physics

Sun based internet

I was just reading about LiFi and I was wondering why not just create window attachments that produce the same effect?  Then you can use the sunlight instead and the window can modulate the light to achieve the same effect as the LiFi.  Then both the lifi bulbs and the windows could work together to achieve optimal coverage.

So, this method only makes sunlight a medium for information to be encoded onto.  Therefore, device to device communication still requires an LED.  The main interest for using sunlight is to allow for regular internet access.

On a grander scale could we modulate earth’s atmosphere to essentially just be a bigger window so that we give internet to everyone on earth through sunlight?  That sounds like an XKCD comic haha :).

EMF in pipes and Mixing in Space

I was thinking that it would be cool experiment to try to see how much current would be produced by flushing magnetic particles through a system of pipes that were wrapped with wire and connected to batteries.  Wonder how powerful the magnets would need to be and how the fact that they are traveling in water effects the field.  Would be interesting to compare to tap water to see how much an emf field is present already.

Just not sure if it would work because:

  1. the magnets would all clump together maybe not due to attraction and repulsion maybe end of
  2. field not strong enough to induce a noticeable current

 

[update] Well I I talked with someone that knows a bit more and he reminded me that even though it might be possible the magnet would be slowing down the water and therefore not doing any good.  He suggested that a mechanical method would be better rather than using magnets as well.

Was wondering how do you mix liquid things in zero gravity?  I would imagine it is either really hard or not possible.  Maybe we could use something like http://phys.org/news175873414.html.  I guess we could just shake them together…

Well as to be expected they have done some experiments and they tried mixing oil in water by shaking them together.  The cool thing is that they stayed together for 10 hours!  On earth they would separate in 10 seconds.  They also tried mixing water and water that had tea in it by pouring them into the same container.  However, since no gravity they barely mixed at all.  However, they did not shake the two.  However, I’m assuming that they would mix and would not separate.  (source: http://history.nasa.gov/SP-401/ch12.htm)