« on: 02/04/2020 04:00:05 »
with respect to the original question:
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Thanks but I didn't say by human ear.
This scenario has been written to assist in the understanding a multitude of aspects of special relatively for the amateurs of us interested in cool physics (including me). I would be grateful for a physicist with a University degree to answer in detail (sorry no half baked musings on this on please).While my answers are not half baked musings, I doubt there are any actual relevant physicists on forums like this one. You want an educated answer, fine, but it's not going to come from a physicist.
Scenario:It isn't really stated, but I presume from this description that C, A, and B are locations in some reference frame and that the observers so named are stationary at those locations and the distance given (the 100m LY) is measured in that frame.
C <-- 100 million light years --> A <-- 100 million light years --> B
1 --> (a = 20 m/s/s until 0.99999c)
2 --> (a = 20 m/s/s until 0.5c)
<-- 3 (a = 20 m/s/s until 0.99999c)
<-- 4 (a = 20 m/s/s until 0.5c)
- Spaceships 1 and 2 set out from observer A towards observer B who is 100 million light years away. Each accelerate at 20 m/s/s (i.e. ~2g) until cruising velocity is made. 1 accelerates to 0.99999c while 2 only accelerates to 0.5c
-Similarly spaceships 3 and 4 set out from observer A to C.
- Each spaceship also decelerates at 20m/s/s as it approaches the target observer such that they stop when they reach the target.
- 1, 2, 3, 4, A, B, C are all fitted with 6 lasers each, directed to each of the different observers and spaceships. The lasers flash once per 100 seconds for 1 second duration. i.e. on the 99th second the lasers turns on for 1 second. The light is green (wavelength of say 532 nm).If it exhausts the reaction mass at 0.9c, it is 90% efficient by that metric. It really doesn't make a different if it is antimatter drive or water rocket like the space shuttle.
Secondary Details for Auxiliary questions :
- Each laser makes 1 GW of effective light emitted during the 1 second bursts.
- Each spaceship weighs 10 Tonnes excluding fuel. Let's assume each ship has some sort of particle accelerate to use as thrust that can accelerate the particles used as thrust to ~0.9c. Also it is powered by let's say some theoretical antimatter/matter source and the whole system can convert all matter into thrust at 99.9% energy efficiency.
Please ignore the expansion of the universe.It wouldn't be SR if we assumed otherwise.
Q1.a) According to spaceship 1, how long did it take to reach B?~447222 years
b) According to spaceship 1, when does spaceship 2 arrive at B?When the ships rejoin, the clock on ship A reads about 100446222 years.
c) describe, inducing a rough timeline, what spaceship 1 observes from the laser lights (i.e. the wavelength, how long between flashes and duration of flashes, the energy intensity) , originating from A, B, 2, 3, 4 as it accelerates to 0.99999c, cruises at 0.99999c, and finally approaches B.The flashes are all the same at first.
a) According to spaceship 2, how long did it take to reach B?I get 173 some million years
b) According to spaceship 2, when does 1 arrive at B?Frame dependent question since spaceship 2 is not present at that event.
describe, including a rough timeline, what spaceship 2 observes from the laser light originating from A, B, 1, 3, 4 as it accelerates to 0.5c, cruises at 0.5c, and finally approaches B.At cruise, gamma is 1.1547 and Doppler is a factor of two, at least relative to the lettered objects. It can be worked out from that.
]a) According to observer B, when does 1 reach it?We haven't stated what the clock at B reads at any particular event, so this cannot be known. If it is synced to A in that original frame, then ship 1 gets there at year 100001000 and ship 2 at 200MYr (plus about 100 days). This is pretty trivial arithmetic.
b) According to observer B, when does 2 reach it?
c) Describe, including a rough timeline, what observer B observes from the laser light originating from 1, 2, 3, 4.Same thing that those ships saw when observing B.
a) According to observer A, when does 1 reach B?Assuming the frame of A and that clocks are synced in that frame, all these events are the same answer as B's answer.
b) According to observer A, when does 2 reach B?
c) Describe, including a rough timeline, what observer A observes from the laser light originating from 1, 2, 3, 4.Same as those that seen by the ships looking at A.
d) According to observer A, how fast are 1 and 3 moving away from each other?That's a 3 way relation, not particularly defined. Ships 1 and 3 are moving at .99999999995c relative to each other period. It's an objective relation, not a frame dependent one.
b) If each laser had a narrow enough focus and the observers had a large enough receiver to capture all of the light emitted to them from each spaceship, what would the energy levels (GW) look like from each spaceship.Work it out as a function of energy conservation.
Cesium is absorbed into our bones - iNo it in't
I think the value for α should be closer to 200, which would then explain why UK childhood leukemia clusters were only found around Sellafield, Dounreay and BurghfieldYes, but it wouldn't explain the other data.
Again, most of my posts are well thought and researched, that a simple google search won't answer them.I beg to differ.
It is a mystery why Earth has a magnetic field, and Mars doesn't (any more).Earth's radius is ~1.87 times that of Mars, This gives it ~3.5 times the surface area, but ~6.5 times the volume of Mars. Earth also has a density of 5.52 g/cc to Mars 3.93g/cc, which makes the Earth over 9 times more massive. All in all, Earth's mass to surface area ratio is ~2.66 times that of Mars. Surface area determines how fast the heat can radiate away and mass determines the total heat contained for objects of the same temperature and like make up. Thus Mars should be expected to lose its heat fairly quickly compared to the Earth
Mars is slightly smaller than Earth, so it would have cooled slightly quicker - but not much quicker.
Perhaps the collision that produced the Moon might have injected a pulse of energy into the Earth's interior, keeping it hotter for longer? The iron core of the impactor would have sunk towards the center of the earth, merging with Earth's core.
Malting produces Maltose (a disaccharide) from Glucose (a monosaccharide).I'm fairly sure that malting turns starch into maltose, rather than glucose into maltose.
But like many biological processes, Malting involves many steps, including creation of the necessary enzymes, breaking down the starch feedstock in the seed, etc.
Nevertheless, Malting is carried out on an industrial scale, so the restriction to a single enzyme is not a barrier in practice.
- I think that Singapore, with a diversity of cultures has done a good job of enforcing non-tribalism, perhaps assisted by the fact that no one ethnicity is numerically dominantReally?