Thursday Throughput for July 4, 2019
[ThT1] My daughter just got the second HPV injection. I’m very glad she got it. Because new research is showing that the results of mass HPV vaccination are stunning. A meta-study of 66 million young people is showing dramatic reductions in HPV infection rates. The effect is so stark, even unvaccinated men and older women are showing the effects because they are less likely to come in contact with infected partners. It’s too soon to see how well this translates into cancer prevention. But there’s every reason to believe that we will see a similar reduction. You can now add HPV and (most likely) cervical cancer to the list of diseases we’re putting on the ropes.
[ThTh2] The headline is a bit brusque: why didn’t plants at Chernobyl die from cancer? But the article is a really interesting look at the difference between plant and animal biology and how they deal with things on a cellular level.
[ThTh3] For a long time, we thought humans inherited their mitochondria — the little things that power our cells — only from our mothers. Indeed, mitochondria have their own DNA and tracing mitochondrial DNA has been a big thing. But our assumptions may not be entirely correct. We can get some mitochondria from our fathers.
[ThTh4] Lots of cool images coming out from this week’s eclipse in South America. Here is my current favorite. And remember, we will have another eclipse in North America in 2024. See you all in Texas!
Fantastic! This is yesterday's solar eclipse as seen from lunar orbit by a small camera on a tiny 45 kg satellite. pic.twitter.com/pdDOmAH72a
— Andrew Jones (@AJ_FI) July 3, 2019
[ThTh5] Who’s up for a Oumuamua update? I’m always up for an update. Last time, I expressed skepticism at the idea that it was a rogue alien solar sail. Now, some papers are coming out that are a bit more rigorous in their skepticism.
[ThTh6] This has happened to me. More than once. In her defense, I think she was probably just nervous. So I post it more for amusement than mocking.
i’m watching the promos for the australian bachelor and…no words pic.twitter.com/YjSimUS1lF
— gi4 (@giaonfilm) June 28, 2019
[ThTh7] I mentioned intra-uterine surgery for spina bifida last time. Here’s how one of the recipients is doing.
[ThTh8] It’s hypnotic. Isn’t it?
The perfection of the Harmonic motion traced by the sand pendulum pic.twitter.com/hU1oNsWfiX
— Physics & Astronomy Zone (@ZonePhysics) June 29, 2019
Interesting as always, but your link for ThTh5 is borken, just the word Oumuamua.Report
Thanks. Fixed the link.Report
He said “astrophysicist”, so she named a constellation.Report
ThTh3: Has anyone been convicted due to evidence that involves mitochondria?Report
Yes, mtDNA is used in cold cases, due to the greater ease in obtaining viable amounts of genetic material from degraded tissue.
I’d consider it incredibly unlikely that anyone has been convicted due to a false match as a result of the tiny amount of paternal mtDNA in a sample though. This information would be much more likely to produce a false negative rather than a false positive match and even a false negative is quite unlikely given what the article discusses. It does throw cold water on the excessively confident 1 in a bajillion confidence forensic specialists give, because that was always premised on an unfounded belief that there was no errors in process or understanding in testing.Report
Cool, thank you.
I don’t know if I should be wondering how many people were falsely convicted or wondering if this will lead to any Hail Mary appeals.Report
ThTh5 – Sometimes a cigar-shaped object is just a cigar-shaped object.Report
Cigars are smooth and cylindrical. That thing is shaped like a hand-rolled joint.Report
We should rename it to CheechChong.Report
ThTh5: The article was short but I’m not seeing the rigor, just more hand-waving. I’m not saying it is an alien spacecraft, just that a natural explanation hasn’t been sufficiently demonstrated to conclusively rule it out.Report
ThTh8: Fancy-pants spyrograph.Report
There does seem to be some energy coupling between the X axis motion and the Y axis motion, which is pretty interesting.Report
Are you perhaps thinking of Foucalt?Report
Not exactly. What I notice is, in the linear version of the 3d harmonic oscillator, each of the two horizontal axes are independent. They each oscillate at a set frequency, and that is that. Even if you use the non-linear model (where you don’t abstract out [Sin x] as just [x]), you should still see the equations decouple.
However, in the experiment above, it appears that energy is being transferred back and forth between the X and Y axis (treating the Z axis as vertical). Specifically, about halfway through the video, you can see that the X amplitude goes down as the Y amplitude goes up, and then they reverse (although both are decreasing due to friction). That’s kind of cool.
I assume it’s something happening in the string, or perhaps the pulley mechanism.
I expect this has nothing to do with the Foucalt thing, which has 24 hour cycles.Report
If I recall undergraduate physics correctly, pendulums following a non-degenerate elliptical path do weird things. If the pendulum deviates from the ideal model, things get even weirder.
The time for a Foucault pendulum to precess through 360° depends on latitude. At the North or South Pole, it’s 24 hours; at the equator, it’s infinite. Where I live, about 37 hours.Report
Could be the attachment point, or it could be the sand not flowing evenly and thus shifting the COG ever so slightly.Report
I would expect there are oscillations being transferred at the attachment point, but actually, it’s everything, which influences everything else.
In math terms, the “nice” equations are something like:
x” = -A sin x – f (x’^2 + y’^2)
y” = -A sin y – f (x’^2 + y’^2)
So there is some interaction between x’ and y’, via the friction coefficient (f) — but that’s always negative. It will monotonically decrease the time-average amplitude.
What we observe is
x” = -A sin x – f (x’^2 + y’^2) + g(x,x’,y,y’)
y” = -A sin y – f (x’^2 + y’^2) + h(x,x’,y,y’)
Where the g and h functions are (in a sense) moving energy between x’ and y’. It’s really cool.Report