Is there any smart material that gets lighter/heavier?

[WakaShocka]

Hi PF,

This could possibly be through a change in size or density...Maybe even programmable matter. I've tried some googling but haven't found anything on actually changing the weight through putting a current through something. It would be extremely useful for my personal hobby. Even through a change in temperature, not necessarily a current would maybe be acceptable. It doesn't have to be anything too big, just a few millimeters/centimeters in size, but some sort of material or substance that can change its weight (preferably without expanding too much, but that would still be interesting to) when a current runs through it or the temp changes..
If you guys have heard of anything like this, let me know!
Thanks :)

 

[berkeman]

Hi PF,

This could possibly be through a change in size or density...Maybe even programmable matter. I've tried some googling but haven't found anything on actually changing the weight through putting a current through something. It would be extremely useful for my personal hobby. Even through a change in temperature, not necessarily a current would maybe be acceptable. It doesn't have to be anything too big, just a few millimeters/centimeters in size, but some sort of material or substance that can change its weight (preferably without expanding too much, but that would still be interesting to) when a current runs through it or the temp changes..
If you guys have heard of anything like this, let me know!
Thanks :)

You could use a solenoid to increase or decrease the volume of an enclosure, or you could use memory metal to do a similar thing. What is the application?

https://en.wikipedia.org/wiki/Shape-memory_alloy

 

[jbriggs444]

Hi PF,

This could possibly be through a change in size or density...Maybe even programmable matter. I've tried some googling but haven't found anything on actually changing the weight through putting a current through something. It would be extremely useful for my personal hobby. Even through a change in temperature, not necessarily a current would maybe be acceptable. It doesn't have to be anything too big, just a few millimeters/centimeters in size, but some sort of material or substance that can change its weight (preferably without expanding too much, but that would still be interesting to) when a current runs through it or the temp changes..
If you guys have heard of anything like this, let me know!
Thanks :)

Hot air balloons.

 

[WakaShocka]

What is the application?

I'm looking to have some sort of material that I can make lighter/heavier on demand to create a weight imbalance in my device (it isn't very large-no more than a few centimeters).

 

[billy_joule]

Many materials change density with current (eg a lightbulb filament) but changing weight would break the law of conservation of mass.
https://en.m.wikipedia.org/wiki/Conservation_of_mass
What you want can't be done.

If you explain exactly what you are trying to do (with diagrams perhaps) and why, we may have more realistic solutions.

 

[berkeman]

I'm looking to have some sort of material that I can make lighter/heavier on demand to create a weight imbalance in my device (it isn't very large-no more than a few centimeters).

Kind of like one of these sipping bird toys?

https://s3.amazonaws.com/cdn.teachersource.com/images/products/pop/db100.jpg

Or are you working on an Over-Unity Energy Generation Mechanism?

 

[Mrdoupi]

Many materials change density with current (eg a lightbulb filament) but changing weight would break the law of conservation of mass.
https://en.m.wikipedia.org/wiki/Conservation_of_mass
What you want can't be done.

If you explain exactly what you are trying to do (with diagrams perhaps) and why, we may have more realistic solutions.

but what about a mechanism that translates energy to mass?? wouldn't that work somehow?

 

[sophiecentaur]

but what about a mechanism that translates energy to mass?? wouldn't that work somehow?

E=mc² is a well known formula. You would need a heck of a lot of energy to change the mass by 1gram. (10¹⁴ joules)

Unfortunately, without some more context, this thread can go nowhere.

 

[Mrdoupi]

E=mc² is a well known formula. You would need a heck of a lot of energy to change the mass by 1gram. (10¹⁴ joules)

Unfortunately, without some more context, this thread can go nowhere.

lets smash the sun then

 

[jbriggs444]

lets smash the sun then

If the objective is to generate energy, then there are unavoidable costs involved with shipping the energy up from the sun. Or exploited for a net gain when that energy is moved about within the Earth's gravitational well.

If you can blow up the sun, powering a dipping bird may not be high on your list of tasks remaining to be accomplished.

You may be better served creating a small black hole and harvesting energy as you drop breadcrumbs in. Be careful how big you make it. If you start at 1,000 metric tons, Hawking evaporation will take only 46 seconds. This is like 2 million Hiroshima sized bombs going off per second for 46 seconds.

https://www.vttoth.com/CMS/physics-notes/311-hawking-radiation-calculator

You are going to need to drop breadcrumbs in at [very roughly] 20 metric tons per second just to break even and keep the debacle from getting worse.

Things get a bit easier if you start at 1,000,000 metric tons. Then you have about 1400 years to add another 1,000,000 metric tons and keep things stable.

 

[berkeman]

lets smash the sun then

Welcome to PF, @Mrdoupi

Please try to avoid resurrecting years-old threads with whimsical thoughts. This old thread is now tied off with the helpful reply by @jbriggs444