Discrete Signals

my professor said that everything in nature is on continuous time domain (continuous signal) and there is no discrete signals. i too know that do you have any idea that why discrete signal are not in nature .i am expecting geeky answers about this.Thank you

Beacause everything in nature is continuous. Like the sun emitts light continuosly and not every whatsovever microseconds. And water floats continuosly and not "step-by-step". So for discrete processes you need a (fixed) time step. But in nature there is no such time step in which things happen. Hope this helps!

the pulse of human is discrete signal ,isnt it?

okay


could some give me example for discrete signals and digital signals?

The human pulse could be treated as discrete values. Cause either there is a pulse (1) or not (0). But it is not time discreet because it can happen at any moment. A time discrete signal would be for example if you read the value of a temperature sensor every second. If the sensor can output values only in fixed steps (e.g. 0.1°) it would be a digital signal (time and value discrete) otherwise it would only be time discrete (like reading the resistance value of a Pt100 every second).