The cooling towers weren't 'properly maintained' by modern standards because the hazard wasn't recognized.

Cooling towers mostly vanished from AC systems in subsequent decades because the maintenance & chemical water treatment regimes are now so onerous and expensive. Air cooled condensers are more usual now.

Similarly, spray humidifiers were replaced with steam humidifiers, etc..

> If it expanded faster, the light would never catch up. I doesn't seem like we should be able to see anything at all.

The mistake here is that you dismiss the fact that speed of the expansion is related to distance. What happens is: "space expands". Imagine that 1m of space at some point becomes 2m. This also means that 100m become 200m in the same timespan. Notice that this means that object which was 1m away is now 2m away (so moved away by 1m) but object which was 100m away is now 200m away (so moved away by 100m).

So while expansion makes everything further away from everything else, the distance change is greater the further the object is. So objects which are closer are getting away slower, and objects which are further are getting away faster (and even faster than the speed of light!).

It's true that light from things very far away won't ever reach us, because space expands faster than the light can travel, but there are lots of objects closer than that, and light from those objects will eventually reach us.

[removed]

I like this Fermilab video for explaining light slowing in a medium: https://youtu.be/CUjt36SD3h8

You can think of it as a wave moving through water with a bunch of ping pong balls. As the wave lifts and drops the ping pong balls they resist the acceleration, and that makes a little inverse ripple within the bigger wave. The big wave and the little ripples stack together into a slower wave, but the energy doesn't change, so once the wave moves past the ping pong balls it goes back to the same speed and height.

[removed]

[removed]

[removed]

[removed]

[removed]

> subatomic particles are made from distinct units, so in theory even if you "mix" them you should be able to follow where each part goes

Actually no. Subatomic particles are all excitations of the same underlying quantum field, and if we are using quantum field theory, they are not really things in themselves.
If you use quantum field theory to model e.g. sound waves you find that you can describe them with particles called phonons. However, if you have a sound wave in a material and pause time, no matter how much you zoom in on the sound wave you will never find it to be made of little balls flowing through the material.
In quantum field theory particles are less the water in my cup analogy, and more the abstract volume measurement of "a cup". You can add or remove 1 particle's worth of excitation, but when you do you do not add a "real thing", you add an amount of excitation to a real thing: the field.

[removed]

+1 to this. The cooling tower ought to be in the secondary circuit - a refrigerant is used in the primary circuit to cool the air in the evaporator - the inside unit of the air conditioner, and condensed back to a liquid in the condenser, with the heat being removed by the secondary circuit water. The water gets warmed up and then cooled down again in the cooling tower.

Was the party out on the terrace near the cooling towers where the legionnaires were exposed to the cooling tower spray carried by the wind?

No, for example -people often hear a thudding type noise when they see something that looks like it is landing hard and causing vibration but not actually making noise

If you know about the concept of neuroplasticity -it has an effect on what noises we hear and causes what are kind of illusions. Native Hindi speakers can discern two different 'd' noises that sound the same to people who did not grow up hearing Hindi. English speakers can very easily discern the words "pen" and "pin" but many language speakers dissimilar to English cannot. German people who did not grow up hearing English (which today is essentially none of them) often could not perceive "th" sounds -if you've heard stereotypical German accents where "the" is pronounced like "ze", it is based on this -back in the day German people usually couldn't hear th sounds

If you've ever heard someone trying to learn a language or tried to learn a language yourself and just not been able to get certain sounds right -this is often why. When the brain did not grow connections to be able to perceive certain sounds, you cannot hear them and your brain creates an illusion of a sound you do know.

There are also tons of visual illusions that we perceive 24/7 the time but do not notice

They are vibrations of quantum fields (in this case the electromagnetic field), so you can say that the fields are passing energy, momentum, angular momentum, etc from one place to another, and this "bucket brigade" of physical quantities is what we call a particle.

You could technically describe this as photons continuously being destroyed as they create new photons in adjacent locations. But it's not that physically meaningful, it's like adding +1 and -1 to the same side of an equation. It doesn't really do anything but use more ink.

[removed]

Only if the heat capacities of the two liquids are identical.

This is actually a very simplistic case since many liquids heat up or cooldown when mixed together due to thermodynamics.

This block of text felt too complex for a leyman like me to fully understand it as I read through, is there a "for idiots" version of it?

[removed]

[removed]

The light would’ve already passed us. We can only see light that hits our telescope every nanosecond and every nanosecond new light from that object reaches us. We can never determine where in the sky that light started to travel. Our snapshot of the universe is exactly that; the light that we see exists in the moment it reaches us locally but the object it originated from is never in the same position as we see it.

>subatomic particles are made from distinct units

Then we enter into the particle vs wave interpretation. If you think of them as rigid particles then you would indeed think that you could follow them (keeping out the fact that observing means interactions, which means altering the state). My particle physics professor said it like this "subatomic particles are spatiotemporal fluctuations of quantum fields", which is a very abstract but interesting way to put it.

A proton for example is made up of three quarks, kind of. In fact, it also contains virtual quark pairs that exist for a ridiculously short amount of time, being fluctuations in the strong nuclear field.

But some things are still conserved. Meaning that if I have two particles with one being spin up, and one being spin down. Then when I measure them I will still find one spin up, and one spin down. But that doesn't mean that the particle remained "intact" and rigid along the way. What is conserved is the total spin of the system. Not that of the individual particles.

Thanks for your reply!

Might this be an effect we need quantum gravity to explain? My intuition is any gravitational effect at that scale would be too small to account for the observation, but tiny relativistic effects do have a way of stacking up in many particle systems.

[removed]

Imagine the Earth is already moving with respect to the preferred frame imposed by the universe's geometry. Then depending on the direction of travel, the traveler could potentially be moving slower than the Earth, with respect to that preferred frame.