B Would it be possible to make something float?

[doglover9754]

While waiting in the doctor’s office, I looked at a balloon sticker on the wall. That made me think (once again). Would it be possible to make something float without using your basic flotation stuff (helium and propellers mostly)? I was thinking in more of a futuristic themed way. Like magnets, would it be possible to make something float by reversing that “force” (I’m honestly not sure what the reaction is between 2 magnets so I’ll just call it a force for now)? I’ve seen magnets float because you put 2 positives together (I haven’t done that experiment in a while so please forgive me if I’m wrong) and then one floats on top the other. Would that be possible for gravity (here I go again with gravity... heh heh. Sorry for all of you who hate my questions)? I was just curious that’s all. I pretty much need a yes or no kind of answer just to clear up my question (no need for a scientific explanation because I just finished school and my brain is fried). If anyone could help me, that would be awesome as usual! Thank you to all of you who put up with this kind of stuff (I’m sure it’s tiring to read all these kinds of stuff everyday)! Also, I’m not sure what prefix this would fall under so please bear with me if I’m wrong.

 

[anorlunda]

Are you asking about floating on water or floating on air?

We already have trains that "float" themselves above the rails using magnetism. We call it maglev. https://en.wikipedia.org/wiki/Maglev It is pretty cool.

But floating on water. What do you think is the difference between something that floats and something that sinks?

 

[Khashishi]

If you just put a magnet over another magnet, it could float momentarily, but it won't be stable. You can stabilize it using active feedback or superconductors or a simple physical rod.
See https://en.wikipedia.org/wiki/Magnetic_levitation

 

[doglover9754]

What do you think is the difference between something that floats and something that sinks?

The density of the object?

 

[doglover9754]

I was just thinking of making floating cars. Dumb idea huh? This is the kind of stuff that I get quite often... ideas that don’t seem realistic sometimes.

 

[Mark44]

I was thinking in more of a futuristic themed way. Like magnets, would it be possible to make something float by reversing that “force” (I’m honestly not sure what the reaction is between 2 magnets so I’ll just call it a force for now)?

Look up "maglev" (short for magnetic levitation). There are trains running in S. Korea, China, and Japan that use this technology.

 

[phinds]

The density of the object?

glass floats on mercury. glass sinks in water. glass density = glass density. Want to try again?

 

[doglover9754]

glass floats on mercury. glass sinks in water. glass density = glass density. Want to try again?

Glass floats on mercury?! I never knew that!

 

[doglover9754]

glass floats on mercury. glass sinks in water. glass density = glass density. Want to try again?

Um... one floats and one sinks? That’s all I’ve got for now...

 

[lekh2003]

Glass floats on mercury?! I never knew that!

You can read up on buoyancy, it isn't very difficult. Objects with lower densities float in higher density liquids. The glass on Mercury observation occurs because Mercury has a higher density than glass.

 

[DrDu]

http://www.ru.nl/hfml/research/levitation/diamagnetic/

 

[doglover9754]

Look up "maglev" (short for magnetic levitation). There are trains running in S. Korea, China, and Japan that use this technology.

I sure will! But I was leaning more towards flotation without magnets. The rails of the trains are magnetic an the bottom of the train is also magnetic right? I heard that somewhere... would it be possible to reverse gravity? Kinda like how you reverse magnets (positive and negative sides). I mean, reversing gravity would mean that things would just float right? Would there be a solution to making a limit to how high it can float above the ground? That’s the kind of stuff I was looking for but I think I have a better idea of how this “reaction” works. Thanks!

 

[doglover9754]

You can read up on buoyancy, it isn't very difficult. Objects with lower densities float in higher density liquids. The glass on Mercury observation occurs because Mercury has a higher density than glass.

Ahhh. So it was density!

 

[doglover9754]

The density of the object?

@lekh2003 I said that above lol

 

[lekh2003]

@lekh2003 I said that above lol

 

[davenn]

I heard that somewhere... would it be possible to reverse gravity?

currently, only in science fiction

 

[sophiecentaur]

Going back to that balloon: You can support a low density object with Electrostatic forces. We have all (?) done the trick involving rubbing a balloon on our hair or jumper and found that it sticks to the ceiling. Electric forces are immensely strong at small distances (they keep solids from coming apart under stress). Unfortunately (you could say) these forces fall off very fast with distance so actually getting something to 'float' at a significant distance from a surface is hard to achieve. A high voltage generator (several tens of kV DC) would achieve this but you would need some feedback arrangement to control the Volts or the object would stick to or fall off from the surface. This is also true for magnetic levitation in most cases (except where you can use a superconductor over a magnet).

 

[anorlunda]

I heard that somewhere... would it be possible to reverse gravity?

It is time to learn some of the rules here @doglover9754. Your not allowed to say "I heard somewhere". On PF, you must give a link to where you read it, so that we can see exactly what it says.

 

[fresh_42]

It seems the thread has run its course with several good answers and advice. Before it will turn into a chat room, I'll close it now.