Heisenberg Uncertainty Principle: The Uncertainty principle or Heisenberg’s uncertainty principle is a part of quantum physics. When scientists were understanding the concept of light they understood a few things. One of their important findings was that light is both a particle and a wave since it has the properties of both. This gave rise to quantum physics which was later used by Heisenberg’s uncertainty principle.

Heisenberg realized that one cannot find the exact position and speed of an object together. There are some approximations that help us find these values. Uncertainty is often explained as the result of the measurement. The act measuring an object’s position changes its speed or vice versa.

Heisenberg’s Uncertainty Principle: Definition

It states that there is a variety of mathematical inequalities in measurements which creates a kind of fundamental limit to the precision. Thus, there is uncertainty in all kinds of measurements because of the property of a particle. Read on and understand the thought process of this great scientist. This will help you can understand what he meant by uncertainty and how he arrived at this principle that helps us in measuring both position and momentum of a particle.

Equation of Uncertainty Principle

Heisenberg’s Uncertainty principle states that:

$$\Delta x\Delta p\ge \frac{h}{4\pi }$$

Uncertainty principle exists since everything in the universe behaves like both a particle and a wave at the same time. In quantum physics, the exact position and the exact speed of an object have no meaning. you may be wondering why I am saying this, so let’s understand this better.

Quantum Physics Has Two Parts

Particles- They have an exact position. A particle can be plotted on a graph to show its position.

Waves- They are in simple terms some disturbances spread out in space. Who’s momentum can be measured.

That means we can understand and measure wave patterns as a whole through something called wavelength (distance between two neighboring crests (peaks)). But a wave can’t be assigned a single position. Wavelength is essential since an object’s wavelength can help to measure its momentum which is mass*velocity.

For example, an object moving fast has lots of momentum which corresponds to a short wavelength. Whereas it’s the opposite in the case of a slow object. That’s about the speed part of the momentum. Now about the mass, a heavy object has lots of momentum even though it’s not moving very fast i.e., again a short wavelength. Therefore, it’s difficult to know the wave nature of an object. To add to this, the faster the object shorter the wavelength. Which makes it, even more, difficult to measure the wavelength. For example the motion of a rocket.

So the problem is, a wave has no position whereas a particle has no wavelength and hence we do not know its momentum. Therefore to get measure a particle’s momentum or a wave’s position quantum physics comes into the picture.

To Measure Both the Momentum and The Position of the Object

Add two different waves, what you get is a wave with a higher peak in some places and plain surface in the other places. This happens because the other peaks line up and cover up some of the troughs creating a plain surface. Therefore, you get two regions one with waves and the other with nothing at all. If we keep adding waves to this, the region where we get nothing at all gets larger and wavy regions get narrower. Now keep adding waves, we get a wave in one small region. This region is a quantum object with both wave and particle nature.

To accomplish this, we had to lose certainty about position and momentum. Since we added up so many waves the position isn’t restricted to a certain point. Therefore, you have a good probability of finding the particle in a certain region that is restricted to the region within the wave packet. Similarly, the momentum could correspond to any one of those waves which we added up. Therefore, position and momentum are uncertain.

If you want to reduce the uncertainty you need to reduce the size of the wave packet, you need to add more waves which creates a bigger momentum uncertainty. If you need to know the momentum better you need a bigger wave packet which makes the position uncertain. So it’s all uncertain and you can’t get the exact momentum and the position together as suggested by Werner Heisenberg.

FAQs on Heisenberg’s Uncertainty Principle

Here are some of the frequently asked questions on Heisenberg’s Uncertainty principle:

Q1: Can I tell that an electron is located at an exact location with 100% accuracy at an exact time through measurement?
A: No it’s not possible.

Q2: Who conceived the idea of the possibility of finding an electron in an orbital?
A: This idea was first conceived by Heisenberg.

Q3: What is an Orbital?
A: Orbital is the space around the nucleus where the probability of finding the electron is maximum.

Q4: Which two scientists proposed the idea of the uncertainty principle and the concept of wave nature of matter?
A: Heisenberg and de Broglie proposed the concept.

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