CC-v.3 said ; Where does this notion of empty space within an atom come from?
Because the empty space inside an atom is not accessible. An atom is a discreet package of subatomic particles floating in orbit around a nucleus, creating a repulsive field.
If atoms are 99.999999999999% empty space then why don’t things pass right through them?
Things don't fall through other things because they are levitating on an electrostatic field! I am not kidding! When you sit on a chair, you are not really touching it. You see, every atom is surrounded by a shell of electrons. This electron cloud presents a rather negative face to the world. Remember that like charges repel each other. When two atoms approach each other, their electron shells push back at each other, despite the fact that each atom's net charge is 0. This is a very useful feature of nature. It makes our lives a lot easier.
Very nearly all of it. Let's take a look at an atom of hydrogen to see how empty it really is. Of course, this diagram isn't drawn to scale...
A hydrogen atom is made from a single proton that's circled by a single electron. How big is a hydrogen atom? The radius of a hydrogen atom is known as the Bohr Radius, which is equal to .529 × 10-10 meters. That means that a hydrogen atom has a volume of about 6.2 × 10-31 cubic meters.
How big is the proton at the center of a hydrogen atom? Recent studies indicate that protons have a radius of about .84 × 10-15 meters, giving them a volume of about 2.5 × 10-45 cubic meters.
We need to do a little more math to find out how much of a hydrogen atom is empty space:
Percent Full = 100 × (Volume Filled / Total Volume)
Percent Full = 100 × (2.5 × 10-45 m3 / 6.2 × 10-31 m3)
Percent Full = 100 × (4 × 10-15)
Percent Full = 4 × 10-13 %
Percent Full = 0.0000000000004% !
That lil dot is spinning amazingly fast, that spin has real world consequences.
You image is frozen into an instant to help us illustrate its structure.*
A perfect example of the Map v. Territory Problem - - then we start arguing that the map is the reality when our minds can’t bend itself around the reality itself.
Well, at least until we can snap a picture of an atom at absolute zero, although seems to me that structure would collapse rather that becoming a frozen solar system.
I am actually aware that electrons don’t really have an “orbit”. The more accurate description I usually see is “electron cloud”. And yes, I know that electrons move around at the speed of light, or very close to it. I wasn’t actually asking questions so much as illustrating that one answer leads to so many more questions. I did not intend for them to necessarily be scientifically sound questions based on the millions more answers we have than I had not mentioned.
Unrelated, but this brought to mind something I was curious about and looked up once. Find an actual photograph which shows both the Earth and the Moon in the same image. The actual distance you have to get away to capture both in the same image, when the moon is the furthest from the Earth from the perspective of the picture, is simply incredible. I think I found this when I was considering what it would take to make a scale representation of the solar system or something. I don’t remember what I came up with, but I do remember it would have been spread over many miles if the Earth were represented as the size of a baseball, or something like that.
Looks like we have a definitive breakthrough in the appearance of amino acids on earth.
Abstract
The membranes of the first protocells on the early Earth were likely self-assembled from fatty acids. A major challenge in understanding how protocells could have arisen and withstood changes in their environment is that fatty acid membranes are unstable in solutions containing high concentrations of salt (such as would have been prevalent in early oceans) or divalent cations (which would have been required for RNA catalysis).
To test whether the inclusion of amino acids addresses this problem, we coupled direct techniques of cryoelectron microscopy and fluorescence microscopy with techniques of NMR spectroscopy, centrifuge filtration assays, and turbidity measurements. We find that a set of unmodified, prebiotic amino acids binds to prebiotic fatty acid membranes and that a subset stabilizes membranes in the presence of salt and Mg2+. Furthermore, we find that final concentrations of the amino acids need not be high to cause these effects; membrane stabilization persists after dilution as would have occurred during the rehydration of dried or partially dried pools.
In addition to providing a means to stabilize protocell membranes, our results address the challenge of explaining how proteins could have become colocalized with membranes. Amino acids are the building blocks of proteins, and our results are consistent with a positive feedback loop in which amino acids bound to self-assembled fatty acid membranes, resulting in membrane stabilization and leading to more binding in turn. High local concentrations of molecular building blocks at the surface of fatty acid membranes may have aided the eventual formation of proteins.
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