We're told flu viruses mutate to multiple new strains every year where we have no existing immunity, why then is it relatively rare to catch the flu multiple times in the same season?

We're told flu viruses mutate to multiple new strains every year where we have no existing immunity, why then is it relatively rare to catch the flu multiple times in the same season?
How do passive amplifiers work?
Has the classification of mental disorders ultimately led to more people getting them through the placebo effect?
How do satellites get power at night?
Did the universe transition from a plasma to a gas when the CMBR was released?
Can the herd immunity threshold for Covid-19 be reduced if everyone wore masks and social distanced (instead of simply slowing the spread)?
Microwave ovens work by exciting water molecules in food. What other substances can be excited by a microwave oven?
What would happen if you got sneezed on by someone with the flu the exact second you were injected with a flu vaccine?
How do we know that COVID-19 doesn't have a dormant phase like HIV-1?
What percentage of the United States is estimated to have had Covid-19?
Why is it difficult to retrieve the source of a compiled program?

Posted: 15 Jun 2020 04:54 AM PDT

submitted by /u/HiddenMaragon
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How do passive amplifiers work?

Posted: 15 Jun 2020 02:43 AM PDT

Passive amplifiers, like the ones you can get for phones, make the sound louder without power. Similar to the horn on an old gramophone. If the sound is louder doesn't that mean it has more energy? Where does the extra energy come from?

submitted by /u/tebla
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Has the classification of mental disorders ultimately led to more people getting them through the placebo effect?

Posted: 15 Jun 2020 05:05 AM PDT

submitted by /u/ehdurudhd
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How do satellites get power at night?

Posted: 14 Jun 2020 02:32 PM PDT

Satellites get plenty of power from the sun during the day, but those in a low earth orbit have to spend half their time in Earth's shadow. How are they powered during this period? They certainly can't afford to bring a ton of Li-ion battery on board. Is it some form of hydrogen fuel cell that recharges by electrolysis? Do they have to enter a "low-power mode" due to limited energy?

submitted by /u/Huge-Coffee
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Did the universe transition from a plasma to a gas when the CMBR was released?

Posted: 15 Jun 2020 06:43 AM PDT

When the universe cooled enough in the very early universe (~ 380,000 years after the big bang) electrons were able to fall into stable orbits around the hydrogen and helium (and trace amounts of lithium) nuclei, allowing radiation to travel freely (the surface of last scattering).

Would it be appropriate to call this a phase shift, analogous to steam (gas) condensing into water (solid), except instead of gas cooling into a solid, it would be the universe transitioning from a plasma state to a gaseous state?

submitted by /u/cellsuicide
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Can the herd immunity threshold for Covid-19 be reduced if everyone wore masks and social distanced (instead of simply slowing the spread)?

Posted: 15 Jun 2020 03:55 AM PDT

submitted by /u/vsbobclear
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Microwave ovens work by exciting water molecules in food. What other substances can be excited by a microwave oven?

Posted: 14 Jun 2020 09:40 AM PDT

submitted by /u/Sup6969
[link] [comments]

What would happen if you got sneezed on by someone with the flu the exact second you were injected with a flu vaccine?

Posted: 14 Jun 2020 03:52 PM PDT

submitted by /u/MechagodzillaMK3
[link] [comments]

How do we know that COVID-19 doesn't have a dormant phase like HIV-1?

Posted: 14 Jun 2020 10:14 AM PDT