We all know the specific sound and effects from the Star Wars movies, that little "pew pew" effect of a blaster firing laser bullets. But what would laser bullets look like in real life?
The answer might surprise you.
Let's face it, there's a lot that Star Wars gets wrong about physics: from the space battles to the duels with light sabers. And now, a team of scientists from the Laser Center of the Institute of Physical Chemistry of the Polish Academy of Sciences in cooperation with the Faculty of Physics at the University of Warsaw have shown that the laser bullets fired from blasters are also different in reality.
The team started their research by using a small, but extremely powerful, laser that fires short quick pulses. These pulses are fast enough to ionize atoms as they fly through the air, which creates a strand of plasma that appears white beside it. The team maintained a delicate balance between the electromagnetic field of the pulse and this strand, so that it wouldn't break up once fired. This gave the pulse a good firing distance.
"It is worth noting that although the light we are shooting from the laser is in the near infrared range, a laser beam like this travelling through the air changes colour to white," says Dr. Yuriy Stepanenko, who led the team. "This happens since the interaction of the pulse with the plasma generates light of many different wavelengths."
Perhaps the trickiest part of their study, though, was capturing the laser pulses on film. Because the pulses are so fast, capturing them on video requires a camera that can record billions of frames per second, which does not exist. Instead, they adapted a camera and synchronized it with laser pulses at around 10 shots per second. With every pulse, the camera captured an image only slightly delayed than the one before it.
"In fact, a different laser pulse can be seen in every frame of our film," says study co-author Paweł Wnuk. "Luckily, the physics always stays the same. So, on the film one can observe all the effects associated with the movement of the laser pulse in space, in particular, the changes in ambient light depending on the position of the pulse and the formation of flares on the walls when the light passes through the dispersing cloud of condensed water vapour."
However, these laser bullets aren't meant for weapons. This team of scientists created these distance-traveling pulses for sending into Earth's atmosphere for studying pollution there. The laser's white light illuminates contaminants.
