What is Dark Matter? A Mystery of the Universe

You've probably heard the term Dark Matter, but what is it, and how do we know it exists?

[wildfire]

Please continue to make more videos! I am an elementary school teacher (still looking for a classroom) but would love to use these videos to teach my future science class. It's these kind of video's that really catch childrens interest. 

[LamirLakantry]

What if there's a dark matter planet out there, with dark matter aliens, wondering what the missing extra 5% of the mass is. :P

[hotguysandhistory]

You are so cool and your videos are so interesting! Thanks for being a role model for women in physics. As a 15yo girl who wants to do a physics degree, your channel is so inspiring and it's great to see another girl/woman who is successful in physics, yet seems so down to earth, friendly and cool!! Keep it up :D

[BryanSeigneur]

I'm in the it's-all-cold-baryonic-stuff camp (and misunderestimated singularity masses). And 'cosmological models say that can't be the case' is the best response I've heard to my assertion. Kudos to Physics Girl for being the absolute first person I ever heard it from! Even after a lot of wikipediaing.

I'd like more explanation of that response. I respect the cosmological models because of the cosmo expansion explanation video she did. Once again, it told me more than I knew and in a super easy way! Go PG, go PG!

[EconomyofTruthHub]

"You see, galaxies are like mean girls and are often found in clusters."  Hahahahahahaha....pure gold.

[DougKutner]

I should be falling asleep but your energy, intelligence, and enthusiasm have sitting bolt upright

[francescamarshall]

Thank you so much for making this video. I knew that there was something called dark matter but I didn't quite know what it was but you have explained it and now I know what it is and I'm really happy!! :D

[brinasuligoj]

Awesome channel! Physics explained in a really simple way! And you're fun to watch! Subscribed!

[timothyperkins]

I like your style of presentation :) Read some very theoretical article in Sci Am about a year back re hypothetical more complex dark matter chemistry with photon analogues - odd terminology I thought! Subscribed, people like you help me understand things better as a layperson. And I think that's more important than ever now. Thanks;

[realitycheck]

I really think your videos are great.but I did kinda felt a bit too simplified in here and there. but you have a way of explaining complex things in pretty simple terms. gotta say, that's soo awesome. and I came here from PBS. he was right, great channel, love to see more.

[tchevrier]

maybe there's a false assumption being made.
Eistein essentially theorized that gravity was simply warped space-time caused by a matter. We assume that matter is the only thing that can warp space-time. So when we're looking for the source of all this missing gravity, we naturally look for missing matter. Maybe its not matter we should be looking for.
Can energy warp space-time? Since matter is essentially energy interacting with its surroundings (possibly the higgs field), it wouldn't be a stretch to think that energy could warp space-time as well.
Then again, maybe space-time is just naturally warped.

[leahg]

Checked out this channel at Vihart's recommendation and I'm here to stay!  I love how you don't just tell us everything and instead ask questions.

[worththekeeping]

Thank you for making physics videos! I hope you continue to make them.

[BeingHumane]

Your Physics Videos are really interesting, informative, thought provoking and awesome...Really loved them...Happy physicing !!!

[szakacsfulop]

physics girl you're the best. I think you're fantastic.

[jdgrahamo]

When you think about it, we don't even know what matter is or what energy is. We interact with (I hesitate to say 'see') certain events; but we haven't a clue what's really going on. Matter is mostly empty space, and the bits that aren't are so small that we have no idea what they are, how they do what they do (or oven what it is that they do) or how they came to exist. 

[sandipbaidya]

why couldn't I have stumbled upon your channel few years ago? I really love the way you talk about things, things become intriguing! and so much more fun.

[crackpapa_]

Darkmatter is phenomenal cosmical power that genies are able to use so Aladdin can show Jasmin his *"WOOORLD!*"

[AaronBrooks]

Great explanation and nice work — Thanks!

[joshuabailey]

First Physics Girl video I've ever seen, Thanks to PBS SpaceTime for the reference. VERY entertaining and informative, and Sans formal education, this type of broad speculation and education is a little more my speed.