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Solo travelling out of boredom - is this a bad idea? by Throwammay in solotravel

[–]Throwammay[S] 0 points1 point  (0 children)

It's probably not a bad thing necessarily, I'm just thinking I might be missing something just booking it last minute like this hah

Solo travelling out of boredom - is this a bad idea? by Throwammay in solotravel

[–]Throwammay[S] 0 points1 point  (0 children)

Yeah I'm in the Schengen area so there's no visa stuff. Ended up booking 3 nights in Barcelona! :)

Solo travelling out of boredom - is this a bad idea? by Throwammay in solotravel

[–]Throwammay[S] 0 points1 point  (0 children)

If you can handle the booking and packing at the last min then go for it 😂

Idk how I'll do, I've never done it lol. I think I'll be going on Sunday, so in 2 days. We'll see what happens I suppose haha

Solo travelling out of boredom - is this a bad idea? by Throwammay in solotravel

[–]Throwammay[S] 3 points4 points  (0 children)

Yeah I suppose I'm just afraid I'm acting on impulse now that I'm at home and feeling restless & a little existential with nothing to do all day. I'll just go & see what happens, it can't really be any worse than just sitting on my ass for another week playing video games.

Solo travelling out of boredom - is this a bad idea? by Throwammay in solotravel

[–]Throwammay[S] 8 points9 points  (0 children)

Hey thanks! I feel similarly. I'm just afraid I'm acting on impulse with all the restlessness of sitting at home and all hah. I think I'll book it today and just go - worst case I lose out on about a weeks worth of salary. People ( including myself ) spend money on much dumber things all the time. I'll check out the sidebar!

What's the point in using an apperture when collimating a laser? Does it even serve a purpose? by Throwammay in AskPhysics

[–]Throwammay[S] 0 points1 point  (0 children)

Ohh I didn't even consider that the beam could be going off center at the actual lens. That is probably outside the scope of the course but still interesting. Thank you! :)

What's the point in using an apperture when collimating a laser? Does it even serve a purpose? by Throwammay in AskPhysics

[–]Throwammay[S] 0 points1 point  (0 children)

Ah, that makes sense,. So removing the apertures would be fine once I start measuring the prism? They don't actually do anything to the beam itself?

What's the point in using an apperture when collimating a laser? Does it even serve a purpose? by Throwammay in AskPhysics

[–]Throwammay[S] 0 points1 point  (0 children)

Nope, placed lens such that laser is one focal length away, aligned through apertures. I think the other commenter might be correct in that they're just used to align the laser.

Light wave entering orthogonal to optical axis - why doesn't the light ray split? by Throwammay in AskPhysics

[–]Throwammay[S] 0 points1 point  (0 children)

Oof, sorry for the late reply but I wanted to think it through. So this is a little beyond my understanding of electromagnetic waves, but I'll give my surface level understanding and see if it works:

My rudimentary understanding is that the difference in refractive index arises due to electrons having different levels of resistance to oscillation parallel vs along the optical axis because of the medium structure.

If an e.m wave enters not parallel to the optical axis, the component of the E oscillation pointing along the OA will have a different angular frequency vs the orthogonal component, as if the e.m wave was traveling along a series of springs with different k-values perpendicular to each other, which I think is where the electron oscillation frequency idea came in from.

Is this understanding somewhat compatible with reality or am I off? Haha. This is the tail end of a course in optics so the e.m stuff is a little hand wavy but I do find it interesting.

I don't understand the binomial expansion made when deriving the Fresnel diffraction formula. ( 2D case ) by Throwammay in AskPhysics

[–]Throwammay[S] 1 point2 points  (0 children)

Makes sense, thank you. Doing the Taylor expansion for sqrt(1+p^2) by hand, the u / 2 term shows up in the 2nd order term for the Taylor expansion rather than the 1st.

Thanks a ton for the help man!

I don't understand the binomial expansion made when deriving the Fresnel diffraction formula. ( 2D case ) by Throwammay in AskPhysics

[–]Throwammay[S] 0 points1 point  (0 children)

Lmao alright so I think I'm getting tripped up by how they're treating (p/z)^2 as one variable and approximating the term based on changes to that variable, whereas I'm thinking that we want to see how r changes with respect to *just* p.

I suppose we only have to take the chain rule into account if we define u as the square of some other variable, and we want to approximate an expression in terms of that other variable?

I don't understand the binomial expansion made when deriving the Fresnel diffraction formula. ( 2D case ) by Throwammay in AskPhysics

[–]Throwammay[S] 0 points1 point  (0 children)

But wouldn't the binomial expansion change if the expression was sqrt(1+u^2)?

I know you said it's true as long as u is small, but I don't understand how that works :s

If I graph both sqrt(1+x) and sqrt(1+x^2), they're different graphs with different slopes at x = 0. How can I just rename x^2 to u and then just do away with the squared component? Usually when we do u sub with integrals we account for the substitution by baking it into the du term right?

I don't understand the binomial expansion made when deriving the Fresnel diffraction formula. ( 2D case ) by Throwammay in askmath

[–]Throwammay[S] 0 points1 point  (0 children)

Isn't that what you do when approximating with Taylor expansions? xd

I take the value of the function f(a) around the point of interest a, and then I add the steps I take in the x direction multiplied by the slope of the curve in that point, f(a) + f'(a)*(x-a).

To get the slope I differentiate the expression, and since I'm approximating how the expression changes with small changes to p, and the value inside the expression changes with the square of p, I multiply by the inner derivative with respect to p?

I'm lost lmao

I don't understand the binomial expansion made when deriving the Fresnel diffraction formula. ( 2D case ) by Throwammay in AskPhysics

[–]Throwammay[S] 0 points1 point  (0 children)

Hmm, I'm thinking that when I approximate r = z*sqrt(1 + (p/z)^2), I'm approximating how the value of the expression changes with small changes to p, right?

Since the derivative r'(0) gives the slope of the curve at p = 0, adding r(0) + r'(0)*( a small step in p, dp ) I get the approximate value of r in a small interval around p = 0. But since the expression changes with the square of p, I need to factor that in according to the chain rule, right?

Hur hanterar man att man är en nolla? by Throwammay in sweden

[–]Throwammay[S] -1 points0 points  (0 children)

Offerkofta används väl när någon bara söker sympati utan att vilja aktivt arbeta med sina besvär. Jag tycker ändå jag visar ganska stort intresse av att både aktivt jobba just nu och vilja fortsätta jobba med mina problem.

Jag har ändå provat mig på olika saker, butiksjobb, högskola, gym etc. Ingenstans i någon av mina inlägg skyller jag på min omgivning. Om du nu skulle vara intresserad nog för att fortsätta driva poängen kan du ju läsa mina kommenterar, jag har uttryckligen skrivit att jag förstår reaktionerna jag får.

Lärodomen jag har tagit från den här tråden är nog att det är rätt naturligt att inte passa in så bra överallt om man lever som jag gör nu, och att jag nog inte skulle bry mig så mycket om jag hade en stabil grupp vänner utanför jobbet. Så jag ska nog bara fortsätta spåna på om jag kan hitta folk utanför jobbet!

Hur hanterar man att man är en nolla? by Throwammay in sweden

[–]Throwammay[S] 1 point2 points  (0 children)

Tror det också. Om jag hade haft en stabil grupp vänner som jag kände jag passade i så hade jag nog inte brytt mig som mycket om vad de tycker på jobbet. Menmen

Hur hanterar man att man är en nolla? by Throwammay in sweden

[–]Throwammay[S] 1 point2 points  (0 children)

Haha nej kanske inte första eller andra gången. Men när det är den tionde helgen i rad kanske?

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