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File: Colony_Drop_2.jpg (152 KB, 1500x1058)
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How much propellant would be needed to push moon onto earth?

Are there any better ways than attacking thrusters and simply pushing it?

Why hasn't anyone done it yet?
15 replies omitted. Click here to view.
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>>10024081
your body doesn't hold together by gravity, but molecular bonds, son
roche limit deals with larger body overcoming the gravity of the smaller body
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a
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>>10023994
under rated comment
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>>10024085
thanks for clarifyng, gramps

So, in the end its impossible to crash anything on earth due to Roche limit? Would speed of passing beyond that limit affect how fast it falls apart?
How would it affect man made satellites and spacecrafts?
>>
>>10024110
>So, in the end its impossible to crash anything on earth due to Roche limit?
no, not at all
roche limit is simply the demarcation line where an object orbiting other more massive object that holds uniform shape due to its own gravity starts to break apart
you are on earth right now and you seem to be doing well
that's because your body doesn't hold together by gravity (you DO have mass and therefore you DO have your own gravity, but gravity is a WEAK force, not just in name. it's actually pathetic in strength compared to things like electromagnetism, but it propagates noticeably the more massive something is
and earth and moon ARE massive
but zoom out and imagine they actually hold together more like patch of foam on top of water
a bigger patch floats by and absorbs the smaller one
it's not 100% accurate, because there are different forces at play here, but as a visualization it's close enough

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Here's a bAnGeR for yall.

In physics third year we were learning about the different ways that a transverse pulse on a taut string reflects at different boundaries. Let's take the particular boundary of a ring sliding up and down a rod with no friction between rod and ring - the ring just holds the tension in the rope. The pulse seems to 'squash' and reach twice its amplitude before returning with the same phase/sign, right? Of course you could explain this by thinking of it in terms of the wave interfering with itself, or using some mathematical magicry, but can you find a purely physical explanation for this behaviour? Yknow, newtons laws on each mass element n whatnot. Why does it return with the same sign/transverse direction? Why does it reach twice amplitude? Why doesn't the ring just stay in its new displacement?

tl;dr:
>Transverse pulse on taut string contacts free/soft boundary.
>Pulse 'squashes,' reaches twice amplitude, returns with same sign, and boundary returns to 0 displacement.
>Can you think of a satisfying physical explanation for these phenomena? Like newtons laws on each string element?
>>
solving the eave equation _is_ solving the equation of motion, ie newton's law. the math says exactly what's going on
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>>10023470
Of course. But can you describe it?
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>>10023480
The wave is created by a torque on the string. The applied torque is a rotation in a plane perpendicular to the string.

This causes the transverse motion.

The explanation for the sliding ring is arbitrary since theres no assumption about the ring being fixed at a certain height, or that gravity pulls it back down, but you can use an argument for energy momentum conservation to argue it has to reflect back.
>>
String theory isn't really science
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>>10023950
Hmmm. I feel like I should understand this e.e

File: Earth.jpg (48 KB, 948x948)
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Why cant you use the earths magnetic field to find out the rough long lat of where you are on earth?
2 replies omitted. Click here to view.
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>>10023353
map and compass.

https://www.youtube.com/watch?v=OBpwIDgJGCs
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>>10023353
>Why cant you use the earths magnetic field to find out the rough long lat of where you are on earth?
The field varies with time, anon. Local intensity even changes from day to day. Worse still, the magnetic poles aren't on the axis, so the equipotential curves aren't lines of latitude.
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>>10024133
>Gravity is magnetism
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>>10024137
They're intrinsically linked in the globe model.

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Go read this book then tell me vaccines dont cause autism.

>B-but we did studies on autism and vaccines, dozens and dozens.

You looked at thimerosal in MMR, now what about DTaP, polio, varicella, hep a, hep b? The CDC has never done these studies on these vaccines or other ingredients in relation to autism.
84 replies and 9 images omitted. Click here to view.
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Anti-Vaxxers should lose custody and be sterilized.
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>>10023857
What’s it like being a subhuman non-autist?
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>>10023965
>subhuman
I don't think it's really a vertical matter.
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>>10023963
Yeah, and anyone who ever questions the government too! They're a danger to society and must be silenced before they challenge our--I mean THEIR power.
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>>10023963
Vaxxers should be put into labor camps, used up, and thrown away as needed.

File: ax.jpg (161 KB, 1280x720)
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>MUH CLIMATE CHANGE

If global warming was an immediate threat to life as we know it governments could quickly release commonplace, cheap sun blocking gases onto the upper atmosphere and assure temperature control for at least a few centuries. Maybe even temperature reduction.

Why don't they just do it? My best guess is because maybe it's not such an emergency after all? Maybe selling "green" stuff is a good marketing ploy?

I'm curious to hear your opinions.
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>>10024078
>>Reducing the amount of sunlight with clear particles is the same as eliminating sunlight entirely or blocking the sky.

>Clear
>Blocking sunlight

You don’t understand physics at all. The problem is heat retention.

>Checkmate, you got me. I admit climate change is not that huge of an emergency. Do you?

It is an emergency, since it will wreak ecological devastation and human property destruction on the order of trillions of dollars in the coming decades and centuries, and efforts to counter it will be very costly in both hard currency and human wellbeing and labor. Delete your strawman troll thread, now.
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>>10024047
Linking my earlier thread.
>>10023086

People will actually try to explain away a deep, clear blue sky turning into a cloudy haze for the res of the day and thensome after a series of jets fly over in a grid / corn row pattern in the space of like an hour. Usually with jets not leaving such "persistent contrails" flying right near them. No, altitude differences don't explain such a rapid and profound effect, nor the nonsense flight directions.
>>
>>10024047
That without a doubt require a global effort where every government agrees to it. That's harder than it sounds. Also, if you don't stabilize your CO2-emissions, you would have to constantly produce anti-greenhouse-gases in the same amount. Doing that is expensive. So you would need have a comparative cost calculation to see whats cheaper, not cutting CO2 and producing gigantic amounts of anti-CO2 to compensate, or invest into producing less CO2 instead.
>>
can't we just plant a fuckton of new forests?
>>
>>10024047
We already have a climate change thread

File: sal_khan.jpg (35 KB, 760x427)
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What does /sci/ think about Sal Khan?
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>>10022583 (OP) #
Helps you immensely if you go by your own pace. The slow pace is because he could explain everything he does to give you an overall more intuitive sense of what is being done, but if you get it, you can skip forward the video.
The reason why it is infinitely better than going to a school or a lecture, is that these videos are personal and you can always stop, skip, rewind, and go back to the previous video. At school, you are speeding forward with the clock, the alloted time for the lesson. Not only that, you can't easily communicate with the teacher when you are straining to figure out something that he did, and the course doesn't stop if you miss something but keeps moving and essentially waste your time and your brain as you are straining yourself trying remember, figuring out something that would make sense of it all. The course in highschool is made for everyone, but most of the time teachers give preferential treatment for the students who are up to date with everything and can answer their questions.

Tl;dr : Khan academy > highschool
>>
>>10024018
This. Genuinely a good educator and businessman. Only pseuds and racists dislike him.
>>
>>10022583
My middle school math teacher, who was actually pretty cool, once recommended khan academy. That was 7 or 8 years ago. I've never actually watched any of his videos.
>>
>>10022583
His videos are low quality compared to some other open source alternatives like MIT OCW and so forth.

The website pedagogical organisation is bad. Especially beyond the freshman level.
>>
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>>10023900

File: rzf.jpg (62 KB, 1500x888)
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Tomorrow just might be the biggest day in century (yet), /sci/.
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>>10023922
You are grossly uninformed.
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>>10023960
>Because in 2000 years no one has invented a better method brainlet. Or, you know, you can give one right now to prove me wrong.
So is it the case that "Logically the only POSSIBLE way to know whether a given number X is prime is to use the Sieve of Erastothenes"? If so can you explain the logical steps?
>>
>>10023960
>It is not logically possible to write a one function that does "entire sieve of erastothenes at once". What you are doing is composing functions.

The entire Sieve can be represented or extracted to a single periodic summation.
That sum, which is numfac, contains all the info of the sieve at once. They aren't constructions, that is you don't need to know any set of numbers in advance, like knowing the primes to find the primes. This is especially true since the sum is valid to infinity, and thus can be taken as a whole. If it equals 2 for a given x, it's prime, as long as j >=x.

You can manipulate numfac to give the exact distribution, and further manipulate that to give a recursive sequence for any nth prime. The result is a single variable equation that terminates on the nth prime, and if you use the product polynomial version, you have the entire family of functions calculable in polynomial time.
>>
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>>10024082
wrong pic, that one is similar but without showing input so it's useless meant to post this
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Anyways, it will be interesting to see what he came up with, I know I want to check it out.

Here's one more I've posted before, for fun's sake. Start with this, it's numfac, there are simpler versions of it too, but its a good place to start.

File: download.jpg (11 KB, 300x168)
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Did he do it guys? Did he prove the Riemann Hypotheshit?
62 replies and 11 images omitted. Click here to view.
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>>10023775
"we must kill him before it's too late"
>>
>>10023775
before final exams I always think of the date of the exam the way pic related depicts it.
>>
>>10023979
I had a thought about Dirac deltas that turned out to be wrong.
>>
>>10023979
http://www.alainconnes.org/docs/rhfinal.pdf
Crazies old men love RH
>>
It's a load of shit. Riemann is unproveable. Allow me to domenstrite. Allow 7 niggawats to equal one watermoln. From this you can deduce that 72 nulecules manifest as the exponential exponent of kurzweil's paradox.

In order to study the role of the cytosolic form of phosphoenolpyruvate carboxykinase (GTP) (EC 4.1.1.32) (PEPCK-C) in skeletal muscle, PEPCK-Cmus mice were created by introducing the cDNA for the enzyme, linked to the human α-skeletal actin gene promoter, into their germ line. Two founder lines generated by this procedure were bred together, creating a line of mice that have 9.0 units/g skeletal muscle, as compared to 0.080 units/g in muscle from control animals. The mice were more active than controls in their cages and could run for up to 5 km, at a speed of 20 m/min without stopping (control mice run for 0.2 km at the same speed). Male PEPCK-Cmus mice are extremely aggressive, as well as hyperactive. During strenuous exercise, they use fatty acids as a fuel more efficiently than do controls and produce far less lactate than do control animals, perhaps due to the greatly increased number of mitochondria in their skeletal muscle. PEPCK-Cmus mice also store up to five-times more triglyceride in their skeletal muscle, but have only marginal amounts of triglyceride in their adipose tissue depots, despite eating 60% more than controls. The concentration of leptin and insulin the blood of 8 to 12 month of PEPCK-Cmus mice is far lower than noted in the blood of control animals of the same age. These mice live longer than controls and the females remain reproductively active for as long as 35 months. The possible reasons for the profound alteration in activity and longevity caused the introduction of a simple metabolic enzyme into the skeletal muscle of the mice will be discussed.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2491496/

It even makes the mice live longer. We could make everyone strong, aggressive, long lived and able to be active many times longer than now.
3 replies omitted. Click here to view.
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>>10021712
>Male PEPCK-Cmus mice are extremely aggressive, as well as hyperactive.
We don't. No need for brainlet supersoldiers with ADHD that consume 60% more food for their weight
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>>10021712
What a Mouse !
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>>10022285
Yes sir.
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>>10021712
Were going to see genetically engineered humans in our life time. This is it.
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>>10024027
Lol. We will see electronics amplifying our brain processing speed by the end of 2030

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Are there any modern fields of science where analytical solutions are practical? I'm only a junior in engineering and every class is basically reading empirical constants from a table or using numerical/iterative methods.
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>>10024041
You'll be replaced by Artificial Intelligence sooner you don't learn analytical methods.

Computer performs numerical/iterative methods better than Humans.

(non Brainlet) Humans still can do analytical methods better than Computer.

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Somebody have an explanation for this bullshit?

How does the number 100, contain 325,000,000 instances of the number 3.
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>>10018998
Inshallah
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>>10022947
Scientific notation is literally just a shorthand so you don't have to waste time writing out all the zeroes. Everyone who's not a massive brainlet should be familiar with it after high school
>>
>>10018984
it doesn't... you're just reading it wrong.
>>
>>10022947
not comparable
5 + 5
1x10^1
or
10x10^0
>>
>>10018998
0.0000000307692308

would you like to become an actor? why?

why choose STEM careers rather than becoming a rockstar or an actor?
21 replies omitted. Click here to view.
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>>10022720
only philosophy does
>>
I'm ugly and don't know how to play instruments or sing
>>
>>10020323
HUZZAH!
>>
>>10022720
Cold hard logic teaches you how to think in small steps.

If anything I think it rather cruel to give someone an unobtainable vision without rigor...
>>
>chose

Choice is an illusion. In reality we all have pretty much our futures set by our circumstances. For us STEM folk our choices are probably very limited. If not STEM, maybe some mid level office job and that's about it.

>2018
>take flu vaccination
>still get the flu

Medicine is a fucking scam and fuck the scientists who promote this shit
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>>10022415
>just take a few sick days and soldier through it, it's only flu.

Unless of course you interact with old people, children or people with compromised immune systems at all.

And, of course, if Spanish Flu II Electric Boogaloo turns up again, being vaccinated may have been a good idea.
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>>10023059
>>
>>10023611
>Vaccine related deaths happen every year.

So do flu related deaths, though.
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>>10019494
I haven't been sick in 9 years. I'm basically the closest thing to a God compared to humanity .

Getting suck is brainlet retard shit for children or subhumans.
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>>10018949

>Flu medicine.

Americans sure do say the darndest things.

File: qi.png (57 KB, 1270x770)
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>nobody is talking about this

http://earthsky.org/space/rocket-thrust-quantized-inertia-qi-darpa-funding

What do you think /sci/? Is this a game changer?
>>
>>10023664
It's literally aether all over again.
Since this crackpot shit is now gaining mainstream attention I can only assume that the powers that be have technology much more advanced.

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4 replies omitted. Click here to view.
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>>10023746
>stays inside of it
you can't even get inside, let alone stay there
the beam tunnel is like 2 inches wide
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>>10023855
well if you e.g. removed the silicon tracker/pixel systems of CMS, you could easily sit or stand if you're short in that space, right in the middle of the detector

your cells would get destroyed pretty quickly, like this guy but sustained much more powerful beams https://en.wikipedia.org/wiki/Anatoli_Bugorski
he lost an ear and paralyzed half his face just from a quick exposure to a beam
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>>10023370
You’re retarded
Sage
>>
>>10023370
A proverbial black hole for money yes. A theoretical non-existing concept regarded as a phenomena? No.
>>
No. If noggerstein and niggerchild are correct, then a black hole needs a lot of mass to form. the size of a black hole that (((could))) reault from particle collision would be smaller than the fundamental building blocks of existence, so it wouldn't and cannot exist.




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