Archived threads in /sci/ - Science & Math - 654. page
Images are sometimes not shown due to bandwidth/network limitations. Refreshing the page usually helps.
Greetings /sci/!
It's been a while I've posted updates and surely a lot have happened meanwhile. We are the Hyperloop Student Competition Team of /sci/, although our team have changed quite a bit - most of our members went away but I got to replace them with others. Anyway, we have a Prelim Briefing Submission coming up and we've pretty much covered our main design features.
I'm here today to do a sanity check - to see if our design ideas are actually valid or not. So before you start saying >he does it for free, let me remind you that this...
Comment too long. Click here to view the full text.
2: Levitation / Propulsion
In all the Hyperloop designs available out there and the further reports & analyses that cover the original white paper by Elon Musk, the compressor and the subsequent air bearing system is the design imperative. The piston effect which occurs within an enclosed tube is one of the main challenges a train speeding near 1 Mach would face, hence Musk proposes a compressor which sucks in the air that accumulates at the front of the train. This air is passed through a compressor, and thus sent to the air bearings that provide the levitation,...
Comment too long. Click here to view the full text.
>>7628801
Lookin good m8
3. Chassis
The chassis will be mainly derived from commercially available Maglev structural designs, that have the following structural characteristicL:
>1) as light as possible,
>2) enough degrees of freedom,
>3) special mechanically-braking mode
>4) unique lateral load way
>5) vehicles fall on rail to slide under emergency
The chassis will be fitted with linear braking systems, pressurized air...
Comment too long. Click here to view the full text.
CLIMATE CHANGERS JUST CAN'T KEEP GETTING AWAY WITH IT
>https://www.nasa.gov/feature/goddard/nasa-study-mass-gains-of-antarctic-ice-sheet-greater-than-losses/
NASA: Antarctica is growing, not shrinking!
NASA has BTFOd the Intergovernmental Panel on Climate Change's 2013 report saying that Antarctica is melting.
Using altimeters on ESA's European Remote Sensing satellites for the period 1992-2001, and on NASA's Ice, Cloud and land Elevation Satellite for 2003-08, NASA has worked out that Antarctica...
Comment too long. Click here to view the full text.
TYB NASA
>>7628505
>implying it's not tectonic uplift
>>7628505
thanks based nasa
I had lost hope in them. But now... I'm in love.
What does /sci/ consider to be pop science? Is it strictly those "sciency" youtube videos that fudge the facts to sound more interesting, or is it anything that isn't written by the guy that discovered whatever he's talking about?
>>7628189
anything that focuses purely on innovation and not at all on evidence
Anything that doesn't have an integral in it.
>>7628189
Retarded shit based in speculation without a deep understanding of the concepts behind it.
It is the trivialization of the knowledge, now you can find assholes doing degrees that are more interested in share memes than spend their time in real study.
That's right, another fucking KIC 8462852 thread, but this time it's different. Instead of just fapping about what we'd if we contact ayy lmao's let's do something useful, let's search for more alien megastructures!
Go to http://www.planethunters.org/ and start searching!
It's the same shit that was used to discover KIC 8462852.
TL;DR let's hunt for ayy lmao's using the internet!
http://www.planethunters.org/
Duude.. There won't be any news atleast until january why the fuck are you making these threads ? Since there is nothing to talk about, the thread gets populated by /x/ and ayylmaologists
>>7623499
>the thread gets populated by /x/ and ayylmaologists
Shhhhh.... These are containment threads.
It keeps /x/ busy while the real /sci/entists are busy discussing why free will can't exist, whether 0.999... = 1, brain uploads, and order of precedence in 6/3*2.
>>7623500
So that you go to: http://www.planethunters.org/
and contribute to science
hey /sci/ fags, if the universe wasn't intelligently designed, then how is it intelligible? If the universe was made out of nothing like you say . . . then there is no reason why it should have an intelligible structure anywhere.
You think you're intelligent or something ?
>>7591879
Of course I'm intelligent, I can abstract universals from particular sense data, e.g. I can abstract the universal "chair" from this object appearing in my vision. This requires intelligence.
>>7591905
And a computer can do that too. Egos like this aren't suited for science.
>Null hypothesis: Population mean = 46.5
>Alternative hypothesis: Population mean > 46.5
>Sample mean: 46.3
>Sample standard deviation: 0.7
>Number of tries: 20
How do I find an approximation for the p-value? It should be greater than 10, yes?
>>7591538
t-test
what confidence?
>>7591547
Sorry, forgot to include: 95% confidence
why are bees dying?
Because they are mortal.
>>7591112
Also pesticides
Varroa & neonicotinoids.
lets say they had the same funding as the DOD, where do you think we would be?
Soviet work camps
No where. Nothing Special will.
You would be bitching about space-industrial complex and how we should spend that money on combating terrorists instead.
Hello
So my lecturer suck. Any of you guys know good resources to study Computer languages course ?
>>7590977
Fuck that, where's the recipe for that bread OP?
>>7591013
no idea man
Try the library idiot
Does anyone know what this is?
This might not be the right place but I am trying to identify what this actually is. It's not mine nor do I know who it belongs to, it was a random post on imgur.
a bag of sand, a plate and a lithium battery
>>7590946
I know that, but why would those be combined in a fridge?
>>7590937
Sand or fertilizer, potentially a grass-seed (since the bag is green, advertising purposes -- bad screen at the moment so can't get a closer look) and fertilizer mixture. The next is a 1.3 Ah, Lithium battery on top of what appears to be a cheap ceramic plate.
Let's have a /sci/ lifehack thread. Can be anything from math tricks, laboratory techniques from all flavours of science, or just using simple chemistry or physics to make life that much easier.
>>Take 90% isopropyl OH from the drug store (or reagent grade if you can get it), make a solution of 60% Isoprop-OH and 40% water. Put that shit in an empty spray bottle, and use it to melt even the thickest of ice on windshields in the morning. Keep it with your antifreeze or where you store that kind of crap, and never worry about scraping ice...
Comment too long. Click here to view the full text.
Never tested it, but I heard you can get rid of a N.A.R.B (no apparent reason boner) pretty quickly by flexing a large muscle like your quadriceps, gastrocnemius, or buttocks for as long as possible.
Adding a pinch of salt to your coffee prevents the bitter compounds in the coffee from binding properly to your tastebuds, reducing the overall bitterness of the brew.
This book has some really fucking cool science behind using physiochemical properties and techniques to change how food tastes, feels, and looks. It also has an entire third of the book dedicated to debunking and/or confirming culinary myths.
My personal favorite goes something like this: Everyone knows that putting lemon on vegetables and non-citrus fruits prevents oxidation. But why? Most people go be the axiom "because it's acidic", but is acidity the actual reason for the prevention of oxidation?
Turns out no.
Some dude at some fancy french biochemistry institute did a really simple experiment: He cut 3 avocados in half. One the first, he basted DI water. The second, lemon juice. These served as his positive and negative controls. Next, he diluted water with acetic acid until he created a vinegar that matched the pH of lemon juice, and basted onto the third. On the fifth, he basted a solution of sodium bicarbonate in water to serve as his base. So, logic would go that if acidity reduces the rate of oxidation, then basicity would increase oxidation rate. On the sixth and final half, he crushed up a vitamin C tablet from the pharmacy in water, and basted it on.
He graded the rate of oxidation based on area of browning and time intervals of like 10 minutes I think for 2 hours.
The results: The only two halves that had reduced oxidation rates were the lemon juice, and the Vitamin C (ascorbic acid). So, it is not the acidity (in terms of pH) that reduces oxidation; it was the ascorbic acid. My father likes to argue semantics and say "well its still the acid", I just face palm and tell him to go sell his cars. It's not really a "hack", but it's a neat bit of info.
/Adderall rant over
Hey /sci/
Is Language in our DNA or is it simply a behaviour?
>>7590823
Said differently, did we evolve language, or did our brains simply by chance have the faculties needed to produce the behaviour of language?
>>7590823
Do you even know what a DNA is?
>>7590835
No. If you are smarter than me could you help me figure out why this is a stupid question so I can try and ask what I mean?
Hey /sci/
I'm a club leader for some kind of C++ programming club.
Just some basic things, nothing too hard or serious.
What should I talk about?
>>7589945
Ask /g/
>>7589945
I remember, when I first learnt about classes, I saw a yt video where someone was implementing a little rpg, where there are e.g. mother classes like character or item with attributes like name, gold, price, weight,... and inheritant classes like sorceress, warrior, armor, potions,... with other attriutes like stats, wichcraft, protection, healing power, etc. Made it pretty clear what a class is.
>>7589945
Vector spaces, the raster space, build up into lenses and 3d engines
As space expands, is there work being done?
My understanding is that since there's no motion, in the traditional sense, involved, then no work is done, so no energy is involved. But then if your distance from a gravitational source increases, so does your potential energy. Is that a contradiction, or do the changing PEs from different sources all cancel out?
More generally, does expansion require energy?
Some kind of invisible energy
It probably blends into the night
Gothic energy, maybe, or shadow energy
Expansion is a property of space (space-time) itself, not of the objects within. Since our laws of motion apply to objects within but not space itself, it's hard to draw similar measurements such as work, force, etc.
dark energy basically
>>7589952
>Gothic energy
Its parents just don't understand it.
Are hyperreal numbers actually useful? Other than making calculus a lot more intuitive by eliminating the need for limits and other shit, do they actually help mathematicians solve other problems? I'm not a mathematician, so I have no idea what kind of problem or proof would require hyperreals.
>tl;dr: uses of hyperreal numbers?
You can use them in physics to perform calculations involving infinite sums where it's not obvious that the sums are going to cancel out to produce something finite. The classic example is in QED, where you need to perform summations over all possible paths that a particle can take between two points. Most of those paths cancel out, but without hyperreals, formal proof that they do is rather difficult. For systems with many particles, you're essentially forced to use hyperreals or some equivalent.
>>7589852
Yes. Nonstandard techniques can go way beyond simple calculus stuff, some results have been proved for the first time using this framework in functional analysis, probability, even in algebraic topology.
But you got it wrong, it doesn't eliminate the need for limits, it's just another way of looking at them.
Cool shit you can do with it:
nice characterization of compact sets - a set K is compact if and only if all x in K is infinitely close to a point in K (when I saw this it seemed quite natural...
Comment too long. Click here to view the full text.
literally everything in mathematics is useless
