The backprop network is hungry...
Keep feeding me data and I'll tell you the answer is - with a high degree of certainty - maybe/maybe not.
I remember my 5 neuron backprop network running on 486 DX2/66 back in the last century. You train it with weather data for a few hours hoping the CPU doesn't overheat and it could accurately predict there would be 'some weather' on a given day. You forget to save your training data and have to do it all over again - doh!
With all this compute power we can have a vastly more accurate maybe now. Think of all those neurons in the fluffy clouds...
