[HN Gopher] Part two of Grant Sanderson's video with Terry Tao o...
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Part two of Grant Sanderson's video with Terry Tao on the cosmic
distance ladder
Author : ColinWright
Score : 102 points
Date : 2025-02-23 18:51 UTC (2 days ago)
(HTM) web link (mathstodon.xyz)
(TXT) w3m dump (mathstodon.xyz)
| j7ake wrote:
| The corrections in his blog post show you the level of precision
| mathematicians are used to.
|
| A regular interviewer would have left the inaccuracies as they
| are because it's too tedious to go over all of them when you have
| a casual conversation.
| maxnoe wrote:
| https://terrytao.wordpress.com/2025/02/13/cosmic-distance-la...
| pavon wrote:
| Note this blog post also has links to both parts of the
| video. (Our corporate firewall annoyingly blocks a bunch of
| new gTLDs, including xyz).
| hakaneskici wrote:
| As a side question, what's the rationale for this? Is there
| a list of nsfw gTLDs?
| pxeger1 wrote:
| .xyz (alongside some others like .top, .biz?) in
| particular have a reputation for phishing/malware/etc., I
| think because they're among the cheapest to register.
| ziddoap wrote:
| The funny thing is, the number 1 & 2
| spam/phishing/malware domains that hit my company's mail
| server is gmail.com and outlook.com, followed by random
| .com domains.
|
| My domain block list is approaching 1,000 domains and I
| don't think I have a single .xyz or .biz in there.
| There's a few .top. But the overwhelming majority is
| .com.
| Gunax wrote:
| This was very entertaining. I had a rough idea of the timeline
| before, but had never thought about it in this way (that is, a
| ladder).
| dang wrote:
| Related. Others?
|
| _Climbing the cosmic distance ladder: Terence Tao book
| announcement_ - https://news.ycombinator.com/item?id=24743177 -
| Oct 2020 (13 comments)
|
| _Terrence Tao: The Cosmic Distance Ladder_ -
| https://news.ycombinator.com/item?id=1782398 - Oct 2010 (6
| comments)
| jessriedel wrote:
| Note that the modern cosmic distance ladder has multiple
| partially independent paths using different techniques, making it
| more like a DAG. The wikipedia page has a nice diagram.
|
| https://en.wikipedia.org/wiki/Cosmic_distance_ladder
| zokier wrote:
| tbh I would love to see full length video walking through the
| work that Kepler did with actual numbers, to me that part
| remained bit unclear. Especially how to get some quantitative
| values out of the analysis, considering how the eccentricity of
| the orbits is not really something easily visually discernible.
|
| > In principle, using the measurements to all the planets at once
| could allow for some multidimensional analysis that would be more
| accurate than analyzing each of the planets separately
|
| (from the blog post)
|
| I'd also love to see this idea expanded further. Intuitively it
| feels like adding Venus into the calculations should dramatically
| help constrain the orbit of Mars, but how exactly that would work
| out I'm not sure.
| asattarmd wrote:
| There are videos by Welch labs that go into detail about what
| he did:
|
| https://www.youtube.com/watch?v=Phscjl0u6TI
| https://www.youtube.com/watch?v=MprJN5teQxc
| csours wrote:
| They don't go into detail, but Cepheid stars are amazing
|
| https://en.wikipedia.org/wiki/Cepheid_variable
|
| Consensus mechanism for pulsation:
|
| https://en.wikipedia.org/wiki/Kappa%E2%80%93mechanism
|
| Basically the changes in ionization state, opacity, and
| temperature all influence each other, causing a cycle.
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