Humanoid robots are causing a sensation online, even Elon Musk is laughing so hard he's crying.

The main character is Unitree G1 , a humanoid robot from China, and the person who shared the story is none other than Elon Musk. With just a "laughing with tears" emoji, the tech billionaire made the story spread from the lab straight to global social media.

A moment of training out of sync.

The video was recorded during a Unittree G1 movement test, a crucial part of the robot's learning to interact with humans. According to the circulating content, the robot followed the trainer's instructions, but during one movement, it accidentally kicked the person in the groin.

But the situation didn't end there. When the coach bent over in pain, the robot mimicked him, creating a scene that was both unbelievable and hilarious. This is the detail that prompted Elon Musk to share the video with a humorous attitude.

When Elon Musk shared something, the community immediately reacted strongly.

The video was originally posted by Wes Morrill, Tesla's Cybertruck project lead engineer, on December 27th. Prior to that, the image had appeared on the Chinese platform Bilibili on December 25th. When Elon Musk reposted it on X, the story immediately transcended the technical realm, becoming a topic of discussion among both the tech community and the online world.

Many people laughed, but there were also many opinions raising more serious questions: humanoid robots are getting closer to humans than ever before, so where are the safe boundaries?

Testing humanoid robots: the more human-like they are, the harder they are to find.

Wes Morrill doesn't shy away from the issue. He frankly acknowledges that testing humanoid robots is a real challenge. Previously, robots were often "isolated" behind walls, fences, or restricted areas for safety reasons. This method is simple but effective.

However, as robots are designed to live, work, and interact directly with humans, those barriers gradually become irrelevant. To make robots "human-like," humans must accept risks during the testing phase.

Unitree speaks out: the fault is not in the hardware.

Immediately after the video gained attention, Unitree Robotics issued a response. According to the company, the "battle" exercise in the video is not a standard program, but rather something the buyer developed themselves. Unitree only provides the basic hardware and platform.

The account that posted the video on Bilibili also explained that the incident occurred due to technical delays during training. When the robot responds more slowly than a human, the movements can be out of sync. This delay is said to be able to gradually reduce as the algorithm improves, potentially down to around 0.1 seconds.

This isn't the first time Elon Musk has taken notice of the Unitree G1.

Not long before that, on December 20th, Elon Musk shared a video of six Unittree G1 robots performing at singer Wang Leehom's concert in Chengdu. The robots' dance moves and acrobatics prompted Musk to leave a short comment: "Impressive."

Observers note that Musk's public praise of Unitree is quite rare. The G1 is considered a formidable competitor to Optimus – the humanoid robot developed by Tesla. Musk's attention partly shows that he cannot ignore the rapid progress of Chinese robots.

Unitree G1: Compact but not "just right"

Launched in May 2024, the Unittree G1 is approximately 1.3 meters tall, weighs 35 kg, and boasts between 23 and 43 articulated motors. This allows the robot to move flexibly, maintain good balance, and perform a variety of complex movements.

Recently, G1 has consistently appeared in videos showcasing martial arts, acrobatics, sports, and natural street walking. These images have helped transform the concept of humanoid robots from a distant dream into a familiar part of modern life.

A small kick, a big question for the future.

The incident in the video may simply be a technical glitch, but it raises a significant question: as robots become increasingly human-like, how complex will ensuring safety become? Amidst the laughter on social media, this serves as a reminder that artificial intelligence and humanoid robots not only need to be powerful, but also need to be able to "understand" humans.