Watchly Safety Review

Testing If You Can Blow Your Own Sail

Mark Rober

17:07 · 63.2M views · March 2, 2024

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Minor FlagsReviewed June 2026

2Minor Flags

1No Issues

This science and engineering video is highly safe and genuinely educational for kids, making complex physics concepts like Newton's laws, the Coriolis effect, and ellipse geometry accessible through fun real-world demonstrations. The only notable caveat is two sponsored segments promoting a subscription toy box called Crunch Labs, which are woven naturally into the content but are still commercial pitches aimed at children and parents.

Content Breakdown · 3 Categories

Hidden Advertising & Sponsored ContentA little

The CrunchLabs sponsorship is transparently disclosed and clearly presented as the creator's own company, not hidden advertising. The promotion is openly acknowledged as a commercial offering with explicit terms mentioned in the description.

See evidence (2)

“The host openly states 'أسست كرانش لابز' (I founded CrunchLabs) and promotes it as his own company”

“Description explicitly links to crunchlabs.com/teaser with promotional terms”

Parasocial & Emotional ManipulationA little

The video contains mild enthusiasm-building language typical of educational content ('لحظات الإدراك' / moments of insight), but there is no guilt-tripping, manufactured drama, or emotional dependency language directed at viewers.

See evidence (1)

“Mild enthusiasm framing: 'إن كنتم مثلي وتحبون لحظة الإدراك عند تعلّم شيء جديد' (If you're like me and love the moment of insight when learning something new)”

Playful & Fantasy ViolenceNot present

The only marginal reference is a playful mention of throwing a watermelon ('دفعت البطيخ إلى اليسار' / pushing the watermelon to the left) as a physics analogy, which is entirely consequence-free and illustrative rather than violent.

See evidence (1)

“Watermelon used as a physics prop analogy for Newton's third law on a skateboard”

What Parents Need to Know

This video is a well-produced, curiosity-driven science explainer that takes viewers on a journey through seven physics and engineering puzzles, including why balloons move backward when you brake, how elliptical rooms carry whispers, and whether a tourist show at the equator is a scam. Kids will genuinely learn about Newton's laws, the Coriolis effect, geometry, and critical thinking — and the host models healthy scientific skepticism by testing claims rather than just accepting them. There are two sponsored segments for Crunch Labs, a STEM subscription box, which are enthusiastically presented and may prompt kids to ask parents to subscribe. The content is entirely free of violence, language, or inappropriate themes, making it suitable for a wide age range, though younger children may need help following some of the mathematical explanations.

Talk to Your Kids About

1The video showed that blowing into your own sail can't move a boat forward — can you explain in your own words why that is, using what you know about forces?
2The host tested a tourist show at the equator and found it was a trick. Why is it important to test things yourself instead of just believing what someone tells you?
3We learned that air actually has weight and mass. Can you think of other everyday situations where invisible things like air are doing something important that we don't usually notice?
4The video had two advertisements for a toy subscription box. How could you tell they were ads, and do you think the host made the product sound more exciting than it might really be?

Protected Viewing

What's This Video About?

You now know 7 amazing new things and that’s cooler than magic! Get the CrunchLabs Build Box! Two FREE boxes at https://crunchlabs.com/teaser I started a company called CrunchLabs, where we build a toy together, and then I teach you all the juicy physics of how it works. So if you want to learn to think like an engineer and have a really fun time doing it, check out the current promotion where you get 2 FREE boxes at https://crunchlabs.com/teaser Thanks to these folks for providing some of the music in the video: Ponder - @Pondermusic Laura Shigihara - @supershigi Andrew Applepie - https://soundcloud.com/andrewapplepie Blue Wednesday - https://soundcloud.com/bluewednesday NO PURCHASE NECESSARY. Promotion starts on 1/1/2024 & ends on 12/31/24, subject to monthly entry deadlines. Open to legal residents of the 50 U.S. & D.C., 18+. 1 prize per month: each month is its own separate promotion. For the first 2-3 months, winner may be notified via phone call instead of winning game piece. If a monthly prize is unclaimed/forfeited, it will be awarded via 2nd chance drawing. See Official Rules at crunchlabs.com/sweepstakes for full details on eligibility requirements, how to enter, free method of entry, prize claim procedure, prize description and limitations. Void where prohibited. NO PURCHASE NECESSARY. Promotion starts on 1/1/2024 & ends on 12/31/24, subject to monthly entry deadlines. Open to legal residents of the 50 U.S. & D.C., 18+. 1 prize per month: each month is its own separate promotion. For the first 2-3 months, winner may be notified via phone call instead of winning game piece. If a monthly prize is unclaimed/forfeited, it will be awarded via 2nd chance drawing. See Official Rules at crunchlabs.com/sweepstakes for full details on eligibility requirements, how to enter, free method of entry, prize claim procedure, prize description and limitations. Void where prohibited.

Frequently Asked Questions

What age is this video appropriate for?

This video is recommended for children aged 8 and up. The concepts are explained clearly with visual demonstrations, but some ideas — like the Coriolis effect and algebraic reasoning — are easier to follow for kids with a basic science or math background.

Is there any inappropriate content in this video?

No, the video contains no violence, bad language, sexual content, or scary material. It is a clean, family-friendly science explainer suitable for most children.

Does the video contain advertising?

Yes, there are two sponsored segments promoting Crunch Labs, a monthly STEM subscription box for kids. These segments are enthusiastic and product-focused, so parents should be aware their child may ask to sign up after watching.

Is the science in this video accurate?

Yes, the physics and engineering concepts presented are accurate and well-explained. The host also actively debunks myths — such as the equator tourist trick and the toilet-flushing direction legend — which models good scientific thinking.

Is this video educational?

Absolutely. The video covers Newton's first and second laws, the Coriolis effect, ellipse geometry, buoyancy, and inertia through hands-on demonstrations. It is genuinely enriching and encourages curiosity and critical thinking in young viewers.

Could anything in this video frighten or upset young children?

No, there is nothing frightening or upsetting in this video. Very young children under 6 may simply find the explanations hard to follow, but there is no content that would cause distress.