#5minphysics 

Lawrence I have to thank you. When ever I feel down, depressed, motionless or demotivated, there pops up a video of your 5minphysics which always makes me fascinated by nature.

From Kepler to dark matter in 10 minutes, all in clear and easy to understand steps. Love this series of videos.

Awesome!

This has channel become one of my absolute favorites... thank you

Connecting dots... always a pleasure! I see a great resemble in the way you present science and in the way Feynman did. I'm not sure if it is related to the Jewish ancestry but I find it really clear and easy to follow. Thanks!

Thank You Prof. Krauss.

Yup, that is my homework for tonight.

It's mind blowing to me that we can infer all this information about the furthest reaches of our universe without leaving our backwater corner of our galaxy. Imagine what we could/will discover if we manage to avoid killing ourselves long enough to actually go to other stars!

It would be great to hear your thoughts on the double slit experiments.

This is fascinating. You're a great teacher.

My new favorite channel! Found it by searching up your name on YT. Thank you so much for everything you do.

Thank You So Much!! to all Physicists to start these series

These videos are released about the same time I wake up great to watch while having my morning coffee

I love this series so much Ty

Thank you so much, it's a real pleasure.

Professor Krauss it always perplexed me the fact that you can know the luminosity of cepheid variables making a relationship between luminosity and pulsation period. I would love to see the maths in a real calculation to determine a distance of any given cepheid. I think is this was the coolest thing ever discovered and as a biochemist I have no idea the physics and maths side of it... I love this channel and your lectures. Take care :)

Loving these lectures

Professor just a clarification in the beginning of the video you said Kepler and I am sure you meant Tycho Brache about the Island and the Danish observatory. Thanks a lot for this series we follow and admire your work.

Lawrence ,I am from India.In this depressed environment your pathbreaking program is soul satisfying one.Wheather Carona or not keep continuing .

Really good! Clear, and easy to follow

🙏 Great. Hope u r safe and healthy.

Very good explanation of the problem. I have seen simulations of what density the dark matter needs to be to produce the measured velocity distribution of the stars around the center of the galaxy. Since this material is proposed to interact basically only via gravity, what keeps it in its current distribution? If it is not revolving, it should collapse. There are significant amounts required to be well above and below the plane of the disk of the galaxy and if they are revolving as well, they should run into the material in the disk. Second, dark matter is supposed to be around us but we don't see it in the motions of the planets. Third, since we are inside the disk of stars that composes a significant fraction of the mass of the galaxy, the stars outside of our orbit are pulling on us. At the center of the galaxy, are the gravitational forces on a star nearly cancelled by the mass all around it that is almost equally distributed?

These 5 minute lecture series are great. Much better than the ridiculous circus of religious debates in your older videos. By the way did your dad teach science at Far Rockaway H.S. in the 1960's and 70's ?

First thanks again, love the 5min talks. Does the density of dark matter change within the overall orb of our galaxy or within the filaments of dark matter between galaxies within a cluster?

A minor errata: Tyco was given the island not Kepler... ;-)) However, can somebody explain a confusion in my mind. We have modeled the weight of a galaxy using Earth speed and distance - so far so good..... But, Vera Rubin discovers the constant speed (?) rather than decreasing -- of what / where - further away from Earth only? Where the original model works and where it doesn't? A bit confusing to me for years -- something is not more explicitly explained perhaps...

It was Tycho brahi sir ,who was given this island .Hven' by Danish king .

Prof Krauss, not many people know how the particle colliders work. I believe in the early versions of colliders they used a very smooth tank with pure water heated to extremely hot temperature. When the subatomic particle are broken away from the atom they make the water impure and therefore the water boils leaving a trail of boiling water behind and that is what they see in the images. So I came up wiht a very simple experiment which people can do at home. When I make pasta I boil the water and as it starts to get hot I can see tiny bubble emerging from the bottom. Before the water boils too much I take a strand of spaghetti and draw a line at the base of the pan. The residue it leave on the base makes the water boil in its track, which is basically the same principle as colliders use. It would be nice if you could demo that for everyone if you agree with me.

Just amazing stuff. So dark matter interacts with matter, as the dark matter is "captured" in the rotational gravitational field of our Universe?

Thanks for the great video. Got a question. How do we know that the equations don't need correction? I mean when the scale goes bigger (from the solar system to a galaxy), then maybe some corrections in the equation may give us an answer rather than looking for dark matter. Can you please explain?

So how do we know, that all that mass that we attribute to dark matter, is not inside a big black hole in the center of the galaxy?

Science! It does the hard stuff that magic pretends to do.

Asking for a young student with excellent marks. Which university anywhere in the world for undergraduate degree with interest in cosmology and astrophysics ?

Oh wait, Lemme get my weighing scales and I'll be back .....

a=v2/r ? Fake

The answer to the question of what is dark matter is obvious, everything points to it. I get mad when I see astronomers telling that they don't know what it is and worse when I hear spooky theories when the answer is straight in front of them. Sometimes I have impression that in physics rules the authority of famous people and not the common sense.