While in college, I put in dozens of hours on an SEM and got pretty good at it. A TEM is a whole 'nother story... I would have needed an order of magnitude (or two!) more training on it to be able to use it proficiently.
> While in college, I put in dozens of hours on an SEM and got pretty good at it. A TEM is a whole 'nother story...
For the benefit of anyone who doesn't know, a SEM (scanning electron microscopy) is an electron microscope that builds an image by scanning an electron beam across a surface and detecting the scattered electrons. A TEM (transmission electron microscopy) passes electrons through the material to detect them on the other side. (Not to be confused is STEM and SEM; STEM is a scanning variant of TEM, and uses similar equipment, and is equally unlike SEM.)
The big difference between the techniques is that, once you want to pass the electron through the sample, a lot changes. First, your electron beam has to be much higher energy, and your electron source much better quality. This makes the microscope a lot larger and more expensive. The big thing though is that suddenly you have to take extreme care preparing your samples. They need to be thin enough to pass an electron through! So sample preparation is typically much, much more difficult and painstaking.
TEM is also more advanced in that the interpretation of your images is non-trivial. With SEM, your image is typically topographic and easier to interpret (you see what's there), but in TEM which is at much higher resolution, the many many different ways the electron beam interacts with your sample on the quantum/atomic-level becomes important, and the contrast you see in your image doesn't necessarily nicely correspond to a real object. You can also use your layers of atoms as a diffraction grating and gather information from the diffraction pattern formed by the electron beam too. So there's a lot going on.
This is something I admit to doing while driving with my kids at times, when they ask to e.g. turn the volume of music up/down and I think it's just fine the way it is. I'll turn it down a few clicks, then turn it up to what it was before.
Works for dinner too... tell them you're having something they detest for dinner and then gradually dial it back to things that are less detestable and then cook what you were originally going to cook and they'll accept it without complaint :P
It's interesting for me to look at your boss's "Good ideas" circle, because for me, Amazon was an obviously bad idea, Uber is still a bad idea, and I thought DropBox was a good idea but when I look at their initial Show HN a good number of other people did not.
I think the problem we all suffer from is that we all have a very limited perspective. Things that we think are bad ideas - because we don't have an immediate need for them, or because we don't understand them - may be an obvious good idea for someone sitting somewhere else. And the trick to picking good startups is to get out of that personal bubble, and understand what is it about the users of that startup that differs from us, and whether that characteristic is going to be shared by more people in the future.
It would be nice to re-think the necessity of AC, as well. It's been around for quite a long time and the ineffectiveness are crazy (same thing with whole-house heating). Why heat or cool your house and deal with the insulation problems that come from having doors and windows and walls and exposure to sun or wind on one side? Your house doesn't get hot or cold, it doesn't care. You get hot and cold.
Supercomputers run on batteries for an entire day or more in our pockets. Powerful mobile gaming machines can be run from a USB socket. There has to be a way to cool me down in the summer without needing to cool my entire house (and watch as the cold air streams out underneath my door).
I am guessing you live alone. Try telling a one year old to put on a snowsuit to eat soup in. Or your dog. When the weather is -40 degrees, a sweater won't save you. When it is 110 you will need a trunk with batteries behind you to power your personal AC 24/7. Give it a try and turn off the heat and AC for a season. You might make it, but will it be worth the $100-200/month?
Edit: don't forget that AC is much more efficient than heating. With AC you are looking to change the temperature by at most 35 degrees and you are moving heat, so you are getting a multiplier there. With heating, you are heating from freezing or below for most places.
> Edit: don't forget that AC is much more efficient than heating. With AC you are looking to change the temperature by at most 35 degrees and you are moving heat, so you are getting a multiplier there. With heating, you are heating from freezing or below for most places.
Its also incredibly efficient if you're using a geothermal system to pull cold out of the ground vs pushing heat into existing hot air with a compressor.
It can be, assuming you are in the right location in the world. The problem is cost efficiency: you are talking about tens of thousands of dollars for a system that will only pay for itself in a decade (often times; in some situations this is the perfect answer). Geothermal is no silver bullet unfortunately. There is physical efficiency, and there is economic efficiency.
I don't live alone, and I live in a place where the weather occasionally dips to -30F wind chill (and in summer occasionally hits 90F), so I understand hot and cold weather. I have a family and pets.
Literally every single person who commented on this has completely and 100% failed to read a single word I wrote. You're wrong, you're missing the point, and it seems like you're intentionally being obtuse.
Sorry if this sounds snappy, but I've read and re-read my original post over and over again and I'm not seeing why everyone interprets it as me telling them AC and heat isn't necessary. Things like "It would be nice to re-think the necessity of AC, as well" and "There has to be a way to cool me down in the summer without needing to cool my entire house" don't mean "turn off your climate control", they mean "let's get better climate control".
Your comment is exactly the kind of thinking that I was arguing against. Right now we need AC and heat for the entire house. Just a few years ago, we needed gasoline to power our cars and just a few decades ago we needed a dedicated room to run a calculator.
I have a coat with a battery that heats up just the coat for when I'm outside in winter. Shrink it to a normal long sleeve shirt that you would wear inside anyway. That's a start. The point is, we need heat/AC now, but are they the best we could possibly do? And is forced air the best we can do?
I believe I understand you correctly. You want some type of smart system to heat/cool only what's necessary. Fair enough, and maybe there is even something to it. I do see problems with it.
If you are talking about a per-room system, latency becomes an issue. If I go from my bedroom to my bathroom, how long must I be in the room until the heat comes on? Moreover, won't turning heat on/off put a lot of strain on the system? This is not convenient. It's an actively worse system than what I have now. Additionally, I'll spend much more energy heating each individual room, unless I have insulated doors and inside walls: another huge expense.
If you are talking about everyone wearing electric coats and blankets and their AC equivalents, forget about it. First, you have to carry a battery pack and charge it every so often. Second, where you used to be able to just turn up the AC a bit and wear shorts, now you have to wear a spacesuit to not suffocate in the summer.
I think HVAC could definitely use innovation, and this goes beyond the really expensive geothermal systems or high efficiency condensers. Boring things like insulation and construction materials is what's going to make a huge difference here. Buildings with good insulation and little air exchange with the outside will use significantly less energy than those with poor insulation. Heating being the #1 consumer of energy in any given house, we need to trap it inside for as long as possible. Remember, it's much easier to insulate a wall that's not moving, sitting, bend, bathing, etc. than a human.
In short, I understand what you are saying, and I think that others on here do too. I simply disagree with it.
Maybe you could have made that post first, rather than "you're wrong, we need AC exactly the way it is".
Look at it like this: in 2006, who thought that having phone that needed to be charged every night and was crazy expensive and ridiculously fragile was a good idea? Sure, there were some people who had a Palm or a Windows Mobile phone, but they weren't very good. Just like people have hand warmers and electric blankets, which are bulky, inconvenient, and not very good. The the iPhone came along and was slightly better, but better enough that people would take it seriously. Maybe something like the Nest fits that analogy. Then suddenly with a few small tweaks and a change of public mindset, everyone is carrying a 12-hour-battery-life, $700, all-glass smartphone in their pocket, to the point where PCs are being phased out and hardly anyone has a house phone anymore.
So what you're saying is, we need mainframes and house phones, but maybe we should have cordless phones and network those mainframes together, because the problem of making a smartphone is just too hard.
So no, I don't think you understand. You know what's not convenient? Walking out the door and having my face frozen off by -30F weather. Having an AC unit in the living room where the cold air never reaches my bedroom at night. Bundling up in the winter. Sticking to the leather in the summer. You want to talk about convenience? That doesn't sound very convenient at all. That just sounds lazy, because it's what we have now. Lazy is not the same as convenient.
Do you have a cell phone, or are batteries too inconvenient? With current HVAC systems, you only have them in your house, your office, or your car. I used to have a bag phone in my car that I could plug into the cigarette lighter. But now I can take my phone anywhere. Why can't I take my HVAC anywhere?
No, there are suits that circulate water to keep someone cool, hand warmers to use for hunting/ice fishing/etc, ice packs that you can wear strapped to your body, and probably many more I've not yet seen. Problem is, they're just not that good. But electric cars weren't that good not that long ago either, so there's room to grow in the space.
Easy answer... it's convenient. You show me a people warming/cooling solution as convenient as whole home heating and cooling and then the conversation can begin. It's about creating an environment to live in that is consistent, has nothing to do with a house's feelings.
I honestly thought I was talking to a group of engineering-minded people. This comment? This is where dreams go to die.
But I guess there's no room for improvement, which is why heated seats were never invented in cars, why hand warmers were never invented, why heated jackets don't exist, why we don't have ice packs, etc. Those things would be crazy and useless.
Maybe you are missing the point here. Heated seats in cars do not replace the heating system in the car. Hand warmer, heated jackets are for outside, not inside. Do you want to walk around, inside your house in a heated jacket and hand warmers? It isn't nearly as convenient as having your house be 70 degrees, or whatever you deem comfortable.
I have a bathroom where the water pipes pass through an outside wall. On nights where the temperature goes below 0 degrees F, I open the cabinet door under the sink so heat can get in there. My thermostat is programmed to drop to 60 degrees F at night but because the thermostat is across the house, our downstairs bathroom gets very cold. It's on a slab too. Pipes always freeze if we forget to prop the door open and the temps get down below or in the single digits.
I had been thinking of getting one of those wires you put on the pipe to keep it from freezing but it's behind a wall and very hard to get too...