Wikipedia:Reference desk/Archives/Science/2019 October 13

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October 13

CO2 and drowsiness

I notice in the Carbon dioxide article under toxicity there is a bit about the effect of elevated levels on people. Seemingly doubling the ambient amount can cause drowsiness in offices. But the current levels are more than double those before the industrial revolution, I was wondering if anyone has done a study of what people's performance on mental tests would be like at pre-industrial levels compared to nowadays? I don't suppose the effect would be large but it is worrying if people are just a bit stupider nowadays because of it. Dmcq (talk) 13:03, 13 October 2019 (UTC)

Are you sure carbon dioxide causes drowsiness ? I associate that more with a lack of oxygen. Of course, both occur as a result of animals or people breathing in a confined space, so it's easy to confuse the two. SinisterLefty (talk) 14:09, 13 October 2019 (UTC)

Ventilation is key here. Offices (being inside buildings) do not have the same amount of airflow as the outside. --Khajidha (talk) 15:09, 13 October 2019 (UTC)

The Flynn effect suggests that people are becoming less stupid rather than more, at least over the course of the 20th century. Alansplodge (talk) 22:16, 13 October 2019 (UTC)

Small correction: the current levels (410) are less than double the pre-industrial levels (280*2 = 560). As far as I'm aware, the effects only start happening at quite high CO2 concentration that occur only in unventilated spaces. I assume that globally, ventilation is still improving so if there is a noticeable effect, we might be getting smarter (still). Femke Nijsse (talk) 12:54, 14 October 2019 (UTC)

Yes I looked at a graph and I see it started in the last ice age at 180, and seemingly it can go up to 280 in between ice ages. Thanks for pointing that out. According to the citations in the article the CO2 level in offices is quite typically higher that the 560 you say and levels of 1500 can be reached in meetings so everyone is yawning. It is a bit sad that people question the article, the citations are there. Though I'm happy to be corrected or the article fixed. I hardly think the Flynn effect is caused by increased CO2. Dmcq (talk) 19:43, 14 October 2019 (UTC)

I wasn't suggesting that it was caused by CO2, just pointing out that people are apparently not "a bit stupider nowadays". Alansplodge (talk) 18:04, 17 October 2019 (UTC)

Why does urine drop from the penis after the brain believes it has done urinating?

Why does urine drop from the penis after the brain believes it has done urinating?

Wikipedia has an article on post-void dribbling, which is one of many types of incontinence.--Shantavira|^{feed me} 17:02, 13 October 2019 (UTC)

With a risk of making fun of myself, I never understood why other men have this problem. A firm squeeze from base to tip deals with this perfectly. Than again, it may have something with personal anatomy. אילן שמעוני (talk) 17:53, 13 October 2019 (UTC)

But remember: if you shake it twice, you're playing with it. {The poster formerly known as 87.81.230.195} 2.121.161.82 (talk) 17:21, 14 October 2019 (UTC)

Physics Question- Is it harder to hit home runs with a softball or baseball?

I have heard that it is harder to hit a home run with a softball than a baseball. This is supposedly due to the fact that harder pitches contribute to baseball's exit velocity, whereas a softball's exit velocity is much more dependent on the hitter. Is this true? 2001:5B0:2965:BF58:8087:99F:B81F:27F3 (talk) 17:29, 13 October 2019 (UTC)

A baseball itself is harder than a softball, hence it can fly farther when hit squarely, because more energy transfers to the ball. A well-hit golf ball can fly even farther than a baseball. There are still plenty of home runs in softball, as the fences are generally much closer. If you google "energy transfer to a batted ball", there are plenty of entries.[1] ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:53, 13 October 2019 (UTC)

On the other hand, here's a story about a guy who allegedly hit a softball 576 feet,[2] although it looks like he's using a metal bat. ←Baseball Bugs ^{What's up, Doc?} carrots→ 19:03, 13 October 2019 (UTC)

BTW, the record for a hit baseball is 634 feet (193 m). [3] Alansplodge (talk) 22:09, 13 October 2019 (UTC)

I would be skeptical of that claim. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:07, 14 October 2019 (UTC)

It's accepted by Guinness World Records, but whether that's a reliable source or not I don't know. They usually make some effort to verify their claims. Alansplodge (talk) 13:08, 14 October 2019 (UTC)

There's an article called Long drive which is about hitting golf balls. It sees even the average amateur can hit a golf ball nearly 700 feet, which is well beyond the longest record baseball or softball distance. The dimples on the golf ball also aid in that kind of effort, reducing wind resistance. ←Baseball Bugs ^{What's up, Doc?} carrots→ 19:07, 13 October 2019 (UTC)

Relevant links are Golf_ball#Aerodynamics and drag crisis (though the latter article is not in a really good shape). Tigraan^{Click here to contact me} 10:47, 14 October 2019 (UTC)

Which is harder Baseball or Softball? suggests that the difficulty lies in the pitcher being a lot closer in a softball game, giving less reaction time and the ball arriving at a different angle. I confess to knowing next to nothing about either sport. Alansplodge (talk) 13:03, 14 October 2019 (UTC)

There's a significant difference between slow pitch and fast pitch. Slow pitch deliveries come in on a fairly high arc and the batter has to supply all the power. Fast pitch is more like baseball, and it does require a quick reaction time because in both versions the pitcher is only 46 feet away. Furthermore, because all softball deliveries are underhand, a fast pitch pitcher can make the ball come up (a "rise") and that can be very difficult to hit solidly. ←Baseball Bugs ^{What's up, Doc?} carrots→ 16:42, 14 October 2019 (UTC)