Do dust particles rising from the ground to a statically charged balloon prove that gravity isn't real, as was implied in an interview shared on YouTube? No, that's not true: The concept described in the video is that of static electricity or static cling. This phenomenon occurs when differently charged objects attract others based on their number of neutrons, electrons and protons, all of which can be influenced by outside forces -- such as rubbing a balloon on a leg -- a physicist told Lead Stories. This idea does not prove that gravity isn't real, a professor of physics also confirmed to Lead Stories.
In an interview with podcast host Joe Rogan posted to YouTube on May 18, 2024, actor Terrence Howard implied that gravity isn't real. At the 1:35:02 mark, he stated:
Take a balloon. Another thing that kills gravity. Gravity is supposed to be, the greater the mass, the greater the attractor. You take a balloon, you rub it on your leg, you put it over the ground, watch the dust particles jump off the ground, off this big mass called the Earth, and jump onto that balloon, because why? Electricity is 137 times stronger than the pull of gravity, or the effects of the so-called gravity.
Here is how the post appeared at the time of writing:
The statement about static electricity and gravity is just confused. Let's grant that everything the actor says about electricity is true. (It isn't, but say it was.) It would still be completely irrelevant. Any force can counteract another. When you fly in a plane, for example, the lift force generated by the wings in the atmosphere can cancel or overcome gravity. But that says nothing about gravity as a force.
Electric and magnetic forces are produced by electric charges, and they act on electric charges. Gravity is produced by and acts on masses. Charge and mass are completely independent physical quantities.
Any everyday force of gravity you will encounter is determined by masses and the distances between masses. That's all. Gravity isn't influenced by other forces.
Dust particles jumping off the ground only demonstrates that gravity is not the only force acting on those particles.
The fact that a balloon, after being rubbed on a suitable material (such as wool or human hair), attracts dust particles has to do with static electricity, Benjamin Knispel (archived here), a physicist with the Max Planck Institute for Gravitational Physics, told Lead Stories in an email received on May 27, 2024. He explained the phenomenon below:
Rubbing a balloon on such materials creates a static electric charge on the surface of the balloon. The rubbing transfers electrons from the wool/hair to the surface of the balloon. Because the balloon is an electrical insulator, the electrons cannot flow away and will stay on the surface of the balloon.
Now, that the surface of the balloon is electrically charged, it creates an inhomogeneous electric field around it. This field electrically polarizes the dust particles, which are dielectric. This means that the balloon's electric field will move free electric charges in the dust grains such that the dust grain is positively charged at the end closer to the balloon and more negatively charged at the end further away from the balloon. The overall charge of the dust grains stays neutral, but since they are now positively charged at on end, this end will be attracted by the negatively charged balloon. The electrically polarized dust grains will move towards higher electric field strength, towards the surface of the balloon.
None of this implies that gravity does not exist or is not a force, in the same way that proving the existence of a cat does not disprove the existence of a dog.
Both gravity and electromagnetism can exist and exert forces at the same time, Knispel wrote. On short distances, electromagnetic forces may well be much stronger than gravity.
The most important difference between electromagnetism and gravity is that electromagnetic forces can be shielded (because there are two types of charges: negative and positive). Gravity has only one charge (mass) and, therefore, cannot be shielded. That's why every place on Earth feels the moon's gravity (tides), he wrote.
The Griffin Museum of Science and Industry outlines the concept of static cling in this children's experiment (archived here), which exemplifies how materials develop static charges. According to the museum:
This happens due to the transfer of electrons from one object to another. Everything has a tendency to either want to hold on to its electrons or give them away. This tendency is why we have static electricity. When two objects - such as your hair and the balloon - rub together, one loses some of its electrons to the other. This makes one object positively charged and the other object negatively charged. The opposites then are attracted to each other.
In Howard's example, the balloon becomes charged when rubbed on the leg. When the charged balloon is put near a neutral object, like dust, the electrons in the object repel away from the balloon and the protons attract it.
"This movement of the electrons causes the neutral object to get a low positive charge," writes the museum. "The negatively charged balloon is then attracted and will 'stick' to the object."
Lead Stories has debunked other science-related claims, which can be read here.
