Chapter 3 Questions


Question:

How do we know that what we are learning is right? After all, Newton and Aristotle thought they were right, too.

Answer:

First, don't fall into the trap of believing that nothing can ever finally be correct. We know the shape of the Earth, and have mapped out its continents. Columbus was wrong (this ain't India), and asserting "How can we be sure about the existence of North America, because Columbus was sure it didn't exist" would be ridiculous.

In fact, both Newton and Aristotle were right about some things, Newton much more than Aristotle. Aristotle had to work with the facts as they were understood in his time. Newton benefited from knowing what had been learned since then, and we benefit because we know what Aristotle, Newton and Einstein learned. We think that much of what we know today is rock solid, and other parts are much better known than used to be the case, although not as solid as we would like. And there are still acknowledged gaps in our understanding. We have tried to be explicit in this book about what things are well established, what things are pretty well established, what things are tentative, and what is still a mystery.

Recall Newton's quote

I seem to have been only like a boy playing on the seashore, and diverting myself now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.
Newton knew better than anyone how much he didn't understand. Such humility is good, but Newton nevetheless made real progress, and this should be acknowledged.

Question:

What would the easiest way to communicate with aliens? Would math suffice?

Answer:

Communication with aliens would require some completely nonunique, noncultural, objective means. Math and physics would offer the best way to do that. The difficult question is whether there would be a way to express those things in some symbology that would be immediately recognizable. We might believe that sending a sequence of beeps, such as BEEP, BEEP-BEEP, BEEP-BEEP-BEEP, would suggest counting 1, 2, 3, but would the aliens recognize this?

Question:

Is there anyone who could be considered the "father" of cosmology (as Freud is the "father of psychoanalysis")?

Answer:

Not generally. I am willing to nominate Einstein for that role since he is the "father of General Relativity" which is the theory that applies to modern cosmology. Others might nominate Aristotle or Plato or someone like Aristarchus for being the first we know to have tried to construct a coherent cosmology. You might also suggest Hubble as the "father of the expanding universe" or Lemaitre as the "father of the big bang."

Question:

In the early days of the US space program how much of the physics of orbiting Earth did scientists understand and how much did they learn from launching the first astronaut (who just went up and came back down without orbiting)?

Answer:

A lot of the basic physics was known, but there were some important questions that could only be resolved with experiment. For example, the Earth's gravitational field is not perfectly spherical but has variations. How much do those variations affect orbits? How high does the atmosphere extend and how dense is it at high altitude? How much radiation is present, and how does it affect spacecraft and humans? How will humans react under high accelerations and weightlessness? How much protection is needed for the human body against the conditions likely to be encountered during the trip? Then there were the engineering problems of building and controlling a rocket.


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Copyright © 1998 John F. Hawley