An actual 4D printer could be trivial though. Just like the 3D printer discretize the height in several layers, the 4D printer would slice the fourth dimension in several hyper-layers and print a 3D object for each slice. We already have the software to create 3D slices out of 4D objects.

The trick will be to reassemble the slices into a 4D object :-)

Just looking at these cross sections could be interesting. Also printing the same object at different resolutions along the fourth dimension could be insightful.

There's more than one dimension- any real parameter is considered a dimension in this context.

In this case, as the PR specifically says, the fourth dimension is time: they are encoding a temporal path within the object.

Ok, we took one dimension away from the title above.

Would you mind adding it back? The press release specifically says that the fourth dimension is time. This is indeed a valid dimension, and I read the PR enough times to verify that they're not padding their claim.

"""...has evolved their microscale 3D printing technology to the fourth dimension, time."""