The science behind why your remote car key has a longer range when held to your head/body (or to a jar of water) [📹 museumofscience]

thanks, but i will use my ass instead of my head i’ve heard of a bunch of people getting brain cancer but never heard of anyone with buttcheek cancer also my ass contains more water

I just use my phone app. I can unlock my car from another country if I want

Another answer could be that your head is acting as a “ground plane”. Antennas (such as the one inside your car key) often work better when they have a reference from which to work - in this case, the conductive bag of impure water which is a human. It could also be that the frequency of your key’s remote is resonating within some structure of your head, or within the cavity of the skull, resulting in an improved signal. For example, at 433MHz (a common frequency for this sort of thing), a quarter-wave is about 17cm, which isn’t all that far from the size of an adult skull.

The increased range of your remote car key when held to your head or body is due to the effect of the human body on electromagnetic radio waves. Here's a deeper explanation: • Remote key fobs use low-power radio transmitters to send signals that lock/unlock the car. But the signal can only travel so far before petering out. • The metal/fluids in the human body interact with and reshape the electromagnetic field emitted by the fob. • Specifically, it causes the radio waves to propagate in more of a sphere shape outward from the fob rather than as weaker plane waves. • This means more of the electromagnetic signal is concentrated and focused outward, enabling it to travel much farther before fading away. • It's why holding it higher by your head boosts the effective range. Your body acts like an impromptu signal amplifier! • Even a water bottle or other container interacts similarly - the polar molecules resonate with and boost signal strength. So in essence, the complex conductive properties of the human body alter and boost the radio waves in just the right way. Your body's innate electromagnetic interactions lend your keys a helping hand to reach further! Pretty fascinating that we can accidentally improve key fob antennas just by how our very makeup meshes with radio physics.

If I put my water bottle to my head I can hear my car gradually becoming sentient

B.S. alarm 🚨 Much more likely that it is just the height above the ground making a difference.

Six months later...

Where are the fact checkers at?

Saw this on Top Gear about 15 years ago.

That's bizarre! Never knew my head could boost my car key range.