Taste

We perceive taste though chemical reactions that take place on the tongue. The tongue has different receptors that react with different types on molecules and ions in the food. This gives us information about the chemical content of the food. 

We now generally recognize five categories of taste:

• Sweet taste is a reaction with dissolved glucose (or sucrose or some other similar molecule). This tells us the food has a lot of easily accessible energy content. If you're an animal this is a very good thing, so sweet tastes good.
• Salty taste is the detection of Na+ ions. Salt (NaCl) dissolves into Na+ and Cl- ions in water, so if our saliva has a lot of Na+ ions we must be eating something salty. Again, in nature salt can be scarce, but is critical for survival, so it tastes good. 

• Sour taste is detection of H+ ion concentration in the saliva. This means that sourness is the same as acidity. 
• Bitter is triggered by a variety of molecules, many are alkaloids which tend to be basic in pH. This usually comes from plants that are producing it as a defensive poison, so the body's first reaction tends to be to label the taste as bad or even gag. Bitter foods like coffee and beer tend to be acquired tastes.   
• Umami is detected by reacting with various proteins, and thus indicates protein-rich foods like meat. This is a savory taste. 

Earth Gravity

If you think about what we have previously learned about gravity, every bit of mass pulls on every other bit. So the dirt right under your feet is exerting gravity, and dirt on the other side of the globe is as well. But the r² term in that equation says that the stuff close to you pulls much harder. It seems that if you want to know how all the earth together pulls on you, you must sum the effects of each individual bit.

The problem is simpler if we can think of the earth (or whatever) as an onion of nested spherical shells, where each shell is about uniform density. This is a fair assumption because for any very large object, gravity itself will collapse the thing down into a sphere shape and roughly sort the material of the sphere with denser material closer to the center. The Shell Theorem, proved by the ubiquitous Issac Newton, says that for any one of these shells, for the purposes of calculating the gravitational effect of the whole, it is equivalent to assume all of the mass is at a point in the center. Now, as you add the shells together, each tells you to model it’s mass at the same center point, so it’s valid to do that for the whole solid sphere.

The interesting flip side of that theory is that at any point Inside a hollow shell, you will feel no gravity from the shell. At the center this is not surprising, it’s pulling you in all directions equally and it cancels out. And with some thought it makes sense when you’re near the edge (but still inside) also. If you consider the part of the shell that is pulling you generally out from the center, it’s small but close to you. The remainder pulling you in toward the center is much larger, but farther away, so the effects balance out.

So, if you were to tunnel down into the earth, the further you went the less gravity you would feel until weightlessness at the center. Similarly, the gravitational effect of the atmosphere on you is roughly cancelled out to zero, because you are inside that shell.

Some have held the theory that the earth actually is a hollow shell, and that others inhabit the interior face with their own atmosphere, and even their own small sun at the center. We see now one reason this is would not work well. The inhabitants of the interior would feel no gravity holding them to the ground, only a slight (about 2 oz) centrifugal force.  The gravitational effect of the atmosphere inside the hollow earth and the small sun would likely overcome that effect and cause everything to  drift up into the center.

G. K. Chesterton Says

Ideas are dangerous, but the man to whom they are least dangerous is the man of ideas. He is acquainted with ideas, and moves among them like a lion-tamer. Ideas are dangerous, but the man to whom they are most dangerous is the man of no ideas. The man of no ideas will find the first idea fly to his head like wine to the head of a teetotaller.

- Heretics

What fairy tales give the child is his first clear idea of the possible defeat of bogey. The baby has known the dragon intimately ever since he had an imagination. What the fairy tale provides for him is a St. George to kill the dragon.

- Tremendous Trifles

The above was aptly paraphrased by Neal Gaiman in Coraline as "Fairy Tales are more than true; not because they tell us that dragons exist, but because they tell us that dragons can be beaten."

Truth must of necessity be stranger than fiction ... for fiction is the creation of the human mind, and therefore is congenial to it. 

- The Club of Queer Trades

The only way to be sure of catching a train is to miss the one before it.

- According to Pierre Daninos

The traveler sees what he sees, the tourist sees what he has come to see.

- The Temple of Silence & Other Stories

I say that a man must be certain of his morality for the simple reason that he has to suffer for it.

- Illustrated London News, Aug. 4, 1906

To have a right to do a thing is not at all the same as to be right in doing it. 

- A Short History of England

The whole modern world has divided itself into Conservatives and Progressives. The business of Progressives is to go on making mistakes. The business of the Conservatives is to prevent the mistakes from being corrected. 

- Illustrated London News, Apr. 19, 1924

I believe what really happens in history is this: the old man is always wrong; and the young people are always wrong about what is wrong with him. The practical form it takes is this: that, while the old man may stand by some stupid custom, the young man always attacks it with some theory that turns out to be equally stupid.

- Illustrated London News, Jun. 3, 1922

Without a gentle contempt for education, no gentleman's education is complete. 

- The Common Man

Precisely because our political speeches are meant to be reported, they are not worth reporting. Precisely because they are carefully designed to be read, nobody reads them. 

- "On the Cryptic and the Elliptic," All Things Considered

Nine times out of ten, the coarse word is the word that condemns an evil and the refined word the word that excuses it.

- The Everyman Chesterton