How can the conservation of mass and energy be true if the universe is constantly expanding?
If new space is constantly being created, then you have to ask what space is made of. Well, its mainly vacuum, right? With interspersed helium and hydrogen that form he intergalactic medium. So where are these new particles coming from? And what about dark matter? In order for gravity to even exist there has to be dark matter. How is this being created in the new space that's being created by the expanding universe? Or is there no gravity at the edges of space?
>>9128802
I blame this retardation on the meme that is Modern Cosmology.
>>9128802
Space has no properties and is nothing. Dark matter does not exist and has not been proved to exist. A logical explination would be that it is merely a larger voidance in "space", but there is still energy in it. You are correct, the universe is in equilibrium as it's the only way a system would abide by the conservation of anything.
>>9128860
Way to not answer the question.
Anyone can insult something to seem superior to it, but hows about an actual response?
>Meter is defined as distance the light travels in vacuum in 1/299'792'458th of a second
Very well then. Proceed to represent me exactly one (1) meter using this definition. Note that you cannot use any standard of length, of course. I'm waiting.
This definition is GARBAGE. Better definition is a prototype bar in NTP conditions, or one based on cube of water.
you use time instead of length
>>9128716
there's nothing wrong twith that. it's a physical constant.
thanksfully the Kg is also being re-defined by the plank's constant(As a Chemfag I actually like the Si atom approach, but whatever). so we don't depennd on shitty metal pieces like the OP.
*measures your distance*
How dangerous is it to melt lead?
I want to recycle old lead pellets and make some weird custom rounds.
I googled it a bit and the answers range a lot. Also, it's either weird forums or tree hugger websites talking about it.
Also I melted some(
~18g) inside my kitchen, I hope I don't get too retarded.
>>9128707
You can melt lead over your stove, just don;t use the whatever you used to contain that lead to so you don't ingest anything afterwards
>>9128707
If you can reach 327.5 °C then just make sure you don't breath it in
I've never done it before but I'd wear a gas mask and gloves and avoid doing it indoors in case it lets off fumes.
what is metastability?
>>9128619
Depends... what is consciousness?
>>9128619
No fags here will know
>>9128621
Depends..what is a faggot?
How do you teach yourself or learn advanced mathematics? Do you use textbooks, or do you think there are more effective and/or less costly ways to do it?
At this level everyone just reads and digests the textbook.
Textbooks(papers on a more advanced level) is the only way. If you are only starting your way then doing exercises is a necessity
bump cuz I have the same doubt. how to read a lets say 500 page textbook and retain information? you people use note taking strategies or what? how not to copy the whole, or mostly, textbook to the paper?
IRC: #studygroup on irc.rizon.net
Imagined as a study group for people who don't have study groups irl, and who are not doing that great academically. Everybody is welcome to come and hang out, pitch in, get advice, and stay for the work atmosphere, not just people from EE or people who stuggle.
>IRC client?
There's millions. https://en.wikipedia.org/wiki/Comparison_of_Internet_Relay_Chat_clients
Maybe the quickest to try out would be Chatzilla. Install it, open it, type
/server irc.rizon.net
/join #studygroup
and voila.
>Productivity tips.
https://www.youtube.com/channel/UCG-KntY7aVnIGXYEBQvmBAQ
>Countless ebooks.
http://libgen.io/
https://cse.google.com/cse/publicurl?cx=001639227550064093264:dznewka3cca
>Pretty okay online resource.
https://www.allaboutcircuits.com/textbook/
>Youtube channels
https://www.youtube.com/channel/UCEBb1b_L6zDS3xTUrIALZOw
https://www.youtube.com/user/DarrylMorrell
https://www.youtube.com/user/derekowens
https://www.youtube.com/user/drjcircuits
https://www.youtube.com/channel/UCmQBM1Ke7MJVxd0O2gUzSGA
https://www.youtube.com/channel/UC6x7DywfEqLg-3Cg_JnyTlg
https://www.youtube.com/channel/UCFe6jenM1Bc54qtBsIJGRZQ
https://www.youtube.com/channel/UCdhGKS28LbzxebigAlA2rDg
Nice thread OP. Bump.
>Everybody is welcome to come and hang out
Why not a /sci/ studygroup?
>hashtags
>that font
>picture looks like a web 2.0 template
couldn't expect less from eng*neers
https://www.researchgate.net/publication/315422540_Characteristics_of_memories_for_near-death_experiences
where were you when science proved we have souls?
>>9128333
i was where i realized that our souls are results of us being sentient and our sentience is a result of our CNS
souls are very real, just maybe not in a religious sense
>>9128338
I tend to believe in the guys who think soul/mind is a sort of field outside the body and that the brain works as a receiver for the signals.
there's been cases where guys got 90% of their brain missing or removed and they function normally.
Memories, consciousness, imagination, vision are outside of our reality. They are not store in our brain (wtf memories stored as chemical thing ? it's a non-sense).
Hello /sci/
I'm building a condenser for a water/alcohol/essential oil still and I am using 316 stainless throughout. I'd like some advise on how to cool the condenser without the aid of water. I plan to have a fan cooling the condenser coils. Is there a metal with a heat capacity to absorb the heat and release it that I can wrap the coils around or is air cooling sufficent?
Water cooling will yield you the best results
t. Moonshiner
>>9128298
>how many degrees & flow rate
not sure what happened there, but it is fixed now
>tfw calculus teacher starts lecturing and opens powerpoint
What are your shitty professors this semester anon
>>9128258
stem teachers that use slides should be shot
>>9128295
If only
There is nothing wrong with slides per se.
Or rather, it's good for images and graphs that aren't easy to draw on a blackboard.
How accurate is this video?
well, it throws out big concepts in a highly oversimplified way. so.. not very accurate. but it was pretty good in that it at least gets people interested in the ideas to begin with.
All the concepts it puts out are intuitively correct.
The much more important thing is that they fucked up saying squirrel because one of the makers must be German
>>9128192
>it will take 10^54 years for a black hole with a mass of our sun (2*10^30 kg) to lose 0,0000001% of its mass (10^23 kg)
>10^-31 kg a year
stopped watching here. there's no way the numbers of these magnitudes are experimentally verified.
a black hole the size of our sun would have a radius of 3 kilometers according to wikipedia on Schwarzschild radius
let's observe that for a year
10^-31 kg is 9*10^-15 Joules according to E = mc^2
wavelength of Hawking radiation is about 16-20 times the Schwarzchild radius (the 3km) according to wikipedia on Hawking radiation
a photon with that wavelength would carry 4,14*10^-30 Joules of energy according to E=hc/wavelength
so the black hole releases about 2,17 * 10^15 said photons a year
nearest black hole is 2,6 * 10^16 km away according to wikipedia on list of nearest blackholes
let's say we observe that and by trigonometry we can get a 3.306*10^-7 degree look on it
assuming all the emitted photons are spread evenly along all degrees,
we can get 2 millions photons from that black hole a year
no wait that actually sounds possible
guess I was wrong
The most based book ever written, stay away from apostol, courant and other bullshit.
This one is practical and not redundant with mathematical masturbation.
I was actually required to buy the 8th edition for my first year of uni.
>>9128241
You are lucky to have such a perfect book.
>>9128129
I haven't read it, why is it good?
Help me understand the speed of light
The fasted anything could ever go is 299,792,458m/s, and that's how fast light moves in a vacuum. So we say that nothing can move faster than the speed of light. Is this speed limit actually tied to light itself?
What I mean is, is 299,792,458m/s the limit because of the nature of light itself? Or is this speed limit set by the nature of whatever quantum foam bullshit the universe is composed of, and light just moves as fast as it fucking can is whatever medium it's travelling through, and the medium of the universe restricts it to 299,792,458m/s?
>>9128103
There is no limit, we've just never discovered anything faster yet.
It is because as you get nearer to the speed of light time will slow down for you. This is because light must always travel at a constant speed relative to you. Because you are nearer to the speed of light time must slow down to allow the speed of light to remain the same relative to you. This means once you hit the speed of light time would stop altogether for you meaning you wouldn't be able to hit it. To reach the speed of light you would also need to have no mass, and all atoms have mass. Only photons are able to reach the speed of light because they have no mass. There are also reasons like the insane amount of energy it would take to reach the speed of light. However there is theories like the Alcubierre drive which states that we can actually contract space ahead of us and expand it behind us to move faster than the speed of light due to space having no speed limit. This means that space would be moving, not the person.
How do they easily get gfs like breathing air if its statistically improbable according to this mathematical proof?
https://logological.org/girlfriend
i get that its not really serious, but if he was more realistic about beauty standards -- not dropping girls who are only 7,8,9s --, then the dating pool would be around 632,000. meaning it would take just under 2 years rather than 90% of his life.
>>9128049
>hurr durr I have to throw in an integral to make myself feel smarter and show the math behind a standard deviation rather than just putting the %
He should also rule out the girls that wouldn't date an autistic sperg: 99.9% of 'em
>doesn't know about correlated coincidences aka synchronicity
>dooming self to a lifetime of loneliness and misery out of misplaced assumptions
proverbial faggot
Is Einstein's view of time still a popular view amongst physicists? Are there any valid criticisms against his view of time?
>>9128037
There is no such thing as time brainlet.
Where is it? Can you touch it? No exactly.
Einstein stole all his work. Your living in a simulation, nothing is real. GET IT. Educate yourself.
>>9128042
>2010 ± 10
>not understanding time
time is a 4D object, we live in an infinitesimal "slice" of this 4D object (dt) and we call it present.
>>9128048
so the future already exists?
Is geometry truly the basis and foundation of all mathematics?
Can everything in mathematics be represented and studied by it?
No. There are things like functors that cant be geometric.
>>9128018
Fuck off highschooler
>no QED at the ned