How Does Dark Matter Influence Our Understanding of Atomic Structure?

[Jøhn]

I recently had some thoughts about the big "space" between electrons and the nuclei and how weird it would be if that space were truly "empty". This led me to try to understand exactly what was empty space and the more I thought about it, the more I began to think about dark matter. I know empty space and dark matter are very different especially in the sense that dark matter has gravitational properties and empty space does not. However, since I do not believe we can say for certain the size of dark matter, it would seem that the gravitational oddities in atoms may be a result of dark matter. I would love any feedback on this, especially those who can say, "Your wrong!" Haha.

 

[MeJennifer]

... it would seem that the gravitational oddities in atoms may be a result of dark matter.

What "gravitational oddities" are you referring to?

 

[Jøhn]

I mean in the sense that we cannot seem to combine gravity within quantum mechanics because at the level of atoms, gravity breaks down.

 

[Wallace]

I mean in the sense that we cannot seem to combine gravity within quantum mechanics because at the level of atoms, gravity breaks down.

Our gravity theory works fine on the scale of atoms most of the time. The problem is when you get an enormous amount of mass ( ~ the mass of a star) compressed to the scale of an atom that problem emerge. There is no major problem in gravity on small scales that would lead to an explanation of dark matter in the way you propose.

 

[Jøhn]

I see, I will have to look further into the ideas of gravity and atoms before opening my mouth again, though I do find it hard do really understand without the math in front of me. Sadly, most of my knowledge comes from speculation and books because I have never really been able to look deeply into the math. If anyone has any suggestions on how to obtain that knowledge, I would be grateful, however I just started calculus :/

 

[Wallace]

I see, I will have to look further into the ideas of gravity and atoms before opening my mouth again

Apologies if my statement came across as harsh, obviously you can't know everything and it's okay to try and link together whatever you do know to try and explain the unknown.

As for getting more knowledge, it is really important to get a firm base in maths if you want to go into any physics areas later on. If you want to get some basic knowledge of the science before you learn it formally in all the gory mathematical details try some good pop sci. Scientific America is usually pretty good, New Scientist is okay but tends to sensationalise things too much and presents new speculation as if it was far more certain than is warranted, but none the less isn't the worst science journalism you can find.

There are also plenty of good books, for instance if you want to know about modern cosmology I would recommend "the Big Bang" by Simon Singh.

 

[Jøhn]

I do not believe your statement came off harsh at all, remember I did say if anyone can tell me wrong I am more than happy to learn from it. Thanks a lot for the suggestions I will be sure to try them out!

Also, most people tell me college will be the answer to most questions, anyone want to vouch for that? I am only a junior in high school.

 

[malawi_glenn]

John, just give it time. Enjoy the ride to become a scientist :)

 

[Wallace]

Also, most people tell me college will be the answer to most questions, anyone want to vouch for that? I am only a junior in high school.

The good (although it may seem bad?) thing about a lot of modern physics, particularly cosmology and high energy (particle) physics, is that college won't tell you a lot of the answers, mainly because nobody knows! We will probably know more by the time you are in college, but there will still be plenty of mysteries for you to solve that you can't simply learn from a book or a lecture by a professor.

I think we will see the next major revolution in physics sometime in the next decade, although such things are of course very difficult to predict.

 

[Nabeshin]

I think we will see the next major revolution in physics sometime in the next decade

QFT!

 

[Jøhn]

Thanks a lot guys! Though, I am still very impatient when it comes to my questions and answers haha. I just become very frustrated in the sense I do not really have anyone to talk to about many of the concepts I learn, mainly due to the fact that I will read books or watch shows in which no one else seems to do... Sigh, college can never come quickly enough!

 

[malawi_glenn]

QFT!

what? elaborate
i know QFT is quantum field theory, but what do you mean by that?

 

[Nabeshin]

Oh wow I didn't even realize that posting that on physics boards is a surefire misinterpretation. Alternate definition of QFT: Quoted For Truth. So in 15 years when someone writes a book about physics they can quote your prediction XD

 

[malawi_glenn]

Oh wow I didn't even realize that posting that on physics boards is a surefire misinterpretation. Alternate definition of QFT: Quoted For Truth. So in 15 years when someone writes a book about physics they can quote your prediction XD

haha, here - abbreviations for physics are prioritized

Remember when Feynman introduced Quantum Electrodynamics (QED), which has the same abbreviation as http://en.wikipedia.org/wiki/Q.E.D. which you often writes after you have prooven something;)

 

[LongOne]

I want to chirp in on the math/understanding issue. Advanced math is necessary to understand the exact operation of many physics processes, but I believe too many people seem to say that advanced math is NECESSARY to understand advanced physics concepts, which I believe is wrong. It is true that most physicists are comfortable with advanced math and readily use that as a tool to explain their meaning; and math makes the meaning unambiguous. But folks miss the point in saying that math is necessary. Mathematics reflects an exact understanding of how nature behaves; it doesn't explain the concepts of how nature works. A good example is Faraday and what's-his-face ( a sure sign I'm getting old, as I know his name as well as my own!). Faraday was a research physicist and had many insights into how electromagnetic properties worked; he developed the concepts. But it was what's-his-face that took Faraday's concepts and turned them into mathematical rules. The mathematics was not the starting point; the concepts were. I defy anyone with no knowledge of Faraday's experiments (or equivalent) to come up with the laws of electromagnetism.

So I encourage everyone to understand, and pursue rigorously to understand, the concepts of physics. The math is just a way of unambigiously explaining the detail operation. Those that say that you can't understand advanced physics without math are hiding behind mathematics due to their inability to explain the concepts.

 

[Wallace]

I think your what's-his-face is Maxwell. Interestingly though, Maxwell didn't actually come up with what we call Maxwell's equations, at least not in the simplified 4 equation form we learn.

You are right that physical concepts are very important to learn and understand, there are many great mathematicians who struggle with physics precisely because physics is more than just a branch of maths. Have you ever seen the play 'Copenhagen'? It is a three character play with Niels Bohr, his wife and Heisenberg. Most of the scenes are Bohr and Heisenberg chatting about quantum mechanics and Bohr constantly says words to the effect of 'but we don't understand it unless we can explain it to my wife' which, although somewhat patronising(!) effectively is what you are saying I think, that is we have the maths (in this case of QM) but unless the concepts can be explained to a non-expert that doesn't know the maths then we don't understand it.

For the most part this is reasonable, the only note of caution I would make is that occasionally some folk who have tried to understand physics by learning the concepts alone feel they can either find flaws in the theory or extend the theory purely in 'words'. This is where the maths really does become absolutely essential. You cannot properly determine the worth of a theory or make a new theory without being conversant with how the theory is defined, which is always (in physics at least) done in the language of maths. Of course you really do need to fully understand the concepts as well, not just the maths, to do this but you really do need both. You often find people saying 'my theory works, I just need someone to work out the maths' which is a nonsense statement.

 

[ZapperZ]

I want to chirp in on the math/understanding issue. Advanced math is necessary to understand the exact operation of many physics processes, but I believe too many people seem to say that advanced math is NECESSARY to understand advanced physics concepts, which I believe is wrong. It is true that most physicists are comfortable with advanced math and readily use that as a tool to explain their meaning; and math makes the meaning unambiguous. But folks miss the point in saying that math is necessary. Mathematics reflects an exact understanding of how nature behaves; it doesn't explain the concepts of how nature works. A good example is Faraday and what's-his-face ( a sure sign I'm getting old, as I know his name as well as my own!). Faraday was a research physicist and had many insights into how electromagnetic properties worked; he developed the concepts. But it was what's-his-face that took Faraday's concepts and turned them into mathematical rules. The mathematics was not the starting point; the concepts were. I defy anyone with no knowledge of Faraday's experiments (or equivalent) to come up with the laws of electromagnetism.

So I encourage everyone to understand, and pursue rigorously to understand, the concepts of physics. The math is just a way of unambigiously explaining the detail operation. Those that say that you can't understand advanced physics without math are hiding behind mathematics due to their inability to explain the concepts.

OK. Would you care to try and "explain" the "concept" of Gauss's Law, for example, without invoking any mathematics?

This is not a trick question. In fact, I will immediately qualify that to say

"The divergence of the electric field is proportional to the charge density"

is nothing more than an English language version of the mathematical statement

\nabla \cdot E = \rho,

meaning that it is still a mathematical statement, just less precise. So use this to illustrate how you are able to explain a concept in physics without it being nothing more than a "human" language statement of a mathematical formalism.

Zz.

 

[g33kski11z]

what? elaborate
i know QFT is quantum field theory, but what do you mean by that?

.. I'm sorry, but that is the funniest thing I've seen all day.

.. and just my 2 cents on the side "math" conversation.

...Advanced math is necessary to understand the exact operation of many physics processes, but I believe too many people seem to say that advanced math is NECESSARY to understand advanced physics concepts, which I believe is wrong...

I'm happy to hear this. I suck at math, but I love reading any and all cosmology/astrophysics books, articles, etc.. Unfortunately, a lot of the concepts that I read about I "take for granted" that they are right because I can't do the math. I've also been interested in topics but unable to find a "layman’s terms" write up of it and thus unable to pursue it.

 

[LongOne]

I read a book recently, titled "The Mystery of Missing AntiMatter" by Quinn & Nir. Excellent book, covering many areas of cosmology, including baryogenesis and other things, yet never invoking any math more difficult than E=mcc. Interestingly, in this one example, I learned more about the concepts of Cosmology, Astrophysics, Big Bang & Quantum Mechanics than I did from several more (unreadably) math-flavored expositions (no, it doesn't cover everything to a fully expressive depth, but I'm talking about learning the concepts, not being able to calculate, say, a field strength).

 

[LongOne]

OK. Would you care to try and "explain" the "concept" of Gauss's Law, for example, without invoking any mathematics?

This is not a trick question. In fact, I will immediately qualify that to say

"The divergence of the electric field is proportional to the charge density"

is nothing more than an English language version of the mathematical statement

\nabla \cdot E = \rho,

meaning that it is still a mathematical statement, just less precise. So use this to illustrate how you are able to explain a concept in physics without it being nothing more than a "human" language statement of a mathematical formalism.

Zz.

Your example is an excellent one. Although I've had advanced math training during my electrical engineering courses, that was forty years ago and I don't immediately recall the mechanics of much of the more advanced topics. When I read "The divergence of the electric field ...", I know exactly what it means. When I see the equation, it causes me to have to dig up math I haven't used in decades, which just slows down my reading and understanding. The "... divergence ..." sentence is all I need; the other is a bother (for my purposes). As an example, I didn't recall offhand the meaning of E and rho, so the equation alone is not enough, by itself, to tell me anything useful. Also, there are many things that cannot be expressed in math; take the Big Bang, for instance (t=0). Or the singularity.

Perhaps the best notion is that working physics folks need the math; understanding doesn't. I think it's only natural that physicists try to explain everything in math, as it's the tool of their trade, but by attempting to do so, they leave a wide gap in understanding between themselves and the general public, including policymakers. And perhaps this gap is why we don't have a CERN here in the US, or why China may beat us back to the moon, etc.

 

[Wallace]

I read a book recently, titled "The Mystery of Missing AntiMatter" by Quinn & Nir. Excellent book, covering many areas of cosmology, including baryogenesis and other things, yet never invoking any math more difficult than E=mcc. Interestingly, in this one example, I learned more about the concepts of Cosmology, Astrophysics, Big Bang & Quantum Mechanics than I did from several more (unreadably) math-flavored expositions (no, it doesn't cover everything to a fully expressive depth, but I'm talking about learning the concepts, not being able to calculate, say, a field strength).

Just a hypothetical, but consider this. How can you judge how well you really understand a theory that is inherently 'mathematical' for want of a better word, without understanding the maths? You can read a book a feel that the book doesn't leave you confused, that you really understand what the book says. However, if you don't actually know the theory, how can you know that what you have understood is really a correct understanding of the scientific theory that the book intended to explain?

Now I'm not having a go a you and your understanding, I'm just raising this as an issue. There are many many threads on PF that show the evidence of this confident misunderstanding. Clearly intelligent people who feel they understand the science via an explanation (sans the mathematical details) they have read try and do the logical thing of piecing together what they 'know' to try have a stab at offering an explanation for something else in science. The results are often horrendous, uncovering the misplaced confidence the person has in their illusionary 'understanding' of the science.

I've nothing against good mathematics free pop-sci, but the readers must be made aware that pop-sci is pop-sci and science is science, and science is written in the language of maths. You cannot reasonably claim to understand a theory unless you understand the language it is written in.

Once you have understood a theory, you can indeed get an intuitive feel for it without always needing to think in the gory details, such as your intuitive understanding of 'the divergence of an electric field'. I would suggest however that unless you understood the mathematics of this back when you first learned this concept, the genuine and accurate intuitive feel for it would not have developed within you.

 

[ZapperZ]

Your example is an excellent one. Although I've had advanced math training during my electrical engineering courses, that was forty years ago and I don't immediately recall the mechanics of much of the more advanced topics. When I read "The divergence of the electric field ...", I know exactly what it means. When I see the equation, it causes me to have to dig up math I haven't used in decades, which just slows down my reading and understanding. The "... divergence ..." sentence is all I need; the other is a bother (for my purposes). As an example, I didn't recall offhand the meaning of E and rho, so the equation alone is not enough, by itself, to tell me anything useful. Also, there are many things that cannot be expressed in math; take the Big Bang, for instance (t=0). Or the singularity.

Perhaps the best notion is that working physics folks need the math; understanding doesn't. I think it's only natural that physicists try to explain everything in math, as it's the tool of their trade, but by attempting to do so, they leave a wide gap in understanding between themselves and the general public, including policymakers. And perhaps this gap is why we don't have a CERN here in the US, or why China may beat us back to the moon, etc.

But you are not answering my question that was directed to you, and in fact, you have now changed the whole issue by bringing up the "general public" and the need to communicate. This is now a different issue completely.

Since this would indicate that you can't do what I requested, then your original point of explaining something in physics without invoking any math is moot, because it doesn't exist.

And for your information, I've written more about communications (or miscommunications) between scientists and the general public than I care to remember.

Zz.

 

[malawi_glenn]

I read a book recently, titled "The Mystery of Missing AntiMatter" by Quinn & Nir. Excellent book, covering many areas of cosmology, including baryogenesis and other things, yet never invoking any math more difficult than E=mcc. Interestingly, in this one example, I learned more about the concepts of Cosmology, Astrophysics, Big Bang & Quantum Mechanics than I did from several more (unreadably) math-flavored expositions (no, it doesn't cover everything to a fully expressive depth, but I'm talking about learning the concepts, not being able to calculate, say, a field strength).

Just a hypothetical, but consider this. How can you judge how well you really understand a theory that is inherently 'mathematical' for want of a better word, without understanding the maths? You can read a book a feel that the book doesn't leave you confused, that you really understand what the book says. However, if you don't actually know the theory, how can you know that what you have understood is really a correct understanding of the scientific theory that the book intended to explain?

Now I'm not having a go a you and your understanding, I'm just raising this as an issue. There are many many threads on PF that show the evidence of this confident misunderstanding. Clearly intelligent people who feel they understand the science via an explanation (sans the mathematical details) they have read try and do the logical thing of piecing together what they 'know' to try have a stab at offering an explanation for something else in science. The results are often horrendous, uncovering the misplaced confidence the person has in their illusionary 'understanding' of the science.

An analogy: Imagine a blind man stating that he understands more about what colours is than what he did when he could see.