1

Chemistry / Re: Can an electron have two orbital directions?

« on: Yesterday at 20:46:55 »

m_l is the closest thing to an "orbit direction"

ie if l = 0 then there is no need to describe a direction
if l = 1 then m_l can be +1 or –1 or 0 (representing each of the axes that the spin could be about)
if l = 2 then m_l can be +2 or +1 or –1 or –2 or 0 (representing each of the pairs axes that the spin could be about) (this one is more of a stretch)

there is no reasonable interpretation of an m_n

2

The Environment / Re: Is the Greenhouse gas effect (GHGE) basic physics?

« on: Yesterday at 16:19:04 »

I will add: the GHGE is basic physics: decreasing the efficiency of energy flow out of a system while maintaining the efficiency of energy flow in must necessarily increase the energy inside the system at any given time.

Climate change is not basic physics. Basic physics only says that the energy contained within the system must increase, it takes much more complex treatments to determine what forms that energy takes. Options include:
• Thermal energy, which as has been pointed out: the hotter the surface, the more effectively it radiates energy, so a new thermal equilibrium can be established, in which increased GHGE is compensated for by increased radiation of hotter surfaces (ie global warming).
• Phase change (essentially thermal energy that doesn't influence temperature--aka latent heat): melting ice and vaporizing water can account for enormous amounts of energy (the latent heat of melting ice is about 330 kJ/kg and the latent heat of vaporizing water is a whopping 2.2 MJ/kg--luckily the vapor pressure of water doesn't change that much with increasing temperatures that are relevant to the climate (https://en.wikipedia.org/wiki/Vapour_pressure_of_water). This change of phase, especially melting ice, is particularly worrisome because it doesn't increase the temperature (which as discussed above, increases the rate of energy transfer out), and actually ends up increasing the net rate of energy absorption because ice and snow typically much more reflective than whatever they are on (ground or sea). (I will note that ice and snow are also very poor blackbody radiators compared to what they cover, but places where the ice is are not places where blackbody radiation is going to be a major player in temp regulation). Finally, melting land ice contributes to rising sea levels, which are likely to be one of the most expensive costs of climate change in the next 200 years.
• Potential energy (mechanical) stored as increased pressure or net lifting of mass against gravity. This is a fairly small effect, but important nonetheless. Higher temperatures means more mass in the atmosphere--think of it as a tiny component of the latent heats discussed above).
• Chemical potential energy. This is unlikely to be significant, but I will mention it. There are many chemical equilibria in the world (not counting phase changes here, but actual chemical reactions). Increased temperatures will slightly change where those equilibria lie, effectively pushing the world to a slightly higher chemical potential. However, there are very few chemical reactions for which there is a major difference between 300 K and 302 K...

And then there are issues of biology, ecology, meterorology etc. that are very far from basic physics.

3

The Environment / Re: Is the Greenhouse gas effect (GHGE) basic physics?

« on: Yesterday at 15:14:49 »

When, where, by whom were observations/experiments done, since 1978, to validate statements made about the GHGE?

My point. Climate scientists measure the temperature of the atmosphere close to the land surface (about 1.5m above the surface).  This is not the same as the actual surface temperature. On a sunny day, the surface is considerably warmer than the air above. At nighttime, the atmosphere above can often be warmer than the surface.

I am not going to do all your research for you, but a few quick google searches have gotten some results that may serve as a good starting point:

Climate scientists measure temperatures on the ground (https://www.sciencedirect.com/science/article/pii/S0034425705001562), in the atmosphere near the surface (https://www.acs.org/content/acs/en/climatescience/energybalance/earthtemperature.html ) and in the upper atmosphere (where temperatures are falling because the heat is trapped beneath them http://www.theclimateconsensus.com/content/satellite-data-show-a-cooling-trend-in-the-upper-atmosphere-so-much-for-global-warming-right), and temperatures of the ocean at the surface (http://www.argo.ucsd.edu/) and deep below the surface (https://www.scientificamerican.com/article/deep-ocean-waters-are-trapping-vast-stores-of-heat/).

1. Is the carbon dioxide (CO2) greenhouse gas effect (GHGE) due to CO2 "trapping" heat?

Yes. CO₂ is transparent to visible light (the form in which most of the energy from the sun arrives at the surface) and absorbs strongly in the infrared (specifically wavelengths around 10 microns, which the part of the spectrum where a significant portion of the radiation emitted from the ground is, and is, incidentally not overlapping with any of the other infrared absorptions (ie water vapor is a powerful greenhouse gas, but the region it absorbs in is already saturated, so changes in water vapor concentration don't change the overall absorption))

2. Does GHGE warm earth by emitting less outgoing longwave radiation (OLR) to space?

We can verify that it is because of greenhouse effect because the lower atmosphere is getting warmer and the upper atmosphere is getting colder-clearly there is a decrease in the rate that energy is getting from the surface to the top of the atmosphere--and these observations are very much consistent with the theory of the action of greenhouse gases.

4

Physics, Astronomy & Cosmology / Re: What can I do in my free time to become a Aerospace Engineer?

« on: 19/02/2019 18:50:22 »

Hard to make recommendations without knowing more about where you are in your schooling, and where you could stand to improve.

Engineers, especially aerospace engineers, need to be very comfortable with mathematics. I recommend learning calculus and differential equations--how ever much you know about them now, learn more, practice more, and then apply them to physics/engineering type problems: related rates, optimizations, orbital mechanics, etc.

There are plenty of resources to help you, from textbooks to websites and youtube videos. With enough ambition, time, and effort, you can go from ignorant to expert (note that "ignorant" is not meant to be derogatory, it just means knowing nothing--it is our default state).

5

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

« on: 19/02/2019 02:29:37 »

mxplxxx, I would try to debate, but I see now that it is not worth my time, so I will leave you with this:

"There are none so blind as those who will not see."

I do hope that you will eventually open your mind to the possibility of experimentally determining facts, but I can not and will not force you to try to understand. Good day.

6

New Theories / Re: Gerald Pollack -- EZ water, a fourth phase of water?

« on: 19/02/2019 01:49:13 »

https://imgs.xkcd.com/comics/physics_suppression.png

7

New Theories / Re: Gerald Pollack -- EZ water, a fourth phase of water?

« on: 19/02/2019 01:43:50 »

Adding and removing electrons from things very much changes their chemical identities (half of my doctoral thesis was focused on work I did in electrochemistry, so I know what I'm talking about here).

H⁺ (just a proton) is the fundamental component of all Brψnsted acids--it is an excellent catalyst for many chemical reactions, and will react quickly with any slightly basic compound.

Add an electron to it, and you get an H atom, which is a free radical. It is not acidic at all, and instead reacts with compounds that have carbon-carbon double or triple bonds in them (alkenes and alkynes) as well as compounds with weak single bonds, like elemental halogens, and organometallic compounds.

Add another electron to it, and you get H^– (hydride). This is not acidic, actually it is a *very* strong base. It won't typically react with alkenes or alkynes, but can deprotonate many organic molecules (alcohols, terminal alkynes, primary amides etc. etc.). Under the right circumstances, it can also react with aldehydes and similar compounds to forms carbon-hydrogen bonds.

Fe is iron. Fe²⁺ is iron minus two electrons, or ferrous ion--which is typically light green in color and highly water soluble. Take away another electron, and you get a pale yellow/orange ferric ion which is typically not very soluble in water.

The list goes on and on...

Long story short, charge is extremely important to the identity of a substance. H₃O₂^– is NOT water.

8

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

« on: 19/02/2019 01:12:05 »

It seems to me that to measure the energy of a photon you have to be moving at the speed of light.

This is a pretty unrealistic requirement. This thread is *full* of ways to measure the energy of a photon, and none of them has any requirement for velocity!

Actually, when moving at such speeds, measurements will tell you more about the angle of your trajectory with respect to the trajectory of the photon of interest, than anything intrinsic to the photon (and will be essentially worthless to anyone in a different frame of reference...)

9

Question of the Week / Re: QotW - 19.02.18 - Why does alcohol make you drunk?

« on: 18/02/2019 18:50:35 »

As far as I know, the exact mechanisms of alcohol intoxication are not known. However, it appears that the primary effects are related to potentiation of GABA pathways in the brain (so many of the effects are similar to those of benzodiazepines, GHB/GBL, gabapentin, and barbiturates, each of which potentiates or activates this pathway in different ways.)

Unlike these other drugs, especially benzos, which are quite potent and selective (a 2 mg dose of valium wouldn't be unusual), alcohol is very weak and unselective--requiring doses typically measured in ounces or deciliters!

As I understand it, activating GABA pathways dampens other signals in the brain--with the effects manifesting more strongly for processes that require more neurons (especially if thee neurons are in different parts of the brain). This means that just a little bit of alcohol can potentiate the GABA pathways a little bit, causing the most change in higher cognitive functions like reasoning and self-control. As the dosage increases, the effects there increase, and it also starts manifesting in fine motor control and response time. When really large doses are reached, even the ability to breath can be compromised.

Acute toxicity of alcohol (for a single large dose) can largely be attributed to loss of the ability to regulate breathing, or aspiration of vomit. But most injuries and deaths due to acute alcohol intoxication are due to loss of gross motor skills and response time, especially when it comes to things like automobiles and stairs...

However, much of the harm from alcohol is not from acute, but rather chronic abuse. Because the dosage is so high, alcohol is very hard on the liver and kidneys. Also, the neural pathways that alcohol acts on become resistant, then accustomed to and then dependent on the alcohol. Those who drink excessively for a long time can suffer from the potentially fatal DTs (delerium tremens), which can cause hallucinations and seizures (both of which can be treated with some of the GABA potentiators mentioned earlier).

10

Physics, Astronomy & Cosmology / Re: How fundamental is time?

« on: 17/02/2019 21:42:40 »

Thanks for bringing it back (I'm not opposed to having some tangents along the way, but the closer we can stick to the main question, the more likely it is that I will learn the answer) 

11

General Science / Re: Can you compare infinites?

« on: 15/02/2019 14:45:30 »

Regarding the title question:

As far as I know there are only two types of infinities: countable, and uncountable (uncountable is infinitely bigger).

All countable infinities are equivalent (can't really talk about equal, because infinity isn't a number), and can be gotten as the result of infinite series.

1+1+1+1.... is the same as 2+2+2+2.... is the same as 100 + 200 + 300 + 400...

It is tricky to understand why they are all equivalent, but the basic idea is that counting forever approaches countable infinity, and it doesn't matter how fast you count, it is still forever. The set of all integers is countably infinite (so is the set of all rational numbers--it's a little trickier to prove, but it can be done).

The set of all real numbers (including irrationals) is WAY bigger, and is actually uncountably infinite. As in, say we start counting from 0.... then, what is the next number? There are actually uncountably many irrational numbers between any two rational numbers (mind-blowing, but true!)

It has been hypothesized that there is no version of infinity that is "bigger" than countable, but still "smaller" than uncountable, but it hasn't been proven, and if I understand correctly, it has been proven that it can't be proven to exist or proven not to exist. https://en.wikipedia.org/wiki/Continuum_hypothesis

12

General Science / Re: Can you compare infinites?

« on: 15/02/2019 14:33:46 »

There is an error in your calculations!

does not converge (and definitely not to one)

1/2 + 1/4 + 1/6 + 1/8 is already bigger than 1 (1.0416666...)

You are probably thinking of :
which does converge to 1.
1 = 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64....

13

Question of the Week / Re: QotW - 19.01.14 - Do trees eat soil?

« on: 15/02/2019 06:15:43 »

photosynthesis: https://en.wikipedia.org/wiki/Photosynthesis

14

New Theories / Re: Gerald Pollack -- EZ water, a fourth phase of water?

« on: 15/02/2019 03:36:20 »

Someone else has spent a good deal of time putting together a critical analysis of Dr. Pollack's work: http://moreisdifferent.com/2015/11/19/debunking-exclusion-zone-water/

Long story short: Pollack has found something interesting, but is making grandiose claims without sufficient evidence.

15

General Science / Re: Why does ice melt?

« on: 15/02/2019 03:10:58 »

Ice forms at different temperatures under different pressures. Lower the pressure and the bond do not form until a lower temperature, super cooled water lower than 0C is present in the lower pressure upper atmosphere due to the energy in the water being more than the force it is experiencing.

I believe you have that backwards--water is an example of a substance that has a higher freezing point at lower pressures (attributed to the lower density of the solid as compared to the liquid). At sufficiently low pressures, the liquid is completely unstable, and only solid and gaseous phases are left to interconvert (by sublimation and deposition).

16

New Theories / Re: Gerald Pollack -- EZ water, a fourth phase of water?

« on: 15/02/2019 03:07:20 »

Ok, now I have watched some of the videos and done some more research.

A few takeaways:
There are lots of people trying to sell H₃O₂ or H₃O₂ generators, making claims about its healing and cleansing properties. This is snake oil, either being peddled by scammers or those who have been scammed.

Dr. Pollack appears to be genuinely interested in finding the truth, rather than trying to scam people. He is observing and measuring many real phenomena, but I question his interpretation. He is making very extraordinary claims, with little evidence to back them up. Additionally, he appears to have made some obviously wrong claims: for instance, his explanations of clouds, steam, mist, etc. are easily debunked (we can observe the exact same phenomena with substances other than water, like acetone and dichloromethane, neither of which are capable of dissociating into protons, or hydrogen bonding with itself).

I would recommend that people be very critical about his proposals.

17

New Theories / Re: Gerald Pollack -- EZ water, a fourth phase of water?

« on: 14/02/2019 23:04:09 »

It is well known that liquid water does form a more highly ordered structure at interfaces with air and hydrophobic materials (this is the source of the hydrophobic effect)
http://www1.lsbu.ac.uk/water/interfacial_water.html


This ordering is very important for things like nucleation of ice crystals (which doesn't happen easily in pure bulk water), and is also essential to much of biochemistry (much of the interesting chemistry happens between organic molecules that are either solvated with water or sandwiched between water and other organic bits (and the structure of water in and around proteins is quite interesting).

That said, anyone claiming that a phase of water can be represented as H₃O₂ is either ignorant or careless. No matter the arrangement, it must have the same empirical formula to be the same substance (I would be ok with H₃O_1.5, or H₄O₂, as long as there is good reason to specify the formula other than H₂O)

I haven't watched the video or followed any of the links, so I cannot comment on the rest.

EDIT: There is a another option for the discrepancy--you haven't reported it properly! Dr. Pollack could be modeling EZ water as (H⁺)(H₃O₂^–), which is reasonable.

18

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

« on: 14/02/2019 03:56:38 »

purist - 1.
a person who insists on absolute adherence to traditional rules or structures, especially in language or style.

Science requires the use of terminology with rigorous and specific definitions. In colloquial English, "forceful," "energetic," "intense," and "powerful" all can be used somewhat interchangeably. In science, each has a different and very specific meaning.

PS: esquire, please don't spam the threads with multiple posts. Also, most of your assertions are very wrong...

19

Chemistry / Re: Is ethanol an acid or a base?

« on: 13/02/2019 21:04:14 »

Alcohol is unlikely to act as a base in aqueous solution, and I'm not sure how it would influence pH. However, recalling that pH is the negative log of the concentration of protons, I think the reason pure ethanol has a higher pH than water is that it has a significantly lower dielectric constant than water (about 24 vs 80), so any acid is less likely to dissociate when in ethanol than when in water (causing a lower concentration of protons, and thus a higher pH).

20

Chemistry / Re: Is ethanol an acid or a base?

« on: 13/02/2019 20:51:38 »

Alcohol, like water, is both a weak base and a weak acid (it is slightly weaker as an acid, and slightly weaker as a base*).

EtOH + H⁺ → EtOH₂⁺ (EtOH is a base)

EtOH → EtO^– + H⁺ (EtOH is an acid)

*The pKa of protonated ethanol is –2.4, while protonated water has a pKa of –1.7, and the pKa of ethanol is 16, while the pKa of water is 15.7 (according to this reference: http://cactus.dixie.edu/smblack/chem2310/summary_pages/pka_chart.pdf )