/sci/ - Science and Mathematics

Sorry for Blogposting
I recently got into amateur astronomy, having this shaky tube standing around (pic related).
700mm main mirror, for 70 eurodollars.
It's really shaky, but I learned using it. I got pretty good at it by observing Sunspots (with a proper objective sun filter, of course). 2x Barlow + 20mm stock objective is perfect for this.
The Sun seems pretty inactive right now.
Other than that I also observed Jupiter and Saturn (both very bright right now, I'm from Luxembourg btw) and saw Jupiters 4 main moons and his stripes. I can't take pictures of these things because I've got neither an expensive camera nor the right telescope to put said expensive camera on for good results. I started drawing the Sunspots on paper, though.
Does anyone here know of something I could use to further filter Sunlight? I watch her in white light only, so watching different visible wavelengths might reveal some currently hidden things, right?
Also, are there filters for planet shine? Jupiter is always very whitish when I observe it.

what are you studying?

what is your favourite branch/field in science and maths?

Hey,/sci/
Let's say I wanna participate in the redbull gravity challange,in which you would have to build something that would prevent an egg falling from 12 meters from cracking.I already have a few ideas but I wanna hear yours

http://www.avgeekery.com/blog/2015/2/2/how-the-us-space-shuttle-lost-its-jet-engines

What a shame, imagine what could have been.


As design work by various aerospace companies began on the Space Shuttle program in the late 1960s, it was a given that the Orbiter would have its own jet engines.


Having its own air breathing engines offered three advantages- they would allow atmospheric flight testing much like any other aircraft was tested and pilots could practice landings in the run up to an orbital mission. The engines also facilitated ferry flights, repositioning the Orbiter amongst various facilities (landing, launch, overhaul, etc.). Having its own jet engine propulsion also gave the Orbiter cross range capability upon return from orbit.

Some designers envisioned the Orbiter rendezvousing with a tanker for additional jet fuel


Consideration was then given to using liquid hydrogen as fuel for the jet engines which would cut out the need for jet fuel tanks. In June 1970, NASA issued contracts to GE to study the feasibility of using liquid hydrogen in the F101 engine being developed for the B-1 bomber. Pratt and Whitney also got a similar contract to study the use of liquid hydrogen fuel in the F401 engine, the planned naval derivative of the USAF's F100 engine planned for the F-15 Eagle. Both companies showed that liquid hydrogen fueled jet engines saved about 2500 lbs of weight per jet engine compared to conventionally-fueled jet engines.

What do you guys think about Soylent? Have you used it? Do you anticipate any health problems due to regular use?

recently encountered two reasonable arguments against the theory of evolution.

The first was the idea that DNA is simply too complex to have simply occurred. I don't have the biochemistry education to properly understand this,, but I think I can dismiss it as the "god of gaps" argument.

"I don't know" therefore god line of thinking.

The second was more challenging. It acknowledges that natural selection can account for considerable variation within a species, but cannot account for the development of a completely new species.

For example,, Humans have been selectively breeding dogs for centuries and have produced all kinds of different results.. but they remain the same species. They can still interbreed and they still have the same number of chromosomes.

We have been making mutant fruit flies for decades.. generation after generation of fruit flies but they remain fruit flies,, they are different but they remain the same species.

According to this criticism of evolution,, evolution fails to describe a process through which an organism can lose or gain chromosomes and change it's DNA to become a new species.

Anyone have something to counter this criticism?
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Damn shame that /sci/ appears to be a pretty slow board. Sorry to shit this board up with a single question, but does /sci/ have an official torrent? /k/ has the mega folder and /g/ has the /g/entoomen library. Does /sci/ have anything similar?

More spacex fun times!

CRS-6's static fire test will be Saturday, and if all goes well, launch will be Monday.

This will be the second time SpaceX will try to land the first stage on the drone ship (well kind of third but last one was cancelled due to weather).

Pic somewhat related; they're also testing the tanks on the in-flight Dragon 2 abort first stage.

Okay /sci/, please help a first year engineering student understand stress and strain in beams. We're covering Euler-Bernoulli beam theory, and they (the lecturers) have stated that curvature is the rate of change of the slope of a beam in deformation. That I understand. I understand how curvature can be related to the radius of a circle, given that we assume the deformation to be in that shape (i.e.: a minimal deformation).

We arrive at
Stress = Modulus X Strain = Modulus X Curvature X Distance from the neutral axis
(Picture 1)

Then this comes up:
>The force acting on the cross-sectional area is equal to the integral of the stress on the cross-sectional area (Picture 2)
I don't understand how they got to that. Can anyone explain?

Guys, I am a Computer Sciences undergrad in Brazil, but there's a problem. I SUCK at math, complete disaster, and I want to become a very good computer scientist/mathematician.
Any tips on how to get started?

Hello /scI/, this is maybe too speculative for this board but maybe some (bio)chemfags can answer some questions.

So, one of my teachers once said that there are probably no silicon humans because their sex would take as long as the universe is old.

The question is, is it maybe possible for silicon based life to exist, in a solar system with planets that have a hotter sun and more pressure, to keep komplex molecules stable?

Are there people who run experiments on hypothtical reactions that could be part of a primitive silicon metabolism?

Can silicon even build complex molecules that resemble proteins?

I wish my ichthyology class had covered sharks more (freshwater pleb here), but I'm having a hell of a time looking this up. Anyone have any idea what the function of this anatomical feature is?

It doesn't appear to be a synapomorphy of any one shark clade, and so many sharks have it that I'd be hesitant to assume it's just a vestigial artifact of development.