Archived threads in /sci/ - Science & Math - 71. page
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How did the ocean get there? I have always wondered such things. Did it rain for many days, was the Earth formed with it, or did it melt off a meteor?
>>8146733
40 days, actually
40 nights too
One day it got a lot more cloudy than it used to be. The atmosphere was thick and rich, like the cum you swallowed last night.
Then it rained for a shit ton of years. Like thousands.
I think the Earth's surface started as 100% ocean, then underwater volcanoes jizzed out a load of molten rock which piled up above the surface, cooled down and made land.
It still happens to this day, so we actually have pictures of it. Pic related.
What pre-requisites are required to understand algebraic geometry, I was planning on buying the two books from the /sci/ wiki, and I only have a mathematical understanding up to calculus 2.
>>8146657
Topology and Commutative Algebra.
k
try learning real analysis, abstract algebra to a graduate's understanding, algebraic topology, and commutative algebra first
>>8146659
fuck
Can someone explain what is physically going on in a CPU in a desktop? Is it literally just a lot of transistors on a Si die?
>>8146473
>Can someone explain what is physically going on in a CPU in a desktop
Electrons move around.
>>8146473
Look up logic gates, FSMs, FullAdders and memory. In that order.
It's still just a shitload of transistors, but the theory behind it is really interesting
on/off switches connected to other on/off switches grouped in logic gates connected to other logic gates grouped in larger logic units connected to other larger logic units etc.
Wow, /sci/. Really makes you think, huh...
It's a pretty interesting question though.
>>8146465
That's why we build shit that can detect it.
>>8146463
really doesn't make you think, it's pretty obvious and straightforward.
http://scitation.aip.org/content/aip/journal/adva/6/6/10.1063/1.4953807
Just interested to hear what other physicists think of this paper. I just found it while looking for something else about EM waves, and it looked interesting.
I'll give you the tl;dr of the paper: EM Drives produce exhaust, thus not violating physical laws.
Also, I understand the skepticism. I was and still am doubtful that the EM Drive is anything more than /pop/sci hopes and dreams, but please read the paper before you /sage/
>>8146257
According to the researchers, the exhaust being blasted out is actually light, photons that have become paired up with another out-of-phase photon in order to shoot out of the metal cavity and produce thrust.
>the two photons in those pairs are out of phase and have no net electromagnetic field.
>the exhaust photons become invisible from an electromagnetic point of view because they're being masked by their out-of-sync partner.
SO...
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>>8146257
Do pairs of out-of-phase photons have less energy than the 2 would have separately?
you would need 100 000 times more energy than this thing is using to create enough photons for the measured thrust.
>>8146356
That's what I was thinking too. OH BOY THERE'S THE SAME AMOUNT OF THRUST AS THERE WOULD BE IF YOU OPENED UP A MICROWAVE OVEN!
is there someone like me who writes very badly, in particular math formulas? how did you improve your writing skill?
try
>>8146192
this was supposed to be a board for relatively smart people
>>8146187
>implicando
what's the point of the so-called 'law of everything', the ultimate physical theory? the unifying theory of the universe?
Imho it's just a delusion; from a philosophical viewpoint, wouldn't it be inferred from a set of axioms given for granted? how can that be 'the end'?
Physics is an open field per se. How can it become a closed theory i.e. how can every physical truth be derived from the axioms?
Am I missing something?
>>8146118
>Am I missing something?
Yes, at least 12 years of physics education, for your opinion to even matter.
It's just a theory that can unify all the theories we have about physics into one shindig, ie. Unifying relativity and qm
>>8146118
two theories that work for different situations..
doesn't that bother you, instead of having on theory that works for ALL situations?
that's the point of physics.
If you want axioms, go do math.
How would you define the term 'explosion'? Could the rapid expansion and fragmentation of a bullet inside of soft tissue be considered an explosion?
>show the crimescene photos
Somehow I don't see that happening and I'm surprised Michael Moore of all people doesn't realize it.
Rapid expansion via sudden chemical reaction
t, W.W
Explosions are defined by detonation and combustion. Combustion being the process by which energy is transferred through a chemical transmission (conflagration), and detonation is by physical propagation (shock, as in pressure waves).
Fragmentation is probably the best word for a bullet separating in the body. It devolves into multiple pieces. Dissassembles might also hold true, but that's usually a purposeful or otherwise orchestrated deconstruction, not an uncontrolled breakdown.
![CBslmsvUgAA0o80[1].jpg](https://i.imgur.com/pEfoZHK.jpg "CBslmsvUgAA0o80[1].jpg")
The Nonty Hall Problem
>On a game show, a contestant was offered a choice of three doors. Behind one door was a car, behind the other two were goats.
>After the contestant had selected a door, Nonty opened a different door, revealing a goat. Nonty offered the contestant a chance to change his selected door to the other, unopened, door.
>Would a door switch have improved the contestants chances of selecting the door behind which a car was hidden?
This is not the...
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>>8145655
sounds like bullshit you just made up
The problem with all the trolls on 4chan is that I cannot just tell you "trust me" because I might be a troll, but... trust me? There really is a difference. You can find it with either a map of the outcomes or through explicit Bayesian updating.
>>8145655
did the host know where the car was an always opens a goat door? - 1/3 to 2/3
did the host not know where the car was and opened a goat door by chance? - 1/2 to 1/2
d = 21.6 (mutational differences found in mtDNA)
r = 0.000996 (mutational rate)
t = ?
so:
21.6 = 2(0.000996) x t
or t = 21.6/0.001992
t = 10,843 years. = The amount of years since mankind's earliest common maternal ancestor (Mitochondrial Eve)
God is real, and evolution is false. Eternal checkmate, atheists.
>>8145450
>>8145450
Are there any objections to this? Please, men of /sci/ence, tell me why I am wrong.
>>8145500
because my textbook says so and my textbook is always right
![curiosity-buckskin-selfie[1].jpg](https://i.imgur.com/FsHqxNT.jpg "curiosity-buckskin-selfie[1].jpg")
http://www.cbc.ca/news/technology/tridymite-mars-1.3634519
More spookyness from Mars baffles the scientists. They found Tridymite, which is a silica-based mineral that only occurs in super hot temperatures. They occur on earth near volcano sites after eruptions.
>>8145320
>Tridymite, which is a silica-based mineral
>silica-based mineral
it's literally just silica.
>>8145346
>it's literally just silica
... formed in high-temperature environment.
Lrn2geology fgt pls
>>8145346
Which tell us that is very likely that there were also volcanoes on Mars.
Math tutors in education-obsessed South Korea literally making millions desu.
https://www.washingtonpost.com/world/asia_pacific/in-education-crazy-south-korea-top-teachers-become-multimillionaires/2014/12/29/1bf7e7ae-849b-11e4-abcf-5a3d7b3b20b8_story.html?utm_content=buffer9b821&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer
Guilt free bump
>>8145176
Good for the teachers to become millionaires. Bad for the students to have no life as anyone on 4chan should know something about.
>>8145176
How come they barely outperform Japan and yet the Korean studies seem to much more hardcore?
I watched an entire documentary on the guy in Op's pic and then looked up their performance on global tests and they barely surpass Japan and Singapore. I view both Japan and Singapore students to be very lax in their studying.
Im starting to do probability/combinatorics.
Any textbook recommendations? Im looking for something easily digestible and leaning on the applied side
>TLDR looking for stewart calc equivalent for probability/combinatorics
>>8145147
Get this shit off of here >>>/trash/
>>8145147
disgusting
Lets say by some miracle we get a colony up and running on mars or something within the next 50 years. What career choices should someone make now to get the best chance of being selected then?
>>8145120
Any engineering you cuck
>>8145125
>marine engineering
>Systems engineering
>Civil engineering
>Manufacturing engineering
>Naval engineering
>Software engineering
Yeah no.
>>8145120
Anything related to using as few resources as possible as efficiently as possible. I'd recommend biology and food production broadly with that goal in mind, because most research in that field assumes massive inputs of given resources are available. Even if they're working on water efficiency, it's still on the scale of millions and billions of gallons. Start working on maximizing water efficiency in a closed loop system of 1000 gallons or something and you should be good.
My local paper's letter to the editor is a bunch of people patting themselves on the back about wind mills and solar energy. I wrote a letter but would like to run it through you guys to see if i sound like an idiot.
>Climate change has been placed in high priority in businesses and politics; however, the talking points are a bit delusional. Cutting carbon emissions by 50% in x amount of years won’t happen without replacing the energy source. Wind and solar are both great but their efficiency is still questionable and they both need subsidies to stay in business, while producing only 4% of our electricity. If we’re not going to have a conversation about our population problem and how the United Nations population forecast on most continents will double within 50 years, then it’s time to talk practical solutions: Fission/Fusion.
>Fission nuclear energy provides 20% of the United States energy. It would be more if oil didn’t drop drastically in the past few years (see our Kewaunee plant). Fission is when you split an atom using uranium. This produces great power but you’re left with a good amount of waste. Steel rods, infected lab equipment, ect, not to mention the average time of the atoms is around a thousand years until they become stable. That is, when ionizing radiation becomes electromagnetic radiation. However, the future is very optimistic with its natural evolution.
continued
>>8145027
>Fusion nuclear is feasible within 20 years (depending on how volatile oil becomes in the future). The hydrogen bomb incorporates the same logic as fusion reactors, which has already been successful. This is the process of smashing hydrogen atoms together, instead of splitting them with uranium/plutonium. This, depending on design, can save up to 99% of nuclear waste, but the benefits don’t stop there. The average time the waste becomes stable is only 50 years, compared to fissions hundreds of years. It produces more power and the smoke coming out of the chimneys are 100% water vapor. Businesses like MIT, Lockheed Martin, Boeing are already creating reactors and engines by incorporating fusion theory. Multiple countries are funding a plant in France (currently the leading country in fission energy) to create a fusion plant that is meltdown proof, China is right behind them.
>What we should be doing is supporting this and get rid of the notion that ionizing radiation is a horrible thing. Just 0.5 ounces of liquid hydrogen can produce as much energy as 28 tons of coal with no waste or pollution. Potassium -40, found in bananas, contains ionized radiation. Also found in kidney beans, sunflower seeds, potatoes, and most nuts. It’s time to think practically instead of regurgitate the most politically popular opinions.
Also general fusion/fission discussion
>>8145027
We get it, you're being paid to shill Nuclear power. Take it to reddit were people are dumb enough to fall for it.
>>8145029
business are wasting millions to shill? is fission a meme, too?
