechanics would calculate in a single equation and not have to juggle multiple equations that only solve for a single thing.

This may not be the best analogy, but think of it like this.

Suppose you wanted to describe to someone where something is on the planet.

All you knew was how to give directions. Go down this street, turn right at the intersection, go for 12 miles, turn left, etc.

How complex this would be would depend on where you started and how far you had to go to get to the spot. Two people could give completely different sets of directions to the same spot because they started in different locations.

Now suppose someone came up with longitude, latitude, and a world map. Finding any spot on the planet would the same, regardless of where you started from., you just have to give the coordinates and look on the map.

As I said, this is not to be thought in anyway literal as to what the Hamiltonian does, simply to give an idea of how much easier it makes doing these things.

Needless to say, it's a well understood tool and is used all the time in classical mechanics calculations.

In a sense, all Schrodinger did was say there is a probability that the result of the Hamiltonian will provide answer A, a different probability it will provide answer B, etc., etc.

Each one of them is a "possible quantum state" that "exist" as probability functions.

Under CI, when an "observation" is made, the probability waveform is said to "collapse" to the single observed outcome.
 

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I have a small handle on theory here, but I don't understand half of what you guys are talking about in these 2 threads.

That said, a physicist friend who shares my reason and reality based, objective philosophy sent me this:

Purely Mathematical? Not a full answer, but on the right track.

"At the frontiers of theoretical physics, many of the most popular ideas have one thing in common: they begin from a mathematical framework that seeks to explain more things than our currently prevailing theories do. Our current frameworks for General Relativity and Quantum Field Theory are great for what they do, but they don’t do everything. They’re fundamentally incompatible with one another, and cannot sufficiently explain dark matter, dark energy, or the reason why our Universe is filled with matter and not antimatter, among other puzzles.

It’s true that mathematics enables us to quantitatively describe the Universe, it’s an incredibly useful tool when applied properly. But the Universe is a physical, not mathematical entity, and there’s a big difference between the two. Here’s why mathematics alone will always be insufficient to reach a fundamental theory of everything."

And: "This was a revolutionary moment in the history of science. Mathematics wasn’t at the root of the physical laws governing nature; it was a tool that described how the physical laws of nature manifested themselves. The key advance that happened is that science needed to be based in observables and measurables, and that any theory needed to confront itself with those notions. Without it, progress would be impossible."
And: "But in reality, there’s only one object. It only follows one trajectory, landing in one location at one specific time. Which answer corresponds to reality? Mathematics won’t tell you. For that, you need to understand the particulars of the physics problem in question, as only that will tell you which answer has a physical meaning behind it. Mathematics will get you very far in this world, but it won’t get you everything. Without a confrontation with reality, you cannot hope to understand the physical Universe."

View: https://medium.com/starts-with-a-bang/no-the-universe-is-not-purely-mathematical-in-nature-d202e2d7f03e

When I was studying physics back in the day, I was taught that math was the "language" of physics.

It has rules akin to "grammar", "spelling", "vocabulary", etc. but it is the language in which physics is "spoken".

And just the same, when one looks at any great work of literature, it is the work of literature that conveys the "idea" the author intended. Yes, it must follow the rules of the language in which it is written, for the idea to be properly communicated, just as any theory in physics must follow the "rules" of math to be properly communicated.

Yes, Sheldon worked with math and was constrained to be consistent with the rules of the mathematical system he employed. However he used that "language" to try and write a piece of "great literature". Most of the stuff he worked on was on the limits of experimental/observational physics. Even the Large Hadron Collider doesn't have enough energy to produce the particles proposed in most of the advanced particle physics theories in sufficient quantities to make detection likely.

The development of scientific theories has always been tied to math this way.

Take the earliest Astronomers, and their theories. They couldn't do any "experiments" and their observational data was limited to the Mark I eyeball. Yet they developed elegant theories about the heavens.

Much of those theories have since been replaced, but they all did what any theory must do. Make predictions that are verified by observations/experiments.
 

BostonTim

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OK, I posted this in the political humor thread with my normal Saturday binge, but it deserves to be here as well.



This is perhaps the best ever representation of the Copenhagen Interpretation (CI) of Quantum Mechanics I've ever seen.

That is one way to interpret what the Schrodinger Equation "means".

Now I'm not going to bog this down with the math, because if you haven't taken advanced calculus, it will be like I'm speaking a foreign language to you.

The thing one has to understand is that the Schrodinger Equation is really nothing other than a Hamiltonian with a probability applied to it.

Now, I'll bet most of you have no idea what a Hamiltonian is, and that's OK.

It is something used in classical mechanics (e.g., Newton's Laws) to "simplify" the calculations.

OK, it's simpler if you know advanced calculus, but it has the advantage that you can capture all types of things that classical mechanics would calculate in a single equation and not have to juggle multiple equations that only solve for a single thing.

This may not be the best analogy, but think of it like this.

Suppose you wanted to describe to someone where something is on the planet.

All you knew was how to give directions. Go down this street, turn right at the intersection, go for 12 miles, turn left, etc.

How complex this would be would depend on where you started and how far you had to go to get to the spot. Two people could give completely different sets of directions to the same spot because they started in different locations.

Now suppose someone came up with longitude, latitude, and a world map. Finding any spot on the planet would the same, regardless of where you started from., you just have to give the coordinates and look on the map.

As I said, this is not to be thought in anyway literal as to what the Hamiltonian does, simply to give an idea of how much easier it makes doing these things.

Needless to say, it's a well understood tool and is used all the time in classical mechanics calculations.

In a sense, all Schrodinger did was say there is a probability that the result of the Hamiltonian will provide answer A, a different probability it will provide answer B, etc., etc.

Each one of them is a "possible quantum state" that "exist" as probability functions.

Under CI, when an "observation" is made, the probability waveform is said to "collapse" to the single observed outcome.
I can't be sure. Is Heisenberg hard at work here?

cheers
 

chevss454

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Interesting article on an advance in computer science with direct relevance to medical research.

It's a NY Times article, but I don't think it's behind their paywall.

And there's a nice video that provides some insight into the development process and the people that did the work.


Love this, TR. It brought me back to an article I read last month in an "Oh, yeah" moment.
Theoretical to tactical to practical.
The first COVID19 vaccine uses messenger RNA for the first time ever to produce harmless strings of COVID19 protein which stimulates antibodies for an immune response. It's all extremely fascinating.

The scientists who developed the Covid-19 vaccine are a Turkish-German power couple
 
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TipRoast

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The M in STEM represents mathematics, but we don't often see articles or other media coverage of that topic.

However, I ran across this article today.


It's rather long, but easy to read, I think. And it contains this lovely bit:

Arrangements of stones
reveal patterns in the waves
as space-time expands​
 
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