didn't realize until now that in units where hbar = c = 1, a particle's mass is equal to the inverse of its compton wavelength.
that's pretty cool
During the physics party at the end of last semester (my lecturers and my university are so awesome that they throw a big party for the physics students at the end of every semester and get several hundred dollars worth of beer and pizza for all of us. One of my lecturers also brings his Wii and 360 and sets them up so we can play games and such) I was having a chat with a guy who took me for timetabled physics tutorials in first year (he's a Ph.D student). He's a really cool guy, a friend of mine knows him quite well and he's very much into the theoretical side of things. He told me if I was interested in theoretical physics that there were three people I should really talk to (one of whom I've had as a lecturer twice before now, great guy!). Party went on as normal, I, and everyone else had a blast, and I kept what he said in mind.
About two weeks back now I was a volunteer for the open day my uni runs for school kids. I was showing people around all day and running a few simple demonstrations to get people to see physics in action (apparently the staff and my lecturers were all very pleased by how enthusiastic I was with my demonstrating - a lot of the parents of kids who came to visit pointed that out to them apparently! Feels good, man). This was the first time that I ever got to interact with one of the other two guys who this Ph.D student had recommended I talk to so I had a brief chat with him and he seemed really excited by the fact that I'm interested in... well, I guess the same stuff he's interested in. He told me to come and see him at some point between class and we'd have a chat (he was busy then so we didn't get to have a proper chat).
Today was the first time since the open day that I managed to find some free time that coincided with him being in his office so I went to see him. He remembered my name (which made me happy seeing as how I had only talked to him for like two or three minutes... then again, like he said, "Scott the Scot," is pretty easy to remember :v: ). Unfortunately he was pretty busy then but he scheduled in some time for me to come around next Wednesday and see him after one of my classes finishes so I'm very much looking forward to that! By the sounds of the conversation we had on open day I think he's very interested in the possibility of perhaps letting me do a project with him (which would be fantastic because having your name on a published paper before you leave your undergrad counts WAY more to getting into a Ph.D than a GPA of 4.0). I also offered him a good solution to a problem he was having involving a doorbell in the brief time I saw him today (his office is in a weird place so there's a doorbell outside of the room connecting to his office so that people can get his attention and apparently the doorbell is annoyingly loud no matter where it's positioned so I suggested he should get one of the double degree physics and electronic engineering students (undergrad or Ph.D - doesn't matter) to tear it open and replace a resistor inside with a larger one to make it quieter and he seemed ecstatic at the idea).
Really looking forward to next Wednesday right now.
[editline]23rd August 2013[/editline]
[QUOTE=Quark:;41899598]Has anyone else here studied microbiology, genetics, and so on? I feel like the only one since everyone else is talking about physics :v:[/QUOTE]
I'm doing a course in it at the moment, actually (part of the nanotech component of my double degree). What I've learned from the genetics component is that DNA is fucking bullshit and I'm not surprised it took evolution like a billion years or so to produce anything properly complex.
The amount of time DNA has to coil or fold itself up somehow simply to FIT within a cell is fucking bullshit.
[QUOTE=sltungle;41926703]
I'm doing a course in it at the moment, actually (part of the nanotech component of my double degree). What I've learned from the genetics component is that DNA is fucking bullshit and I'm not surprised it took evolution like a billion years or so to produce anything properly complex.
[/QUOTE]
Part of the reason behind this is that mutations occur due to radiation and/or plain accident, and some mutations are entirely harmless, because it might cause the same things to be made:
[img]http://biology.kenyon.edu/courses/biol114/Chap04/chap04a_files/code.gif[/img]
For example, if an initial UUU sequence is radiated and is forcefully changed to UUC, Phenylalanine is produced either way and it wouldn't affect the organism, and wouldn't be noticed, but would still be passed down most likely. However, if, instead of a C, a G is used, Leucine is made and this might prove fatal for the organism and it won't live to pass on any genes.
I'd like to say that the vast majority of mutations are either completely harmless or completely fatal. The rest either render the organism [I]sterile[/I] or result in a living, reproducing mutant relative. This is how life differentiated on Earth and lead to all of the fascinating species we see every day. The very fact that there are [B]SO[/B] many different species [I]currently[/I] living on Earth is clear proof that DNA isn't perfect, but it [I]is[/I] awesome!
[QUOTE=Quark:;41931247]Part of the reason behind this is that mutations occur due to radiation and/or plain accident, and some mutations are entirely harmless, because it might cause the same things to be made:
[img]http://biology.kenyon.edu/courses/biol114/Chap04/chap04a_files/code.gif[/img]
For example, if an initial UUU sequence is radiated and is forcefully changed to UUC, Phenylalanine is produced either way and it wouldn't affect the organism, and wouldn't be noticed, but would still be passed down most likely. However, if, instead of a C, a G is used, Leucine is made and this might prove fatal for the organism and it won't live to pass on any genes.
I'd like to say that the vast majority of mutations are either completely harmless or completely fatal. The rest either render the organism [I]sterile[/I] or result in a living, reproducing mutant relative. This is how life differentiated on Earth and lead to all of the fascinating species we see every day. The very fact that there are [B]SO[/B] many different species [I]currently[/I] living on Earth is clear proof that DNA isn't perfect, but it [I]is[/I] awesome![/QUOTE]
I think there's bigger issues than just that that lead to it taking billions of years to produce anything significant in the first place, though. Although that's certainly one of the issues.
I actually saw that table for the first time in my life two days ago in class. I find it interesting that codons with a cytosine in the middle ONLY ever code for a single amino acid.
So, I'm in Grade 10 and I'm aiming to go for High Level Sciences, Bio, Chem and Physics. Right now my main problem is doing an experiment fully. I need some help on writing an hypothesis, conclusion, interpretation and evaluation. The experiment is about seeing how temperature affects the rate of reaction.
Woke up on Saturday morning several hours before work because in my sleep my mind had decided to become angry at the fact that the wave model of light I've been given my entire life doesn't make sense, dammit.
Magnetic field lines have to be joined at both ends (unless monopoles exist). How in the hell then can electromagnetic radiation have a planar magnetic component that is joined at both ends?! PLANAR AND JOINED TO ITSELF AT BOTH ENDS! What the hell is that shit?!
[editline]27th August 2013[/editline]
[QUOTE=GentlemanLexi;41971293]So, I'm in Grade 10 and I'm aiming to go for High Level Sciences, Bio, Chem and Physics. Right now my main problem is doing an experiment fully. I need some help on writing an hypothesis, conclusion, interpretation and evaluation. The experiment is about seeing how temperature affects the rate of reaction.[/QUOTE]
My best advice to you would be to find a bunch of scientific papers on a topic you're interested in (so you'll pay attention), a topic that you yourself could imagine performing an experiment on, and then just read them. See how they lay them out. You get the hang of it pretty quickly after writing a few proper, big reports.
snip
My half hour meeting with that lecturer and researcher at my uni wound up going for an hour and a half today and we wound up discussing way more than we had initially intended to.
If I can learn a little bit more about the research he's interested in doing there's a very real possibility of a summer project! I'm so happy right now!
Physics is one of my favourite subjects, it is so good and so interesting.
So I stumbled onto one of the scariest things ever: [url=http://youtu.be/5uZwYg4W7JE?t=4m]Idiots handling hydrofluoric acid[/url].
How the hell did they even get their hands on it?
[QUOTE=Cakebatyr;42016061]So I stumbled onto one of the scariest things ever: [url=http://youtu.be/5uZwYg4W7JE?t=4m]Idiots handling hydrofluoric acid[/url].
How the hell did they even get their hands on it?[/QUOTE]
Oh wow. Oh WOW.
They are lucky they didn't die in one of many horrific ways you could die in such a situation.
Hardwick is an amazing comic, but not an amazing chemist.
[QUOTE=Headhumpy;42022400]Oh wow. Oh WOW.
They are lucky they didn't die in one of many horrific ways you could die in such a situation.[/QUOTE]
You can see that as he was pouring it out he dipped the tip of one of the glove's fingers in it.
Edit: Oh, I just looked at the date, this was from a year ago. They got off lucky then.
My professor:
"Remember, Astrology is bullshit. Study Astronomy more."
[QUOTE=areolop;42024837]My professor:
"Remember, Astrology is bullshit. Study Astronomy more."[/QUOTE]
I had a big discussion with someone over how science proved astology (spoiler: it did quite the opposite)
That led into that person claiming that ghosts are actually entangled photons, which I...
[B][I]ANYWAYS[/I][/B] I'm volunteering up at my observatory tonight. That'll be fun.
[QUOTE=Yahnich;42037842]i'm pretty sure science proved astronomy[/QUOTE]
Oh, I'm smart. I meant [I]astrology[/I]
Had space on my brain last night :v:
[QUOTE=Yahnich;42037842]i'm pretty sure science proved astronomy[/QUOTE]
There's no real 'proving' in science, but let's say astronomy has predicted and explained a lot more things than astrology in a rational way.
gosh, just get it right then ffs
Urgh. So many bad feels.
Yesterday evening I learned of a summer vacation scholarship program being run by CSIRO (Commonwealth Scientific and Industrial Research Organisation).
[quote]The 2013 CSIRO Astronomy & Space Science (CASS) Vacation Scholarship Program is a fantastic opportunity to undertake a research project at one of the world’s leading radioastronomy facilities. As part of this program scholarships are being offered in astrophysics, computing and operations. All the 2013-14 positions will be based at CASS headquarters in Marsfield, Sydney.
In addition to your research project you will spend a week on a fieldwork trip to one of the largest radio telescopes in the world, either Parkes, home of “the Dish”, or Narrabri where the Australia Telescope Compact Array is situated. The costs of this field trip will be included in the scholarship as will travel to and from the site where you are based if you are from outside the area.
These scholarships are open to students currently undertaking their undergraduate degree and who have completed (by November 2013) at least three years of that undergraduate study, have maintained a credit average or higher and are available for 12 weeks from 25 November 2013.
Participation in this program has influenced previous scholarship holders in their choice of further study and future career options. Many have gone on to pursue a PhD in CSIRO or to build a successful research career within CSIRO, a university or industry.[/quote]
Sounds fucking fantastic. I figured today I'd wake up first thing, head into uni, talk to some of my current lecturers or previous lecturers and ask if they would act as references for me (most of them seem to remember me fairly well even if they don't currently teach me), and then fill out an application form, write a letter as to why they should accept me, and then send it all in.
I wake up this morning, log onto my computer and try to find the application again to get specifics on what I need to do... and I can't find it on the CSIRO website. I do a google search for it, find the link, click it.
[quote]Closing date for applications: 11.30pm AEST Sunday 1 September 2013. Applications received after this date will not be considered.[/quote]
*sigh* Maybe next year.
-snip-
Kinect bombardment isn't too powerful. It'd also be too expensive seeing that regular bombs produce the same results as a metallic rod could.
[QUOTE=credesniper;42058131]Physics question here.
In the latest G.I Joe movie (science fiction ahoy), they (BBG) has satellites that drop hollow tungsten rods that gain energy from gravity alone. What would one falling to Earth do to anything? They claim it's just as powerful as a nuclear missile (they never specify what size/megaton).[/QUOTE]
[url=https://en.wikipedia.org/wiki/Kinetic_bombardment]Yup[/url]
Basically, in the 50's in between fucking with the Ruskies and going to the Moon, we decided to combine them and make Project Thor. Using that, they would hurl tungsten rods 6 meters (20 feet) long and 0.3m (1 foot) in diameter striking the surface at speeds in excess of Mach 10 (spoiler: fucking fast). According to a USAF paper, that rod would have the kinetic equivalent tonnage of 11.5 tons of TNT.
SALT II banned the fuck out of nukes in space, but not kinetic weapons, so this is technically legal to do, although it's expensive as all fuck.
[editline]2nd September 2013[/editline]
If you want me to do the nerdy math shit:
(GARRY BRING BACK SUB TAGS)
Ek = 1/2mv^2
(preemptive edit: Took a break here to eat dinner. The above equation was a question on Jeopardy. Meant to be)
Assuming the rod is solid tungsten:
Density of Tungsten = 19.25 g/cm^3
Volume of cylinder = 1.7247 cubic meters
This gives us 33,200 kg
Mach 10 at MSL is 6612 knots or 3402 m/s:
1/2(33,200 kg)(3402m/s)^2
1.922*10^11 kg m^2/s^2 AKA Joules
1 ton of TNT = 4.184 GJ
Therefore that equals about 46 tons of TNT.
That's a lot more than USAF report, but still within the realm of possibility. That's a bit more than the [url=https://en.wikipedia.org/wiki/FOAB]largest conventional explosive[/url] so I'll buy it.
[editline]2nd September 2013[/editline]
So that got me wondering: how much would this cost?
In 1950, the price on tungsten was $0.01/kg (0.76 euro cents or 64p)
One rod would cost $332 (251.71 euro, 213.55 gbp) in 1950 money, or when adjusted for inflation $3239.83 (2546.31 euro, 2083.98 pounds)
Today, the cost of tungsten is $46.70 per kilo, which means a rod would cost $1.58 million (1.2 million euro, 1.01 million gbp)
wait why am I doing this again?
Wow tungsten was cheap back then.
Until the aerospace industry kicked off we had no use for it. In the sixties the price skyrocketed
You can also ramp the size of the rod up to ridiculous sizes to get yields in excess of some nuclear weapons.
Rods from god, bitches!
If you were able to get the rod going to escape velocity, which is the max speed you could ever achieve from gravity alone, it would be 995 tons TNT equivalent. That's approaching nuclear yield territory, but most of the energy would be absorbed directly into the ground, and it wouldn't make for a very efficient weapon. Most nukes are detonated a few thousand feet above ground zero to maximize damage.
[QUOTE=Falubii;42072644]If you were able to get the rod going to escape velocity, which is the max speed you could ever achieve from gravity alone, it would be 995 tons TNT equivalent. That's approaching nuclear yield territory, but most of the energy would be absorbed directly into the ground, and it wouldn't make for a very efficient weapon. Most nukes are detonated a few thousand feet above ground zero to maximize damage.[/QUOTE]
The highest speed you can get it going is entirely dependent on how high you put the thing in the first place. You could tow it off to some arbitrarily absurd distance, drop it, and let it accelerate under Earth's gravity from tens of thousands of kilometres away. At any given point I want to say the instantaneous velocity that you could achieve would be equal and opposite to the escape velocity at that distance from Earth, but you'd have to integrate over the whole distance between the rod and the surface of Earth (keeping in mind that g is a function of x, or h, whatever you want to call it) at to achieve the total speed it could fall at.
As an example,
[URL]http://www.wolframalpha.com/input/?i=velocity+of+object+dropped+from+50000+km[/URL]
31 km/s is faster than the escape velocity of Earth at its surface (about three times higher from memory). If you're thinking of using kinetic bombardment in terms of a mortar attack, then sure, v_f = v_i (assuming no friction of course), but for just dropping the damn things you have to think of energy conservation and whatever you use to take the rods up to space is most likely going to be larger than the rods itself (you need fuel after all) so on the way down the thing is going to have less mass, same energy, and as a result a higher speed.
[editline]4th September 2013[/editline]
Also, things I learned today:
Quantum mechanics is probably superluminal but non-instantaneous.
Time might not actually exist.
Things I understood today: NONE OF THAT! ... well, actually, the superluminal tunneling I sort of get (sort of), but the possibility of time not existing made me sad.
[QUOTE=Yahnich;42076792]is there any specific reason tungsten has to be used compared to something cheaper[/QUOTE]
It's dense and can withstand the compressive heating forces that happen during atmospheric reentry.
[QUOTE=Dacheet;42081389]It's dense and can withstand the compressive heating forces that happen during atmospheric reentry.[/QUOTE]
A while back I was wondering if you made a tungsten shell around some sub-critical rod of some fissile material like plutonium or uranium and used as a kinetic bombardment weapon if, upon impact, the fissile material would compress enough to become critical and then add to the yield of the explosion.
Hell, I think I even asked in this thread (or the old physics one).
[QUOTE=sltungle;42083869]A while back I was wondering if you made a tungsten shell around some sub-critical rod of some fissile material like plutonium or uranium and used as a kinetic bombardment weapon if, upon impact, the fissile material would compress enough to become critical and then add to the yield of the explosion.
Hell, I think I even asked in this thread (or the old physics one).[/QUOTE]
Right let's see here
46 tons of TNT = 1.20127×10^24 million electronvolts
200 MeV is required to undergo fission in U-235
1.2*10^24 > 200
So yeah, I think you might have just enough energy to start a fission reaction :v:
[QUOTE=Dacheet;42086780]Right let's see here
46 tons of TNT = 1.20127×10^24 million electronvolts
200 MeV is required to undergo fission in U-235
1.2*10^24 > 200
So yeah, I think you might have just enough energy to start a fission reaction :v:[/QUOTE]
I was thinking more would the fissile material compress on impact into a denser, supercritical mass or would it just be blown outwards in even smaller sub-critical chunks?
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