Dark matter. Or what?

In this video I explain just what physicists mean when they speak about "dark matter" and what reasons we have to think that dark matter exists. In my two follow-up videos, I speak about the alternative explanation, modified gravity, and explain why the right solution might well be a combination of both ideas.

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[DingbatToast]

There's something strangely refreshing about listening to a presentation unencumbered by fanatical hyperbole and sensationalism
Excellent video!

[RagdollRocket]

Finally I found a serious scientist on youtube. Thank's Sabine!

[lindsayforbes]

You're good at this, well done. Graphics support the script. That's what is needed. Not a production. You are building a reputation in this medium for telling it as it is, no bullshit.

[polemeros]

The fact that English is not her first language makes her presentations even more impressive. Clearly an extremely bright and capable woman.

[wanderkunstler]

Thank you Sabine, your videos are my favorite ones about physics. I have a physics degree but could not continue to a doctoral research. I read as much as I can about theoretical physics, and I am also surprised about how much damage is being done by "popular videos, books " etc. to serious physics thinking. Thank you for maintaining the rigor here on YouTube (as much as possible.)

[benevolentintelligence]

Sabine: "now of course we don't have dark matter in bags"
(looks off camera, in visible annoyance at not having dark matter in bags)

[AndaPet]

I just love that physicists take time to produce these videos to help us all understand what is going on. Thank you Sabine Hossenfelder et all!

[darioinfini]

I love your voice -- there's a cutting clarity and precision in it that communicates difficult concepts effectively. There are a number of Youtubers blessed with wonderful voices. You're one of them :)

[tikke]

Excellent video; very clear and balanced presentation, no hype, just pure facts what we know at the moment. Definitely the best science video in Youtube what I have come across. I really hope you have time and energy to do these more. Thank you

[sgatea]

Excellent video ! No hype, no super-sensational, just facts and a clear presentation of where we stand with this cosmological "mystery". Thank you !

[bfwebster]

Possibly the single best discussion of the topic I've run across. Looking forward to 'the next time'.

[mkst]

9:30 "now here is where it gets interesting". It was pretty damn interesting up to that point.

[jong-heepark]

What a clear and highly distinctive presentation on the Dark Matter. Thanks you very much Professor Sabin Hossenfelder.

[LearningWithSuj]

You're doing amazing work!- Not only as a physicist but as a science communicator.

[merlinby]

This is the clearest explanation of DM 's properties I have ever heard.

[archisgore]

I love your videos. Been watching physics videos for years, and you are so precise, to the point, and efficient. You're also so very intuitive.

[jonb]

Good to see an intelligent scientist being honest instead of pretending she knows things that she doesn't!

[mydogbrian]

- Damn it! I pride my self in being knowledgable & on the cutting edge of astro physics & then she comes around & always floors me. I dont like intellectual boxing with her. She makes me feel like a grade school student.
- But I get up & lick my wounds & wait for her next presentation. "Keep up the good work!"
- A devoted fan

[buckrogers]

Godammit woman, I just love your presentation style and sensibility ("It just doesn't make any sense!") Indeed, science has much gooblygook and you are like the cleaning fluid that clears the way!

[erickbush]

Great video. Balanced and unbiased (or at least that how it appears) like science is supposed to be. Just pros and cons of competing ideas.