Physics: Principles and Problems


Archives 

Physics: Principles and Problems Glencoe Online
Science Home Product Info Site Map Search Contact Us  

In the News
Archives

For use with Chapter 27
Quantum Theory

Beam Me Up!
Posted April 28, 2000

Teleportation has always been a dream of science fiction writers. However, experiments are now being done in quantum physics that have made teleportation a reality--at least at the quantum level. Scientists have been able to teleport particles of light called photons.

In the case of such "quantum teleportation," the photon moves from one point in space to another instantly. This may seem to contradict Einstein's Theory of Relativity, which states that nothing can go faster than the speed of light. Quantum teleportation, however, doesn't break this rule - it goes around it. The photon doesn't actually travel across the space. Instead, it disappears from one place and reappears in another instantaneously.

This works because two particles (in this case, photons) can be linked together, a process known as "entanglement." When this happens, both particles take on the exact same quantum properties. They become identical in every way. When the properties of one particle changes, the other changes along with it. And this happens at exactly the same time, even if the two particles are hundreds of light years away.

A third particle can be introduced into the system and compared to one of the entangled particles. When the third particle causes a change in one of the entangled particles, the other entangled particle goes through an identical change. The third particle can then be replicated at the second location. Because entangled particles change at the exact same time, the teleportation is also instantaneous.

Although the change in the entangled particles is instantaneous, the entire process may still be limited by the speed of light. Quantum teleportation is only accurate 25% of the time. To compensate for this, a message must be sent between teleportation points that confirms the accuracy - and this is still limited by standard methods of communication.

While these experiments are ground-breaking, don't start expecting to see Star Trek transporter beams any time soon. Teleporting a photon is very different from teleporting a human being. Some scientists even suggest that such a feat would be so complicated that it will never be accomplished. Other scientists just see it as a matter of time.

 

Activity
Use the sources given here to learn more about teleportation. In your science journal, write a science fiction story about teleportation. Be sure to include the scientific theories behind it and how it is possible.

References

 


The McGraw-Hill 

Companies
Physics: Principles and Problems