How is physics knowledge used in everyday life?

[Buckethead]

For me,the answer to the OP's question is both because it's empowering, and because you may find you like it after you dive into it. Empowerment is very important as it gives one the confidence to make decisions about things that one might otherwise delegate to someone else. Take climate change for example, I know science illiterate folks that say things like "Well, no one really knows" and staying out of the discussion because of it. I've even heard comments like "I don't trust scientists, they're always changing their minds" (I'm not kidding!). When one studies physics, one just simply feels more aware and capable to step up to the plate about almost anything in life. The second part, you might like it, of course is important as well. Every try painting? You might like it, and more importantly you might actually be good at it. Same with physics. Oh and people just like to feel they're smart, that's another reason. How society moves forward as a whole depends a great deal on the confidence level of it's citizens. If you don't know, you don't care, if you don't care, well...

 

[Dr. Courtney]

Knowing physics well, I find myself using it all the time in every day life - sports, driving, home improvement, health.

 

[gleem]

Do you think that the frequency in which some of us use physics frequently in our everyday lives is more a result of our innate curiosity of our environment rather than just our actual knowledge. Even if persons achieved a facility in physics would they necessarily be inclined to use it?

 

[mathwonk]

this may be an unusual job, but one of my friends who is a stunt man said all the savvy stunt car drivers definitely use basic physics to be able to clear those obstacles safely, e.g on jumps.

 

[.Scott]

We all know the question: why do I need to know this?

As a private pilot, I need to do weights and balances - making sure my center of gravity lands within the specified zone for the type of flying I will be doing.

Sometimes the Physics I use doesn't really come with numbers - at least not explicitly. Without Physics, MacGyver (https://en.wikipedia.org/wiki/MacGyver) looks pretty good. But how many of his ideas would have really worked? Sometime all you need to do is to be able to do is make rough estimations.

I was working late at a workplace in a small remote town. I was programming a device through a UV programmable chip - and I only had three of them - and I ran out. There was no UV eraser available on site. I could have called it a day, but I didn't want to. So I looked around - lots of electronic gear including DC power supplies. One good for 40 volts and lots of amps... and I had a #2 pencil. I broke the pencil in two, carved out enough wood to expose both ends of the graphite in both pieces and wired them up to allow me to generate an arc. As it turned out, that arc erased the UV prom in less that half a minute, 50 times faster that most UV erasers.

 

[DennisN]

We all know the question: why do I need to know this? I have been thinking recently about how to add relevance to my curriculum. What I am struggling to come to grips with is how knowing physics, the topics typically taught in a high school intro course, can be useful in everyday life. I am not looking for everyday examples of physics concepts. I mean real actual examples of using Newton’s laws or momentum in real life purposefully. For example, understanding ratios from math is applied purposefully to compare grocery store prices.

Can you think of a time when you actually used your physics knowledge in everyday life?

Thanks,
Bill

Yes, I know the question "why do I need to know this?" In fact, I was once asked what's the use of mathematics? We were a couple of floors up in an apartment house, and I decided to show the person with a physics example, so I told him that I can predict how long it takes for an object to drop to the ground. I did an estimation of the height, and calculated the time on a piece of paper using classical mechanics. Then I dropped an object, something that was not dangerous, and we took the time, and my prediction for how long it took until it hit the ground was quite good. And with that example I showed the usefulness of both math and physics.

 

[Andy Resnick]

We all know the question: why do I need to know this?

Can you think of a time when you actually used your physics knowledge in everyday life?

I've been thinking about your question for a few days; I also think most of the answers here miss your point- perhaps most pithily stated as "Most people do not USE Physics in everyday life, [...] Physics uses YOU in everyday life" (post #13)

It's easy to invent contrived examples showing how to apply basic physics to everyday experiences- but I don't think that's a good enough response given the increasingly Utilitarian approach to life: higher education is really expensive and underemployment is increasingly common.

So, I'll present a different approach. "Physics knowledge" is more than being able to regurgitate formulas. One of the core discipline elements of Physics, something that distinguishes it from other science and engineering disciplines, is the quantitative notion of 'simplifying' real systems via approximation to arrive at an abstract idealization, which is then used to (approximately) solve an actual problem at hand. Creating an abstract model and deciding what can be ignored and what must not is an (maybe THE) essential element of problem solving, and AFAIK, is primarily (exclusively?) taught as part of the introductory Physics curriculum.

I could also present an argument that parallels any liberal-arts discipline, invoking non-Utilitarian modes of interacting with the world, but others have already made that argument.

 

[Auto-Didact]

I think Feynman said it best: 'Physics is like sex: sure, it may give some practical results, but that's not why we do it.' As was remarked earlier, having a working knowledge of physics will not help you in the vast majority of things in life; in fact, as has also been remarked already, it's even worse than that: many of the regular accepted physics explanations for complicated everyday phenomena not directly reducible to or a direct application of classical/modern physics are simply incorrect and more of a hamper than of actual utility in actually understanding said phenomena in a practical way. I will try to illustrate this, by giving an example of a culture of which I am apart, which is both deeply scientific, yet extremely practical, namely medicine.

In medicine, a discipline which is for the most part deeply based in the natural sciences, the disconnect between physics and practice is much clearer than usual. This can be immediately seen in that almost no physics or mathematics is taught during medical training nor utilized in the practice of medicine; this often comes as a surprise to anyone in medical school deeply convinced of the scientific nature of medicine, a stance which is exemplified in medical research as 'evidence based medicine'. Before and in my early years of medical school, I was also convinced that all useful knowledge in medicine could and therefore should be reduced to physics; I was astutely aware that my viewpoint was a very tiny minority view both among students and teachers. During the latter years, I began to realize that the opposite does in fact seem to be true: theoretical explanations of phenomena in medicine grounded in physics are almost entirely useless in clinical practice; for biomedical science this is of course an entirely different matter.

The fact that physics based knowledge seems specifically useless for clinicians is two-fold: namely a) the theory of physiology has not been fully reduced to a working biophysical model and pretending that it has is a dangerous delusion, especially for science; the mathematical methods required for such modelling has often not yet even been discovered and simplifying things in order to comform to standard mathematical techniques usually simply means throwing out the baby with the bathwater, and b) there is no actual full correspondence between what clinicians think is happening in a patients body based on their diagnostic investigation and what is actually happening i.e. in terms of known or unknown physics. What these physicians think to know is merely a mental model; practically speaking, the question is not whether that mental model is correct in terms of physics or natural sciences, but it is instead whether that model is efficient in identifying disease in a quick and reliable manner.

So, I'll present a different approach. "Physics knowledge" is more than being able to regurgitate formulas. One of the core discipline elements of Physics, something that distinguishes it from other science and engineering disciplines, is the quantitative notion of 'simplifying' real systems via approximation to arrive at an abstract idealization, which is then used to (approximately) solve an actual problem at hand. Creating an abstract model and deciding what can be ignored and what must not is an (maybe THE) essential element of problem solving, and AFAIK, is primarily (exclusively?) taught as part of the introductory Physics curriculum.

While I agree with you partially, I do not do so without sufficient hesitation. During my undergraduate years in college, doing a double major in physics and medicine, I was fully convinced that the points you are making here were true. Now many years later, I'm more convinced of the opposite: a large part of mathematical reasoning used in (theoretical) physics is based on intuitive reasoning for which there has to date been given no proper mathematical justification. For core physics knowledge i.e. classical physics as taught during undergrad, we have identified the mathematical theories which in many cases actually formalize and sometimes even subsume much of this intuitive reasoning; these are the mandatory basic mathematics courses every physics student has to take.

The remaining 'physics' part of the theory is often merely a qualitative semi-mnemonic scaffolding capable of directly exemplifying some core properties of these simplified mathematical theories and linking them to experiment. In terms of actual physics, i.e. when more carefully analyzed with more advanced physical frameworks (soft and condensed matter physics, biophysics, fluid dynamics, nonlinear dynamics, theory of critical phenomenon, etc) and more advanced experimental techniques, these simplifications, i.e. methods of approximation and linearization, tend in many cases to breakdown quickly and often spectacularly when carefully looking at an actual phenomenon in the non-idealised case.

The relative ease (and therefore seductiveness) of the mathematical methods learned early on in the simplified canonical theories is then actually a psychological bias among physicists during further theorisation or extrapolation of a theory beyond empirically tested limits, which can be summed up as the following: theories i.e. mathematical models or explanations of phenomenon of which the mathematics is already academically understood and consistent with the mathematical methods that the physicist has already learned are strongly preferred to non-standard theories; the physicist might even refer to one theory as more beautiful or more aesthetic for these reasons. This 'beauty' depends on where the mathematical focus of further training outside of the core curriculum has taken them. Particle theorists tend to find group theoretical notions beautiful, fluid dynamicists tend to find (complex) analytic notions beautiful and relativity theorists tend to find differential geometric notions beautiful, while at the same time finding the other's respective notions far less aesthetically pleasing or even downright hideous.

Historically speaking, this has always been an issue which has caused divide among mathematicians, e.g. Euler, Gauss, Riemann and many if not most of the classical mathematicians would have found generalized functions such as the Dirac delta function hideous, not even to speak of the everywhere continuous but nowhere differentiable functions, i.e. fractals, which they even termed as 'pathological' i.e. sick because they do not conform to the reigning notion of beauty from the theory of analysis, namely the intuitive connection between the key concepts of continuity, smoothness and differentiability. Due to the increased specialization of the 20th century and the lack of an actually accurate and self-consistent overarching picture, such ideological differences have become exacerbated. This innate desire to have a theory fully conform to some particular existing mathematical methods one already knows is a non-experimental systematic bias to be controlled for when mathematically and theoretically investigating known physical phenomena and their theories more deeply; this seems to be true for both theories in fundamental physics as well the more applied subjects I referred to above and many mathematical physicists actually do take this into consideration when writing reviews.

 

[HAYAO]

Crows, despite with a birdbrain, can do something pretty smart such as placing a hard nut on the road for the passing car to crush it, so that they can eat the contents. There are a lot of empirical physics going on here, but crows can naturally do this.

Now, I know what you are thinking. But HAYAO, is that really physics or are the crows just doing that based on the observation that cars can crush things? You are right, it's most likely the latter. However, what should also be noted is that physics is a generalization of the laws based on such observation and empirical evidence. If such laws can be derived, then the reverse process of finding laws can be done: engineering.

By just living a life, you obtain many information based on observations. Your brain naturally develops empirical laws based on them. As such, you naturally apply that law into your life. You are probably doing more physics than you think. And the physics in academics is simply a more rigorous, logic-heavy, and objective version of that.EDIT: Just in case you don't believe it

 

[FactChecker]

I don't think that people generally use physics in everyday life. If they don't have a job or hobby that makes them apply physics, then the most anyone needs is a general, vague, intuition about forces and reactions.

(Of course, the devices they use for entertainment, living comfortably, and general existence, depends on a lot of advanced technology and physics. But they are using that without knowing much about it.)

 

[symbolipoint]

Crows, despite with a birdbrain, can do something pretty smart such as placing a hard nut on the road for the passing car to crush it, so that they can eat the contents. There are a lot of empirical physics going on here, but crows can naturally do this.

Now, I know what you are thinking. But HAYAO, is that really physics or are the crows just doing that based on the observation that cars can crush things? You are right, it's most likely the latter. However, what should also be noted is that physics is a generalization of the laws based on such observation and empirical evidence. If such laws can be derived, then the reverse process of finding laws can be done: engineering.

By just living a life, you obtain many information based on observations. Your brain naturally develops empirical laws based on them. As such, you naturally apply that law into your life. You are probably doing more physics than you think. And the physics in academics is simply a more rigorous, logic-heavy, and objective version of that.

Baby crow says to Momma crow:
When will I ever need to know about dropping a nut onto a street?

 

[HAYAO]

Baby crow says to Momma crow:
When will I ever need to know about dropping a nut onto a street?

Gotta learn about the birds and the bees first, sweetie.

 

[Andy Resnick]

<snip> Certainly mathematical trade-offs between light intensity, aperture size and shutter speed are well know even among those who don't understand them.

This is true, but it's also true that my "physics knowledge" provides additional insight- for example, that operating a lens at maximum aperture (considering the trade-off mentioned above) is also operating the lens at maximum aberrations. 'Civilians' learn this as photographic lore- lenses achieve maximum sharpness when stopped down a little from their maximum aperture- but never understand it beyond a 'rule of thumb'.

 

[Luis Babboni]

Physics allow us to guess the future and this is a very important thing to have greater chances to survive in Darwin´s natural selection terms.

 

[symbolipoint]

Baby crow says to Momma crow:
When will I ever need to know about dropping a nut onto a street?

Gotta learn about the birds and the bees first, sweetie.

Afterthought is that my little remark was not so on point. The learning to drop a nut onto the street would be a very specific act in context; which is very different from "when will I ever need to know this?"

 

[Orodruin]

I feel that my knowledge of physics let's me adapt better to new situations, in particular when trying out a new sport or activity. It is one thing to learn how to do an activity from an instructor, but that is helped along significantly if you can understand the underlying mechanisms. Would I have needed to know physics to learn how to scuba dive? Probably not, but it certainly helped. I will never forget my course in Nitrox diving (diving with a different mixture of nitrogen and oxygen than the atmospheric one). The students were me, my father, my sister, and my brother-in-law. I am a theoretical physicist and they are all medical doctors and at some point I almost felt sorry for the poor diving instructor who had to "teach" us about the physical and physiological effects of different gas mixtures.

Another use of physics knowledge is avoiding overly pedantic physicists nitpicking on internet forums ...

- A simple acknowledgment of momentum increasing exponentially with speed could have kept her out of the ditch in the first place.

Momentum increases linearly with speed, unless you go at relativistic velocities where it increases faster than exponentially.

- McDonald's might have something to say about how much latent heat is in a hot cup of coffee.

Nothing contains latent heat (or any type of heat). Heat in general is energy that is thermally transferred between two systems and latent heat is the heat released to (or absorbed from) the environment without temperature change during a first order phase transition. What you are implicitly referring to here are the heat conduction and heat capacity properties of hot coffee.

 

[Rive]

How is physics knowledge used in everyday life?

Well, I think the answer is more or less the same for science in general, not just for physics. People are just fine with the surface, and there is no need for 'real' knowledge anymore.

As I see our civilization is advanced through creating (working) operating instructions: science was/is a successful tool for this. But this success also means that most people will never met with science: they will met only with the instructions. This makes things easy - but also makes science to something distant//mystic//difficult//boring for the most.

 

[hmmm27]

Another use of physics knowledge is avoiding overly pedantic physicists nitpicking on internet forums ...

More than fair enough. I'll take you up on the perceived back-pedant opportunity, of course - conductivity seems of rather negligible import compared to heat-capacity in the McDonald's coffee incident.

 

[Orodruin]

More than fair enough. I'll take you up on the perceived back-pedant opportunity, of course - conductivity seems of rather negligible import compared to heat-capacity in the McDonald's coffee incident.

If heat conductivity was negligible you would not burn yourself. It would mean the stored internal energy (given by the heat capacity) would have no way to transfer to the skin in the form of heat.

 

[hmmm27]

If heat conductivity was negligible you would not burn yourself. It would mean the stored internal energy (given by the heat capacity) would have no way to transfer to the skin in the form of heat.

One could (will) argue that thermal conductivity is applied as a macro property, and that the shape of the spill, ie: a meniscus thick or less, minimizes its relevance.

 

[Orodruin]

One could (will) argue that thermal conductivity is applied as a macro property, and that the shape of the spill, ie: a meniscus thick or less, minimizes its relevance.

That still does not make it irrelevant. It still needs to be above some reasonable threshold to equilibrate quickly enough to produce a burn. Of course, that threshold is minimised by a larger contact surface and the fact that both body and coffee are mostly water makes it likely that this condition is satisfied. But it is still not irrelevant to mention it.

 

[hmmm27]

That still does not make it irrelevant. It still needs to be above some reasonable threshold to equilibrate quickly enough to produce a burn. Of course, that threshold is minimised by a larger contact surface and the fact that both body and coffee are mostly water makes it likely that this condition is satisfied. But it is still not irrelevant to mention it.

I think I'm going to pull the ripcord here, and mention that - while I see your point, completely - turbulence of a spill is going to constantly put the newest(ie: hottest) liquid directly onto the contact area.

 

[gleem]

Without delving into the profiles of the endorsers of the usefulness in physics in your everyday life I would bet that most here are physicists or had a strong physics background. As a potential student thinking about taking a physics course for its purported usefulness in everyday life wouldn't you put more credence in the endorsements of non physicists?

 

[nrqed]

Another use of physics knowledge is avoiding overly pedantic physicists nitpicking on internet forums ...

.

This reminds me of an argument I hd with someone on this forum who was adamant that time is exactly the same as space because the two are combined in the metric.. :-)

 

[nrqed]

We all know the question: why do I need to know this? I have been thinking recently about how to add relevance to my curriculum. What I am struggling to come to grips with is how knowing physics, the topics typically taught in a high school intro course, can be useful in everyday life. I am not looking for everyday examples of physics concepts. I mean real actual examples of using Newton’s laws or momentum in real life purposefully. For example, understanding ratios from math is applied purposefully to compare grocery store prices.

Can you think of a time when you actually used your physics knowledge in everyday life?

Thanks,
Bill

People use physics intuitively all the time, and they do much more often than using chemistry, say, and that at a very young age.. One interesting example is the non trivial physics involved when a child use his/her center of gravity to transfer potential energy to kinetic energy in order to start moving on a swing without touching the ground.

Another example is race car pilots who use the fact that in order to go as fast as possible on a curve, one has to maximize the radius of curvature (to minimize the centripetal acceleration. v^2/R), so before getting to the curve, one has to go on the opposite side of the road, and the one has to "hug" the curve and then head to the opposite side of the road when exiting the curve. I am pretty sure they do not know the physics explanation but they all do that instinctively.

But I think you are probably asking examples where people use their knowledge of physics they have learned in school in a conscious way to solve some problem in everyday life, and the answer is clearly "almost never". People do not use any knowledge from their studies in chemistry, or biology either. And people almost never need to use their knowledge of mathematics either, except for maybe adding or multiplying, and even that they usually do with a calculator.I read a great sci-fi short story once, I am pretty sure it was by Asimov. In it, a person from the future was brought to the present day, but just for a very short time. Of course people ask the visitor from the future things like "will cancer be cured?" and the person answers that cancer was cured. They ask how!? The person canonly say "well, when someone is diagnosed with cancer, the doctor gives us some pill and make us sit in a machine and we are cured". Which is of course the situation today as well, people use technology based on advanced science without knowing the principles involved.

 

[Orodruin]

This reminds me of an argument I hd with someone on this forum who was adamant that time is exactly the same as space because the two are combined in the metric.. :-)

I don’t think this is an argument that I would use. I would say that it is natural to use a system of units where time and length have the same physical dimension since they are both just (non-angular) coordinates on the same manifold relating to the length of curves in that manifold and it makes no sense to introduce an arbitrary conversion factor (apart from convenience for everyday at will show up essentially everywhere to obstruct the actual physics.

 

[marthasimons2]

I don't know if this example is exciting enough to demonstrate the laws of physics in our daily life, but it still is worth mentioning. When you want to open a door, you just use the handle that is situated on the other side of the door's hinge. It would be really difficult to open the door if the handle was situated somewhere in the middle, for example. What is used here is the rule of turning forces. Your goal is to create a large moment around a pivot. This idea can be used in various physical activities in real life. When you know the right way of applying your force, it becomes easier to reach your goal.

 

[pinball1970]

I am not a physicist so this should count. Charging up glow in the dark applications at work I used D65+UV in the light box to get quickest results. Other options being Tungsten, TL84, UV on its own or D65 on its own.

 

[symbolipoint]

Piano (acoustic) and guitar (acoustic), depending on what you know and how much you know.
vibrating strings, and tone-woods.
Why? Waves and wave interference.

Also, have you seen a chladni pattern?

 

[RPinPA]

I grew up in a snowy, icy place. I have a peculiar step I use on ice which my wife calls my "ice walk". I almost never fall down or slip on ice because of it, despite the fact that most of the time I am wearing unsuitable footwear (sneakers).

It came from direct contemplation of the physics. I realized that we normally walk by relying on friction. You push on the ground and expect static friction to cause a force moving you forward. Remove the friction and your foot just slides backward, throwing you off balance.

Better: try as much as possible not to do that backward push. Lift the feet and put them down vertically. Obviously there has to be some forward force as you need to move horizontally, but you are deliberately trying to minimize it. If you do it right, you'll be able to get across a lot of slippery patches that are defeating other people.

I also find myself thinking about the physics constantly around the house, with little fix-it things. How many nails, placed where, would give this thing the right structural strength. How do I stabilize this structure? (A single diagonal brace turns an unstable square structure into a stable one). How can I open this jar? (When I realized that it was the vacuum that created the friction of the jar lid, the answer was simple: pry the lid up just a bit and let the air in). What's the quickest way to get 6" of snow and ice off my windshield? (Ice melts at 32 F/0 C. The first thing you do is open the car and start the heater and then wait a minute. It only has to get the window to 0 C to make your life a lot easier).

There are literally hundreds of examples like that. I think about the physics all the time.

 

[CWatters]

It's a fine line between consciously or unconsciously using physics knowledge...

When you buy a phone you check or compare the battery capacity with other models.
When you buy a light bulb you choose how bright it is.
When you buy a car you check it's fuel consumption figures.
When you buy a duvet you look at the TOG value.
If you replace windows in your house you care about insulation and U-Values.
When you go to the beach you might estimate when the tide will come back in.

 

[Frigus]

I think This video has perfect answer(at least for me) for this question.