List of Figures

View Image Figure 1:
Heisenberg’s microscope. A photon moving along the x-axis scatters off a probe within an interaction region of radius R and is detected by a microscope (indicated by a lens and screen) with opening angle 𝜖.
View Image Figure 2:
The length of a string is not the same as its average extension. The lengths of strings in the groundstate were studied in [173].
View Image Figure 3:
Spacetime uncertainty (red, solid) vs uncertainty from spherical black holes (blue, dotted) in D = 10 dimensions, for g < 1 s (left) and g > 1 s (right). After [318], Figure 1. Below the bound from spacetime uncertainty yet above the black-hole bound that hides short-distance physics (shaded region), the concept of classical geometry becomes meaningless.
View Image Figure 4:
Cross section for scattering of two scalar particles by graviton exchange with and without running Planck mass, in units of the low-energy Planck mass √ --- 1∕ G0. The dot-dashed (purple) line depicts the case without asymptotic safety; the continuous (blue) and dashed (grey) line take into account the running of the Planck mass, for two different values of the fixed point, ∘ --- 1∕ &tidle;G∗ = 0.024 and 0.1 respectively. Figure from [261]; reproduced with permission from IOP.