Dark Matter and Dark Energy: The Frontier of Astronomy

For a while now, we've been discussing all of things we know about the universe. What about some of the things we don't know? If we look to the current frontier of astronomy, we find two mystifying concepts, dark matter and dark energy. What are these things? How do we know they exist? Do we have any guesses as to what they are? Find out here!

Check out "Is This Wi-Fi Organic?", my book on disarming pseudoscience!

[tom]

Considering that before I started watching you I thought stars in the night sky were just all planets and literally didn't know what a "star" was, to now having a general understanding of our universe and what it's made of, hats off to you Dave. You're an amazing teacher.
There's always more to learn!

[thephantomeagle]

I love how you threw in Douglas Adams early on. Easily one of my all time favorite book series.

[thegoodlydragon]

Thanks for clarifying. I had thought previously that it was called dark because it wasn’t yet understood. I think it’s interesting that it’s dark in the literal sense that it doesn’t emit light.

[macparnami]

Discovered your channel after your debate with, as you quote " A greasy Pig". Love your videos on Science courses . your channel is actual Gem . Thank you

[gautamchettiar]

You can create an institute where youre the physics, chemistry, maths, biology, Italian, English, astrophysics, astronomy and quantam physics teacher.

[mixtressreve]

I know this video is two years old, but the fact that we have such an in-depth understanding of the universe and what lies within it is so amazing to me. I'm amazed I haven't watched your videos sooner, and frankly, I can't wait to see where science goes next. Forces and energy in particular are so interesting to me, because I've always thought of them as some arbitrary system, but they are really linked with the physical.
Thanks, Professor Dave.

[dudley]

I see the flat earth community is starting to infect all your videos now.

I guess views are views.

You are a good teacher. Concise, organized presentations.

[Sunilaralikatti]

Incredible content. Underrated channel

[constpegasus]

Again, thanks for the great explanations that tie these different subjects in each video.

[Emcee_Squared]

Excellent video Prof. Dave! Keep up the great work!

[MohammedAbdullah-mxvg]

Great video, do you think you may be able to make a video on some of the concepts in m-theory

[PolarisNC]

"Visible matter makes up only 5% of our universe, which is dominated by dark, unexplained forces.

Congrats on being one of the sparkly bits"

--Dr. Katie Mack

[qwertyqwerty-jyfc]

Also thank you for clarifying the circle graph saying mass energy equivalence, I have always had problems understanding how energy can be on the same graph as matter

[pankajharijan]

He literally deserves 10 million subs!!

[adamzaidi]

I immediately subscribed because of the brilliant intro.

[XraynPR]

Hello Dave, this paper seems to suggest that there is no Dark Energy (as in a particle of sorts), but rather, that it is an effect of time dilation:
"Supernovae evidence for foundational change to cosmological models"
Antonia Seifert, Zachary G. Lane, Marco Galoppo, Ryan Ridden-Harper, David L. Wiltshire

Interesting stuff!

[spacedrifter]

how this is have only 440 likes?! Prof. Dave, you have VERY interesting channel, your vid about star formation was very informative, and I like when you summarized a section before a lot! Cheers! (my english is bad :P)

[kaynekayne]

Hello proffesor Dave, I have a question.
In nuclear fusion, 4 protons come together to form a helium nucleus, a neutrino and a positron and gamma rays. So how does the sun produce visible light? Are there electrons somewhere I am not aware of?

[fernweh]

At 1.57 you say "if something is not capable of producing photons in this manner, or relate nuclear processes, it can't produce visible light". As far as I know, all electromagnetic radiations (visible or not visible to our eyes) consist of photons emitted by the same process you have described for visible light, that is: electrons moving from excited states to lower states.

[Kilbu]

Super interesting video! thank you for sharing <3