Cepheid Variable Stars - IB Physics

[@jonnygrossman]

When so many use the internet for disinformation or misinformation, it's so cathartic to see a person who reminds us that it has incredibly noble utility. I'm 68 yo and have been looking for clarity on this subject for decades. I picked a winning lottery ticket with your video. Thank you so much!

[@AndyMasley]

Aw thanks so much! So happy this was helpful!

[@Johnny-sj9sj]

@@AndyMasley I second that! An excellent presentation about a fascinating subject.

[@jitttttt]

Am I stupid or what? I have been searching and watched countless of videos about Cepheid Variables but still don't have a clue what Cepheid Variable are... until I watch your video. I am dumbfounded by your excellent presentation and explanations. Now I am totally understood what Cepheid Variables are. Thank you so much!

[@joserobertopacheco298]

I tried several times to understand this method without sucess until I found this video. EXCELLENT! So I subscribed the channel.

[@in2minutesorless64]

This was EXCELLENT! The best explanation I've heard so far - great job! I subscribed.

[@AndyMasley]

Thanks so much!

[@lewislee9201]

It's not every day you get an aha-moment, but your explanation of Cepheid variables did it for me. I was going to watch a last video to get to sleep, but now I'm wide awake. Your students are lucky!

[@blakeb9964]

Wow this explains it so easily. Also, Levitt was a genius for figuring this out.

[@carolineboyden7580]

This was so good! It turned a land of obscure confusion into something genuinely really interesting. The comparison between the 100ly, 50,000 ly, and 20 million ly actually blew my mind.

[@AndyMasley]

Aw so nice to get this feedback, thank you!

[@danialabdi9843]

Wow I can't believe that some people don't even know that this Turning point happened in our history, I guess there's lot more that I don't know so I guess I have to subscribe Tanks for the video

[@Astronomynatureandmusic]

Lots of thanks for making our personal universe a bit larger by showing this important turning point in history, explaining it, and allowing us to make our own calculations. Wow!

[@anthonysacco2276]

This is by far the best explanation on Cepheid variable I have come across. Thank you. Keep it up.

[@wafaamin6395]

such a nice explanation and head off for lady astronomer she did a good job indeed

[@StonesonExperience]

+1 for best explanation and another subscriber for you

[@jimtkerker]

I find your pace and clarity to be excellent and exemplary! Your usage of diagrams and equations is similarly well paced and precise! Thanks and God Bless you and yours.

[@AndyMasley]

So happy it's been helpful!!

[@raiyan9638]

You explained it so nicely and with so much detail. Keep up the great work

[@SKY-lf5sy]

tysm!! this video was super helpful and I can't imagine how long it took to film these. I appreciate your work immensely :)) keep going !

[@ammar9279]

Wow! this is extremely helpful and clear. Thanks!

[@davida.t375]

man you are a life saver

[@lilgeniusgaming9243]

Super Helpful!!!

[@sasa2safi]

Brilliant!

[@IrfanAhmed-tm9di]

Very Good My Salute

[@shahidiqbal-og9pu]

Outstanding

[@PhysioAl1]

Very well done! Thanks very much for your help with this:)

[@MeneerHarks]

I had a question. at 12:56 you mentioned that de brightness witnessed on earth is b = 4,57*10^-17 w/m2. Because of the change in the brightness of the star, is this the maximum intensity we measured? Also the luminosity that is measured because of the period/days, is that there max luminosity? *great video by the way, its probably me that i don't know but i couldn't find it.

[@-wheel38]

Our doctor preferred your medicine for Astrophysics

[@24granaathome75]

Are all these variable stars roughly the same mass? That is; are there Sol sized up to Betelgeuse sized Cepheid variable stars?

[@maitriborthakur7360]

Sir,what about the spectroscopic parallax or main sequence fitting which can be used to measure distance using the relations of brightness and luminosity upto 10^5 light years ?

[@mandarparipurna7948]

The closest known cepheid is is polaris which is around 500 light years aways, how come we have cepehids stars under 100 light years?

[@HankSwankerton]

-Wait then how have we been measuring the distance of stars? -Weren't actual hypothesis of star make up verified with calculations including refraction of light. ---Am I wrong here? -Wait how does this even work because stars different in brightness. How can you tell if these stars are breaking the rules? -How come we can't see years in the future from our earth view point, to a set star if we are using a telescope that not on earth? But light years closer to star x? Wouldn't we see a whole new topography hundreds f years past what we see on earth?

[@MajSolo]

Efficient lecture. These techniques makes the ground under the feet of the astronomers more stable. But I think they should be careful using the word "exact".