I'm grant-wishing myself. The grant I'm currently wishing for relates to mitochondrial paternal leakage in birds. It is comforting to know that gods/sky faeries are in the same boat.
True, well argued.
For there to be an energy flow, the life needs to be in a temperature range intermediate between the source and the sink. I'm still a bit worried that if there is a sufficient energy source (most likely a star or geothermal) it will raise the entire environment of the planet significantly above the ambient universal 270K.
However, it really isn't a significant issue. If 270K cosmic temperature is too high for life on planets for whatever reason, it will be comfortable a few million years later. The basic argument of 'a few million years friendly for life everywhere' still holds.
To locally decrease entropy (as life must) you need both an energy source and an energy sink (i.e. somewhere to send your waste heat.) I think this era of the universe would have problems with the energy sink bit. If the coldest available sink is 270K, life would need to be much hotter to be able to use it, which is likely too hot for complex organic reactions.
Having said that, a little bit after (say when the microwave background was at 200K) might have been pretty good for life. Now you only need a little help from a star and planetary atmosphere to get liquid water, so a star's Goldilocks zone should be much larger than at present.
It is common for the inside and outside of a BWR/PWR reactor vessel and its core structures to be manually inspected during refuelling outages, for example.
Interesting. As I understand it, typically during refuelling only a portion of the fuel rods are removed and replaced, and during this process the core and the waste fuel pool are one continuous body of water. So the person inspecting the core is a diver? And the water provides sufficient shielding from the remaining fuel rods? (Or am I just wrong about some fuel rods being left in at this point?)
The thing that has me really worried about LFTR is the removal of fission products.
In a conventional nuclear reactor, the fission products are confined within the fuel cell cladding. The only place rendered long-term insanely radioactive is the reactor core, which is mechanically pretty simple.
In a LFTR, there is a facility for removing fresh fission products from the liquid fuel. This is a combination of multiple processing steps, high temperatures, corrosive chemicals, and way too much radiation to let humans anywhere near for running or maintaining the equipment. Then the removed products either need short term storage, or to be rendered into a form suitable for long term storage - requiring still more processing.
I'll grant you that the core of a LFTR isn't going to cause an accident, but removing and dealing with those fission products on a regular basis with such a huge price on failure sounds like an engineering nightmare.
I do not think it means what you think it means.
Psychology is a huge field. Perception, experimental analysis of animal behaviour, clinical psychology, cognitive biases etc. etc. (Note that only one of those involves psychiatrists.) Some bits allow for harder science than other bits.
I personally don't know enough about psychiatry to form a judgement on how scientific they are, but unlike you, at least I know what a psychologist is (or something of the range that they could be.) Your trite dismissal says much about your ignorance and nothing about psychology.
Because the Canadians were the only ones good enough to find the President's analyst.
Having quickly skimmed the paper, I'll give an example of the problem.
I couldn't quickly find a real data set that was easy to interpret, so I'm going to make up some data.
Chance to die before reaching this age
Age woman man
We have a person who is 90 years old. Taking the null hypothesis to be that this person is a man, we can reject the hypothesis that this is a man with greater than 95 percent confidence (p=0.04). However, if we do a Bayesian analysis assuming prior probabilities of 50 percent for the person being a man or a woman, we find that there is a 25 percent chance that the person is a man after all (as women are 3 times more likely to reach age 90 than men are.)
(Having 11 percent signs in my post seems to have given
Personally, I've considered results with p values between 0.01 and 0.05 as merely 'suggestive': "It may be worth looking into this more closely to find out if this effect is real." Between 0.01 and 0.001 I'd take the result as tentatively true - I'll accept it until someone refutes it.
If you take p=0.04 as demonstrating a result is true, you're being foolish and statistically naive. However, unless you're a compulsive citation follower (which I'm not) you are somewhat at the mercy of other authors. If Alice says "In Bob (1998) it was shown that
A great many of the known exoplanets are large, close to their star or both. It should be noted that this does not directly represent how common large close in planets actually are.
We find exoplanets in two ways - by Doppler shift of the star, or by transits.
When a planet orbits a star, the star also orbits their common center of mass, so it wobbles slightly. By looking for subtle Doppler shift in its spectral lines, we can try to detect this wobble. The larger (mass) the planet, the further the star wobbles, and the larger the Doppler shift. Similarly, the closer the planet, the faster (and so more detectable) the wobble. (Even though it has less distance to travel, this is more than compensated for by how much shorter the orbital period is.)
When a planet transits its star (moves between the star and us) we can detect a decrease in the received light, as some is blocked by the planet. The larger (radius) the planet, the greater the decrease, and so more likely we'll be able to detect it. The closer the planet, the more likely that chance alignment will allow us to observe a transit. Also, the closer the planet, the more frequent the transits, and so the more chance one will happen when we're observing the star.
So this weird planet was quite possibly thousands of times easier to detect than an Earth-like planet in an Earth-like orbit. (In this case, discovery was by transit, targeted observations measured the Doppler shift. The combination allowed an estimate of its density.)
The article does comment on this.
If you're using a maximum likelihood analysis, your model can allow for unreliable data. E.g. you could assign a 10% chance that the paternity is not as recorded. Then you would have probability calculations like
P(child inherited gene from father)=0.9*P('father' (according to genealogy) had the gene)+0.1*P(random male in the population had the gene).
You can even make the 'false paternity rate' a parameter in your model, so the data itself will tell you what value is best. However, if the data is too unreliable, all that your maximum likelihood analysis will tell you is "we can't conclude anything from this data". (Assuming you correctly model the unreliability. If you don't, your analysis is liable to give false results.)
Maximum likelihood is not always computationally feasible, depending on the model you're trying to fit and how much data you have.