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Videos (135) | Sift Talk (8) | Blogs (13) | Comments (588) |
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MIT lab amazing 3D printer.... using molten glass
I'd guess that it would cause warping as the structure got bigger, they need the previous layers to cool rapidly to prevent deformation (although the previous layer needs to be hot enough to get a good water tight bond). Coming up with the right temp so that it forms a seamless flat surface would be difficult without causing running.
Not to be "that guy" (okay, what the hell, I love being "that guy") but aside from arty stuff, light shades, the aforementioned ashtrays and perhaps some really funky vases/glasses, this really seems to be limited by the method of extrusion and the refraction caused by having so many curved surfaces throughout the piece.
So to make it seamless would they need to up the ambient temperature plus the speed of the nozzle? Or could they just make the nozzle quick enough that the previous layer hadn't started to cool before the next one hit?
Don't Stay In School
If you did high school bio, think about what you covered that has any sort of influence on medicine... =)
Frog or rat dissection? Covered that in Bio 101 in the first year of my Applied Chemistry degree (and yes, you can give a rat a Columbian necktie... . Photosynthesis? Mating?
Yeah, Bio was pretty much introducing you to broad concepts and it's nothing that doesn't get rehashed in the first 6 months of Uni via intro subjects. I think of it more as a way to dip the toe in the pool and see if the subject matter excites you enough to try and turn it in to a career.
eg. At 40 now (and having forgotten my chem degree and gone in to IT as a sys admin after working as a chef, bouncer etc), I could go back to uni barely remembering anything about chemistry and start from scratch and be none the worse for it. The keystones you talk about are literacy and numeracy, that's about it. And they are learned in primary school.
Oh sure, it helps if you can do some higher math, but English lit? Physics? Drama? Almost nothing you do at high school has any real defining affect on most of what you do as an adult. It's more like a sampler platter, and of course a way of grading students (on a curve of course, we can't have people's scores based on their own merit) to distinguish what tertiary studies they should be eligible for.
School should be about igniting curiousity as much as practical skills for life. I did "Home Economics" (ie. cooking/sewing/budgets etc) and typing (on real mechanical typewriters no less) as opposed to wood/metal shop ( I was awful at shop). My home ec teacher was always interested in making different food, so we tried some pretty out there things in grade 8 (~13 years old), and I've always been interested in cooking since. Similarly, learning to touch type has made my life radically simpler, particularly in IT (try writing a 40 page instruction manual hunting and pecking).
Most of the high school grads we see as cadets or trainees are essentially useless and have to be taught from scratch anyway. Most of the codified BS we have these days doesn't prepare kids for life, doesn't encourage critical thinking or creativity, it a self justification to keep schools open.
I disagree. You can't show up at Uni at 18 expecting to do medicine without having spent the preceding years learning biology, and probably maths as well. Of course, it's true that this knowledge is eventually eclipsed, but I don't think you can look at the cap stone and dismiss all the stones at the bottom as unnecessary.
How to make a Hattori Hanzō katana (Kill Bill): Man at Arms
Interesting, but they might have messed up the process. I think the blade should be straight until they quench it after claying. The curve of the blade is a product of the different shrinking between the hard steel outer edge and the soft core, which is why it's so perfectly curved when done in the traditional manner.
RedSky (Member Profile)
Your video, The Rummy Returns - Learning Curves Are for Pussies, has made it into the Top 15 New Videos listing. Congratulations on your achievement. For your contribution you have been awarded 1 Power Point.
Colorblind Dad Experiences True Color for the First Time
I had never heard of these -- I'm still a bit baffled as to how they could possibly work. I'm not colorblind myself but a good friend is red/green colorblind, I'll have to see if he knows about them.
Assuming $400 is an accurate price, it still really doesn't seem that expensive to me. I'm pretty extremely nearsighted -- roughly minus 8 -- and my glasses (with frames) already cost almost that much just because my prescription is on that far end of the bell curve. Without glasses I can't see a damn thing more than 3-4 inches in front of my face, so I basically *need* them no matter the price.
Actually, I remember having a reaction somewhat like this guy when I got glasses for the first time ("holy crap! I can see *leaves* on trees!"), and my eyes were much better then than they are now...
$400+ seems crazy expensive for glasses that offer a pseudo cure.
I think I'll wait until they can inject the cure directly into my eyeballs.
Elon Musk introduces the TESLA ENERGY POWERWALL
Thank you very much for your answers -- here's a couple more questions maybe you can give thoughts on if you have time:
Quick googling says the average US home uses a bit under 12,000 kWh per year. Divide that by 365 and get ~33 kWh per day, divide that by 24 and get ~1.4 kW per hour (rounding up in all instances). Of course, that's going to be higher in the day and lower at night, but one of the points of the batteries is to help smooth out that usage curve and make it transparent to the homeowner / user.
Anyway, questions related to those figures:
*Do those numbers sound ballpark to your experience?
*You've got 1kWh of lead acid batteries. Ignoring the fact that night usage would tend to be lower than daytime, an "average home" draw of 1.4 kW per hour would give you about 40 minutes of off-the-grid power (without help from the solar). That would probably require lifestyle changes to deal with; it seems like an average home couldn't get through a night without fully draining the batteries. True?
A 10 kWh pack like shown in the video would give 7+ hours, not accounting for lower drain at night. Seems like an average US house might well be able to go a whole night with that kind of battery without any lifestyle adjustments (assuming solar can handle 100% of the load during daytime PLUS charge up the batteries).
* Could your existing solar cells handle daytime load and charging of 1 or 2 of these 10 kWh packs so that you could be comfortably 100% off-grid?
* How much area do your solar cells cover?
I'm been very impressed with Tesla as a car company, even though I've never driven or even seen one in person (only a very few super-rich people have imported Teslas to Thailand). I thought that electric cars were going to be impractical toys for really out-there tree huggers, but everything I read about the Model S and other Tesla cars tells me that they are the real deal, actually superior to internal combustion for MOST use cases.
Hopefully without sounding too much like Howard Hughes, I believe that baseline practicality will let economy of scale take over and make Tesla and other electrics the way of the future. And this makes me likewise optimistic that Musk can similarly revolutionize the future of energy in general. Pretty exciting stuff!
I have solar now, so I'll answer.
Today, if you want battery power at home for storage of solar, wind, even micro hydro generated power, you have one real choice....lead acid batteries.
Pros (compared to lead acid)-At best, lead acids are large, unsightly, need an enclosure, need a charger, have a 1000 cycle life span, need maintenance, can't be frozen or allowed to get too hot, use acid, are expensive to dispose of, and are more expensive than this (better?) technology by almost a factor of 4. I recently replaced my battery bank of just over 1KWH for around $1200-$1400, while he's advertising 10KWH for $3500!
Cons-likely lots of 'rare earth minerals' needed, which cause massive pollution where they're refined (China), unknown rate of failure/fire, other unknown problems, and anti-renewable energy people's heads exploding trying to come up with new reasons that renewable energy sucks.
Strong Wind Vs.Train On A Bridge
If tracks were perfect, it should make no noticeable difference...until you fall over, then being stationary is obviously preferable.
BUT...tracks aren't perfect, so the train being bounced side to side WOULD make it easier to be pushed over.
Also, curves have a slight angle to them, so trains going a certain speed will remain flat in the curve...so going too fast or too slow puts you off balance. It's hard to tell if that piece of track is curved.
Wheels are designed so they are ALWAYS using static friction , even when moving. The portion of the wheel in contact with the ground is stationary. (except when skidding)
Question: Does a slow moving vehicle (train or truck) have more, less or the same chance of tipping then vehicles not moving? Assuming the winds impact is perpendicular to the vehicle. I would guess stopped would do better. Does the contact of wheels with the surface have more friction when stopped thus harder to push over? Anyone?
So, some smartass went and reinvented the wheel ...
Great! But how does it do with large side forces, like cornering at high speed? If they do well, perhaps this is a way to eliminate suspension in electric vehicles, reducing weight but keeping a smooth ride. That would be a big leap forward!
I've seen something similar with maybe 20 curved 'spokes' (looking like a turbine from the side) that was tunable, made harder or softer by adding/removing 'spokes'. The issue with them was the spokes created lots of resistance...like turning a turbine.
Virtual reality, explained with some trippy optical illusion
You went farther than I did then.
All I can say is when I cut out squares in a piece of paper, I could see a difference until they 'masked off' the image, then it had changed. I know these can work without fudging, which is why I was disappointed.
Did you note the difference between the 'colored' image and the 'masked off' image? It sure seems like there's a difference to me, if I stop it 1/2 way through and cover all but 2 squares, one is slightly lighter than the other on my monitor. That went for both the cubes and the floor tiles. Maybe it's 'eye memory' or something, but it sure seemed to me that the center tile was noticeably lighter until the 'masking off' happened.
I used a piece of paper against my monitor to measure the table,....I must have moved it when marking it, because now when I do it, it seems the tables ARE the same size. Damn touch screen, kept starting the video every time I touched it.
If those lines were really pixel straight, my paper is cut with a curve or my monitor has a problem.
Again, you went farther than I did to prove it, so I'll defer to you and accept I'm seeing things, even when I mask them off myself.
EDIT: Just a thought why I may have seen it differently, do you think it's possible that 'light bleed' or 'color bleed' on my monitor has anything to do with it? I mean, since the pixel next to the 'grey' block might be glowing bright yellow, it could color the grey slightly yellow, while the RGB value would not change?
Sorry, newt, but that's simply inaccurate.
I saw two grey pills too, but you're completely wrong about the others. I screen shotted all the images into paint.net to verify them.
The rubix cube image is 100% real. The RGB values for the blue and yellow tiles are identical (127,128,129).
Same with the the tiles under the table. They are are off by a small amount (rgb 70 68 71 vs rgb 70 68 70), but I'd but that down to the video encoding.
Ditto with the checkboard; zooming in with paint.net the lines are pixel straight (there is some anti-aliasing at the edges, but it doesn't affect the "straightness of the checkerboard").
The tables too, are the same size. I rotated the vertical table.
If you don't believe me, try it yourself.
Virtual reality, explained with some trippy optical illusion
OK. Looking extremely closely and using paper to block out the image, I have to say they fudged things on some of them.
I saw two grey pills the whole time.
The colored tiles fade to grey as they "mask off" the other tiles, they start no where near the shade of grey they end up as, their color has faded a lot in the process.
The grey tiles on the floor also change shades as they are 'masked off' quite clearly. I went 1/4 speed, and also tried masking them off myself, they clearly faked this one.
I put a straight edge on the checker board and sure enough, those lines are slightly curved....just barely but they are.
The two table tops are NOT the same size at first, I measured and the vertical table is definitely longer on the long side. That one's obvious. (EDIT:I'm wrong about that)
The spinning dots does work for me, as do convex images and auditory illusions.
So I'm not ready to call 'fake' on this, but IMO it's fudged badly.
biking jerk meets driving jerk
Lady got rude much quicker than bike dude who had every right to be annoyed, the same way I am annoyed when a driver puts on their blinkers and takes up a lane near an intersection or after a curve- they're inconsiderate assholes and they deserve to get called out. I would have parked my bike in front of her car and told her to enjoy the nice fucking day.
AAA crash analysis videos of teen drivers
What amazes me is how many of these happen in the middle of a curve in the road. I mean it's stupid enough looking away from the road for more than a second on a straight patch, but in the middle of a turn?!
UNREAL PARIS - Virtual Tour - Unreal Engine 4
tldr: Actually, games do this all the time, but usually only for water surfaces!
The reason for this is that the way you render a proper reflection is to "flip" the camera to the other side of the reflective surface plane: looking down on a lake, you'd render the water reflection from the point of view of the camera looking up from under the water surface, flipped over. This is called "planar reflection". In order to do this, you render your entire scene again, so it's not cheap. Also, the reflection only works for that one plane: if you had two altitudes of water (or two differently angled mirrors) they'd be on different planes and so you'd have to render a reflection for each one.
You can't render curved surface reflections this way, though. For example it doesn't work on a car (what plane would you flip the camera over?). For that, the trick is called "cubic environment maps". I won't go into the details, but it only really works well for faking reflections on objects since it shows the correct view from a single point. You can create them dynamically for things like racing games, but they require 6 scene renders (one for each face of the cube) for each environment map.
Half Life offered both techniques for water reflections, so one could fire that up and compare them that way.
This demo seemed to use environment maps for the mirrors and I suspect all of the other shiny surfaces.
Note that these techniques are to get detailed reflections: specular lighting (where you don't reflect an image, but instead mathematically simulate simple light bouncing) is easier and cheaper, since it's just math to get a color and strength.
You could do planar reflections for every mirror, but it's a full scene re-render for each one so your frame rate would tank or you'd have to take out other features. Compromises!
Game graphics is all trade-offs and smoke and mirrors: it's our job to fake things and make you think the game is doing sophisticated simulation when actually it's doing as little as it can to get as much as possible.
It's a shame that even with all this they still cant get proper 1:1 mirrors working in game engines
Explaining Double Pool Vortex - Physics Girl
Maybe the black hole is just an end of a half-vortex in space, or is that a wormhole?
Also, I'd let her move her curved coherent vortex line through my stationary matter.
badum, cha!
SO COOL!
Anyone else notice the shadows look like little black holes with event horizons?
Nixie: Wearable Camera That Can Fly
I don't understand, why would they have to bend in multiple directions? it seems they need to be straight or curve in one direction. Did I miss something?
I'm estimating the size, about 6" around one's wrist makes it 6" 'wide', and near 3" 'long'...yes the blades seem about 1.25" diameter. You would know more than I about that being enough, but I do know there are different prop configurations for different applications, perhaps they have an ultra efficient prop and motor pair? There are certainly more powerful motors available, if you're willing to pay for them.
Adding blue tooth is minimal in weight and power drain, and the lag shouldn't be an issue in most applications (I wouldn't try making it run a gauntlet of obstacles though).
Camera batteries are pretty powerful today, allow fast drain, and come in small sizes. Maybe not enough yet, commercially available, but certainly possible to make...if you're willing to pay.
For your issues....
1)super thin spring steel could work, but wouldn't look like the plastic they showed. What's the issue with 'slap bands'? They seem perfect.
2) power is an issue, as is flight time. I feel like early adopters would sacrifice flight/record time for the advantage of size...but only time will tell.
3) object avoidance IS an issue. Likely the solution is to limit it to use where there's no obstruction above it and not too much in front. Slight lag isn't an issue, if it's not moving fast. Return to the object it's centered on should be no problem, it tracks an object to film it, it shouldn't be too hard to return to it. Now, catching it while hanging on a cliff....yeah...that's tough.
4)Does not Go-pro already wirelessly send it's video in real time "HD"? They cost under $400.
I'll agree with you, you would be MUCH better off buying a larger one that works NOW instead of sending money in hopes they come out with this super miniature one. That said, I still think this is possible...just expensive and difficult to make work.
Yeah there are slap bands out there, but they don't work like this is presented to work. The arms would have to bend in multiple dimensions, and then straighten out and be able to provide a stable flying platform. The closest thing I think of for doing something like that is the "bendy" character toys where the metal wire is co-molded inside the body. That is a very heavy solution.
I misspoke on the 2" square, it is 2" x 2", so 4" square. I'm not sure that I agree that theirs is 6" x 3", but even if it is that would mean that the prop size would have to be about 1.25" and that doesn't work for a 6" x 3" vehicle. There isn't enough thrust and the motors at that size don't provide enough RPM's for that kind of weight.
On the electronic side, they show it connecting to a smart phone with video feedback. That means you have to have bluetooth at least, or a 5.4ghz video system if you want more than 30' range. or it has to have a Wifi TX on it. All of those thing require power. Sure it could analyze the video signal to determine subject matter, and provide guidance but you have some very serious issues there. If you do it on board it requires some processor power (More drain), if you do it on the smart phone app it will create lag.
Your phone has over 1,000 mAh in it (1440 in Iphone 5), that is a TON (4-10x) more than what this thing would have. Battery technology may be a big research project right now, but there isn't anything on the horizon that will get them to where they need to be. Most of the tech research is in sub 1C rated batteries for things like full size cars. Something like this needs a 10C rating minimum if not a 20C rating. Unfortunately most of the upcoming technology can not handle drains that fast. Things tend to go "Boom!". When you do something small, and even 6" x 3" is small, you have very serious power vs weight issues. It all comes down to issues of power density, and nothing exists today that will give it to them as they would need..
So right now these guys need to figure out:
1) A new light weight material that can lock rigid but also bend as needed in multiple directions.
2) A new battery technology that allows them to get the power they need, for a 6 axis gyro, 4 motors, control board,a RX, a HD camera and some sort of VTX while reducing weight. How long it powers all of that would be open, but if it is under 10 minutes I think people would be a little disgruntled. Right now people are wanting the video quads to get about 30-45 minutes of flight time on the 5200+mAh batteries.
3) Write code that allows them to analyze video in real time so as to provide object tracking and avoidance without lag while capable of running on a smartphone. It would also need to return to home when the battery runs low. That would be a little tricky on a cliff face, or if you are riding a bike through a forest. Another issue is that they tilt the camera down, they don't say if this is actuated, or done by hand, but it could lead to serious issues with programming object avoidance if you can't see anything above you.
4) Since they show the image as HD on the phone screen, they would also need to come up with a new way to broadcast HD video wirelessly. Right now that system costs $40K and is rather large.
All in all it is a dream product that people are going to get suckered into funding it. Some tech may come out of it that could be monetized, but I don't see the item coming out in this format, at least not in the next 3-5 years. You'd be better off going with AirDog.