This wasn't the point as i read, the question was about confidence. And this has little to do with how "pretty" you are. Your confidence is only in your mind. Sure if others think of you as ugly, it's harder to gain confidence. But I think especially a lot of girls have confidence issues with their appearance despite looking "good".
lurker2718
joined 2 years ago
Good description, but I would say even the parallel and seemingly rational analysis can be very one sided. I noticed on myself that in similar situations my "rational" analysis swings in the same direction as my mood. And if it doesn't, I sometimes do not believe, or more precisely, do not feel it. So it doesn't really help quite a lot. This doesn't make it useless, just a side note to not be to harsh on yourself if it doesn't work.
Another thing which also helps me in such situations, is to remember these are just feelings. Sometimes you just feel worthless or dumb, but this are just your feelings, not you. And just because you feel this way, it doesn't need to be true. Acknowledge the feeling, but try to still notice it is just a feeling.
When there is only 50% totality, photovoltaic also makes 50% less. You just do not notice it when looking around, because your eyes adjust to the changed brightness. So a photovoltaic produces less for a longer time. What I found, for the 2017 eclipse, was that around 16GW were impacted with at most a reduction of 5GW in one moment.
Yes. One place in space has different temperatures. I would assume even individual particles are not distributed by a Maxwell distribution, so the concept of temperature is hard to apply. The background radiation has one temperature. If you add the sun, however, you already have a problem as the sun radiation is not in thermal equilibrium. So depending on how you look at it, you get different temperatures. The particles have a high energy, so also a high temperature. But they are so rare, that radiation is the dominant mode of heat transfer and determines the temperature of a thermometer placed in space.
I think it is actually the other way around. You can consider the air inside the balloon to have internal energy from the heat. And additionally you have to make room for the balloon in the atmosphere, so you have removed the atmosphere from the volume the balloon takes, which also needs energy. If you consider both you arrive at the concept of enthalpy (H = U + pV), which is very useful for reactions in the atmosphere as pressure is constant. For this example it is not that useful as outside pressure changes when the balloon rises.
Another way to see it, the pressure has no "real" energy. In a ideal gas, the only energy comes from the kinetic or movement energy of the atoms. Each time a gas molecule is hits the balloon envelope it transfers some momentum. The cumulative effect of the constant collisions is the pressure of the gas. If the balloon is now expanding slowly, each collisions also tranfers some energy, in sum building the work the system has to do to the atmosphere. Leading to a decrease in internal, so "real" energy in the balloon. This corresponds to a decrease in temperature.
The stratosphere is heated not by the ground but directly from solar radiation leading to higher power input at the upper layers. So the top is hotter and now convection never starts and you get no cooling of the air when rising.
While I agree in general, one point is a bit to simplified in my opinion
In other words, there are fewer air molecules per cubic foot (volume of air). The molecules are farther apart and can hold less heat energy. Because "heat" is what we say when we mean molecules are moving around.
Less molecules mean less heat, it has nothing to do with the temperature, if you just decrease the density by removing half the molecules, you have the same temperature.
It cools down because it expands adiabatically. Consider a very thin balloon filled with air which is warmer than the surrounding. This now rises up, but as it does, the pressure decreases, causing the balloon to expand. During this expansion, the balloon transfers energy away from itself, because it has to push away air, to make room for expanding in the surrounding. This work cools the air inside the balloon. Assuming the air inside is dry, it would cool around 10 °C per km it rises. Now if you think about it, the balloon just stopped the inside from mixing with the outside. If you look at a large "piece" of air, it does not mix very fast, so you can remove the balloon and just consider what happens with warm air heated from the ground.
Now this does not mean, it has to be cooler when higher up. The same points hold, inside a house, but there it is often warmer when higher.
The best explaination is when looking where the heat comes from and goes too from the air. The atmosphere is mostly heated from the surface of earth, so the bottom and cooled from the upper layers. So naturally it gets hotter where it is heated. The question is now by how much? There are three modes of heat transfer in the atmosphere: radiation, conduction and convection. The first two are very slow. Connection is fast but has limits. Consider the piece of air, if it rises, it cools. So at some place it may be the same temperature as the surrounding air, so it stops rising. This means the convection works only when the air gets cooler by 10 °C/km going up (~6.5°C when the air is moist and precipation happens). So this temperature gradient is observable very often.
Yes, the file itself (so the data and inode) is not gone as long as the handles live on. Only the reference is gone. You canstill recover the file. https://superuser.com/questions/283102/how-to-recover-deleted-file-if-it-is-still-opened-by-some-process#600743
Ja das stimmt, da hab ich aus der Physik kommend zu anwendendunsorient gedacht.
Aber für die Frage ob komplexe zahlen gebraucht werden, reicht es, eine isomorphe alternative zu haben. Die komplexen Zahlen haben auch nicht mehr mit Quantenmechanik zu tun wie die Matrizen, nur sind sie leichter handzuhaben.
Die gesamten 2x2 R Matrizen nicht, aber es gibt eine Untermenge die ein Körper ist und isomorph zu C. Nämlich alle die sich durch Linearkombination der Einheitsmatrix und der Rotationsmatrix um 90° ergeben.
Also a+ib ~ [[a, -b],[b,a]]
https://math.stackexchange.com/questions/1028371/complex-number-isomorphic-to-certain-2-times-2-matrices#2644514
Acapellascience (Tim Blais)