Watchly Safety Review

SCIENCE CLASS #2- Does Farting Make You Weigh Less?

Mark Rober

30:44 · 3.2M views · March 25, 2020

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Minor FlagsReviewed June 2026

3Minor Flags

3No Issues

Mark Rober, a former NASA engineer turned educator, uses humor and hands-on experiments to teach physics concepts about density and buoyancy—yes, through the lens of whether farting makes you weigh less. While the topic might make parents raise an eyebrow, the video is genuinely educational, using the silly question as a hook to explain real science principles with demonstrations involving boats, balloons, and floating objects.

Content Breakdown · 6 Categories

Strong & Crude LanguageA little

The video contains bathroom humor centered around the topic of farting, which is the main subject. While not profane, it involves crude bodily function references throughout.

See evidence (4)

“Does farting make you weigh less”Throughout - main topic

“farts are less dense than air”Mid-video - scientific explanation

“farting makes you heavier”End - conclusion

“eat a lot of beans to temporarily have that gas in you”

Parasocial & Emotional ManipulationA little

Mild parasocial language detected with friendly, inclusive phrasing typical of educational YouTube content. Not manipulative in nature, but creates connection with audience.

See evidence (3)

“hey welcome back to science class with me mark rober”Beginning - greeting

“hello beckham i love you”Mid-video - nephew reference

“I love giving this gift to you guys”End - closing remarks

Beauty, Body & Lifestyle PressureNot present

Very minor reference to weight and scale reading, but presented in a purely scientific context without body-shaming or pressure. The weight discussion is about physics principles, not appearance.

See evidence (1)

“that's scary to see that number literally i'm like wait that's not right okay i weigh more”Mid-video - scale demonstration

Geopolitical Commentary & AdvocacyNot present

Very brief, non-partisan reference to coronavirus as context for why he's teaching online rather than in a classroom. Not advocacy or political commentary.

See evidence (2)

“life pro tip if you want to do something don't do it for the first time in front of 1.4 million people but uh coronavirus here we are”Beginning - context setting

“this is me punching coronavirus in the face”End - motivational segment

Engagement Baiting & Manipulative CTAsA little

Mild engagement requests typical of educational YouTube content. Includes asking viewers to comment answers and participate in challenges. Not manipulative or guilt-based.

See evidence (3)

“put in the comments tell the person you're next to”Throughout - interactive questions

“I want you to make a guess in the comment below”End - challenge assignment

“send it to me on either twitter or instagram or facebook and i'll pick my favorite one”

Playful & Fantasy ViolenceNot present

Very minor playful reference to the Titanic movie sinking scene, recreated with toys in a humorous, educational context. No actual violence.

See evidence (1)

“this is jack... here's rose jack why are you wearing a skirt it's not a skirt it's a kilt... oh the titanic never let go there it goes”Mid-video - Titanic demonstration

What Parents Need to Know

This video uses bathroom humor (specifically farting) as the central question to teach physics, which may not appeal to all families but is handled in a scientific, non-crude way. Mark Rober is a legitimate educator with NASA credentials who's working toward teaching certification. The content is genuinely educational—covering density, buoyancy, pressure gradients, and forces—with clear explanations suitable for middle schoolers and up. There's one brief moment where he jokes about his nephew in sand (shown in a clip), but it's presented as playful family content. The video encourages hands-on learning and includes a challenge for kids to try density experiments at home. Parents should know the farting angle is used purely as an attention-grabbing device to teach legitimate science concepts.

Talk to Your Kids About

1Ask your child to explain density in their own words—can they think of other examples of things that float or sink and why?
2Discuss why scientists sometimes use funny or unexpected questions to teach serious concepts. Does humor help them remember the lesson better?
3Try the 'Will It Float?' challenge together at home using household items. Can your child predict which objects will float based on what they learned?
4Talk about Mark Rober's message about the 'Super Mario Effect' and not being afraid to fail when learning something new. How does this apply to challenges they face?

SCIENCE CLASS #2- Does Farting Make You Weigh Less?

Protected Viewing

What's This Video About?

This is a juicy one. 70% people get this one wrong. I stream science LIVE M-W-F 1pm PT. NEW PDF WITH A QUIZ FORM THAT WORKS NOW!!! https://www.dropbox.com/s/5giflfs8y9new5x/SCIENCE%20CLASS-%202.pdf?dl=0

Frequently Asked Questions

Is this video actually educational or just bathroom humor?

This is genuinely educational content from a former NASA engineer. While the central question involves farting, it's used as an engaging hook to teach legitimate physics concepts including density, buoyancy, pressure gradients, and forces. The science explanations are thorough and age-appropriate for middle school students.

Why does the video focus on farting to teach science?

Mark Rober uses an unexpected, kid-friendly question to capture attention and make physics memorable. The farting angle is handled scientifically (explaining that farts contain methane, which is less dense than air), not crudely. It's a teaching strategy to make abstract concepts stick by connecting them to something surprising and relatable.

What will my child actually learn from this video?

Kids will learn core physics principles: how density determines whether objects float or sink, what buoyancy force is, how pressure gradients work, why boats float despite being made of metal, and how helium balloons work. The video includes multiple demonstrations and encourages hands-on experimentation at home with a 'Will It Float?' challenge.

Is Mark Rober a credible science educator?

Yes, Mark Rober is a mechanical engineer who worked at NASA for nine years and is currently pursuing teaching credentials. He has over 20 million YouTube subscribers and creates educational content that makes complex science accessible. His teaching style emphasizes understanding principles over memorizing facts.

Are there any inappropriate elements parents should know about?

The video is remarkably clean given the topic. The word 'fart' is used frequently but in a scientific context. There's one brief clip showing his nephew in a sand experiment (presented as playful family content) and a joke about making a Lego figure 'modest' with a duct tape kilt. No crude language, inappropriate visuals, or content that would concern most parents.

Can younger kids watch this or is it only for older students?

While the core physics concepts are best suited for ages 8-12, younger children could enjoy the demonstrations and experiments even if they don't grasp all the science. The visual nature of the floating/sinking experiments and the humor make it accessible, though the detailed explanations of forces and density are more appropriate for upper elementary and middle school students.

What age is "SCIENCE CLASS #2- Does Farting Make You Weigh Less?" appropriate for?

Watchly's safety review recommends "SCIENCE CLASS #2- Does Farting Make You Weigh Less?" for ages 8 and up. See the content breakdown above for the category-by-category findings behind this recommendation.