41

The Environment / Re: If the Earth is losing mass, is the atmosphere expanding?

« on: 24/10/2021 15:56:14 »

much of the solar radiation is returned to space, hence why all the furore over a slight increace in co2, which is a tiny proportion of the atmosphere.

For the Earth to remain at thermal equilibrium the amount of energy radiated to space must equal the amount of energy that comes in (mostly from the sun, but there is also some geothermal energy too). If the amount of energy that is radiating out is less than the amount coming in, the average temperature on earth will increase until the the balance is re-established (hotter objects radiate more). So any change in how effectively the atmosphere allows heat out (no matter how small) will also result in a change in the average temperature on earth. It turns out that even very small changes in average temperature have significant changes on climate. Hence the furor.

water also has "greenhouse" properties and is there in significant quantities.

Yes. But there hasn't been a major change in the amount of water available to the atmosphere recently (other than driven by climate*). We have increased the amount of available carbon dioxide by more than 35% in the last 100 years (and methane by 100%)

*As the temperatures increase, more water vapor gets into the atmosphere, increasing the greenhouse effect of the atmosphere, but there are also complications with cloud cover, snow/ice distribution, and heat distribution... so unlike co2, where it's a simple more co2 means stronger greenhouse effect and more warming, with water, there is no simple relationship.

42

The Environment / Re: What's going on with the climate?

« on: 22/10/2021 16:54:52 »

even diamonds

https://www.reuters.com/business/sustainable-business/made-from-co2-concrete-lululemons-diamonds-spark-investor-excitement-2021-10-04/

43

The Environment / Re: If the Earth is losing mass, is the atmosphere expanding?

« on: 21/10/2021 19:34:19 »

Perhaps the Atmosphere will expand & extend to engulf the Moon.

Not in any meaningful way, thankfully!

If the Earth overall is losing mass, the effect it has on gravity, however slight, may affect our atmosphere in a much different way than simply allowing hydrogen and helium to escape as a natural consequence.

Well, yes, you're right that decreasing the mass of the earth will naturally lead to a lower surface pressure, and allow the atmosphere to puff out a little more. I think it's important to consider the magnitudes involved though. The change in mass that we can expect the earth to have over the next several centuries is a fraction of a fraction of a fraction of a percent. This will not have a significant effect on the composition or mass of the atmosphere.

As we convert solid fuels (fossil and other) into heat, two factors occur at a minimum: release of hydrocarbons and infrared heat.  Add to this the loss of water stored in 3 trillion trees lost, and the amount of water vapor / heat being created by combustion is a SUBSTANTIAL NUMBER.

The heat being released by burning fossil fuels is surprisingly insignificant compared to the heat budget of the earth. (One full 24 hours of sunlight on the whole earth is many times greater than all of the heat produced by all of our power plants and cars and industry etc. in an entire year!)

But the generation of carbon dioxide, and to a lesser extent, water, is significant. The amount of water in the atmosphere is essentially a function of how warm it is (higher temperatures allow more water to be in the vapor form), so producing a bunch of water vapor doesn't necessarily mean that the atmosphere will get more massive (it may just lead to more precipitation).

With carbon dioxide the story is different. There is some degree of solubility in water which is temperature-dependent, but the solubility of carbon dioxide in water is not very high, so most of the carbon dioxide that is produced does go into the atmosphere.

The atmosphere used to have LOTS of carbon dioxide. Before photosynthetic organisms there was no significant concentration of molecular oxygen in the atmosphere: basically, for every molecule of oxygen in the atmosphere now, there is an atom of carbon buried in the ground in the form of fossil fuel, and it used to be a molecule of carbon dioxide in the atmosphere (and the atmosphere is currently about 20% oxygen, and 0.0004% carbon dioxide)

And before THAT, there were a bunch of microorganisms that pulled carbon dioxide out of the atmosphere to make their calcium carbonate shells. As they died, their shells piled up and eventually became the limestone deposits that cover the earth (limestone is basically just crushed ancient microbe exoskeletons). That was a LOT of carbon dioxide.

44

The Environment / Re: What's going on with the climate?

« on: 20/10/2021 14:30:34 »

Aren't there ways to just suck up the  CO2 back from the environment?

https://www.cnn.com/2021/10/20/world/carbon-capture-storage-climate-iceland-intl-cmd/index.html

211018110821-01-carbfix-climeworks-iceland-carbon-storage-super-169.jpeg (137.24 kB . 1100x619 - viewed 3402 times)

It opened last month and currently removes about 10 metric tons of CO2 every day, which is roughly the the same amount of carbon emitted by 800 cars a day in the US. It's also about the same amount of carbon 500 trees could soak up in a year.
It's a fine start, but in the grand scheme of things, its impact so far is miniscule. Humans emit around 35 billion tons of greenhouse gas a year through the cars we drive and flights we take, the power we use to heat our homes and the food — in particular the meat — that we eat, among other activities.

45

The Environment / Re: What's going on with the climate?

« on: 17/10/2021 16:22:10 »

Hi Chiral!
🙂

Thanks for All those Statistical slides.

you're welcome :-)

Honestly, it's Scary!

It's certainly not comforting...

Aren't there ways to just suck up the  CO2 back from the environment?

Yeah, but there are two major problems with it: how much money and material and energy is spent cleaning it up, and what do we do with it then? There are some advances being made with people using captured carbon dioxide to make fuels (at least that's carbon neutral), solvents, simple edible organic compounds, and even diamonds (cool, but not practical). Some are trying to pump it into volcanic chambers where it can be absorbed by the calcined minerals.

We are still not really capable of controlling climate, but atleast We could try somehow?

We need to try a lot harder (and faster!)

Have WE reached the Point of No Return?
☹️

There isn't a point of no return really (Earth has had many climates before), it's just an issue of whether we can return in our lifetimes, (unfortunately, almost certainly not mine or yours–climates typically change slowly, and I doubt that we will be able to just "pop it back" to the way it was), or those of our grandchildren, or if we are jut going to have to limit the change and adjust to a new normal. (+1.8 °C is not great, but it's better than +4.2 °C!!)

We can begin our return at any moment by reducing greenhouse gas emissions, helping to regenerate carbon-negative ecosystems, investing in industrial-scale carbon capture/conversion technologies, and maybe even trying to increase the albedo of various parts of the globe with mirrors.

46

The Environment / Re: What's going on with the climate?

« on: 17/10/2021 16:20:26 »

Hi Chiral!
🙂

Thanks for All those Statistical slides.

you're welcome :-)

Honestly, it's Scary!

It's certainly not comforting...

Aren't there ways to just suck up the  CO2 back from the environment?

Yeah, but there are two major problems with it: how much money and material and energy is spent cleaning it up, and what do we do with it then? There are some advances being made with people using captured carbon dioxide to make fuels (at least that's carbon neutral), solvents, simple edible organic compounds, and even diamonds (cool, but not practical). Some are trying to pump it into volcanic chambers where it can be absorbed by the calcined minerals.

We are still not really capable of controlling climate, but atleast We could try somehow?

We need to try a lot harder (and faster!)

Have WE reached the Point of No Return?
☹️

There isn't a point of no return really (Earth has had many climates before), it's just an issue of whether we can return in our lifetimes (unfortunately, almost certainly not mine or yours–climates typically change slowly, and I doubt that we will be able to just "pop it back" to the way it was).

We can begin our return at any moment by reducing greenhouse gas emissions, helping to regenerate carbon-negative ecosystems, investing in industrial-scale carbon capture/conversion technologies, and maybe even trying to increase the albedo of various parts of the globe with mirrors.

47

Physics, Astronomy & Cosmology / Re: Can we ever truly describe space as empty?

« on: 17/10/2021 15:49:16 »

You say the universe cannot leak into anything since there  is nothing outside of the universe to leak into. However do we know that for sure. I would say our currently understanding of the universe is not good enough to disregard many possibilities , We simply don’t know enough.

It’s possible that what we consider to be the  universe is not the full story .

It's kinda definitional. Our universe is everything that is. If something is. It is part of the universe. If it's part of the universe then it is.

If you want to go all metaphysics and talk about multiverse stuff that's fine too, but then either each universe is a different facet of the same whole multiverse, and you have just swapped "multiverse" for "universe," or the universes are all distinct unique independent universes, and then there isn't any "leaking." If something can interact with part of our universe, it is part of our universe.

Maybe as we learn more about the universe we will need new words to describe new relationships and phenomena. But for now, we don't need to quibble about which word we will use to describe "everything"

48

The Environment / Re: What's going on with the climate?

« on: 16/10/2021 19:06:31 »

Sorry for the extra snark y'all, but I just get really frustrated having the same silly little arguments over and over about whether or not anthropogenic climate change is real, when we should be arguing about what to doing about it!

It's not natural cycles with the sun or our orbit. It's not volcanos. We can trust our data (whether that's CO₂ measurements, or surface temperatures, or IR emissions, isotope ratios...) Sea levels are rising. The water is acidifying. Land ice and permafrost are receding. Storms are becoming more frequent and stronger.

And I get that science is not a 'consensus is correct' kind of field... but when the one guy in the room disagrees with "all the experts" he must have a very compelling case. Not just, "Sunspots!" or "how do you know your instruments aren't wrong?"

49

The Environment / Re: What's going on with the climate?

« on: 16/10/2021 18:37:04 »

no discernible effect

Discernible to whom and by what method? As demonstrated by the argument between Bored chemist and alancalverd, it would seem that, maybe, just eyeballing isn't a good way to impose a limit of detection for the average slope of a slightly noisy sloped sinusoidal curve?

It's like the bootlegger who assures you that there isn't any methanol in their moonshine, cause it tastes pure... And then a quick GC is like: oh, theres 0.44% methanol in here, don't drink this!

Ok, back to CO₂! Let's see if anybody has actually quantitatively looked at the data... oh look here it is:
https://gml.noaa.gov/ccgg/trends/gr.html

co2_data_mlo_anngr.png (73.24 kB . 666x489 - viewed 3410 times)

and the data show that 2020 had an overall increase in CO₂ levels (+2.3 ppm) about 9% less than the overall in 2019 (+2.5 ppm).

50

Physiology & Medicine / Re: What are the harmful effects of Vaping?

« on: 16/10/2021 03:34:53 »

Note that apart from the nicotine and the vegetable oil, most of the key ingredients in vaping pens are used by the medical community to administer drugs, and have been tested for long term use. Glycerine and propylene glycol are simply not a concern. The nicotine itself is somewhat toxic, but compared to smoking it, forget about it.

Vegetable oil sounds a bit weird, I wouldn't inhale that.

Whether for nicotine or thc, there are can be many additives for flavor/aromas (menthol, limonene, eugenol, butane dione, isoamyl acetate, etc. etc.) as well as for setting/maintaining color, viscosity, vaporizability etc. Butane dione in particular has been implicated in lung damage ("popcorn lung")

Many of these compounds are generally recognized as safe when eaten or used externally, but route of exposure/administration is very important when considering toxicology. The GI tract is protected by mucus that keeps corrosive compounds away from sensitive tissues (ie hydrochloric acid in the stomach), and even is loaded with enzymes designed to break down potential toxins (very significant concentrations of monoamine oxidase in the GI tract, which renders many alkaloids orally inactive). Also, just recall: a little bit of an innocent and non-toxic compound like water in the lungs can be fatal (it's called drowning).

Here is a peer-reviewed report that indicates that inhaled propylene glycol can trigger mutations (in mice): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5641932/

Also, there was a rash of cases of lung damage (some cases being fatal) being reported in the US shortly before COVID become THE NEWS. If I understand correctly, one of the prime suspects (I don't know if it was confirmed), was vitamin E acetate, which was used as a diluent in illegally produced thc vape pens (it has similar viscosity and vapor pressure as thc), and while vitamin E acetate is perfectly fine to eat or as a component of creams/lotions, apparently inhaling significant quantities of it majorly ƒµçk$ up the lungs!

It's almost certainly safer to vape than to smoke, but we know how bad smoking is, and there are already hints that vaping isn't much better.

51

The Environment / Re: What's going on with the climate?

« on: 15/10/2021 21:03:49 »

2020 & 2021 were/are Lockdown Years.

Most of Us sat Indoors.
Lot of pattern changes in the ambience of the environment, Right?

Perhaps Our drastic change in actions might somehow explain the " Weird " Climate.

Probably once Everything kicks back in full motion, say 2022 onwards, then maybe it would be Weather as Usual/Normal.

(Guess Work)
✌️

Interesting guesswork... but that does not seem to me to be consistent with the evidence before us* (at least it is a verifiable hypothesis, and we shall see if things return to normal as the economy lurches forward, or if it continues to spiral out of control)

*2020, and then 2021, were both record-breaking on many levels (high and low temps, hurricanes/typhoons, fires, draughts and floods, etc.) But it's not like they were completely out of the trend: the 2018–2019 Australian fires foreshadowed what we saw in 2019-2020, and the wildfires in California have clearly been trending upward over the last few decades (https://www.valuepenguin.com/wildfire-statistics)

Screen Shot 2021-10-15 at 3.51.36 PM.png (341.29 kB . 1452x888 - viewed 4475 times)

And tropical storms in the Atlantic have been increasing (at an increasing rate) over the last several decades as well.

number-of-named-storms-and-hurricanes-1.png (318.42 kB . 1747x1211 - viewed 4429 times)

52

The Environment / Re: What's going on with the climate?

« on: 08/10/2021 18:35:18 »

I think it is "global wierding"

Of course, it's not good practice to confuse weather (stochastic events localized in time and space) and climate (overall systematic view with global spatial extent, and spanning several years). But I agree, 2021 has seen SO MANY weather events absolutely smash previous records (and it is continuing trends observed over the last few decades), so we can now safely say that we are seeing the effects of climate change.

This list of 2021 "most" extreme events only goes to a few weeks ago:
https://www.theweek.co.uk/news/environment/953574/worlds-most-extreme-weather-events-2021

So it doesn't include the gobsmacking rain in Italy over the last week (what does 29 inches (740 mm) of rain in 12 hours even look like? a faucet?):
https://www.cnn.com/2021/10/06/weather/italy-flood-oman-climate-change/index.html

Please, let us try to reverse course as quickly as possible!

53

General Science / Re: Do the theories of quantum and relativity have to be unified?

« on: 03/10/2021 00:20:40 »

Our understanding doesn't influence how the universe works (except insofar as we can use our understanding to make parts of the universe do weird things).

That said, I was at a seminar yesterday which was discussing the need to include general relativistic terms into quantum calculations when trying to model very heavy elements: the methods that I use to model light atoms like hydrogen through chlorine do abysmally when trying to model heavier elements (like it would not get that gold is yellow, or that mercury is liquid at room temperature, and would apparently be off by nearly 30% when estimating the redox potential of lead), and only when quantum and relativity are combined can useful ab initio models of these elements (and compounds containing them) be done.

54

Physics, Astronomy & Cosmology / Re: What is TIME?

« on: 01/10/2021 19:10:21 »

Time cannot be motion. That's just common sense 

The question of what time is, is a good one, and again, probably one you won't get a satisfying answer for.

The best one-line quip definition of time I've heard is:

time is what keeps everything from happening at once.

55

General Science / Re: Why (or how) does salt make food taste better?

« on: 28/09/2021 00:06:21 »

It wouldn't make ice cream taste better

I don't know... having enjoyed ice cream with pretzels in it, and salted caramel ice cream.... I don't think salt and ice cream are mutually exclusive. (just don't add enough to melt it!)

56

General Science / Which of the platonic solids is MOST special?

« on: 22/09/2021 19:21:39 »

Not really science, and definitely not important, but...

I was recently thinking about how the ancient Greeks had associated each of the platonic solids with an element (tetrahedron for fire, octahedron for water, cuber for earth, icosahedron for air, and dodecahedron for "quintessence"

Supposedly the existence/identity of the dodecahedron was at one point secret/sacred??

My question is: based on the mathematical properties of these shapes (I am coming at this more from group theory), shouldn't the tetrahedron be the odd shape out?

My case (most of these points are very much inter-related):
1) The cube and the octahedron are a pair (you can inscribe a cube in an octahedron such that each of the 8 vertices of the cube is in the center of one of the 8 faces of the octahedron, and you can inscribe an octahedron in a cube such that each of the 6 vertices of the octahedron is in the center of one of the 6 faces of the cube. Similarly the dodecahedron (with 12 faces and 20 vertices) and icosahedron (with 20 faces and 12 vertices) are a pair. The shapes within each pair is very closely related: they belong to the same point groups (and thus are isomorphic).

The tetrahedron, with 4 vertices and 4 faces is its own partner (you can inscribe a tetrahedron in another larger one).


DWRDUG6VQAIjX1J.jpeg (106.56 kB . 933x1200 - viewed 7801 times)

2) The tetrahedron is the only platonic solid that lacks a center of inversion. (when a tetrahedron lies on one face, there is a vertex directed straight up, making the shape useful for caltrops (ouch!))

3) The tetrahedron is the only platonic solid that lacks a hexagonal projection (it can’t make a hexagonal shadow). Best it can do is a square.

4) The tetrahedron is the only platonic solid for which the number of faces (and vertices) is a perfect square.

5) It is pleasing (which the Greeks cared about, I think) to arrange the four elements in a tetrahedral array. (how meta)

Screen Shot 2021-09-22 at 2.14.31 PM.png (29.7 kB . 432x406 - viewed 6902 times)

57

Geology, Palaeontology & Archaeology / Re: Can anyone explain these insect fossils?

« on: 18/08/2021 15:50:56 »

From the photos, I see what appear to be two spiders, a whole wasp, and a wasp's head. It is entirely possible that you are looking at a discarded bug collection, and this could be confirmed if the coating is clearly anthropogenic (like epoxy or acrylic).

Getting an FT-IR (Fourier transform infrared) spectrum with and ATR (attenuated total reflectance) detector would be a non-destructive way to shed light on or even positively identify the substance they are coated with. Most universities would have at least one of these instruments available (at least in the US, Western Europe, and East Asia... I don't know where you are).

It would be quite easy to distinguish amber, epoxy, acrylic, glass, chitin (bug shell), etc. (one can even distinguish between types of amber and types epoxy resin using these methods):

https://www.persee.fr/doc/anata_1018-1946_2012_num_20_1_1325
https://www.researchgate.net/figure/FTIR-spectrum-of-the-epoxy-resin_fig2_227327777

58

Question of the Week / Re: QotW - 21.08.22 - How long does it take the food I eat to become part of me?

« on: 16/08/2021 19:10:39 »

As soon as the food is in your mouth (or hand) its weight would be added to your own (if you were on a scale while you were eating, it would tick up every time you picked up your next bite, and then it wouldn't change as thee food moved from hand to mouth to stomach to intestines to blood etc.). If you're not actually on a scale while eating/drinking, but weigh yourself frequently, each meal or beverage would count as a "step up."

As far as loosing wight goes, you have to consider urine and bowel movements (which would show up as steps down), breathing (you exhale quite a bit of CO₂ and H₂O all the time, and if you've been drinking alcohol, then also ethanol and acetaldehyde will be exhaled). Also sweating may play a role in weight if you live somewhere very hot, exercise, or spend time in saunas...

As far as when the food "becomes part of you" that would require better definitions of what "you" are and what "food" is. do the atoms in the food need to become covalently bound with atoms that were already "part of you?"
do water molecules become "part of you" as soon as they are in your body, or must they be incorporated into a body fluid first (like blood, or lymph, or intracellular fluid, etc.) or can water ever be considered "part of you"?
are our gut flora "part of us?" if so, how about multicellular stowaways like demodex?

59

Chemistry / How does one detect fake/diluted honey?

« on: 16/08/2021 18:58:24 »

You couldn't use the stuff we normally call "sugar" to make fake honey; it's sucrose and honey is largely glucose and fructose.

Depends how it’s done. When there is a poor nectar flow - we are about to enter one - beekeepers feed sucrose solution to tide the bees over. The bees will invert the sucrose, but you end up with a diluted flavour so you can’t (or rather shouldn’t) extract it for sale.
We also use an invert syrup with same glucose/fructose mix as honey so the bees don’t waste energy converting it, but same problem of saleability. Unscrupulous people could add the invert directly and I think this has been detected in imported honey.

But you could use golden syrup- which is a partially inverted sugar (and thus is much more similar to honey).

Honey police will get you 
Golden syrup contains high amount of 5-hydroxy methyl furfural (HMF). Honey is tested for HMF as it is a sign that the honey has been overheated in processing and adding golden syrup would push it above the legal limit.
Most amateur beekeepers don’t heat their honey in order to keep it as natural as possible.

Testing for fakes is interesting enough as a piece of analytical chemistry, but more than a little off topic.

That would be a very interesting topic. Particularly if you know a simple test to identify sucrose in honey.

Does polarimetry count as simple? I would expect that even a rudimentary polarimeter should be able to identify if significant amounts of sucrose had been added to a fructose/glucose mix…

https://en.wikipedia.org/wiki/Specific_rotation

60

Physics, Astronomy & Cosmology / Re: Could plutonium-238 dioxide fuel be used for interstellar travel?

« on: 31/07/2021 18:18:26 »

What's the point of sending off telescopes into space instead of waiting on earth the extra minutes for the light to come to you?  I mean it's even silly when you realise the radio signal from the camera ship will take just as long to travel. 

Indeed, it is silly if one were to use these probes in this way.

But there is useful information to be gained:
1) The farther we can spread our cameras the more significant the parallax of their combined images. We can use this information to get more precise distances and use that information to more tightly calibrate some of our other measurements.

2) If the camera can get sufficiently close to any object that its resolution is significantly better than any earth-based or solar-system based telescopes could get.

3) If many of them are launched in different directions, based on survival rates we will also get an idea of how dangerous interstellar space is, and possibly sort of map of which regions (trajectories) are more or less dangerous.

4) also, specifically getting off the earth means that we can avoid problems introduced by the atmosphere (improving our resolution, and allowing many more wavelengths to be observed)