**Ask a monkey a physics question thread**

[BananaStand]

I don't know dude. That all really sounds like a lot of maybes and excuses.

Still sounds to me like doing the exact same experiment will yield two different results based on whether or not certain parts of that experiment are being observed.

That's spooky fucking shit!

[OngBonga]

Still sounds to me like doing the exact same experiment will yield two different results based on whether or not certain parts of that experiment are being observed.

observed = measured

The act of measuring changes the initial conditions. Of course there will yield two different results based on whether or not it was observed. That's not spooky, it's totally intuitive. How do you "meausre" the velocity and location of a particle? Or, more to the point, how do you do this accurately without altering its trajectory and thus changing the conditions? Hint - you can't, see "uncertainty prinicple".

The double slit experiment can be explained by pilot wave theory. I'm not sure what to make of it all, but the basic gist is every particle has an associated wave, and the wave essentially carves out a geomoetric path for the particle to follow. The trajectory of the particle is determined by its initial conditions, at least until we try to measure it, thus changing its trajectory.

[BananaStand]

The act of measuring changes the initial conditions. Of course there will yield two different results based on whether or not it was observed. That's not spooky, it's totally intuitive.

So I can change the temperature outside by walking outdoors with a thermometer? Sorry, I'm not buying it.

The fact that I can change the behavior of matter in a way that defies the rules of physics, merely by exercising my own consciousness, pretty much proves that I am God.

Or at least, a god

[MadMojoMonkey]

So I can change the temperature outside by walking outdoors with a thermometer?

Theoretically, yes... ish.
Your presence is definitely emitting ~75 Watts of heat when you're inactive. It can be as high as ~150 Watts under intense physical exertion, like any time your breathing is elevated for a sustained period.
This is going to trump the small amount of heat being absorbed or emitted by the thermometer as it comes into thermodynamic equilibrium.

Being able to measure and prove the heat a body emits in a well insulated room of any size is standard. In laboratories where temperature control is essential, there is generally a line of 100 W lamps in the room and whenever a researcher enters the lab, they turn off a light, and turn it back on when they leave. This helps maintain the heat being generated in the lab.

Proving this happens in the atmosphere with a thermometer is going to be impossible.

Conservation of Energy still holds that if you're emitting heat into the atmosphere, then the atmosphere is getting warmer. Whether or not you're inside is probably of minimal relevance. The air in your house is cycled with outside air more often than you may think, but it varies widely. It's just that the atmosphere is really big [citation needed] and the cumulative effect your body heat has on global climate is negligible.

Sorry, I'm not buying it.

There goes my retirement!

The fact that I can change the behavior of matter in a way that defies is explained by the rules of physics, merely by exercising my own consciousness, pretty much proves that I am God.

Or at least, a god

FYP, oh mighty god-brother.

[MadMojoMonkey]

observed = measured

In this context, yes.

The act of measuring changes the initial conditions. Of course there will yield two different results based on whether or not it was observed. That's not spooky, it's totally intuitive. How do you "meausre" the velocity and location of a particle? Or, more to the point, how do you do this accurately without altering its trajectory and thus changing the conditions? Hint - you can't, see "uncertainty prinicple".

This is measurement uncertainty and it is a separate problem than quantum uncertainty laid out in the uncertainty principle.

Measurement uncertainty is a common problem. Consider measuring your car's tire's pressure. By attaching the pressure gauge to the tire, you obtain a reading by releasing some of the pressure into the tire pressure gauge. You cannot measure the pressure with that gauge without altering the pressure you're trying to measure.

This applies to quantum particles, too, but it is NOT the uncertainty principle.

The uncertainty principle says that, even with "perfect" measurement devices, you still cannot simultaneously measure the position and momentum of something to arbitrarily high precision. Those properties DON'T SIMULTANEOUSLY EXIST IN THE UNIVERSE for any particle... because particles are waves, and waves have this property.

The double slit experiment can be explained by pilot wave theory. I'm not sure what to make of it all, but the basic gist is every particle has an associated wave, and the wave essentially carves out a geomoetric path for the particle to follow. The trajectory of the particle is determined by its initial conditions, at least until we try to measure it, thus changing its trajectory.

That pilot wave is the imaginary portion to the solutions of Schroedinger's Wave Equation. Particle wave functions are complex-valued. To determine probabilities of observing certain properties of a particle, you square the wave function and integrate over some domain. The squaring eliminates all negative and complex values from the result, making them neatly measurable predictions.

There is no known way to measure a complex-valued wave, and the pilot wave theory is predicated on these imaginary solutions directing the particles' apparently random motions in deterministic ways. It's a comfortable view, but not falsifiable by any known means, so not, strictly speaking, science.

[MadMojoMonkey]

I don't know dude. That all really sounds like a lot of maybes and excuses.

Still sounds to me like doing the exact same experiment will yield two different results based on whether or not certain parts of that experiment are being observed.

That's spooky fucking shit!

This is mostly spot on, actually.

I mean,there are no maybes* or excuses, but it does sound like I'm making stuff up.
Like I said: There's no reason you should believe hearsay on the internet, whether from me or colonel Sanders in spandex.

It is spooky. There are more spooky aspects to quantum, too.
Check out the EPR paradox.


*OK, saying that the position and momentum of all the things are actually best described by squaring a complex-valued probability density function, then integrating that over some domain - that sounds dangerously close to maybes... but it's really not. That probability density function is well-defined and repeated experiments continue to confirm its utility.

[BananaStand]

This is mostly spot on, actually.

I know. What about the subsequent post where we determine that I'm God? You on board with that too?

I mean,there are no maybes* or excuses, but it does sound like I'm making stuff up..

For what it's worth, it was better than Ong's explanation where photons shoot out of your eyeballs.

Like I said: There's no reason you should believe hearsay on the internet, whether from me or colonel Sanders in spandex

Let's be clear on one thing. This is the last time you badmouth the colonel.

It is spooky. There are more spooky aspects to quantum, too.
Check out the EPR paradox.

No shit it's spooky. So fuck your EPR paradox. I'm not interested in giving myself nightmares.

*OK, saying that the position and momentum of all the things are actually best described by [nerd talk]

I can sorta wrap my head around the idea of things being two places at once and all that. Like the electron passing through the double slit is both a particle and a wave. And it goes through both slits, and neither. Or just one. Or just the other. All at the same time. Fine.

What's not clear to me is how I can personally determine whether it's one thing or another just by my conscious decision to pay attention to it or not.

The idea that a thought is a physical thing that interacts with the environment around it is a pretty incredible thing to think about. Imagine the power that might be unleashed if a whole bunch of people all had the same thought at the same time!