The Dumb Science Questions - Pro Science Answers Megathread

[Chakrai]

If you can't explain physics without using ridiculously complicated maths, you're simply not good at explaining.

No, you can make really bad analogies and make stuff so simple it bears no relation to the actual subject. That's why I have a dislike for stuff on the discovery channel or half the stuff the BBC makes - it's too simplistic for me. I've taken to watching uni lectures on youtube sometimes to get a grasp of something because wikipedia is too dry and the "popular science" books and videos are too basic.

The maths itself is an analogy to what is really going on. It's simply a language that we have built that is better suited to describe physical processes than what we normally communicate in. It is most definitely possible to describe almost everything in physics without resorting to maths. It's a lot harder and you can't be quite as precise though, but you don't have to end up in dodgy analogies. At least not more than you would using more rigorous methods.

Think of it like trying to describe FHC without using the words anal, pony, EVE, clamdongue, quack, shitpost or mantrain. It's definitely possible, but not quite as precise and a little more roundabout.

[Frug]

You can explain with words. But for why and how you need math.

Pretty much this. I can explain what happens, but I cannot give understanding without the math. What path does a projectile follow without air resistance? A parabola. Why? There's a constant acceleration towards the surface, and no acceleration parallel to the surface. Why does that lead to a parabola, and not some other shape? :math:. Easy math, but still math. Without understanding all you get is faith, and that's not worth much.

All of this. It gets harder to explain the more specialized the field and specific the question. It is a gift for some scientists to be able to break down complex concepts into the most salient points and then convey those using appropriate analogies. The most interesting guys to talk to are the guys who can do this.

My experience was only with math, and the way some math profs could explain what they were doing well, while others simply lacked the gift. Both were good at actually doing the operations, both understood them perfectly, but only some could actually convey that meaningfully to someone who's learning. In every case I came across, it was possible to explain things with only words if you knew how to pick the right ones. Only in the really esoteric fields would I believe that such a feat is impossible.

I was just making an assessment about the subjective validity of an experiment to an individual, though. Trying to point out that until you understand why an experiment (or anything) works, you can only take it on faith that it's valid, and faith isn't science. You can accept it, but I wouldn't say it has any validity to you if you're investigating it. Otherwise you might as well believe the first convoluted experiment that proved the existence of god that you couldn't understand.

[Steph]

If you travel at the speed of light, will you have a shadow?

Why wouldn't you?

[Tarminic]

If you travel at the speed of light, will you have a shadow?

Why wouldn't you?

Actually, I suspect that the answer to this question is more complex than it might first appear. When travelling at or near the speed of light, isn't your physical appearance (from someone else's frame of reference) distorted as a result? So what shape are you, if travelling at 99.999% the speed of light, to the frame of reference of other light particles moving perpendicular to you?

[definatelynotKKassandra]

If you travel at the speed of light, will you have a shadow?

Why wouldn't you?

Actually, I suspect that the answer to this question is more complex than it might first appear. When travelling at or near the speed of light, isn't your physical appearance (from someone else's frame of reference) distorted as a result? So what shape are you, if travelling at 99.999% the speed of light, to the frame of reference of other light particles moving perpendicular to you?

I remember that this is a standard problem in special relativity 102. Unfortunately I can't remember the answer. I do remember that it's not that complex though, once you know how to start.

Helpful, I know

[Pacefalm]

I think you would have a shadow yes, though indeed a different form than you normally would have.
Just like you can still hear a jet that moves faster than the speed of sound.

E: Actually on second thought that analogy has nothing to do with it, but still you will have a shadow

[SAI Peregrinus]

If you travel at the speed of light, will you have a shadow?

Why wouldn't you?

Actually, I suspect that the answer to this question is more complex than it might first appear. When travelling at or near the speed of light, isn't your physical appearance (from someone else's frame of reference) distorted as a result? So what shape are you, if travelling at 99.999% the speed of light, to the frame of reference of other light particles moving perpendicular to you?

I remember that this is a standard problem in special relativity 102. Unfortunately I can't remember the answer. I do remember that it's not that complex though, once you know how to start.

Helpful, I know

You'll certainly have a shadow at angles not perpendicular to your path of travel. Of course that assumes you are still matter, even if infinitely thin and massive. Otherwise you just have an interference pattern.

[Maximillian]

I was thinking about the shadow question and if you accept that a shadow is a form of information (.i.e. it is a 2D representation of a 3D object) then at the speed of light all information breaks down so I assume the shadow would be lost.

[Aramendel]

Pretty much this. I can explain what happens, but I cannot give understanding without the math. What path does a projectile follow without air resistance? A parabola. Why? There's a constant acceleration towards the surface, and no acceleration parallel to the surface. Why does that lead to a parabola, and not some other shape? :math:. Easy math, but still math. Without understanding all you get is faith, and that's not worth much.

Nope.

You forget how we came to know this math in the first place - by doing tests and measuring the results. You can explain your example without math by explaining the logical reasoning which lead from those to the mathematical formula.

If Math would be necessary to explain physics Mankind would be trapped in a catch 22 loop. It started without the math for physics, so if it needed math to get an understanding for physics it would never have been able to develop physics in the first place. Math is the result of understanding physics, not the basis for it.

[theBlind]

Math is the result of understanding physics

As a former math student, I have to call you a heathen at this point!

(I agree with the rest of your post though)

[walrus]

The Central Bureau for Astronomical Telegrams has just sent out a notice about an important event tonight for observers with large telescopes and video-recording capability.

According to Leslie Young (Southwest Research Institute), Pluto may occult a 13.8-magnitude star around 3:22 June 14th Universal Time (11:22 p.m. June 13th EDT) at a low altitude in the sky for the eastern United States and Canada. The star is at right ascension 18h 35m 48.69s, declination –19° 17' '43.6" (equinox 2000.0).

You'll need a large enough telescope to record a half-magnitude light drop, with good time resolution, in the combined 13.3-magnitude image of Pluto and the star.

From the announcement:

"Topocentric predictions for the midtime depend on the combination of Pluto and star positions used, and vary by about 50 seconds for any location. The midtime also depends on the location, affecting the midtime by about 1 minute over the portion of visibility. Adding uncertainty for Pluto's extended atmosphere and the chance of systematic errors in the star's right ascension, the recommended observing time spans 3:20 to 03:37 UT.

"Any location near the entire east coast of North America has a good chance of being in the shadow. Pluto only subtends 0.1 arcsec, so small errors in the star position and Pluto ephemeris can move the predicted shadow path substantially. Predictions tend to be good to about 500 miles, barring systematic errors.

"Multiple [timings from different locations] are critical for reconstructing, after the fact, the geometry of Pluto's passage."

Pluto and the star will be only about 20° high in the southeastern sky as seen from Boston, Philadelphia, and Baltimore; somewhat higher as seen from farther south, lower farther west.

Young describes the scientific motivation for good observations of this event:

"Pluto's thin, nitrogen atmosphere is in vapor-pressure equilibrium with the surface ice, and changes seasonally. We've seen [the atmosphere] double since 1988, and now we measure its pressure once or twice a year. The technique we use is stellar occultation, when a star passes behind Pluto's atmosphere. The atmosphere defocuses the starlight. By the timing of the fading of the star, we measure the pressure and temperature in Pluto's atmosphere at about 10 km resolution."

For more information see:

wiki.boulder.swri.edu/mediawiki/index.php/2012-06-14_Pluto_occultation

occult.mit.edu/research/occultations/Pluto/P20120614/

http://www.lesia.obspm.fr/perso/brag...ampaigns/#June

sauce

[Pacefalm]

Pretty much this. I can explain what happens, but I cannot give understanding without the math. What path does a projectile follow without air resistance? A parabola. Why? There's a constant acceleration towards the surface, and no acceleration parallel to the surface. Why does that lead to a parabola, and not some other shape? :math:. Easy math, but still math. Without understanding all you get is faith, and that's not worth much.

Nope.

You forget how we came to know this math in the first place - by doing tests and measuring the results. You can explain your example without math by explaining the logical reasoning which lead from those to the mathematical formula.

If Math would be necessary to explain physics Mankind would be trapped in a catch 22 loop. It started without the math for physics, so if it needed math to get an understanding for physics it would never have been able to develop physics in the first place. Math is the result of understanding physics, not the basis for it.

Actually no... your reasoning is fair as far as pre 1900 science goes but quantum mechanics is something else entirely. Read SAI Peregrinus post again "I can explain what happens, but I cannot give understanding without the math". This is not because he is bad at teaching, it is because quantum mechanics is for some parts just not comprehensible without invoking maths. It is like trying to explain a 3d world to someone who lived only in a 2d one.
Simple example is the double slit experiment. Even if you shoot electrons or photons 1 at a time, eventually there is an interference pattern. It is easy to explain what happens: the electron goes in and it becomes a wavefunction that interferes with itself, with high and low points corresponding with the interference pattern. But then 'why'? As far as I know nobody knows why not even Schrodinger himself knew why. BUT you can create a mathemetical formula that correctly predicts the pattern. Plug in the formula -> correct thing rolls out. This is what is meant by "it is impossible to understand it without knowing the math", the math itself is the only thing that is understandable about it.
Why do you think theres a billion different interpretations of quantum mechanics? It is because nobody really understands 'why' the experimental results are what they are.

[Frug]

Actually no... your reasoning is fair as far as pre 1900 science goes but quantum mechanics is something else entirely. Read SAI Peregrinus post again "I can explain what happens, but I cannot give understanding without the math". This is not because he is bad at teaching, it is because quantum mechanics is for some parts just not comprehensible without invoking maths. It is like trying to explain a 3d world to someone who lived only in a 2d one.
Simple example is the double slit experiment. Even if you shoot electrons or photons 1 at a time, eventually there is an interference pattern. It is easy to explain what happens: the electron goes in and it becomes a wavefunction that interferes with itself, with high and low points corresponding with the interference pattern. But then 'why'? As far as I know nobody knows why not even Schrodinger himself knew why. BUT you can create a mathemetical formula that correctly predicts the pattern. Plug in the formula -> correct thing rolls out. This is what is meant by "it is impossible to understand it without knowing the math", the math itself is the only thing that is understandable about it.
Why do you think theres a billion different interpretations of quantum mechanics? It is because nobody really understands 'why' the experimental results are what they are.

edit: actually I re-read it twice and I think I agree with you. If we actually do lack an explanation for why quantum mechanics work the way they do, then all we have is math for describing what happens and that can be hard to explain to someone without knowledge of it.

I'd only disagree with SAI's wording that the math for projectile motion is required for understanding. Anyone can understand why the arc is shaped the way it is without being able to provide a function for the arc.

But the Bell Inequality tests are an experiment which are used for physical verification of a theory. That goes beyond purely mathematical description. I can still ask conceptual questions like "if a waveform collapses upon observation, how is it possible to know that the waveform existed prior to observation?" which goes outside the realm of pure math.

So far I think Bell answered that with something like "if the values existed prior to observation, we would expect normal statistical results to hold under repeated testing, but the results we actually see are different" and I think with enough work it must be possible to squeeze more useful details that are understandable to laypeople.

[Shiroi Okami]

Was talking to a mate of mine the other day who studies astrophysics and he mentioned that there is some theory (in string theory maybe?) about some section of space that contains no bosons of any kind. He wasn't able to elaborate though so I'll ask it here; how could that be possible? Wouldn't it be completely impossible to observe or even find such a space? What's the point of theorising it's existence?

[Aramendel]

As a former math student, I have to call you a heathen at this point!)

Well, not math in general of course I meant the mathematical formula describing a certain process in physics.

...BUT you can create a mathemetical formula that correctly predicts the pattern. Plug in the formula -> correct thing rolls out...

And how exactly does that explain the "why"? It doesn't, you yourself say that noone really knows that.

Showing someone how a mathematical formula for a interference pattern works is in no way different than showing someone a physical experiment of it. It shows a person *what* happens reliably under certain circumstances. The math for it is in the end only a model of the physical process. Both can be understood. Neither explains *why* it happens.

[definatelynotKKassandra]

Please demonstrate why something happens. Anything, in any way.




Unless you're very careful, 'why' becomes a meaningless question.


Edit: anyone have a link to the video of Feymann being asked 'magnets - how do they work?'.

[Frug]

Please demonstrate why something happens. Anything, in any way.




Unless you're very careful, 'why' becomes a meaningless question.

Oh you poor child. Has nobody explained anything to you before?

[Glyken Touchon]

Please demonstrate why something happens. Anything, in any way.




Unless you're very careful, 'why' becomes a meaningless question.


Edit: anyone have a link to the video of Feymann being asked 'magnets - how do they work?'.

[Irion]

Please demonstrate why something happens. Anything, in any way.




Unless you're very careful, 'why' becomes a meaningless question.

Oh you poor child. Has nobody explained anything to you before?

Nobody ever played the 'why' game with you?

[Lallante]

I still don't really get how if two people set off from the same point in opposite directions at 2/3 the speed of light, one of them isnt going faster than the speed of light relative to the other one.

Also if one of those people shines a torch directly behind them, and there is a third person standing stationary at the two persons' origin, why doesnt the light seem to be going "slow" to him (i.e. 1/3 of the speed of light)? Does the light ever reach the other person?

Basically, explain relativity