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I'm imagining a "gigantic" scientist (as big compared to the Earth as we are compared to a hydrogen atom). The scientist lives to be 15 billion years old, and has a very slow metabolic rate (e.g., 1 heartbeat every 500,000 years).

If this scientist made observations on the Milky Way galaxy, would celestial bodies still appear to move according to Newton's mechanics, or would they exhibit quantum-relativistic interactions?

To reverse the question, I'm imagining a scientist about the size of a proton. The scientist lives only a fraction of a second, and has a heart rate near the speed of light. Would subatomic particles appear to exhibit Newtonian mechanics to such an observer?

No, there seems to be a natural scale to the Universe. The problem is that as something get bigger (more massive) its effective wavelength gets smaller. So subatomic particles (electrons, protons, neutrons, etc.) have a dual wave/particle nature that is observable because the wavelength of the particle is "close" in size to the particle. If you get larger, things get more disparate. A human body has a wavelength that is so small, there is nothing for it to interact with, and a galaxy even smaller.

Dr. Eric Christian

Someone falling a foot and a half will reach about the same speed whether they are 6 feet or 2 inches tall. Actually the 2 inch tall person will probably not be moving as fast because of more air resistance. So the damage will not be "scaled". This is why cats, mice, grasshoppers, etc. can jump or fall much larger distances relative to their size than a man, and still not take any damage. A mouse would scarcely notice a foot and a half fall, and their legs are much thinner relative to their body size than a man's.

Dr. Eric Christian
(May 2000)

If you drive down a street after a snow and all the houses on one side are facing south and the other facing north, you will easily see that the Sun can very easily melt snow. There are about 1300 watts per square meter of area of energy from the Sun. Given that reasonable aluminum mirrors can reflect upwards of 90% of sunlight in the infrared region, I see no reason why you can't arrange 1 or 2 mirrors to melt snow off of something in your yard.

Dr. Louis Barbier
(November 2001)

Dynamos, as they are most often discussed today, relate to the way that an electrically conducting fluid can self-generate a magnetic field. It's true that the traditional definition relates to how to generate electricity by using magnets, but electric motors and electric generators are now well understood. So, let's look at your basic question, and that is how to reverse a magnetic field.

Magnetic fields arise from currents. Magnetic force in classical physics describes the attraction or repulsion between two currents. That might seem odd, since you can touch a bar magnet without getting a shock and there aren't any currents there that you can easily measure, but the currents in a piece of magnetized iron lie within the atoms themselves. When all the atoms align correctly, there is a hidden, but very real, current circulating within the metal.

So now the answer to your question is easy - to reverse the magnetic polarity of your magnetized boots, you simply reverse the currents in the boots. That means either you have currents in wires within your boots and you reverse a switch, or you have magnetized material in the boots and you reverse the material. You can, instead, place the boots with their magnets in place on a stronger magnet that will reverse the orientation of all those little atoms and that's how you magnetize a piece of iron in the first place.

You should know that as far as I know the astronauts do not wear magnetized boots. The material that spacecraft are made of tends not to be magnetic. They use things like Velcro straps to hold their feet to the floor when they are working. Magnetized boots are still a thing of the future.

Dr. Charles Smith
(April 2004)

The information from your teacher is incorrect. You can accelerate an electron up to high enough velocity so that it would go through a wall, but it does so the same way a bullet does: it slows down and does damage (ionization damage) along the way. The electron doesn't become "unstable" and neither would the wall. And to pass through the wall, the electron needs many millions of volts of acceleration and to be traveling near the speed of light. In addition, a person has both positively charged nuclei, as well as electrons, and the electric field would accelerate them in different directions. It just doesn't work.

Dr. Eric Christian

(June 2010)