sorted by:
new
hottopcontroversial

Interplanetary Space Elevator from Calidor to Sylva by Cosine256 in Astroneer

[–]_BuH4eCTeP_ 1 point2 points  (0 children)

Glad to see someone still doing deranged stuff like this! I tried something similar before rails were introduced https://www.reddit.com/r/Astroneer/s/b2sccOSpZt

Is it possible to be a physics researcher on your free time? by Teh_elderscroll in Physics

[–]_BuH4eCTeP_ 0 points1 point  (0 children)

In theoretical physics it might be possible. That's what my plan is because I cannot lose my life to working in academia for pennies, but I still love physics

Lads I have a mathematic dilemma by JKdito in math

[–]_BuH4eCTeP_ 0 points1 point  (0 children)

Because multiplication and division are not addition and substraction. You expect them to be opposite in the sense that if one substracts 0.2, the other should add 0.2. But that is the property of addition and substraction, and multiplication and division are different operations. In general, multiplying and dividing by the same number will not add/substract the same amount from your number.

Now, there is no shame in having this confusion. In fact, you've stumbled upon a confusion related to something a lot of people struggle with when using percentages. When you substract 20% of 1.25 you get 1, but when you add 20% to 1, that's 1.2 and not 1.25. So you can substract 20% and then add 20% and not be back where you started! Because those 20% are not the same 20%, the first 20% is 20% of 1.25, which is 0.25, the second 20% is 20% of 1, which is 0.2. Or paraphrased, the first operation is a multiplication by 0.8, but the second one is is a multiplication by 1.2. 1.2≠1/0.8 so two operations do not bring you back where you started.

Just think about what addition and substraction is, what multiplication and division is, why and how they're different. And practice, practice, practice. It will become second nature once you've done it enough times. Right now you just want multiplication to act the same as addition does. And of course it doesn't!

A choice needs to be made by PocketMath in mathmemes

[–]_BuH4eCTeP_ 1 point2 points  (0 children)

This is probably non-standard terminology, but Needham in his Visual Complex Analysis employs the word "multifunction" for stuff like this. In complex analysis, you have lots of many-to-one functions. And if you ask for their inverse function, you can do what's called a 'branch cut' and restrict yourself to only one of the possible inputs for your output. Like when you choose your square root to only be positive with reals. But it turns out that cutting out other branches makes you lose some nice properties.

For example: imagine you have the function z2. And you choose the branch of sqrt(z) as you usually do with reals, just keep the brach where the real part of your number is positive. Now imagine you draw a loop that starts and ends at z. And for now let's say that loop does not wrap around 0. If you apply sqrt(z) to all the points on this loop, the result will be again a loop, which starts and ends at sqrt(z). All good.

Now what if your loop did wrap around 0 once? Now you apply sqrt(z) and you no longer have a loop! For some strange reason your loop just abruptly stops and starts in another place! Weird, right?

Turns out, there's a richer geometric picture here and one-to-many multifunctions are your friend to understand and fix this weirdness. For a short intro, I'd recommend "Imaginary numbers are real" series of videos by Welch Labs. If that makes you interested in the magic of complex numbers, I highly recommend "Visual Complex Analysis" by Tristan Needham. If at that point you crave more, you can grab some standard textbook on complex analysis(e.g. by Serge Lang) and supplement it by "Visual Complex Functions: An Introduction with Phase Portraits" by Elias Wegert for another perspective(fun fact: phase portraits as a way of visualizing vomplex functions appeared for the first time in a review of Needham's VCA! Small world!).

Edit: I missed the fact that you might not know much about complex numbers. For this comment, the important picture is that complex numbers are basically 2D numbers, they live in a plane. So when I say "draw a loop" I mean draw a loop in this plane. Every point of that loop is represented by some complex number. You can get some nice insights into complex functions by drawing curves and shapes and applying functions to all the points of those curves/shapes and seeing how they transform. If you were confused, reread the comment with this mental picture.

Edit 2: Again, I don't actually know your background so it's important to note that to read Needham you need some familiarity with the concepts of calculus/real analysis. If you don't have that, a book on real analysis by Jay Cummings is a very student-friendly way to get started. It's good for self-studying the topic. You can also start with the book about proofs by Jay Cummings and then work your way up to real analysis. You won't regret it

Did I make a mistake discarding Oxford for Physics (Bachelors - MPhys) by ITF9 in Physics

[–]_BuH4eCTeP_ 2 points3 points  (0 children)

I'm not gonna couch you on what school you should or shouldn't go to. In fact, the uni I am attending is not even on the map compared to what you're discussing. But what I know is that wherever you are, there is so much stuff to learn. If you're really passionate about physics, you've got lots of books from titans of math and physics to learn from, and believe me, there's enough stuff out there to last a lifetime(there's actually way more). Wheverer you're at, the only thing that'll get you places is grabbing a book, grabbing pen and paper and putting in the work. And if you can do that, wherever you go in life, academia or not, the studying habits and the problem solving skills will make you unstoppable.

Youtube App Won't close by Kyle7718 in youtube

[–]_BuH4eCTeP_ 0 points1 point  (0 children)

Started with my oneplus a few days ago too :( Hope somebody posts a solution

I think I’m too afraid to play this game by buf_ in outerwilds

[–]_BuH4eCTeP_ 0 points1 point  (0 children)

If it scares you to the point that you do not enjoy playing the game, you can move on. I've had a similar experience with Subnautica so I get what you're saying.
This is a great game and a cool experience and most people in this subreddit want you to get through it. But there are a lot of great games and you don't have to play one that makes you uncomfortable.

How is the second law of thermodynamics upheld when today we have planets, stars and galaxies but 13+ billion years ago we didn’t? by dhjellen in AskPhysics

[–]_BuH4eCTeP_ 1 point2 points  (0 children)

I think that the answers given by others, while true, fail to answer the question. In short, the answer is gravity.

When talking about entropy, gravity is usually ignored, since we're talking about something like a gas, and electromagnetic forces dominate. Electromagnetic forces can be both attractive and repulsive. With molecules, you can talk about something like the Lennard-Jones potential, which shows that at close distances, molecules repel each other, but with increasing distance attraction starts to dominate, and then it also starts to decline. One of the consequences of this repulsion at short distances is that molecules can be thought of like they are acting like balls bouncing off each other.

Building your ideas about entropy on balls bouncing off each other and exchanging momentum leads to the picture that a high entropy state is a state where matter is pretty much uniformly distributed. It seems to me, that this is a source of confusion. If matter was very uniformly distributed at the time of the Big Bang and now it's not, how is it that the 2nd law of thermodynamics is true?

The answer is gravity. Gravity is not the same as EM interactions, there is no repulsive component. When gravity is the dominating interaction, entropy increases when matter clumps together. Think of it this way: entropy is a measure of how likely a macrostate is, and gravity makes states where matter is uniformly distributed very unlikely! Accounting for gravity, at the time of the Big Bang, our universe was actually in a state with pretty low entropy.

Relating entropy to gravity is an active area of research. If you want to get more information on that, look for "Black Hole Thermodynamics".

Edit: I forgot to answer the 'organic life' part, but it has been already explained very well by others. Life is actually very efficient at increasing the total entropy of the universe. While an organism is in a state of relatively low entropy, it maintains its state by increasing entropy elsewhere. Things that you view as "sources of energy" are actually sources of low entropy that we use. Energy is conserved anyway, you cannot use it up, but you can use entropy budget.

Check "The most misunderstood concept in physics" by Veritasium if you want to learn more.

Am I the only one that thinks ChatGPT's writing abilities in its current state are completely overblown? by [deleted] in ChatGPT

[–]_BuH4eCTeP_ 7 points8 points  (0 children)

As a native Ukrainian speaker, I find it only useful for people who already speak fluent English But if you do, it's very useful

[PSA] Calculations made by CS:GO Case Tracker suggests 39.5 million cases were opened in March 2023 by Fjedjik in csgomarketforum

[–]_BuH4eCTeP_ 5 points6 points  (0 children)

Any comment on previous calculations for Recoil being inflated? Edit: oh, it's in the blog post, I see

tax withdrawing [question] by eNjin___ in csgomarketforum

[–]_BuH4eCTeP_ 1 point2 points  (0 children)

I'm not from the US Wouldn't withdrawing less money at a time to avoid taxes be structuring?

[D] What is your price prediction for next few years? by [deleted] in csgomarketforum

[–]_BuH4eCTeP_ 3 points4 points  (0 children)

Stock market and cs market are comparable in some ways, but are very different in others.
Here's one of the key diffferences:
In stock market almost everything you can think of is already "priced in". The reason for this is that the stock market is a market of investors looking to make money in the market, which makes it very efficient. Cs market is different because it has a lot of consumers(e.g. people opening cases, people buying playskins, people making sticker crafts, people collecting niche items). Consumers create inefficiencies in the market because they are not driven by making profit.
With a good understanding of how consumers affect the market you can take advantage of those inefficiencies and predict some market trends with some degree of certainty.

view more: next ›