what are the comparison of old and modern quantum theory?

Answer 1

There is no "old" versus "modern" -- just one.

Answer 2

Trust me, there is quantum theory...I got a B in it when taking PhD physics.

The new quantum theory is called super-string string theory or simply string theory, even though that has given way to M theory. String theory posits that everything in our universe is made up of infinitely thin, very short (10^-35 cm) vibrating strings, which are the new quanta.

To get an idea how small these strings are, imagine your finger nail being expanded to the size of the known universe. At that point, your finger nail at the size it really is now would represent the size of a single string in your expanded finger nail universe...pretty small, strings.

How each string appears to us in the observable universe depends solely on the frequency it is vibrating at. Thus, one string can appear as a photon; while another might look and act like a graviton just because it's vibrating at a different frequency.

All the old quantum theory quanta, like bosons, muons, quarks, leptons, etc. can be explained by vibrating strings. In fact, that's one reason string theory has become popular, it can even explain the graviton, the messenger particle for gravity...something the theory of relativity and the old quantum theory could not do.

Answer 3

Modern quantum theory, which includes string theory and other refinements, is simply more detailed and complete. That's because we've had a century to confirm it, and fill in some of the theoretical gaps.

Answer 4

There is no "old" and "modern" quantum theory. There isn't any "quatum theory" at all. What we have is a field within the science of physics called "quantum physics". Within that field, scientist try to develop theories as like as they do in any other field. But there is nothing as like as what you are asking for.

Answer 5

It's pretty wide.
Basically because of today's technological achievement.

Without boring you with explanations...
Allow me to simply juxtipose and an analogy.

About 105 years ago, manned flight seemed impossible.
A couple of brothers figured out a way two years later, and they only flew for a couple of hundred feet. That's feet!

Sixty-six years later, a man landed on the moon.
In 66 years mankind went from a flight lasting less than thirty seconds to sending a man to the moon and back safely.

Quantum physics was only in a molecular level years ago.
And at that time, molecualr activity was small... Very small.
Now we're at the nano level; much smaller than your atoms and particles.

Now if you're talking about quantum theory dealing with time travel? That's like landing a man on Mars...

Not impossible, but currently improbable...