Nerd Pride Radio

This thread is for people to post questions without fear of judgment from other people making fun of them for asking "stupid questions." Be nice.

If I'm standing four feet from a mirror and looking at my reflection, are my eyes focused on "me" eight feet away (the "depth" of my reflection in the mirror) or four feet away (the distance between me and the flat mirror)?

They say that time is the fourth dimension, but I don't get that. Is time the fourth dimension, and if so: huh?

Follow up question, I read that higher level dimensions are too fragile to exist in time space and collapse on themselves as "strings" (of the "string theory" fame and fortune). Is that true? If so, is that all dimensions beyond the third? If not: which ones haven't collapsed?

Kyle wrote: ↑Tue Dec 07, 2021 2:25 pm If I'm standing four feet from a mirror and looking at my reflection, are my eyes focused on "me" eight feet away (the "depth" of my reflection in the mirror) or four feet away (the distance between me and the flat mirror)?

8 feet. The way light moves, your eye treats the reflected world as real space on the other side of the glass. It's the reason that moving back and forth in front of the mirror changes your 3D perspective of the reflected image, but moving back and forth in front of a life-sized flat photo does not.

And the other question?

Kyle wrote: ↑Tue Dec 07, 2021 2:29 pm They say that time is the fourth dimension, but I don't get that. Is time the fourth dimension, and if so: huh?

The 4th dimension is better described as 3 dimensional objects moving through a space. And for us humans, that movement creates the perception of time.

To think about why a 3 dimensional object moving creates a new dimension, I use this description.

A point has no dimension.

A point moving through the first dimension creates a line, a 1 dimensional object.

A line moving through the second dimension creates a plane, or 2 dimensional object.

A plane moving through the third dimension creates a cube, or 3 dimensional object.

A cube moving through space is perceived as time.

You can only observe, accurately, your own dimension and those lower than our own. We are limited in that we cannot enter the fourth dimension to see the interaction of time with our own we are stuck. But! Black holes very well may be higher dimensional objects intersecting our own. Just like a cylinder moving through a plane is a circle or oval, a black hole may be the consequence of a 4th dimensional object moving through our 3rd dimensional space.

Citation: Flatland: a novel. Also the Universe in a Nutshell.

Eli- that's awesome. I guess I knew that because I've read Flatland (highly recommended, everyone- even today), but that's a great summary of it.

So question- how does gravity work at higher dimensions?

Kyle wrote: ↑Tue Dec 07, 2021 3:27 pm So question- how does gravity work at higher dimensions?

Now you're getting into strings and P-branes and my understanding fades rapidly. Thinking about it, I am also wondering about gravity in lower dimensions, too. Can something in the 1st or 2nd dimension have mass, and therefore gravity? No?

If my eyeglasses become bent, can it cause double vision?

Eliahad wrote: ↑Tue Dec 07, 2021 3:48 pm

Kyle wrote: ↑Tue Dec 07, 2021 3:27 pm So question- how does gravity work at higher dimensions?

Now you're getting into strings and P-branes and my understanding fades rapidly. Thinking about it, I am also wondering about gravity in lower dimensions, too. Can something in the 1st or 2nd dimension have mass, and therefore gravity? No?

Sure, but in the second dimension, the effect of mass has an effect on the second dimension, right?

DMDarcs wrote: ↑Wed Dec 08, 2021 9:28 pm If my eyeglasses become bent, can it cause double vision?

I’m guessing, but it might if it’s slight enough that your eyes are fighting to properly focus through the misaligned lenses. But if the bend is too severe, I suspect that it just gets fuzzy like an improper prescription.

If my power company does not send me bills, am I still legally responsible for paying them?

Not a lawyer but I'm going to say yes. Because of fear of the consequences.

DMDarcs wrote: ↑Sat Dec 11, 2021 2:20 pm If my power company does not send me bills, am I still legally responsible for paying them?

Yes. And if your power company is a government entity, then double yes, and there’s little you can do about it.

Why is a slow population growth a bad thing? All the arguments I've heard that it's bad are about a human constructed system of physical or digital pieces of paper that we have given weight and turned into a method to trade for goods and services. Is it actually a bad thing?

Eliahad wrote: ↑Tue Dec 21, 2021 11:25 am Why is a slow population growth a bad thing? All the arguments I've heard that it's bad are about a human constructed system of physical or digital pieces of paper that we have given weight and turned into a method to trade for goods and services. Is it actually a bad thing?

I'm probably at the same spot as you, things seem fishy but I don't have the expertise to really say why. I think our models are economic growth are partially based on the value of real estate increasing over time. But, long term, the same amount of resources spread over fewer people should be better, right? (Assuming a slow decrease, not a population crash which kills all the functions of modern society).

Typically when your population starts to age, a bulge of elderly workers start hitting the age where they can't work at the same time. If there aren't enough people in the younger generations to: (1) care for them; and (2) replace their labor-- then you run into real problems with worker shortages.

In fact, the numbers are now showing that this is the largest contributing factor to the labor shortage we're experiencing right now. While everyone wants to blame young people for "being lazy and not wanting to work," the truth is that many pre-pandemic seniors in the workforce: (1) died from Covid; (2) took early retirement at the onset of the pandemic; and (3) simply chose not to come back to work while Covid is still raging and posing a threat to their lives.

All of that said, I agree that our economic models of "proper growth" are flawed. Particularly when we look to companies and say that it's not good enough for them to simply be the same size and generate the same profits from year to year. We live in an unrealistic world where your company loses its value if it's not constantly expanding- even if that doesn't make sense for your business.

Kyle wrote: ↑Tue Dec 21, 2021 12:03 pm Typically when your population starts to age, a bulge of elderly workers start hitting the age where they can't work at the same time. If there aren't enough people in the younger generations to: (1) care for them; and (2) replace their labor-- then you run into real problems with worker shortages.

And that's how you get Logan's Run.

That's why the rate of population drop matters. Places like South Korea and Japan, with very low birth rates and little immigration, could feel some pain.

Thus we see loony right-libertarians and right-reactionaries demanding more babies. The world has plenty of babies but they don't want to import any. There is no scenario in which any of this turns out well for the general class "women", who are already experiencing radical pressures to depart from the workforce, or work and do everything else, due to covid.

Anti-family policies make it nearly impossible for women to stay in the workforce and have kids, yet the media blames school boards and teachers unions for the teacher shortage. Nurses are not quitting due to vaccine mandates, but due to burnout caring for the unvaccinated. College students are changing their minds about this career after seeing how maltreated nurses really are lately.

No one in the media wants to talk about the impact that 4 years of Trump/Miller far right immigration policies are having on the present labor crisis, because that might disrupt the false narrative that suddenly millions of people are running across the southern border all at once, most of them with, all of them demanding welfare payments and voting rights. We need to bring in people.

I think that the advancement of technology will actually ameliorate a lot of the issues of a shrinking population. The problem is that we have to rethink our capitalist economy to do it (i.e., not everyone has to sell their labor to survive).

This is such an important point. We don't value labor very well or very fairly, it seems. And for many people there is just no point.

After reading these questions about growth and labor shortages, I then read where even more nursing homes are shutting down, on top of hospital services that have already been closed earlier in the year, because they don't have enough people and they don't make enough on Medicaid reimbursements to cover the cost of what staff they are able to get. So if it's a for-profit place, there's no longer any profit in it. The state might try to change this by adding more money for Medicaid patients, but at that point you wonder why the state doesn't just pay for the whole thing and operate it at cost, instead of paying companies that are already doing a substandard job of providing care. It's not like these are great places to be! And people go into them possibly having enough money to hire their own private nurse, but it's difficult to obtain that service as well. This is something I've done a lot of thinking about with respect to my parents, and I would rather run their funds down to the Medicaid level if necessary by paying a human being who nurses them personally, rather than putting them in one of these homes, which is a bunch of misery. The question is whether people need skilled care of a level that you can't get or afford with a home health nurse easily. Different levels cost radically different prices. It's something we will all deal with eventually. This comes full circle to the problem of women not being able as a group to handle all of the care demands in our society and also be fully into the workforce.

If I’m standing in the middle of a field holding a firehouse and turn it on full blast, it’s going to push me backwards from the force of the water coming out. If there’s a wall ten feet in front of me that the hose is pointed at, I assume it pushes me back with more force. I make this assumption because if I point it at the ground, it will force me upwards, but if I’m suspended in mid air it won’t. Why does it do this? Does the water push back on the flow of water when it hits the wall (or ground)?

Not sure the wall has any impact on forcing you back. Sure you get wet, but the pushback is from the air not being able to get out of the way fast enough; it creates pressure. That effect has limited range, which I bet we could measure..My guess is less than five feet.
The force is the same regardless of direction, It could be enough to levitate you, or knock you over, but since you're already poised to fight gravity, shooting it up is unlikely to crush you.
The wall, or ground, at close range, gets in the way of the air being pushed by the water, which is why a close surface might give you the feeling of amplified force. It's basically shoving the air into a higher pressure space.

I bet we could demonstrate his with a little car and a balloon (even a water balloon)

I'm not a physicist, so maybe this isn't correct, but every vector here is measurable.

If you get egg on your pants... And then wash your pants on a hot water cycle in the washing machine... Would that poach the egg?

I don't think the water gets hot enough. It has to be almost boiling to poach the egg properly. It might cook the egg without poaching?

If you add detergent it will just wash away the egg, but I assume you're not doing that, in which case I agree with Phoebe.

Even if it poached the egg (I concur with previous opinions), the poached egg wouldn't long adhere to most fibers. You might leave a spot on cotton or other natural fabric, but likely couldn't find it without good light.

Not sure if I can design and execute an experiment without costly consequences...