3 ms·

You do realize that your summary is equally wrong, yes? There are indeed 118 recognized elements, but there are many more "types of atoms", only some of which

by dalke 12y ago

You do realize that your summary is equally wrong, yes? There are indeed 118 recognized elements, but there are many more "types of atoms", only some of which are due to differences in proton count. There are also isotopes; tritium is a form type of hydrogen that is radioactive, and several times heavier than normal (1H) hydrogen. Then there are charged atoms, including more esoteric forms where an inner shell electrons are removed instead of an outer. And there are excited nuclei, like the metastable isotope technetium-99m. While chemically very similar to 99Tc, it emits gamma rays that make it a useful medical radiotracer. That is, atoms differ not only because of the 'different combinations of subatomic particles', but also because of the specific energy states involved. FWIW, there are the exotic atoms, like positronium (an electron-positron atom) and muonic atoms (where one of the electrons is replaced by a muon). These are still different combinations of subatomic particles. Also, "smallest things we have managed to measure" becomes a meaningless phrase. Under current physics, an electron has no radius. It's a point particle, and no one is talking about strings which are smaller than a point. Instead, string theory proposes that the zero-dimensional point should be replaced by a one-dimensional string, or higher-dimensional branes. These should count as being larger objects than the current model for how electrons work. We have oodles and boodles of frontiers to our scientific knowledge. No class can touch on every case. We have to give approximations and limited cases, as otherwise the result will be overwhelming. For example, in geography class we ask students to identify the US on a map. We usually mean the 48 continental states plus Hawaii and Alaska. But the US also includes Puerto Rico, Guam, and other territories, including Kingman Reef and Bajo Nuevo Bank. Teachers have to figure out if it's more important for students to know that only the US considers Bajo Nuevo Bank to be part of the US[1], or if the students should instead learn more details about DNA, or string theory. ([1] While it could be an interesting segue into the International Court of Justice, Guano Act, the War of the Pacific, phosphate strip mining of Nauru, the Haber-Bosch process, and gas warfare in WWI, these are students who can't yet identify the lower 48 on the world map!)

anigbrowl 12y ago
Yes, you should totally apply the standards for a textbook to an example of sketching scientific concepts that I composed in the space of 3 minutes. There's no middle ground between mentioning the most basic things and throwing in everything including the kitchen sink. I am a very bad person and I feel bad about it.
- dalke 12y ago
  Yes, just like you should totally believe that your teachers are short-changing you by not summarizing perfectly the details they decided to not cover. And believing that you could remember all the details should they have done so. Don't you feel horrible for never having been taught that contested unorganized, unincorporated United States territories like Bajo Nuevo Bank exist? Your life must be upside down by first learning that the correct name for 'Brontosaurus' is 'Apatosaurus' and then to learn recently that it's now considered a valid genus of sauropod distinct from Apatosaurus. You meant your example as a demonstration of how it's possible to teach string theory at the same time as F=MA. Otherwise, why did you even spend three minutes at the task? My response was to show that it isn't easy. If a teacher trips up over even a single point - eg, to explain that an atom is made of electrons, protons, and nucleus - then a future version of you will complain and say you were shortchanged, because there are atoms which are NOT made of those subatomic particles. But few primary or secondary school teachers will know about these special cases, and for the vast majority of people it's useless information.
  - anigbrowl 12y ago
    You meant your example as a demonstration of how it's possible to teach string theory at the same time as F=MA. No I didn't. I think one should take a lot of time breaking down the details of F=MA and showing why it works and so forth. But I also think it's OK to allude to the existence of string theory early on when you're trying to establish the scope of what physics is about and why you might want to study it, even though it would probably take 10 years for someone to go from hearing about its existence to studying it directly. Meanwhile, I'm grateful to have had some science teaches that were willing to identify some frontier areas of science by name, while admitting that they were beyond their own understanding (eg QM), and also so spend a bit (not too much) of class time letting us spitball ideas on things like time travel or anti-gravity in order to engage the subject imaginatively as well as meeting the specific curricular requirements.
    - dalke 12y ago
      If "No, I didn't" then what was your purpose in writing that example? In any case, you wrote "If you think there are only 4 bases and then later find out that there are others, the first reaction t that is to feel short-changed about your previous education and stupid about all the new stuff you have to absorb." Either you will feel short-changed about all of the other things the teachers didn't tell you - did they tell you that atoms were made of electrons and a nucleus without mentioning exotic atoms? Did they tell you that noble gases don't chemically react with other molecules without mentioning things like xenon hexafluoride? Did they tell you that the pH goes from 0 to 14? Did they teach you that "the key to healthy eating is to enjoy a variety of nutritious foods from each of the 5 food groups" but not mention that a meat and fish diet is another way to eat healthy? Did they teach you that thrown objects (without wind resistance) fall in a parabola, without explaining that it's actually an approximation to an ellipse, which is an approximation to general relativity? Did they teach you that velocities add without explaining that it's an approximation only valid for low velocities? Did they teach you that DNA is right-handed when it forms a double helix, without telling you about Z-DNA? Did you learn that different parts of the tongue have different taste receptors when that's not actually true? Did they teach you that black holes absorb everything and neglect to mention Hawking radiation? Did they teach you that microwave ovens work by being tuned to the resonant frequency of water? Or that there is an physical correlation between left-brain/right-brain and creativity/analytical tasks? If so, then by your definition your teachers short-changed you, and you no doubt feel pretty stupid right now. If not, then your education was exceptional. http://pubs.acs.org/doi/pdf/10.1021/ed083p1465 http://pubs.acs.org/doi/pdf/10.1021/ed083p1465, for example, is a paper from the Journal of Chemical Education titled "Negative pH Does Exist". It says: > The misconception that pH lies between 0 and 14 has been perpetuated in popular-science books (1–3), textbooks (4–8), revision guides (9), and reference books (10–16). I find it unlikely to the point of laughability that your elementary grade math class mentioned that you can ignore relativistic affects when adding the speed of an airline passenger to the ground speed of the plane to compute the ground speed of the passenger. When you finally learned about special relativity, you might have felt like quite a fool for having previously only been taught about Newtonian mechanics.

by dalke 12y ago

anigbrowl 12y ago

Yes, you should totally apply the standards for a textbook to an example of sketching scientific concepts that I composed in the space of 3 minutes. There's no middle ground between mentioning the most basic things and throwing in everything including the kitchen sink. I am a very bad person and I feel bad about it.

dalke 12y ago
Yes, just like you should totally believe that your teachers are short-changing you by not summarizing perfectly the details they decided to not cover. And believing that you could remember all the details should they have done so. Don't you feel horrible for never having been taught that contested unorganized, unincorporated United States territories like Bajo Nuevo Bank exist? Your life must be upside down by first learning that the correct name for 'Brontosaurus' is 'Apatosaurus' and then to learn recently that it's now considered a valid genus of sauropod distinct from Apatosaurus. You meant your example as a demonstration of how it's possible to teach string theory at the same time as F=MA. Otherwise, why did you even spend three minutes at the task? My response was to show that it isn't easy. If a teacher trips up over even a single point - eg, to explain that an atom is made of electrons, protons, and nucleus - then a future version of you will complain and say you were shortchanged, because there are atoms which are NOT made of those subatomic particles. But few primary or secondary school teachers will know about these special cases, and for the vast majority of people it's useless information.
- anigbrowl 12y ago
  You meant your example as a demonstration of how it's possible to teach string theory at the same time as F=MA. No I didn't. I think one should take a lot of time breaking down the details of F=MA and showing why it works and so forth. But I also think it's OK to allude to the existence of string theory early on when you're trying to establish the scope of what physics is about and why you might want to study it, even though it would probably take 10 years for someone to go from hearing about its existence to studying it directly. Meanwhile, I'm grateful to have had some science teaches that were willing to identify some frontier areas of science by name, while admitting that they were beyond their own understanding (eg QM), and also so spend a bit (not too much) of class time letting us spitball ideas on things like time travel or anti-gravity in order to engage the subject imaginatively as well as meeting the specific curricular requirements.
  - dalke 12y ago
    If "No, I didn't" then what was your purpose in writing that example? In any case, you wrote "If you think there are only 4 bases and then later find out that there are others, the first reaction t that is to feel short-changed about your previous education and stupid about all the new stuff you have to absorb." Either you will feel short-changed about all of the other things the teachers didn't tell you - did they tell you that atoms were made of electrons and a nucleus without mentioning exotic atoms? Did they tell you that noble gases don't chemically react with other molecules without mentioning things like xenon hexafluoride? Did they tell you that the pH goes from 0 to 14? Did they teach you that "the key to healthy eating is to enjoy a variety of nutritious foods from each of the 5 food groups" but not mention that a meat and fish diet is another way to eat healthy? Did they teach you that thrown objects (without wind resistance) fall in a parabola, without explaining that it's actually an approximation to an ellipse, which is an approximation to general relativity? Did they teach you that velocities add without explaining that it's an approximation only valid for low velocities? Did they teach you that DNA is right-handed when it forms a double helix, without telling you about Z-DNA? Did you learn that different parts of the tongue have different taste receptors when that's not actually true? Did they teach you that black holes absorb everything and neglect to mention Hawking radiation? Did they teach you that microwave ovens work by being tuned to the resonant frequency of water? Or that there is an physical correlation between left-brain/right-brain and creativity/analytical tasks? If so, then by your definition your teachers short-changed you, and you no doubt feel pretty stupid right now. If not, then your education was exceptional. http://pubs.acs.org/doi/pdf/10.1021/ed083p1465 http://pubs.acs.org/doi/pdf/10.1021/ed083p1465, for example, is a paper from the Journal of Chemical Education titled "Negative pH Does Exist". It says: > The misconception that pH lies between 0 and 14 has been perpetuated in popular-science books (1–3), textbooks (4–8), revision guides (9), and reference books (10–16). I find it unlikely to the point of laughability that your elementary grade math class mentioned that you can ignore relativistic affects when adding the speed of an airline passenger to the ground speed of the plane to compute the ground speed of the passenger. When you finally learned about special relativity, you might have felt like quite a fool for having previously only been taught about Newtonian mechanics.