When you turn on a telescope, the image of an astronomical body can be a “virtual universe”, an image that appears to exist within your field of vision.
Astronomers have long known about this phenomenon, but it was not clear how this virtual universe could be created in the first place.
Now a team of researchers from Germany and Japan has discovered how to create it.
The research is published in the journal Science Advances.
“We can now create an image of the cosmos in which everything is real, and which, in its realness, we see as a hologram,” says team member Dr Tetsuo Ishikawa from the University of Stuttgart in Germany.
The team created the image by first creating an image with different wavelengths of light in different wavelengths.
This creates a different “virtual” image, in the same way that you can see the light coming from the sun and the moon from different angles.
The scientists then used this virtual image to create the illusion of an object at the centre of the galaxy known as the “sphere of interest”.
The researchers say this hologram of the real world is created by a process called optical mixing, where the images are combined to create an overall image that is perceived as the image in the telescope.
It is a technique that has previously been used in astronomy, but was never seen in real life.
The idea of creating a virtual image is not new.
For example, astronomers have previously created images using a process known as optical harmonisation.
Optical harmonisation involves creating an optical image of a sphere of light, like the one above, and then combining this image with images of stars and galaxies that have been imaged by other telescopes.
The combined image can then be viewed in a telescope’s optical optics.
But optical harmonisations have typically been done in a very high-powered optical microscope, so the images of the stars and other objects would be much larger than the image taken in the microscope.
“When you see a star in the sky, you know that there is a star there, and you can zoom in on it with your telescope,” Dr Ishikawa says.
“But when you zoom in with your smartphone, it’s much harder to see the star because you’re seeing light that is so dim that it’s barely visible to the naked eye.
This is the real image that the telescope sees.”
The researchers used a similar technique to create a virtual version of the sphere of interest, with the same parameters.
The images of galaxies in the virtual sphere are similar in size to the images taken by the telescope, but because they are combined, the resulting images are much smaller.
“To create the hologram, the team took the real and the virtual image into account, and created the real version of an image by using optical harmonization,” says Dr Ishigawa.
“Then they used this holographic image to make a virtual copy of the same image that has been created by optical harmonizing.”
“It is quite astonishing how well it works,” says the lead author of the paper, Dr Jürgen Ebert from the Department of Physics at the University and Research Centre in Darmstadt, Germany.
“The hologram is very strong, but at the same time the image is quite blurred.”
Dr Ebert says that while it has been observed before, the new technique could be used to create images that have already been created before.
“It will probably become the basis of many future research projects.
It’s possible that in the future, we might have a holographic universe that has already been produced, and it could be useful for creating the images that we see in our telescopes,” he says.
But Dr Eberts team is not done yet.
They are currently working on creating a holograms of the entire universe, and the team is currently seeking collaborators in other countries.
“With the right partners, we are hoping to create holograms that span across the entire observable universe,” he adds.
“One day we will be able to create image holograms, and in the meantime, we will continue to work on creating holograms in our real universe.”