If I recall, the bet is framed on the wall in a 3 Rd floor hallway in one of the astrophysics buildings at Caltech. One of my buddies who worked on LIGO showed it to me once. I chortled breifly. Ah, science.
The difference between a hackerspace and a workshop is huge. The key difference is the community, it doesn't belong to anybody so anything goes, it's like hippie commune meets workshop meets research lab minus the proposals and endless journal paper spewing. It's not so much about making the tools available (like techshop does), but more about building a group of engineers, tinkerers, and technodweebs to hang out with after work is over.
Yeah there's a weird maker movement thing that people are pushing along side it, but hackerspaces are a place to hack, a place to figure out why you keep getting that "the printer is on fire" message. A place to admonish the newbs who tell repost jokes from reddit. You can get a project done alot faster when the guy next to you working on the ARM based LED vest can email you instructions on how that quadrature encoder you found in the drawer in the back outputs grey code in 5 minutes instead of spending half a day online looking for just the right answer.
I'm super glad I found Crashspace in LA, it's like my in person version of slashdot, and I'm living the technodream:D
When are people going to realize that hacking is now a meaningless buzzword applied to anything that has thought put into it? I feel like this was a neat side project for a few electrical/software engineers, nothing was co-opted or done without permission, no hardware was repurposed, nothing was "hacked". They just got alot of commercial off the shelf stuff, put it together with a little know-how and did what engineers do every day. I know this was posted here because it's MIT, and everyone loves it to death when they do anything remotely tech related, but lighting up buildings with LED's has been going on forever, there's nothing particularly novel here other than their specific implementation, no advances in tech have been made.
I'm not sure they're understanding how anything works, it seems like they just figured OH HEY ELECTRONS HAVE MASS I MUST BE SMRT. Here's why.
When you download an E-book from amazon, electrons aren't directly transferred to your tablet, a memory chip is burned, or bits are flipped, to represent the book in memory. (so either a magnetic or optical piece of information is stored by changing the configuration of mass that is already present) This would if anything remove mass from the e-reader, because electrons from the battery that are used to change the configuration of the memory would be lost as heat energy.
now when you charge the battery it might gain a little mass, but electrons don't just hang around once they flow in from the interwebs (that's not how it works:D) I'm fairly certain some people need to go back to school, and then those people who wrote an article need to go back to journalism school.
Sincerely, your friendly neighborhood rocket engineer:D
that part in parenthesis, about terraforming, is the point. You would terraform mars and build the facilities there to make it self sufficient. Biosphere is wayyyy too small scale. We're talking a planet wide population, not just a tiny outpost. You'd have factories, mines, farms, cities. Forests. Think Red Mars (it's a good book, read it)
Even if we don't find life on mars, it will be important as a second establishment of civilization, this is more important than finding other life (because it will prolong the period we can look for it)
If you would like to work on automobiles I recommend sticking with ME, and just doing that for now. Mechanical engineering is quite an undertaking on its own and if you double major, plan to spend at least 6 or 7 years in college to get a good understanding of both subjects. If you try to double major with mechanical engineering as one of the majors in the standard 4 years, you will either not gain a satisfactory understanding of the fundamentals and theory or you won't have any time to participate in the practical non-classroom experiences that make a mechanical engineering degree worthwile. I would recommend joining the Baja or formula SAE team at your university or college to get a better understanding of what goes into real world vehicle design, also project oriented teams look great on the resume. You will pick up a little CS and EE in Mechanical engineering if your school is doing it right. You might want to get a green minor if you're interested in biodeisel and low carbon emmisions vehicles, but make sure your university offers this first. Getting the math minor is easy, but probably won't do alot for you in the long run (most mech e's have one by default).
And Controls theory is definately a mech E subject, you can get very in depth in mechatronics and controls courses offered through a mechanical engineering department, and you'll get alot more real world hands on examples than you would in an EE course (EE's tend not to care about mechanisms, and are more interested in the electric theory) I would say if you're interested in cars, go the ME route and stick to it.
(This advice is coming from a practicing Mechanical Engineer who got his BSME in 4 years (at Virginia Tech)) I focused on robotics (CHARLI and RAPHaEL were my pet projects) but had alot of friends who loved cars). I work at SpaceX on rocket stuff now.
Also, you should probably know, the job you get might not be exactly what you planned for or learned the most about in school, but engineering, like life, is an adventure, so stick it out and you'll be sure to have fun.
Unfortunately it's not a code for anything, we just have a frozen yogurt bar at work and they change the two flavors bi weekly. It's normally original tart cause elon supposedly likes that the most, but we get some interesting things every once in a while
And we've got a bunch of programmers, jobs are posted on the main site (careers page) if you're interested
yeah it's not so bad when you don't have to talk to people at the cape all the time. (those guys wake up crazy early, and with the time difference it's like 4am here in Cali when we're doing stuff sometimes)
Hope you had a good summer, and enjoy your last couple days, Thursday the froyo flavor is going to cake batter, should be a high note to go out on.
This goes more into what's been going on running up to the launch, and has some great pictures of the rocket/capsule/facility in hawthorne (I took one of them:P)
The primary cause of rolling resistance is hysteresis (or internal friction) of the tire material, which occurs as the tire flexes
it increases with higher load higher tread design agressiveness (net to gross footprint ratio) higher tread depth and decreases with increasing tire pressure (i.e. less contact patch)
it can be calculated at the contact patch as
F_r= [(s+1)(t_in/R_l)-F_x]cos(a)-F_y*sin(a)
where F_r is the rolling resistance s is the slip ratio= (Omega*R_l/V_0)-1 F_x is the longitudinal force (+ driven - braking) F_y is lateral force Omega is the angluar velocity of the wheel in rads/second V is the forward velocity (in ft/s) a is the slip angle R_t is the tire radius and T_in is the driving torque
so on to camber angle
camber angles is the tilt of the center of the tire patch axis from vertical
camber is positive (if viewing from the front of the car) if the tops of the tires are further away from each other than the bottoms
Trucks run positive camber to account for different loads
a small camber is used to account for road crown
some trucks have different camber settings to account for the huge torque their engine can output (this counteracts the torque of the engine's affect on the suspension
mechanics used to bend axels to give cars positive camber ( they shouldnt be doing this anymore >)
so some reasons why camber angle would increase gas efficency
well for one, it makes the effective tire radius larger (by a tiny bit) which should decrease rolling resistance, also, it makes the contact patch smaller, however, depending on the sidewall strength of your tires, this could merely cause more internal hysteresis friction and decrease your effective gas milage
one of the big reasons you probably should not do this is... most consumer tires are manufactured assuming no camber angle, so you'd probably run into some issues with tires wearing out quickly. Also, if you, like most people, forget to check tire pressure before every ride, it would probably be fairly easy to blow out your sidewall in a tight corner, especially if you were running with a heavy load
and if you're especially stupid, and put too much negative camber, you could probably screw up your suspension geometry enough to make your tires move further than the designed rattle space in you car (the open area where the suspension can move) and perhaps your tires would rub on the inside of the wheel wells before the suspension bottomed out.
but it really depends on the type of suspension your car has (and there's wayyyyy to many to list) to get a definite answer as to whether this is doable or advisable. I would go with the factory recommended settings personally and just firkin keep your tire pressure high enough (the recommended amount) and you'll save a TON on gas
oh and a warning, ALWAYS REPLACE REAR TIRES if you're only gettin 2 tires, if you replace the front tires (regardless of a front or wheel rear drive car) only, you could potentially put your car in an oversteer condition, and that is what causes people to lose control, and spin out, unless you're a formula 1 driver and you know WTF you're doing, always keep your car in an under steer condition (i.e. more traction in the back dawg)
This is what i got for taking a land vehicle dynamics class, i hope you find some of it useful
I was playing Halo 3 the other night and my network connection was acting up, then the game lurched, froze and put tons of bars across the screen, followed by a loud screeching noise
so yeah, my Xbox RROD'ed on Sept 1st. I think its kind of odd that this story would pop up on/. within a week of it happening to me. I should pry call Microsoft sometime soon to get it replaced, but seeing as I'm a busy engineering student I haven't gotten around to it yet. Does anyone have any tips for dealing with Microsoft concerning this problem?
I'm a second year ME major at Virginia Tech, and about half of my friends are CS majors.
From what I've seen here it does not really matter where you go, but what projects you've worked on and completed.
Also whether or not you have a 3.0 or higher GPA.
You really have to be careful when you're going for a CS degree straight out of high school, because most people who are 'good' with computers and like video games and web design don't really want to do CS. Of course if you're all into algorithms, complex math and finding the most efficient sorting method, then by all means go for it.
When trying to get jobs typically there will be a short technical part of the interview and then a general interview, and as long as you nail the general stuff in your classes you should be Ok for the technical part, and the rest rides on your personality. This of course is based on what I've gleaned from working on our annual engineering expo (job fair).
You might want to go with the liberal arts school just so you can get a more rounded education, as smaller departments generally mean alot more individual attention, check into the school's hire rate out of college from their CS department, as that is normally the best indicator of whether or not its a school you want to go to if you're focused on getting a job.
Don't forget to enjoy life along the way, if either of the school's campuses are miserable, you'll be living there for the next 4 years:D
Good luck with your decision
Because honestly, for what that arm was, it could have fired alot further than they had it going. I built a floating arm trebuchet 2 years back for my high school senior project and it had a least twice the range of that arm.( It could fire a half gallon of water about 250 feet. )I admit, that may have been less weight than their arm was firing, but that was because I only had about 300 pounds of counterweight. Their problem is in the release time, and the sling could stand to be a bit longer. Its still pretty cool that they got ahold of it, but for about $150 worth of wood, screws and some rope and you could build yourself something just as good or better.Oh, and here's a link to a pic of my treb slightly before it was finished (i dont have the arm up on the tracks yet here.) http://i147.photobucket.com/albums/r284/risknc/Treb/DSCN0138.jpg
I'll upload a video later
I'm an RA at a college in the east (unnamed for keeping my job reasons) that recently had a fairly paramount tragedy, and as an RA I have to call the cops ALL the time because of inebriated people and otherwise incapacitated people who I'm somewhat obligated to help out (I love the job, and couldn't feel safer:P cause our cops are awesome)
Nevertheless I have a LG phone that makes the loudest most annoying *emergency call* sound when I dial 911, and the worst part is the resident that I'm trying to help gets distressed because they think I'm out to get them arrested (normally I'm trying to look out for their well being). I cant turn it off and I'm always a little afraid that someone could get violent or attack me if they hear it go off when I go to make the call. I think this needs to be fixed, or optional, or in order to accommodate the handicapped, have it only enabled on phones that the purchaser specifically asks the dealer to enable it on.
Slashdot Mirror
If I recall, the bet is framed on the wall in a 3 Rd floor hallway in one of the astrophysics buildings at Caltech. One of my buddies who worked on LIGO showed it to me once. I chortled breifly. Ah, science.
The difference between a hackerspace and a workshop is huge. The key difference is the community, it doesn't belong to anybody so anything goes, it's like hippie commune meets workshop meets research lab minus the proposals and endless journal paper spewing. It's not so much about making the tools available (like techshop does), but more about building a group of engineers, tinkerers, and technodweebs to hang out with after work is over.
Yeah there's a weird maker movement thing that people are pushing along side it, but hackerspaces are a place to hack, a place to figure out why you keep getting that "the printer is on fire" message. A place to admonish the newbs who tell repost jokes from reddit. You can get a project done alot faster when the guy next to you working on the ARM based LED vest can email you instructions on how that quadrature encoder you found in the drawer in the back outputs grey code in 5 minutes instead of spending half a day online looking for just the right answer.
I'm super glad I found Crashspace in LA, it's like my in person version of slashdot, and I'm living the technodream :D
When are people going to realize that hacking is now a meaningless buzzword applied to anything that has thought put into it? I feel like this was a neat side project for a few electrical/software engineers, nothing was co-opted or done without permission, no hardware was repurposed, nothing was "hacked". They just got alot of commercial off the shelf stuff, put it together with a little know-how and did what engineers do every day. I know this was posted here because it's MIT, and everyone loves it to death when they do anything remotely tech related, but lighting up buildings with LED's has been going on forever, there's nothing particularly novel here other than their specific implementation, no advances in tech have been made.
Maybe I'm jaded...
I'm not sure they're understanding how anything works, it seems like they just figured OH HEY ELECTRONS HAVE MASS I MUST BE SMRT. Here's why.
When you download an E-book from amazon, electrons aren't directly transferred to your tablet, a memory chip is burned, or bits are flipped, to represent the book in memory. (so either a magnetic or optical piece of information is stored by changing the configuration of mass that is already present) This would if anything remove mass from the e-reader, because electrons from the battery that are used to change the configuration of the memory would be lost as heat energy.
now when you charge the battery it might gain a little mass, but electrons don't just hang around once they flow in from the interwebs (that's not how it works :D)
I'm fairly certain some people need to go back to school, and then those people who wrote an article need to go back to journalism school.
Sincerely, your friendly neighborhood rocket engineer :D
that part in parenthesis, about terraforming, is the point. You would terraform mars and build the facilities there to make it self sufficient. Biosphere is wayyyy too small scale. We're talking a planet wide population, not just a tiny outpost. You'd have factories, mines, farms, cities. Forests. Think Red Mars (it's a good book, read it)
This is the correct answer.
Even if we don't find life on mars, it will be important as a second establishment of civilization, this is more important than finding other life (because it will prolong the period we can look for it)
If you would like to work on automobiles I recommend sticking with ME, and just doing that for now. Mechanical engineering is quite an undertaking on its own and if you double major, plan to spend at least 6 or 7 years in college to get a good understanding of both subjects. If you try to double major with mechanical engineering as one of the majors in the standard 4 years, you will either not gain a satisfactory understanding of the fundamentals and theory or you won't have any time to participate in the practical non-classroom experiences that make a mechanical engineering degree worthwile. I would recommend joining the Baja or formula SAE team at your university or college to get a better understanding of what goes into real world vehicle design, also project oriented teams look great on the resume. You will pick up a little CS and EE in Mechanical engineering if your school is doing it right. You might want to get a green minor if you're interested in biodeisel and low carbon emmisions vehicles, but make sure your university offers this first. Getting the math minor is easy, but probably won't do alot for you in the long run (most mech e's have one by default).
And Controls theory is definately a mech E subject, you can get very in depth in mechatronics and controls courses offered through a mechanical engineering department, and you'll get alot more real world hands on examples than you would in an EE course (EE's tend not to care about mechanisms, and are more interested in the electric theory) I would say if you're interested in cars, go the ME route and stick to it.
(This advice is coming from a practicing Mechanical Engineer who got his BSME in 4 years (at Virginia Tech)) I focused on robotics (CHARLI and RAPHaEL were my pet projects) but had alot of friends who loved cars). I work at SpaceX on rocket stuff now.
Also, you should probably know, the job you get might not be exactly what you planned for or learned the most about in school, but engineering, like life, is an adventure, so stick it out and you'll be sure to have fun.
Unfortunately it's not a code for anything, we just have a frozen yogurt bar at work and they change the two flavors bi weekly. It's normally original tart cause elon supposedly likes that the most, but we get some interesting things every once in a while
And we've got a bunch of programmers, jobs are posted on the main site (careers page) if you're interested
yeah it's not so bad when you don't have to talk to people at the cape all the time. (those guys wake up crazy early, and with the time difference it's like 4am here in Cali when we're doing stuff sometimes)
Hope you had a good summer, and enjoy your last couple days, Thursday the froyo flavor is going to cake batter, should be a high note to go out on.
Launch Ops Represent!
but seriously, avionics is always rollin in at 10am like they're too cool for school, what's with that?
Are you over in intern land or with the mass of avionics?
SpaceX Update
This goes more into what's been going on running up to the launch, and has some great pictures of the rocket/capsule/facility in hawthorne (I took one of them :P)
WAIT hold on guys, I just took a land vehicle dynamics class last semester and if I find my notes.....
Oh here they are one sec let me find the section on Camber caster, and kingpin inclination angles
alright first off rolling resistances
influenced by:
applied load
inflation pressure
tread design
compound
The primary cause of rolling resistance is hysteresis (or internal friction) of the tire material, which occurs as the tire flexes
it increases with
higher load
higher tread design agressiveness (net to gross footprint ratio)
higher tread depth
and decreases with
increasing tire pressure (i.e. less contact patch)
it can be calculated at the contact patch as
F_r= [(s+1)(t_in/R_l)-F_x]cos(a)-F_y*sin(a)
where
F_r is the rolling resistance
s is the slip ratio= (Omega*R_l/V_0)-1
F_x is the longitudinal force (+ driven - braking)
F_y is lateral force
Omega is the angluar velocity of the wheel in rads/second
V is the forward velocity (in ft/s)
a is the slip angle
R_t is the tire radius
and T_in is the driving torque
so on to camber angle
camber angles is the tilt of the center of the tire patch axis from vertical
camber is positive (if viewing from the front of the car) if the tops of the tires are further away from each other than the bottoms
Trucks run positive camber to account for different loads
a small camber is used to account for road crown
some trucks have different camber settings to account for the huge torque their engine can output (this counteracts the torque of the engine's affect on the suspension
mechanics used to bend axels to give cars positive camber ( they shouldnt be doing this anymore >)
so some reasons why camber angle would increase gas efficency
well for one, it makes the effective tire radius larger (by a tiny bit) which should decrease rolling resistance, also, it makes the contact patch smaller, however, depending on the sidewall strength of your tires, this could merely cause more internal hysteresis friction and decrease your effective gas milage
one of the big reasons you probably should not do this is... most consumer tires are manufactured assuming no camber angle, so you'd probably run into some issues with tires wearing out quickly. Also, if you, like most people, forget to check tire pressure before every ride, it would probably be fairly easy to blow out your sidewall in a tight corner, especially if you were running with a heavy load
and if you're especially stupid, and put too much negative camber, you could probably screw up your suspension geometry enough to make your tires move further than the designed rattle space in you car (the open area where the suspension can move) and perhaps your tires would rub on the inside of the wheel wells before the suspension bottomed out.
but it really depends on the type of suspension your car has (and there's wayyyyy to many to list) to get a definite answer as to whether this is doable or advisable. I would go with the factory recommended settings personally and just firkin keep your tire pressure high enough (the recommended amount) and you'll save a TON on gas
oh and a warning, ALWAYS REPLACE REAR TIRES if you're only gettin 2 tires, if you replace the front tires (regardless of a front or wheel rear drive car) only, you could potentially put your car in an oversteer condition, and that is what causes people to lose control, and spin out, unless you're a formula 1 driver and you know WTF you're doing, always keep your car in an under steer condition (i.e. more traction in the back dawg)
This is what i got for taking a land vehicle dynamics class, i hope you find some of it useful
right, well my time machine only needs to hit about 40 to go back to the future, so the increase in power makes up for the 48 mph
FINALLY! The Mr. Fusion is only a few years away!
No longer will I need Plutonium to generate the 3.3 Jigawatts nessecary to power my Flux Capacitor.
I was playing Halo 3 the other night and my network connection was acting up, then the game lurched, froze and put tons of bars across the screen, followed by a loud screeching noise
so yeah, my Xbox RROD'ed on Sept 1st. I think its kind of odd that this story would pop up on /. within a week of it happening to me. I should pry call Microsoft sometime soon to get it replaced, but seeing as I'm a busy engineering student I haven't gotten around to it yet. Does anyone have any tips for dealing with Microsoft concerning this problem?
wish me luck
Yeah, I dont HTML format my comments very often, mainly cause I dont post on Slashdot very often
But whatev, ive got the hang of it now
I'm a second year ME major at Virginia Tech, and about half of my friends are CS majors. From what I've seen here it does not really matter where you go, but what projects you've worked on and completed. Also whether or not you have a 3.0 or higher GPA. You really have to be careful when you're going for a CS degree straight out of high school, because most people who are 'good' with computers and like video games and web design don't really want to do CS. Of course if you're all into algorithms, complex math and finding the most efficient sorting method, then by all means go for it. When trying to get jobs typically there will be a short technical part of the interview and then a general interview, and as long as you nail the general stuff in your classes you should be Ok for the technical part, and the rest rides on your personality. This of course is based on what I've gleaned from working on our annual engineering expo (job fair). You might want to go with the liberal arts school just so you can get a more rounded education, as smaller departments generally mean alot more individual attention, check into the school's hire rate out of college from their CS department, as that is normally the best indicator of whether or not its a school you want to go to if you're focused on getting a job. Don't forget to enjoy life along the way, if either of the school's campuses are miserable, you'll be living there for the next 4 years :D
Good luck with your decision
Because honestly, for what that arm was, it could have fired alot further than they had it going. I built a floating arm trebuchet 2 years back for my high school senior project and it had a least twice the range of that arm.( It could fire a half gallon of water about 250 feet. )I admit, that may have been less weight than their arm was firing, but that was because I only had about 300 pounds of counterweight. Their problem is in the release time, and the sling could stand to be a bit longer. Its still pretty cool that they got ahold of it, but for about $150 worth of wood, screws and some rope and you could build yourself something just as good or better.Oh, and here's a link to a pic of my treb slightly before it was finished (i dont have the arm up on the tracks yet here.) http://i147.photobucket.com/albums/r284/risknc/Treb/DSCN0138.jpg I'll upload a video later
I'm an RA at a college in the east (unnamed for keeping my job reasons) that recently had a fairly paramount tragedy, and as an RA I have to call the cops ALL the time because of inebriated people and otherwise incapacitated people who I'm somewhat obligated to help out (I love the job, and couldn't feel safer :P cause our cops are awesome)
Nevertheless I have a LG phone that makes the loudest most annoying *emergency call* sound when I dial 911, and the worst part is the resident that I'm trying to help gets distressed because they think I'm out to get them arrested (normally I'm trying to look out for their well being). I cant turn it off and I'm always a little afraid that someone could get violent or attack me if they hear it go off when I go to make the call. I think this needs to be fixed, or optional, or in order to accommodate the handicapped, have it only enabled on phones that the purchaser specifically asks the dealer to enable it on.