Sciencemadness Discussion Board

Mass Youtube Video

Finnnicus - 8-5-2013 at 22:44

http://youtu.be/Ztc6QPNUqls

I suggest watching this video! Although I'm pretty rotten at physics something about this video doesn't agree with me. Is it just me?

PS: Why is there no 'other sciences' section on this site? It is called sciencemadness, ya know?

MrHomeScientist - 9-5-2013 at 07:09

Neat video! Sounds reasonable to me. Mass is, in essence, a highly concentrated form of energy. What doesn't agree with you specifically?

Finnnicus - 9-5-2013 at 08:14

Now thinking about it, the idea of the energy (quarks) just sitting on the field, that's what. Probably many other things as a result of my ignorance.

MrHomeScientist - 9-5-2013 at 13:39

Well it takes energy to disturb the field, and "clean up the vacuum" or whatever phrase they used. The energy would be stored as the absence of fluctuations in the flux tubes. Sort of like potential energy - think of a sealed box of air at the bottom of a lake (weighted, of course, so it stays there). The water would rather fill the void, so as long as the box is sealed there's a lot of stored potential energy in the water waiting to rush in. Open the box, and the energy is released as it is converted into kinetic energy of the inflowing water.

maxpayne - 12-5-2013 at 01:49

Ok. Sounds great on Earth, but what will happen in so called zero gravity with the box and the potential energy of the water?

MrHomeScientist - 14-5-2013 at 13:02

In a zero- or micro-gravity situation, there can be no buoyant force. So if you had a container of water with a box of air inside it aboard, say, the International Space Station, opening the box wouldn't have much of an effect. The air bubble wouldn't rise because there isn't a preferred direction for it to go! In reality, it would probably move around from the turbulence caused by lifting the box's lid, but it would have no buoyancy and wouldn't be driven in any particular direction. Depending on how much water you have, the pressure might compress the air bubble until equillibrium is reached.

The water-and-box analogy is, of course, simplistic and limited, so trying to extend it to other situations might not be all that useful.

EDIT: After writing the above, I remembered I had actually seen this done on the ISS! Here's a great video showing this situation actually happening on the space station: http://www.youtube.com/watch?v=xFLo07H2p8U

At one point, they manage to get an air bubble inside a water bubble inside an air bubble inside a water bubble! Bubbleception!

[Edited on 5-14-2013 by MrHomeScientist]

elementcollector1 - 14-5-2013 at 13:29

Quote: Originally posted by MrHomeScientist  
At one point, they manage to get an air bubble inside a water bubble inside an air bubble inside a water bubble! Bubbleception!

[Edited on 5-14-2013 by MrHomeScientist]


Verily, a mad science breakthrough.

maxpayne - 15-5-2013 at 12:32

Quote: Originally posted by MrHomeScientist  
In a zero- or micro-gravity situation, there can be no buoyant force. So if you had a container of water with a box of air inside it aboard, say, the International Space Station, opening the box wouldn't have much of an effect. The air bubble wouldn't rise because there isn't a preferred direction for it to go! In reality, it would probably move around from the turbulence caused by lifting the box's lid, but it would have no buoyancy and wouldn't be driven in any particular direction. Depending on how much water you have, the pressure might compress the air bubble until equillibrium is reached.

The water-and-box analogy is, of course, simplistic and limited, so trying to extend it to other situations might not be all that useful.

EDIT: After writing the above, I remembered I had actually seen this done on the ISS! Here's a great video showing this situation actually happening on the space station: http://www.youtube.com/watch?v=xFLo07H2p8U

At one point, they manage to get an air bubble inside a water bubble inside an air bubble inside a water bubble! Bubbleception!

[Edited on 5-14-2013 by MrHomeScientist]


Thank you for your answer! Nice explanation, I like the word preferred direction (winning gravity field).

But could you say something more about E=mc^2; They clearly said that mass is energy and vice versa, but AFAIK energy can not be something, only something can HAVE energy, which is very different. Explaining mass by exchanging E for m is a belief for me, not fact. I do not know any other mathematical formula which could be used to disprove my "ignorance" to this mass explanation. Do you know any?

MrHomeScientist - 15-5-2013 at 13:36

A correction on my previous comment:
Quote: Originally posted by MrHomeScientist  
Depending on how much water you have, the pressure might compress the air bubble until equillibrium is reached.


There also would be no water pressure in zero gravity! Pressure is caused by the weight of the fluid around and above you, and of course with no gravity there is no weight. I think the only thing governing the size of the air bubble inside the water is the force of water's surface tension.

======================

maxpayne:

E = mc^2 is precisely the formula you need. Look up mass-energy equivalence for some in-depth discussion (for example, the wiki page: http://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence )
That page sums it up as "mass is a property of all energy; energy is a property of all mass; and the two properties are connected by a constant." The last part of the Practical Examples section gives some really neat examples where adding energy to a system (in the form of heat, motion, etc.) actually increases its mass.
There's also a subtle distinction between "mass" and "matter" - mass is a conserved quantity and cannot be created or destroyed (like energy), but matter can be (as in nuclear reactions or particle-antiparticle annihilation). In a closed system, no matter what happens to the matter (particles being created or destroyed, etc.) the total energy of the system always remains constant (and because of Einstein's equation, so too does mass).

Hope that didn't just confuse you more!

gregxy - 16-5-2013 at 11:20

A helium filled balloon in a car it moves in the opposite direction
to everything else. When the car accelerates the balloon moves
forward and when the car breaks the balloon moves backwards.
The balloon behaves like it has negative mass since it has less
mass than the surrounding air.

The balloon provides a nice analogy for holes in semiconductors.