Getting a control/test subjects is pretty easy.
You just have to sit down and think 'What am I going to measure?'
For instance, if I was measuring the effect certain chemicals had in the water of plants as to respiration, then my control would be identical (plant in water) without the things you're testing (the added chemicals).
It's the red giant phase he's talking about.
ps.
Faf: you can ignore the first 850 of those 1000 years. Horse driven carts to, say, (in the near future), maglev trains, and nothing to flight...
Although personally I'd go back 350 years, to Newton.
Oh, and a control should be, say, a brick or something rather than just nothing. Something that shares all the properties of the things you're testing apart from the variable. Paper, or similar.
Saying 'live plant' and 'dead plant' as seperate things is about as useful as saying 'food'; I'd presume that 'different types of plants' was the condition undergoing testing.
it's not accelerating at the moment, because there's no resulting force.
On an object in mid air, there is a resulting force (gravity) so there's an acceleration. (F=ma)
The desk is providing a normal reaction to your phone, so there's no force.
An additional argument: If someone isn't accelerating when it's stationary, how would anything EVER move?
ps
:lint:0dt can still equal a constant, for the maths.
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