Depends on the wavelength of lidar. Near IR lidars (850 nm to 940 nm, like Ouster, Waymo, Hesai) will be focused to your retina whereas 1550 nm lidars (like Luminar, Seyond) will not be focused and have trouble penetrating water, but they are a lot more powerful so they instead heat up your cornea. To quote my other comment [1]:

> If you have many lidars around, the beams from each 905 nm lidar will be focused to a different spot on your retina, and you are no worse off than if there was a single lidar. But if there are many 1550 nm lidars around, their beams will have a cumulative effect at heating up your cornea, potentially exceeding the safety threshold.

[1] https://news.ycombinator.com/item?id=46127479

▲ tennysont 2 days ago | parent | next [-]

Follow up question that you might know: would multiple LIDAR sensor actually be additive like that? If you can stand a foot away from a car's LIDAR sensor and be unharmed, then can't you have:

  | Distance | # of Sensors |
  | 1        |            1 |
  | 3        |            9 |
  | 5        |           25 |
  | 10       |          100 |
  | 25       |          625 |
  | 50       |         2500 |
  | 100      |        10000 |

x^2 sensors at x feet from you and have the same total energy delivered? If sensors are actually safe to look at from 6in or 3in, then multiple the above table by 4 or 16.

It seems like, due to the inverse square law, the main issue is how close you can get your eye to a LIDAR sensor under normal operation, not how many sensors are scattered across the environment. The one exception I can think of is a car that puts multiple LIDAR arrays next to each other (within a foot or two). But maybe I'm misunderstanding something!

▲ stoneman24 2 days ago | parent | prev [-]

Do you if there has been any work how lasers affect other animals and insects?

Am I being catastrophically pessimistic to think that in addition to swatting insects as it moves forward, the cars lidar is blinding insects in a several hundred meter path ?

I’m very optimistic about automated cars being better than most humans but wonder about side effects.

▲

fragmede 2 days ago | parent [-]

If we have automated anti-mosquito vehicles just roaming around, the world would be a better place. There might be some second order effects from removing mosquitoes that we haven't predicted, but fuck mosquitoes.

	▲	dash2 2 days ago \| parent [-]
		Unfortunately not all insects are mosquitoes, and one reason we have many fewer birds in (e.g.) the UK than when I was young, is the decline of insect life.