Recent comments in /f/explainlikeimfive

Lirdon t1_jabfli7 wrote

The edge of the universe is not necessarily observable for us. But the edge of the universe that is observable to us is not only far away, it is far away in time, more primordial than anything.

According to our current observation and understanding, the universe is expanding and accelerating. That is to say that is expanding ever faster, to the point that at the edge of our observable universe it expands faster than the speed of light. That creates a kind of spacial horizon we cannot observe beyond, because light coming from the other side will never reach us. And this horizon is drawing ever nearer to us. Eventually, many of billions of years in the future an observer from our galaxy, may not be able to see past our galaxy.

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FriendlyCraig t1_jabfj6y wrote

We can taste a greater variety of flavors than you listed. It is merely a limitation of language that there are limited words to describe different flavors. For instance English also uses the words creamy, rich, tangy, hot, spicy, and herbaceous to describe flavors. These just aren't the "basic" flavors you listed above, but totally distinct flavors.

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breckenridgeback t1_jabfez1 wrote

The expansion is not the kind of expansion you're thinking of. It isn't like a sphere getting bigger. It's more like every ruler in the Universe is getting smaller, so all measurements of distance stretch to be longer even though nothing "really" moved.

There is, as far as we are aware, no edge to the Universe even if it turns out not to be infinite (which current evidence suggests that it probably is). If the Universe were finite, it would be more like the surface of the Earth where you could get back to where you started after going "all the way around".

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BurnOutBrighter6 t1_jaber0p wrote

It's the apparent size something appears to be based on how much radar signal it bounces back.
So a stealth bomber with a radar cross section of 10 square feet bounces back as much radar signal as a non-stealth blunt object with a surface size of 10 square feet facing the radar station. So it appears as a tiny object on the radar, if it appears at all, despite actually being big.

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BurnOutBrighter6 t1_jabeprl wrote

You haven't answered what radar cross section is though. It's the apparent size something appears to be based on how much radar signal it does bounce back.

So a stealth bomber with a radar cross section of 10 square feet bounces back as much radar signal as a non-stealth blunt object with a surface size of 10 square feet facing the radar station. So it appears as a tiny object on the radar, if it appears at all, despite actually being big.

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zeratul98 t1_jabck7x wrote

A really weird and interesting thing I learned recently is that even though your nose is doing the smelling when you eat, it's different from smelling when you inhale. People feel a different response to the same compounds when they enter the olfactory center from the back of the throat than through their nostrils

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AliMcGraw t1_jabc0b8 wrote

Lunar months are actually about 29 1/2 days; most ancient lunar calendars that don't correct for the sun use 12 months and come out with 354 days ... which is why Ramadan moves back 11 days every year (purely lunar calendar).

Most ancient calendars do correct for the sun. :) They stick in bonus days in various ways -- whole bonus month every couple years, bonus week somewhere, etc.

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Hanzo_The_Ninja t1_jabbjuq wrote

There are two types of radar: Primary and secondary. Secondary radar works by detecting an aircraft's transmitter and doesn't apply here, but primary works by sending radio waves from a ground station and then monitoring for signals that are returned to the ground station -- reflections -- to make a determination about an aircraft's speed and bearing. The radar cross-section of an aircraft is a measure of how susceptible it is to detection by primary radar from different angles.

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AliMcGraw t1_jabbit3 wrote

Also deadass giveaway that someone is a man who doesn't know much about women and generally lacks curiosity about the world when it doesn't occur to them that a lunar cycle would be of INTENSE INTEREST and OBVIOUS USE to the 50% of humans who menstruate on roughly a lunar cycle.

"Well, I don't need to know the lunar cycle, so I don't see why ANYONE would," u/icelandichorsey harrumpfs to himself, before explaining to the woman unfortunate enough to sit next to him on public transit how science works, actually.

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urzu_seven t1_jabb5qy wrote

The difference is you made a false assumption that 1 month = 4 weeks. This is only true for ONE month (most of the time, hi leap years!) February. Every single other month has 2-3 more days which makes up the difference.

  • Jan: 4 w + 3 d
  • Feb: 4 w + 0 d (1 d in leap years)
  • Mar: 4 w + 3 d
  • Apr: 4 w + 2 d
  • May: 4 w + 3 d
  • Jun: 4 w + 2 d
  • Jul: 4 w + 3 d
  • Aug: 4 w + 3 d
  • Sep: 4 w + 2 d
  • Oct: 4 w + 3 d
  • Nov: 4 w + 2 d
  • Dec: 4 w + 3 d

Totals: 48 w + 29 or 30 d = 52 w + 1 or 2 d

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