Welcome to Cosmology and its Fundamental Observations

This video combines chapters 1 and 2 of the videos in my new series of Cosmology.
(This is an updated version correcting a couple mistakes.)
I'm going through Dr. Barbara Ryden's textbook "Introduction to Cosmology". If you follow along, you'll get a full upper-division undergraduate course in Cosmology. I used this textbook at William Paterson University. This course will cover the current state of the science of Cosmology. To follow along, it'll be a good idea for you to ge to know your calculus. Here are the topics of this video:
Introductory Cosmology:
Chapter 01: What is Cosmology?
Chapter 02: Fundamental Observations
-- 01: What is Olbers' paradox?
-- 02: The Universe is Isotropic and Homogeneous
-- 03: Redshift is Proportional to Distance
-- 04: Different Types of Particles
-- 05: Cosmic Microwave Background
What is Cosmology?
Units of Distance, Units of Mass, Units of Time, Units of Energy and Power, The Very Small, Fundamental Constants of Nature, Planck Units, Geometrized Units, and The Briefest History of Cosmology
Some things covered from Fundamental Observations:
Where did it come from? How is Copernicus involved with this? Is the Universe infinite in extent?
Is the Universe infinitely old? Why is Edgar Allan Poe so grumpy? What are homogeneity and isotropy? How can we measure them? How does the Cosmic Microwave Background apply to this? What does the Hubble Deep Field Survey add? What does this mean for the laws of physics? Why are we alone in the local universe? Nearly all Galaxies Show a Redshift. Does cosmic redshift happen by chance? Does the redshift violate the cosmological principle? How can we quantify the expansion of spacetime? What are the Hubble Time and Distance? How does measuring the rate of expansion give us the age of the universe? What is the Steady State Model? Why does the Big Bang win over the Steady State? What's beyond the cosmic horizon? Elementary Particle Physics. Quarks, Leptons, Bosons and Hadrons. Introductory quantum chromodynamics. Baryonic and non-baryonic matter
Photons and the blackbody distribution. Neutrino flavors and their mysterious masses. Dark matter. The Nature of Photons. Blackbody Radiation. An overlooked origin story to the CMB, starring: Ralph Alpher, Robert Hermann, George Gamove, Arno Penzias, Robert Wilson, and Robert Dicke. COBE, WMAP, and Planck CMB Missions. The origin of the CMB from Quark-Anti-Quark soup to the epochs of Recombination and Decoupling.
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[@learntolearnl2l]

its crazy that this is free on youtube. thank you so much.

[@scottdorfler2551]

I recommend this channel all over KZbin to anyone who'll listen.

[@zeropol]

Thanks Jason, thanks Barbara, thanks physical sciences. May our hearts be as insatiable as our curiosity.

[@JasonKendallAstronomer]

Absolutely!

[@ace0q688]

why do i wake up at this videos end every time lmao

[@AakashSambharwal-f1d]

Man this is gooooooooooooooooooood

[@Jaggerbush]

Thanks for sharing this with us!

[@DrDeuteron]

Neutron mass is not bigger because it’s made from a proton, electron and antineutrino, neutron is more massive because the down quark is more massive than the up quark. Why the quark masses differ is whole thing (chiral symmetry breaking), which may or may not affect cosmology (idk), but I wouldn’t be surprise if it’s part of baryogenesis.

[@petervisor]

Thanks!

[@JasonKendallAstronomer]

Thanks for your support!

[@scottdorfler2551]

5:30 You mention parallax and one AU. Isn't parallax measured six months apart from the opposite side of the sun? Wouldn't that be two AU? I'm a little confused. Well I'm a lot confused, but that's besides the point.

[@JasonKendallAstronomer]

Yeah. It would be. But the definition of parallax uses the right angle with the Sun at the vertex. This means it’s half the total annual shift.

[@scottdorfler2551]

@JasonKendallAstronomer Thank you!

[@scottdorfler2551]

Sorry, follow up question. Is the reason parallax is done at a right angle/one AU, because not all objects are going to be visible six months later? Especially the objects farther to the south, in the northern hemisphere. The opposite in the southern hemisphere. For instance, parallax of Polaris could be done six months apart at two AU, but the night sky changes more throughout the year the farther south you observe. So to make it uniform all parallax is done at 3 months?

[@JasonKendallAstronomer]

It’s actually much simpler. Right angle triangles make the math easier. There’s LOTS of astronomy thingies like this out there. Someone does a thing. It gets published. Everyone follows. It doesn’t make sense when viewed from a broader perspective. But we have it now. This frequently happens in any science where you start with a huge need to organize things into coherent groupings. The groupings make sense on some level but don’t fit in a bigger sense that might need to merge the groups with some broader concept.

[@scottdorfler2551]

@@JasonKendallAstronomer One more annoying question. Does Gaia take measurements of stars every six months?

[@malinkifox2011]

Your cosmic distance debate video needs an update with James Webb stuff. Your video became a bit outdated

[@JasonKendallAstronomer]

Yes, I know. I have a lot of updating to do….

[@AakashSambharwal-f1d]

?

[@HardcoreHokage]

So are you a cosmologist or an Astrophysicist?