Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The dangers of sleeping through Science class.

  1. Apr 4, 2006 #1

    Janus

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Last night there was a story on the local new about gas prices. During it they mentioned that some people have taken to putting nitrogen in their tires rather than air because they thought that it would improve their gas milage.
    The logic behind this? Apparently they believe... now get this... that nitrogen does not expand and contract with temperature like regular air does.
     
  2. jcsd
  3. Apr 4, 2006 #2

    FredGarvin

    User Avatar
    Science Advisor

    Oh dear lord....I'm home schooling my kids.
     
  4. Apr 4, 2006 #3
    Indeed they're right! The physical properties of nitrogen gas... are very different from those of nitrogen gas.
     
  5. Apr 4, 2006 #4
    Just be happy they are not trying to fill their tires with 'natural gas,' if you know what I mean.
     
  6. Apr 4, 2006 #5

    mrjeffy321

    User Avatar
    Science Advisor


    HAHAHA,
    Was this a serious news story? Or did they debunk the claim?
     
  7. Apr 4, 2006 #6

    Janus

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    The furthest they went was to ask a employee of a tire shop whether he thought it would make a difference. He said that he didn't think so.
     
  8. Apr 4, 2006 #7

    brewnog

    User Avatar
    Science Advisor
    Gold Member

    I thought it was to eliminate the rubber perishing (oxidising) from the inside out. Obviously not a factor with car tyres, because for almost all users, they'll wear out before they age. For heavy duty and specialist tyres though, this is an issue.

    Also, compressed nitrogen is dry, - compressed air will have a wetness fraction which can freeze, and can also expands a lot more with heat. I don't really buy this second argument, especially for the low pressures and low sensitivity on pressure for road use, but I suppose it's worth a thought for high performance and critical applications.


    I suspect the real reason is that people saw race/rally teams using compressed nitrogen because it's more convenient, assumed that it offered a significant technical advantage, and copied them.
     
    Last edited: Apr 4, 2006
  9. Apr 4, 2006 #8

    Chi Meson

    User Avatar
    Science Advisor
    Homework Helper

    Keep telling myself:

    "be part of the solution..."


    "be part of the solution..."


    "be part of the solution..."
     
  10. Apr 4, 2006 #9

    dav2008

    User Avatar
    Gold Member

    My 2nd grade teacher told me that to convert from Celsius to Fahrenheit you just add 32 :(
     
  11. Apr 4, 2006 #10

    chroot

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Oh, dear lord, if we start catalogging the mistakes of my primary school teachers, we'll be here all day.

    - Warren
     
  12. Apr 4, 2006 #11
    I don't remember anything from primary school. Which may or may not be a good thing...and I'm starting to think it's a good thing, actually...
     
  13. Apr 4, 2006 #12

    Astronuc

    User Avatar

    Staff: Mentor

    WE have a second Science Jokes thread? :rofl:
     
  14. Apr 4, 2006 #13

    brewnog

    User Avatar
    Science Advisor
    Gold Member

    One of my primary teachers taught us that a, e, i, o and u aren't letters. They are vowels. It's a wonder I have an edjukashun.
     
  15. Apr 4, 2006 #14

    chroot

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I had a chemistry teacher who told the class that "a milliliter is a milligram." When I objected, and said that was only "true" (though not well-stated) for water at STP, she admonished "honey, a pound of feathers is a pound of lead." When I objected again, and said that a pound of feathers has a different volume than a pound of lead, she said "honey, a milliliter is the same as a milligram."

    - Warren
     
  16. Apr 4, 2006 #15

    mrjeffy321

    User Avatar
    Science Advisor

    If your not part of the solution, your part of the precipitate.
     
  17. Apr 4, 2006 #16

    russ_watters

    User Avatar

    Staff: Mentor

    Dude, I am here all day!
     
  18. Apr 4, 2006 #17

    russ_watters

    User Avatar

    Staff: Mentor

    I had a math teacher in 7th grade that told us there was a year zero. Having just read about the history of the calendar in "3-2-1 Contact Magazine", argued with him, and he bet me a soda that there was. I showed him the magazine and he changed to 'uh, I meant a zero point'. Yeah, like I would have misunderstood that? :rolleyes: He never did admit he was wrong, but I still got my soda. :biggrin:
     
  19. Apr 4, 2006 #18
    My high school had ass crap for science classes. They were a joke, utterly utterly worthless. The only good thing offered was biology, and I was not interested. Makes for a sucky way to start engineering school, eh?
     
  20. Apr 4, 2006 #19

    DocToxyn

    User Avatar
    Science Advisor

    I'm with brewnog on this one. This discussion also came up on my recumbent bike forum, it gets a little geeky, but hey this is PF.
     
  21. Apr 4, 2006 #20
    My Biology teacher told the class that a species is two animals being able to re-produce last week (didn't mention fertile off-spring nor naturally re-producing).

    I found enormous pleasure in correcting her :devil: .
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?