Hot Air Balloon(Heat)
"To keep the balloon rising, you need a way to reheat the air."
https://science.howstuffworks.com/transport/flight/modern/hot-air-balloon.htm
Negative Mass Blimp(Gas / Steam)
"a transformer generates high temperature in the matter in between the spheres and a force is applied on the inner face of the outer sphere by the inner hallow sphere and the system looses its weight depending on the temperature."
"the system now looses it's weight depending on the pressure and temperature of the matter in between the hallow spheres and the system is called the "anti gravity system"."
https://patents.google.com/patent/WO2001009509A2/en
Sound (Negative Mass)
"Attached to the keyboard were many tuned resonation plates and
vibratory mechanisms. Mr. Keely said that when the plates were
polarized with “negative attraction” the airship would rise and
float above the ground."
https://www.unexplainable.net/info-theories/history-of-the-mystery-airship-sightings-in-the-late-1800s.php
Rotational Mass & Angular Momentum
"After the power supply is switched on, the mercury rotates anticlockwise at high speed under the action of electromagnetic force"
https://patents.google.com/patent/CN110857151A/en
"Water vapor steam (100 oC) 477.5
Water vapour steam 6 MPa (350 oC) 571"
https://www.engineeringtoolbox.com/speed-sound-gases-d_1160.html