<div dir="ltr"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><span style="font-family:arial,sans-serif">On Fri, Oct 13, 2017 at 1:20 PM, William Flynn Wallace </span><span dir="ltr" style="font-family:arial,sans-serif"><<a href="mailto:foozler83@gmail.com" target="_blank">foozler83@gmail.com</a>></span><span style="font-family:arial,sans-serif"> wrote:</span><br></div><div class="gmail_extra"><div class="gmail_quote"><br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><div style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">> </div>No one of any age should be insulted when someone tries to cure their ignorance. I don't mind being ignorant. It's not shameful to me. I just enjoy not being ignorant any more, so I am thankful to all who help me.</div></div></blockquote><div><br></div><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><font size="4">And that is a very enlightened attitude! </font></div></div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><div style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">> </div>I still don't get some of it. Say you take a less dense object and put it underwater. Since it is less dense, does that mean that gravity pulls less on it?</div></div></blockquote><div><br></div><div><font size="4"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">Yes.</div> </font></div><div> <br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><div style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)"> <div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">> </div>And why should the water exert less of an upward force than on something more dense<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline"> </div>Or is it gravity?</div></div></blockquote><div><br></div><div><font size="4"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">Gravity exerts less of a downward force on on something less dense than water then it does on water, it would rise for the same reason a balloon does. </div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">A bubble of air at atmospheric pressure is 784 times less dense than water so it rises in water, but air is compressible and water is not, and the pressure increases by one atmosphere every 10 meters down in the ocean you go, so at about 78,400 meters a underwater bubble of air would have the same density as water and so would not rise, and any deeper than that and air would be more dense than water and the air bubble would sink. </div></font></div><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline"><br></div></div><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline"><font size="4">Only trouble is the sea is not 78,400 meters deep, at least not on this planet, and long before that the air would diffuse into the water, but you get the idea.</font></div></div><font color="#000000" face="arial, helvetica, sans-serif"><br></font><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><div style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">> </div>If I were standing in a vacuum, would there be less holding me up since there is no air to exert an upward force on my body? </div></div></blockquote><div><br></div><div><font size="4"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">In a the air when you step on your bathroom scale there is a gravitational force pulling you down but there is also a less strong force from the air pushing you up, so in a </div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">vacuum the reading on the scale would be slightly higher.</div> </font></div><div><br></div><div><div><font size="4"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">By the way, Einstein says acceleration and gravity are the same thing, so when a car accelerates it pushes you into your seat but when you put on the brakes you're pulled toward the windshield, however if Einstein was right then a helium balloon in a car should move in the opposite direction that you do because it is less dense than the air in the car but you are not. This video tests to see if that is really true:</div></font></div><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline"><br></div></div><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline"><a href="https://www.youtube.com/watch?v=y8mzDvpKzfY">https://www.youtube.com/watch?v=y8mzDvpKzfY</a><br></div></div></div><div><br></div><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><font size="4">John K Clark</font></div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><div style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)">If this is correct, I am beginning to get it, eh?</div><div style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)"><br></div><div style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)">bill w</div></div><div class="gmail_extra"><br><div class="gmail_quote"><div><div class="gmail-h5">On Fri, Oct 13, 2017 at 11:40 AM, Mike Dougherty <span dir="ltr"><<a href="mailto:msd001@gmail.com" target="_blank">msd001@gmail.com</a>></span> wrote:<br></div></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div><div class="gmail-h5"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><span>On Fri, Oct 13, 2017 at 12:07 PM, Dylan Distasio <span dir="ltr"><<a href="mailto:interzone@gmail.com" target="_blank">interzone@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr">I hope I'm not insulting by linking to an explanation, but I think it would help if you think about water displacement and how a less dense object floats in water. It is the same exact principle when you have a less dense object (the helium balloon) compared to the air:<div><br></div><div><a href="http://science.howstuffworks.com/helium1.htm" target="_blank">http://science.howstuffworks.c<wbr>om/helium1.htm</a><br></div></div><div class="gmail-m_6056196652481685395m_2214061799709644354HOEnZb"><div class="gmail-m_6056196652481685395m_2214061799709644354h5"><div class="gmail_extra"><div class="gmail_quote"><br></div></div></div></div></blockquote><div><br></div></span><div>Have we figured out how to fill a balloon with near-enough to nothing at all to make a lighter than helium balloon?</div><div><br></div><div>I know the structural requirement for a large volume of empty space is considerable in Earth atmosphere. I've been curious about the use of aerogels with enough crush-resistance to make lighter-than air craft literally filled with nothing - which would be cheaper and much safer than the only [non-]thing with more lifting power than helium (see: Hindenberg). I mean sure, worse case scenario your balloon fills with environmental air and crashes to the ground wouldn't exactly be a good time but at least you wouldn't also be exploding and burning on the way to the impact.</div><div><br></div><div>I was also wondering if you could tether enough of these together to encircle the globe, if you could hoist objects from this floating platform and literally throw them into space. Imagine a trebuchet floating on a ship launching rocks lifted from the ocean floor, but the ship is floating on the atmosphere and the rocks are aerodynamic sling bullets heading to space.</div><div><br></div><div>Well, enough thought experiment for now, I have to do actual work.</div></div></div></div>
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