1

COVID-19 / Why are daily new cases so periodic?

« on: 30/06/2020 04:28:35 »

Screen Shot 2020-06-29 at 11.10.30 PM.png (89.32 kB . 1226x622 - viewed 754 times)

This data (screen grabbed from the New York Times just now) clearly shows a periodic (possibly sinusoidal) variation in new cases reported each day. The period appears to be is exactly 7 days (1 week). With maxima coming on consecutive Fridays (with the occasional Thursday).

I see a few possible explanations:
1) This is an artifact caused by weekly patterns in data reporting (file the report by the end of the week.)
2) This is an artifact caused by when it is easiest for most people to get the tests.
3) This is real and represents a weekly pattern in when people get sick (maybe folks go out Saturday night, get infected then, and then feel bad enough to get tested 6 or maybe 5 days later.
4) This is real and represents ripple effects of more people get infected when there are more infectious people around, and because of the induction period there are actually bulges that propagate at a period of about 1 week.
5) something else?

Looking at the deaths graph offers more insight:

Screen Shot 2020-06-29 at 11.15.34 PM.png (113.1 kB . 1264x678 - viewed 752 times)
1) is challenged by the fact that the reported deaths, although also following a weekly periodic undulation, peak on Wednesdays. (presumably there would be similar reporting biases)
2) is also not supported by the deaths graph (people don't tend to only die when it is convenient)
3) could be supported, if the length of time from showing symptoms to death is fairly consistent (and not supported if it varies widely)
4) see above
5) ??

2

General Science / Who can find a more poorly behaved function?

« on: 26/06/2020 19:01:16 »

f(x) = lim    x^a     or just f(x) = x^∞
         a→∞

for –1 < x < 1, f(x) = 0
for x = 1, f(x) = 1
for 1 < x, f(x) = ∞ (unbounded, strictly positive)
for x = –1 f(x) = no f*n clue! (it's neither positive nor negative)
for x < –1 f(x) = no f*n clue! (it's completely divergent, neither positive nor negative)
I'm not sure if x

I'm sure ya'll can come up with some other poorly behaved functions

PS: I remember sin(1/x) is also a baddie when trying to get close to 0, but I think the above is worse.

3

Physics, Astronomy & Cosmology / Is Wolfram's new hypergraph approach to a TOE valid?

« on: 17/04/2020 21:10:12 »

https://writings.stephenwolfram.com/2020/04/finally-we-may-have-a-path-to-the-fundamental-theory-of-physics-and-its-beautiful/

If you don't care about the personal aspect, scroll down to "How it works" in. the link above.

I have only worked my way through about half of this, but I am quite intrigued...


0409img5.png (410.3 kB . 1236x868 - viewed 2146 times)

4

COVID-19 / How badly do hospitals dealing with COVID19 need O2?

« on: 15/03/2020 19:30:01 »

I recently read an article that said that oxygen generators are in short supply in some places.
( http://www.cidrap.umn.edu/news-perspective/2020/03/global-covid-19-cases-pass-100000-mark )

Is this going to be a worry in most places as they become inundated with patients, or is it really just some particularly isolated locations?

How bad does it have to get for a hospital in the US to accept non-medically rated oxygen generators (provided the oxygen produced can be proven to be of sufficient purity/safety)?

My lab studies electrochemical oxygen generation. I know it's not as energy efficient as pressure swing oxygen concentrators, but we can generate arbitrarily large volumes of oxygen per second with minimal capital expenditure (and no moving parts!) compared to what I see medical oxygen concentrators going for...

Inspired by academic biochemical labs that have risen to the occasion and offered their expertise in running tests, I wonder, "is there anything a lowly chemist can do?" Or should I just start selling off our solvents as disinfectant?

5

Physiology & Medicine / How bad can stats reporting be in mainstream media?

« on: 24/02/2020 20:56:33 »

CNN (I know... I bring it upon myself... it is one of many news outlets I get my info from) had an interesting article online today, concerning the usage rates of seniors (65+) using cannabis. (https://www.cnn.com/2020/02/24/health/weed-marijuana-seniors-wellness/index.html )

But the discussion of the statistics was SOOO BAD, I have to vent here!
In one excerpt:

In 2006, only 0.4% of seniors over 65 reported using marijuana products in the past year, they said. The newly published study found that by 2015, the number had doubled to 2.4%. By 2018, it had doubled again, with 4.2% of seniors over 65 using weed.

2.4% is not twice 0.4% (that's a sixfold increase), and 4.2% is not twice 2.4% (1.75x is not terribly far from 2x, butt still...)

But simple arithmetic issues are only some of it.

They go on to say (a few paragraphs later)

One of the most disturbing findings, he said, was an increase in cannabis use among older adults who also use alcohol. In 2015, only 2.9% of seniors reported both alcohol and cannabis use (although the data cannot say if they use simultaneously). By 2018 it had jumped to 6.3%.

Huh? If only 2.4% of seniors reported using marijuana in 2015, how did 2.9% use marijuana and alcohol? And again, if 4.2% of seniors reported using marijuana in 2018, how did 6.3% use marijuana and alcohol?

Presumably they are discussing different datasets or different studies or different definitions of "use" or something.... but come on! This is the most basic aspect of reporting science... no wonder people don't trust science!

(sorry for the rant)

6

Physics, Astronomy & Cosmology / For... Science?!?

« on: 23/02/2020 06:17:31 »

I just read that "Mad Mike" Hughes died today when his steam-powered rocket crashed as he tried to prove that the Earth is flat....

I have mixed feelings.

Obviously, he was a human being, and as such his death is sad. On the other hand... what a way to go! At least he was a professional daredevil, whose hobby included amateur rocketry, so his family and friends couldn't have expected too different an outcome (it's a matter of when, not if).

And I can respect that he was so devoted (obsessed?) to empirical testing of his hypothesis. If only he could have been satisfied by less dangerous methods!

I remember hearing about his ambitions to fly to space in a homebuilt rocket a few years ago. This is about what I imagined would happen...

7

Technology / MOVED: Why do transition metals and ligands have opposite electron properties?

« on: 18/02/2020 15:26:11 »

This topic is better suited to the Chemistry sub-forum, and has been moved there.

Find it here: https://www.thenakedscientists.com/forum/index.php?topic=78659.0

8

Physics, Astronomy & Cosmology / MOVED: I solved dark matter

« on: 27/11/2019 18:42:50 »

This thread has been moved to the "New Theories" section due to its highly speculative nature (find it here: https://www.thenakedscientists.com/forum/index.php?topic=78174.0 ). For future reference, please do not post content in the main sections that is not based in generally accepted science (we are much morre flexible with questions than statements)

9

Physics, Astronomy & Cosmology / What is this fifth fundamental force I have just read about?

« on: 25/11/2019 17:02:05 »

Apparently there have been a few studies over the last 3 or 4 years that have indicated quite strongly that there is a new boson (they are calling it the X17 boson). From the pop-sci article linked below, it appears that they cannot match their observations with a model that
Can anyone with better relevant physics chops tell me how likel y an interretatio conserves energy unless they account for this new boson. And now they are looking for what kind of force this particle may be a force carrier for (as photons are for light, gluons for the strong force, and W and Z bosons for the weak force).

https://bigthink.com/surprising-science/fifth-force-nature

Can someone with a better background in physics tell me how likely this interpretation is, and what its implications would be?

10

The Environment / MOVED: Can we conduct a climate model "acid test"?

« on: 10/11/2019 17:02:07 »

This trolling thread has been moved, find it here, if you wish...
https://www.thenakedscientists.com/forum/index.php?topic=77972.0

11

Physiology & Medicine / does blood sugar crash immediately after eating?

« on: 24/09/2019 19:13:20 »

I have recently gotten into a schedule that only allows me to eat two large meals a day (depending who you ask this is healthy or unhealthy... but that's not my question).

I often find myself getting hungry right before the big meal (no surprise there), but it is immediately after the meal, that I become completely incapable of performing the most basic thought processes--I am unable to focus, become irritable, and feel terrible. This lasts maybe 20 minutes, then I am right as rain.

At first I thought that this was just a lag time between when I got the food into my stomach, and when it finally reaches the blood, but that can't be the whole story... If I delay the meal by an hour I am still a little hungrier and grumpier ("hangrier") than I was an hour earlier, but not in such an extreme way. Then, like clockwork, as soon as I eat...wham!

What's going on?

12

Chemistry / Can single bonds be pi bonds?

« on: 10/09/2019 18:50:03 »

I teach chemistry at both the undergraduate and graduate levels (and general public level as well occasionally), so I am no stranger to explaining the same phenomena in different ways that are not necessarily in good agreement (undergraduate level often being oversimplified dramatically for ease of understanding). But every so often I find myself trying to figure out whether undergraduate "facts" are valid and hold up to scrutiny of more complex models... this is one of those times.

Undergraduate level understanding of single and multiple bonds:
• A single bond is always a sigma bond, while a double bond is one sigma bond and one pi bond, and a triple bond is one sigma bond and two pi bonds.
• This explains why single bonds are free to rotate while double bonds cannot (rotating a bond with pi symmetry would require breaking the bond.)

Screen Shot 2019-09-10 at 1.41.35 PM.png (134.37 kB . 1116x698 - viewed 20868 times)

Advanced level:
• We have to look at the molecular orbitals to accurately describe the electronic structure.
• For example, the molecular orbital diagram of B₂ predicts a Bond Order of 1 (4 electrons in bonding orbitals and 2 electrons in antibonding orbitals) And because the filled sigma bonding and filled sigma antibonding orbitals cancel, and the unbalanced bonding electrons are in pi bonding orbitals, the single bond must be a pi bond.


Screen Shot 2019-09-10 at 1.43.20 PM.png (26.87 kB . 332x720 - viewed 3045 times)

What I'm struggling with now, is trying to think if there is some actual experimentally verifiable consequence of this (like restricted bond rotation). Unfortunately, bond rotation is meaningless for the linear B₂ molecule, but perhaps someone who hasn't been overthinking this can suggest another molecule that appears to have a single bond with pi symmetry, and would have other bonds that could be used to define rotations.

Other probing questions welcome--anything to break myself out of this current and useless perspective... thanks!

13

Physics, Astronomy & Cosmology / Could LIGO "see" alien warp technology?

« on: 01/09/2019 20:22:23 »

If there were aliens capable of using a "warp" drive (like an alcubierre drive, or star trek, etc.), how "big" would it have to be for LIGO to see (let's assume it's in our galaxy)? What about on the Earth? (we could see if anyone had successfully tested such a thing)

What would the signal look like?

14

Physics, Astronomy & Cosmology / MOVED: Do you think sports is sciencee?

« on: 26/06/2019 18:32:32 »

This thread can now be found in the "Just Chat" subforum: https://www.thenakedscientists.com/forum/index.php?topic=77243.0

15

Chemistry / why do phosphines and isonitriles smell so bad, while CO is odorless?

« on: 10/06/2019 22:45:07 »

I’m not sure which section this goes in (could also be physiology or biology).

Why is it that we have such a strong visceral reaction to the smell of compounds like primary phosphines, even at very trace levels? (some have odor thresholds below 1 ppb) They are toxic by inhalation at the ppm level, but I don’t think our ancestors would ever have had the pleasure of smelling such compounds. Sulfides, sure, but phosphines? The perception of these compounds by smell could be  very similar (sulfides and phosphines are chemically similar), but why are they sooo bad?

Also, isonitriles are similarly wretched-smelling, but the analogous carbon monoxide (which is chemically fairly similar) is completely odorless. And I am quite confident that our ancestors came into quite a bit of contact with carbon monoxide while they were working out the whole fire thing.

It is all quite curious…

16

Physics, Astronomy & Cosmology / MOVED: How do we measure the energy of a photon?

« on: 30/03/2019 19:03:06 »

What initially appeared to be an interesting question regarding quantum epistemology has turned out to be (or transformed along the way into) the original poster trying to proselytize a new theory that is outside generally accepted science--thus I have moved the entire thread to the "New Theories" section, where this discussion may continue.

You may find it here: https://www.thenakedscientists.com/forum/index.php?topic=75960.0

17

General Science / I can haz complete list of Realz?

« on: 05/03/2019 19:30:14 »

Hello!

I am interested in knowing how many different types of numberz there are. Please provide a complete list.

18

Just Chat! / What does Russia do after Putin?

« on: 04/03/2019 19:17:26 »

Vladimir Putin has been the leader (de facto and official) of Russia since 1999. As I understand it, he solidified his image by dramatically improving life for Russians after Yeltsin, and he now maintains a very tight grip on Russian politics and money by keeping the wealthiest Russians (oligarchs) happy enough, keeping other aspiring politicians down, ruthlessly attacking media and opposition groups at home and abroad, and keeping the general population distracted.

But Putin (as far as I know) is mortal, and if the wikipedia page can be trusted (big IF, I know), he is only 5 years away from the expected lifetime of Russians (Putin is 66.5 years old, and life expectancy in Russia is only 71.5 years!). Of course as an ultra-wealthy and very powerful man, he probably has much longer than that, but somehow I doubt there will be more than another decade of Putin in power (his term officially ends in 2024). Having so few other major politicians, how does succession look for Russia?

19

Physics, Astronomy & Cosmology / MOVED: Is my Theory Of Gravitational Field valid?

« on: 12/02/2019 16:54:23 »

Please find this new theory posted in the New Theories section of the forum: https://www.thenakedscientists.com/forum/index.php?topic=76176.0

20

Physics, Astronomy & Cosmology / Moved: Photoelectric effect as resonance phenomena?

« on: 30/01/2019 14:48:03 »

This New Theory has been moved to the New Theories subforum:
https://www.thenakedscientists.com/forum/index.php?topic=75994.0