Results 1 to 29 of 29

Thread: Wouldn’t pointing it over his shoulder do the same thing?

  1. #1
    Join Date
    Jul 2008
    Location
    Tacoma, WA
    Posts
    15,708

    Default Wouldn’t pointing it over his shoulder do the same thing?

    The Algorithm Is Watching

  2. #2
    Join Date
    May 2015
    Location
    The Garden State
    Posts
    7,957

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    that was my thoughts as well. Probably get more control that way too.
    "If you think you are too small to make a difference, try sleeping with a mosquito"

    -Dalai Lama

  3. #3
    Join Date
    Dec 2003
    Location
    Portland, Oregon
    Posts
    67,314

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    Same thing? Doubtful. It would propel the air behind him backward, not him forward. The umbrella provides something for the blast to push against.
    Last edited by David G; 10-19-2020 at 12:50 PM.
    David G
    Harbor Woodworks
    https://www.facebook.com/HarborWoodworks/

    "It was a Sunday morning and Goddard gave thanks that there were still places where one could worship in temples not made by human hands." -- L. F. Herreshoff (The Compleat Cruiser)

  4. #4
    Join Date
    Oct 2003
    Location
    Valley of the Sun
    Posts
    104,531

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    you guys have seen leaf blower scale model planes right?

    64A2A50A-8C60-4369-881C-84D4339721DD.jpg
    Simpler is better, except when complicated looks really cool.

  5. #5
    Join Date
    Feb 2010
    Location
    northern Georgia, or Mississippi Delta USA
    Posts
    21,859

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    It doesn't matter with the electric skateboard underneath. Pointing it backwards and ditching the umbrella would be less air resistance.

  6. #6
    Join Date
    Dec 2003
    Location
    Portland, Oregon
    Posts
    67,314

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    Quote Originally Posted by Jimmy W View Post
    It doesn't matter with the electric skateboard underneath. Pointing it backwards and ditching the umbrella would be less air resistance.
    So the video is a deliberately staged fraud?
    David G
    Harbor Woodworks
    https://www.facebook.com/HarborWoodworks/

    "It was a Sunday morning and Goddard gave thanks that there were still places where one could worship in temples not made by human hands." -- L. F. Herreshoff (The Compleat Cruiser)

  7. #7
    Join Date
    Oct 2003
    Location
    Valley of the Sun
    Posts
    104,531

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    Quote Originally Posted by David G View Post
    So the video is a deliberately staged fraud?
    quickly now, to the ddwfttw thread!!!
    Simpler is better, except when complicated looks really cool.

  8. #8
    Join Date
    Feb 2010
    Location
    northern Georgia, or Mississippi Delta USA
    Posts
    21,859

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    For every ... equal and opposite ...

    The leafblower would be pushing back as much as forward.

  9. #9
    Join Date
    Feb 2005
    Location
    Abbotsford, B.C.
    Posts
    5,311

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    Musk is probably pulling his hair out. He spent millions to achieve the same thing.
    basil

  10. #10
    Join Date
    Dec 2009
    Location
    Cows
    Posts
    76

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    Quote Originally Posted by David G View Post
    So the video is a deliberately staged fraud?

    Jimmy W. got it right. The wheels of the bucket are different when he dumps out the water. Later they are skate board wheels, and he is steering like one would with a skateboard.

  11. #11
    Join Date
    Nov 2011
    Location
    Salt Spring Island, BC
    Posts
    7,417

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    Quote Originally Posted by Jimmy W View Post
    For every ... equal and opposite ...

    The leafblower would be pushing back as much as forward.
    It's pulling the air from below, not behind.

  12. #12
    Join Date
    Oct 2003
    Location
    Valley of the Sun
    Posts
    104,531

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    Quote Originally Posted by Gib Etheridge View Post
    It's pulling the air from below, not behind.
    but, thrust
    Simpler is better, except when complicated looks really cool.

  13. #13
    Join Date
    Jul 2017
    Location
    huntsville, al, usa
    Posts
    6,435

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    physics fail

  14. #14
    Join Date
    Oct 1999
    Location
    St. Paul, MN, USA
    Posts
    56,663

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    Quote Originally Posted by Jimmy W View Post
    For every ... equal and opposite ... The leafblower would be pushing back as much as forward.
    Exactly.
    "For a successful technology, reality must take precedence over public relations,
    for nature cannot be fooled."

    Richard Feynman

  15. #15
    Join Date
    Jan 2007
    Location
    Winnipeg MB
    Posts
    21,360

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    Yep. Obvious from the get-go. It's exactly analogous propelling a sailboat with a deck-mounted fan.

    What are you doing about it?




  16. #16
    Join Date
    Oct 1999
    Location
    St. Paul, MN, USA
    Posts
    56,663

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    It could work if he ditched the umbrella and pointed it backwards, but it probably has nothing near enough power.
    "For a successful technology, reality must take precedence over public relations,
    for nature cannot be fooled."

    Richard Feynman

  17. #17
    Join Date
    Aug 2006
    Location
    Rockford, IL
    Posts
    11,560

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    So, all of the jet aircraft in the World just "push air out behind them? BS. I've seen a lot of jet aircraft but have never seen one with an umbrella(s) deployed at the rear in order to give them "something to push against".

  18. #18
    Join Date
    May 2005
    Location
    Bradford, VT
    Posts
    9,096

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    Not in the least, he would be able to see where he was going

  19. #19
    Join Date
    Oct 2003
    Location
    Valley of the Sun
    Posts
    104,531

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    Quote Originally Posted by Nicholas Scheuer View Post
    So, all of the jet aircraft in the World just "push air out behind them? BS. I've seen a lot of jet aircraft but have never seen one with an umbrella(s) deployed at the rear in order to give them "something to push against".

    actually they do of sorts,
    onliest thing is
    is they are thrust reversers. . .

    Simpler is better, except when complicated looks really cool.

  20. #20
    Join Date
    Jul 2009
    Location
    Zbigit
    Posts
    1,767

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    Um....I think that Newton would have issues with this...you know, every action has an equal and opposite reaction.

    Not sure how that works, at all.

  21. #21
    Join Date
    Jul 2010
    Location
    Tampa Bay, Gunshine State
    Posts
    8,019

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    I've never seen an electric blower with a pull-start.

    And wouldn't one of you sailors here have noticed the umbrella backdrafting?

    Jimmy nailed it, you can see the battery hanging under the skateboard. And I posit that blower isn't even running.
    ______________

    Life is short, play with your cougar.

  22. #22
    Join Date
    Feb 2013
    Posts
    117

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    They did this on Myth Busters, using a small boat and square sail type thing. It worked! Only by accident, to get the forces to cancel each other out is much harder in real life than on paper. Which way and how fast would be hard to predict, but what you see is fake.

  23. #23
    Join Date
    Dec 1999
    Location
    Oriental, NC USA
    Posts
    5,328

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    Quote Originally Posted by David G View Post
    Same thing? Doubtful. It would propel the air behind him backward, not him forward. The umbrella provides something for the blast to push against.
    Its OK to be wrong but David is wrong on both counts. All such things work on impulse of material in opposite to direction of travel. Its mass and velocity. Sometning to push against is not necessary and actually reduces thrust. Some people picked up the faults and its obviously a scam but we don't know the particulars.
    Tom L

  24. #24
    Join Date
    Jul 2009
    Location
    Zbigit
    Posts
    1,767

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    It's a FUN scam, though!!!

  25. #25
    Join Date
    Feb 2010
    Location
    northern Georgia, or Mississippi Delta USA
    Posts
    21,859

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    Quote Originally Posted by David G View Post
    So the video is a deliberately staged fraud?
    It was deliberately staged to get YouTube views. He probably doesn't care whether or not you believe it as long as you click on it.

  26. #26
    Join Date
    Nov 2008
    Posts
    31,551

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    Quote Originally Posted by David G View Post
    Same thing? Doubtful. It would propel the air behind him backward, not him forward. The umbrella provides something for the blast to push against.
    This same argument was made decades ago to show that rockets would not work. It was wrong then and it's wrong now. The "blast" doesn't push against anything. It's conservation of momentum - push the air back and you push the engine forward.

    Now that I think of it, that's why the video is a fake.

  27. #27
    Join Date
    Feb 2013
    Posts
    117

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    This same argument was made decades ago to show that rockets would not work. It was wrong then and it's wrong now. The "blast" doesn't push against anything. It's conservation of momentum - push the air back and you push the engine forward.
    Are you saying Rockets work in space?

  28. #28
    Join Date
    Oct 1999
    Location
    St. Paul, MN, USA
    Posts
    56,663

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    More accurately, the rocket exhaust gets pushed back, the rocket goes forward. If you pointed the blower backwards, and threw away the umbrella, you'd get some thrust, not much, a function of the mass of the stuff that goes backwards and its acceleration.
    Last edited by Keith Wilson; 10-19-2020 at 06:35 PM.
    "For a successful technology, reality must take precedence over public relations,
    for nature cannot be fooled."

    Richard Feynman

  29. #29
    Join Date
    Dec 1999
    Location
    Oriental, NC USA
    Posts
    5,328

    Default Re: Wouldn’t pointing it over his shoulder do the same thing?

    Quote Originally Posted by ShorelineJohn View Post
    Are you saying Rockets work in space?
    Are you saying that rockets don't work in open space? Don't tell NASA since that is how they have used them for decades.
    Tom L

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •