8 August 2009

Science You Learned, That Just Isn't True!

Posted by Dan Satterfield

Many times it’s easier to oversimplify a scientific concept than to take the time to figure out how to explain it correctly in a more simple way. This has led to a lot of people believing things that just aren’t true. In some cases, it’s because the misconception used to be thought correct, but we now know better. So here is a post about some scientific concepts that you might think are true, but really are not.

I’m also going to add in a couple of things you think are true without really thinking about it, and let’s hope I get it right. Why? Because some of it is pretty deep stuff, like quantum mechanics. Richard Feynman once said “that my students do not understand quantum mechanics, because  their professors do not, and I teach their professors about it, and I don’t understand it!” (However, he did win a Nobel Prize for his misunderstandings.)

So if I get any of this wrong, forgive me first and tell me second.

Number one: The Electron is a tiny object that orbits the nucleus of an atom, like planets orbit the sun.

Not really the best way to think of Atoms...

Not really the best way to think of Atoms...

You have seen the diagrams since you first opened your 5th grade science book. That’s the way atom works right??

Not really. The way I understand it, it’s better to think of the electron has a string of energy in a wave around the nucleus. It can only vibrate at certain different frequencies. This is why atoms will absorb a certain wavelength of energy, but ignore many others. If they can absorb a bit of energy and pop their electron into another allowed vibration, they will. Otherwise, they ignore the photon of energy.

The more correct way to think of an Atom and it's electrons.

The more correct way to think of an Atom and it's electrons.

The experts tell us, that we can’t even really know where an electron is, only the probability it will be at a certain place. Oh, and if you look for it there, that changes things, and it will not be there! (That gets into Schrodinger and his cat though, far beyond the scope of this site!)

Number 2: God does not play dice with the Universe.

I didn’t say that, Albert Einstein did, and he was almost certainly DEAD WRONG.

Imagine you have a chunk of Uranium 238. This chunk is radioactive, and the atoms in it will all eventually explode and end up as lead. It will take a long while for this to happen. In 4, 470 million years half of it will turn into lead. Half of the remaining Uranium 238 will turn to lead in another 4,470 million years.

Ahhh, but, here is the spooky part!!

Let’s look at just one uranium atom. Pick any one atom, it doesn’t matter. Now, how can we predict when that atom will fly apart and turn to lead? Can we look at the protons and neutrons and deduce which atom will go first?  What about the sub atomic particles (Quarks) that make up the neutrons and protons??

The current thinking of the experts in Quantum theory, is this:  There is no way of knowing when the atom will explode and begin the change to lead. Understand here, that I’m not saying that we can’t tell now. I am saying there is NO WAY TO EVER TELL. It’s chance. A roll of the dice.

There is no discovery we can make that will ever allow us to know. A bit uncomfortable to think about isn’t it? God plays Texas Holdem?

Seems that way.

Number Three:  Nothing can travel faster than the speed of light.



Actually, only information is limited to light speed. Photons cannot travel faster than light speed. The universe itself can though!

It’s still expanding, and one of the greatest discoveries in the last 100 years, is that it’s expanding faster and faster. It will eventually expand faster than the speed of light!

Another misconception is that the cosmic afterglow is the edge of the Universe. Even with a perfect telescope, (which does not exist) we can only see back 13.7 billion light years. Why, because that is how old the universe is. Light from galaxies farther away, has not had enough time since the universe began to reach us.

Every second, we can see 300,000 km farther away! It’s thought by many Cosmologists, that the universe is nearly infinite. Look up “inflation”. Put the words “big bang” in the search as well, or you will get Economics. (Scary thought in itself, isn’t it!)

Number 4 Gravity is a strong invisible force holding the planets in orbit (and us to the ground).

It was Einstein, of course, who put this myth to bed. First of all gravity is by far the weakest of the fundamental forces that rule the Universe. Magnetism, and the weak, and strong nuclear forces are many magnitudes stronger.

Go to your fridge and look at the magnets holding up the pictures and grocery lists. That little magnet is stronger than the gravity produced by the entire Earth at your feet!
Anyway, the planets are all going in a straight line. It’s space that is curved. Large masses bend space and time. One of the best, and easiest to understand illustrations of this is the image below. (You probably saw it on NOVA if in America, or the BBC.)

The real reason satellites orbit. Space is curved.

The real reason satellites orbit. Space is curved.

If you like thinking and learning about things like this, then I have a great tip for you. Go to the iTunes store and search for ASTRONOMY CAST. It’s free to download, and you will learn a lot more about topics like this! They get into much more detail, but explain it it all in very simple language. Even a Meteorologist can understand it!