Concepts in physics that would astound a 17th century person

Great Debates
1

So if someone from 300+ years ago (the age of enlightenment roughly) were told about contemporary ideas and discoveries in physics, what would they be astounded by or bowled over by?

I am sure some of these concepts are wrong, so feel free to correct them. But concepts like the following would be pretty interesting to hear since they are counter-intuitive or challenge unspoken assumptions about existence:
We live in a (likely) 3rd generation star system. A star was created, existed then died and its waste material made another star. That star was created, existed then died and our star is made from the waste material of that star. The heavier elements in our bodies were made in those dying stars billions of years ago.

The moon was formed when two proto-planets crashed into each other over 4 billion years ago, the collision created the moon.

Retrocausality seems to exist in quantum mechanics (I am not sure how many experiments have been done to verify it)

Observing physical phenomena can effect its outcome

Subatomic particles disappear than reappear all the time

The universe was once smaller than an atom

As you approach the speed of light your mass increases and time slows down

Our star is only one of about 10^22 that exist in our known universe, there could be infinite universes aside from ours

If the dozens of physical parameters of our universe were even slightly different then virtually nothing would be able to exist because chemistry wouldn’t work or be stable (fine tuned universe).

A drop of water has about 10^21 molecules of water in it (more chemistry than physics but still)

Most of the matter we see is empty space, it is the electric fields interacting with each other that we notice. In more dense matter like a neutron star a teaspoon weighs as much as a skyscraper, and gravity is so powerful that dropping something from a height of 1 meter would cause an object to accelerate to 4 million mph before hitting the surface.

Energy can be converted into matter, and vice versa

This isn’t physics but life is almost 4 billion years old and in the last 600 million years there have been about 6 mass extinction events that have killed much of the life here. Evolution in general would be pretty new as a concept.

2

Nitpick: ALL matter is essentially as you say, electricomagnetic fields interacting with each other. We cannot “see” the empty space between, because there’s nothing for photons to bounce off of.

The very concept of atoms, molecules, and how chemical reactions work would be baffling to a 17th century person. Heck, most elements we take for granted – such as oxygen – weren’t even “discovered” until the 18/1900’s.

Plagues and illnesses caused by tiny creatures too small to see? HA! What nonsense!!

Most people from that era still believed in witchcraft, magic, and spiritual creatures from leprechauns to gods. Wait, come to think, that part hasn’t changed all that much…

3

IIRC the 17th century was right around the time Copernicus and more seriously Galileo actually did astound people by starting to prove that everything didn’t revolve around the Earth but rather the Earth and most of what they could see revolved around the Sun.

4

Show them a working television, then try to explain the photoelectric effect.

5

The biggest bummer for them would be that humans don’t occupy a special place in the cosmic order.

6

How about radiology. Every time I’ve had to have something like an MRI or CT done, I think about how amazing it is that I can get something like a slipped disc or kidney stone diagnosed in minutes when, hundreds of years ago, the best they could do is hand you some willow bark and hope for the best, not having any idea what the problem might be.

They could take some guesses, but cutting for stone is a big risk for what might end up being a UTI or a dislocated rib.

7

I think a scientific minded person could get a good understanding of a CRT TV if you gave them some time. Especially if we assume, for a moment that they were learning ‘in a vacuum’. That is, they weren’t distracted by everything else going on. They were just here to learn about how a TV makes a picture. Even down to the atomic level, it’s pretty straightforward.

Now, airplanes, those shouldn’t fly, they’re way to heavy.

8

I am pretty sure people in the 17th century were familiar with birds.

What is the debate supposed to be here?

9

Birds don’t have fixed wings. Airplanes don’t flap.

I’m familiar with birds as well and living and working near an airport I see a lot of airplanes. Still, seeing something the size of a 747 take off, it just seems like it should drop out of the sky.

10

First, they’d be astounded to learn that the 17th century was 300 years ago, and not 400 years ago. :wink:

The problem with picking the 17th century, that is the 1600s, is that it was in mid century when Newton published his findings. Pre-Newton, people might be astounded by Newtonian Mechanics. Post-Newton, not so much.

But once that is out of the way, one needs only explore the history of physics and astronomy:

  • That electricity and magnetism were the same force.

  • That we live in a galaxy and there are other galaxies out there

  • QM

  • Relativity, General and Special

  • The photo electric effect.

  • Particle Physics

  • etc.

There are also lots of things in chemistry that would astonish them, but if you are distinguishing between the two sciences, then maybe that’s not worth exploring.

11

One that would even blow the minds of most 21st century people is that nothingness doesn’t exist, empty is not empty. (anti)-Particles are popping in and out of existence everywhere.

The “vacuum of space” is not empty space. To produce real empty space takes a massive amount of energy and it is not at all a stable state.

12

“We can resurrect the dead.”

…

“Ha, just kidding. Here, play with this laser pointer for a while.”

13

My opinions:

The size of the universe.

The age of the universe.

That we all evolved from single-celled life.

That the universe was compressed into a very small space.

However:

I don’t think this would be surprising to anyone. Once you know that vision is based on light, and every other way to observe something is based on interacting with it with some other physical bits, it shouldn’t be surprising that interacting with something can affect its outcome.

14

I really have a hard time getting my head around the proposition that I’m affecting the sunset by watching it.

15

On the macro level, you can imagine using a tire-pressure gauge. It lets a little air out when you check, so your “looking” at the tire pressure affects the tire pressure.

But this is generally only really interesting at the micro level (quanta, particles) that have wave-particle duality. See the Uncertainty Principle.

16

That’s a problem for most Americans in the 21st century.

17

I think a lot of the above examples would simply “not compute”. The age and scale of the universe would be difficult enough to grasp, never mind the number of molecules in a drop of water. How about just a Vietnam-era sniper’s rifle? Or that we can send something up in the sky, have it orbit the earth, then return?

18

You have to consider what a 17th century person would know of physics in the first place.

“Subatomic particles disappear than reappear all the time.”
“Okay…what are subatomic particles?”
“Oh, sorry, those are the things that make up an atom.”
“And what’s an atom?”

People need to appreciate how short the history of modern physics is. My grandfather was born the year that the electron was discovered. Everything in physics from electricity to string theory happened in his lifetime.

19

Explaining the chemical composition of a fart.

20

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