```r
set.seed(2018) # set seed for reproducibility
(bb_world = st_bbox(world)) # the world's bounds
#>   xmin   ymin   xmax   ymax 
#> -180.0  -90.0  180.0   83.6
random_df = tibble(
  x = runif(n = 10, min = bb_world[1], max = bb_world[3]),
  y = runif(n = 10, min = bb_world[2], max = bb_world[4])
)
random_points = random_df %>% 
  st_as_sf(coords = c("x", "y")) %>% # set coordinates
  st_set_crs(4326) # set geographic CRS
```