Recent comments in /f/askscience

Eltuine t1_jc3qcml wrote

Hank Green has a really good explanation about this in a video on the Vlogbrothers youtube, starting at about 7:33 - https://youtu.be/hIGtTImeYU4?t=452

The short answer is, since the reactor was cooled with regular instead of heavy water (hence, cheaper), pulling the control rods out didn't speed the reaction up as much as it would if they were to use the (more expensive) heavy water, as regular water absorbs more neutrons. So, instead of just "removing" control rods, the reactor pulled in graphite rods behind the control rods. (Graphite being a substance that would "speed up" the reaction, thus counteracting the slowing of the water).

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OlympusMons94 t1_jc3ndu7 wrote

On Earth, volcanic or man-made gases can lead to acid rain, with a bit of strong acids such as sulfuric acid (H2SO4) dissolved in water. On Venus, there is very little water. What little is left has mostly combined with SO3 to form H2SO4. The clouds and rain are made of very concentrated, even anhydrous (no water as a solvent), sulfuric acid. This rain never reaches the surface. Because of the heat, it evaporates before reaching ~30 km altitude. (A phenomenon called virga, which is common with H2O on Earth when the surface air is very dry.)

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CrateDane t1_jc3k5ov wrote

If there's a sequence of AUG in an RNA, then an RNA-dependent RNA polymerase can copy that to UAC in a newly synthesized RNA, because those bases "fit" in base pairs. Then the UAC in that RNA can be copied into AUG in a new RNA that's identical to the original one.

A ribosome can read the exact same AUG sequence and insert a methionine into a protein.

One method is essentially just straight copying while staying in the same language, while the other is translating to a different language. That's why the process of making proteins is called translation.

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OlympusMons94 t1_jc3jq6v wrote

CO2 near Venus' surface is a supercritical fluid, which is neither gas nor liquid, but has properties of both. At present, the CO2 is more gas-like, but in the past Venus' surface pressure may have been even higher, possibly enough to support a more liquid-like supercritical CO2 (Bolmatov et al., 2014).

There is also supercritical CO2 within Earth's crust. Supercritical and even actual liquid CO2 are released by hydrothermal vents on the sea floor.

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babar90 t1_jc3jiw3 wrote

All the translation (making of proteins) is done by the cell's ribosomes (this for almost every viruses) from mRNA strands as the cells do everydays to make proteins.

But the replication and transcription (making copies of the full length RNA genome and some mRNA copied from parts of it) is achieved by a viral polymerase, a RdRp.

This is for RNA viruses. Many DNA viruses do something along the same lines, but some do not and make their genome enter the cell nucleus to exploit either its DNA replication machinery or its DNA->RNA transcription machinery, or both.

Retroviruses are some kind of hybrid between the two strategies.

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not_my_usual_name OP t1_jc3gw7y wrote

This is interesting. My understanding was always that the viral RNA is seen as RNA coming from the cell's DNA, and the cell's protein assembling machinery would assemble a virus according to the virus' RNA. You're saying that the virus' RNA actually has the cell's machinery assemble a virus factory "replication complex"?

Presumably in the replication complex, there's some molecule producing viral RNA. Does it do that by looking at and copying the original strand of RNA (or copies)? If not, then was the RNA production machine built "knowing" how to make the viral RNA? I'd think that involves some compression, which is what I'm most curious about.

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not_my_usual_name OP t1_jc3fnd8 wrote

What I mean is that if each base in the injected RNA specifies exactly one base of the produced RNA, then there aren't any bases left in the injected RNA to specify how to build anything but an identical strand of RNA. It seems like there must be something more efficient going on, and I'm interested in what it is from an information science perspective.

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Sythix6 t1_jc3eo36 wrote

I'd agree with that argument, everyone was warned, everyone still followed bad orders, all because Russia cannot look weak at any time, Soviet era Russia was rampant with these types of accidents, not as globally impactful though, most stemming from lack of quality materials caused by embezzlement from generals and other higher ups.

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