Given that radiowaves reduce amplitude according to the inverse square law, how do we maintain contact with distant spacecraft like Voyager 1 & 2? | AskScience Blog

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Friday, June 5, 2020

Given that radiowaves reduce amplitude according to the inverse square law, how do we maintain contact with distant spacecraft like Voyager 1 & 2?

Given that radiowaves reduce amplitude according to the inverse square law, how do we maintain contact with distant spacecraft like Voyager 1 & 2?


Given that radiowaves reduce amplitude according to the inverse square law, how do we maintain contact with distant spacecraft like Voyager 1 & 2?

Posted: 05 Jun 2020 12:18 AM PDT

Do high flying birds need less oxygen?

Posted: 04 Jun 2020 08:09 AM PDT

Do high flying birds need less oxygen in their breaths, or do they take breaths when they are lower altitudes (like whales surfacing for air)?

submitted by /u/VonBeegs
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By blowing the outer sides of a mug, how much more or less effective is this than blowing the top of the mug (directly at the liquid)?

Posted: 05 Jun 2020 04:59 AM PDT

Background: The question comes as result of my high school science teacher suggesting in order to cool our solution in the beaker, we should blow the outer sides of the beaker and shouldn't blow from the top directly down into the solution (like most would when cooling a hot beverage). I believe he said this at the time because the fumes of the solution may have been hazardous or the solution may splash if we blow too hard.

Thoughts: The sides of mugs usually have a bigger surface area than the top of the hot beverage. Via conduction, my thoughts are that the heat should disperse into the mug quite rapidly. Additionally, if the hot beverage is stirred, the surface area touching the sides of the mug is even more significant.

Personally, I feel blowing the top of the mug has always been better because I feel the heat escaping as I blow but I'm not sure if this means it's actually better than blowing the sides.

Also, possible variables to consider is stirring and if this would change the outcome, and for the sake of having a clearer direction for this question, lets say the mug is ceramic and holds approximately 250ml (just imagine a typical white mug with a handle).

submitted by /u/ProfessorJimHarris
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Why didn't the Greenland ice sheet melt after the ice age?

Posted: 04 Jun 2020 08:39 AM PDT

Part of the Greenland ice sheet is at the same latitude as where the ice sheets that covered Canada and northern Europe were and those melted, so why not the Greenland one?

submitted by /u/Albert_Camus129
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What is a phase 3 clinical trial when we talk about vaccines?

Posted: 05 Jun 2020 06:38 AM PDT

My understanding of the phases of clinical trials goes like this;

Phase 1: test safety in small number of healthy people.

Phase 2: test safety in small number of sick people and obtain early data whether it works.

Phase 3: test efficacy in large number of sick people.

Phase 4: use new treatment in the clinic and study it.

My question is this. Vaccines are given to healthy people to prevent the sickness. So who gets studied in Phase 3? Do you just wait to see how many of those people end up sick after they get the vaccine?

submitted by /u/Hmm_I_dont_know_man
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Can someone please explain some aspects of E=MC^2?

Posted: 04 Jun 2020 09:15 PM PDT

Sorry in advance if these are dumb questions, just trying to understand Einstein's equation better.

I understand E represents energy, usually potential energy, but what unit is E measured in? Is it dependent on what units are used in the case of M and C (i.e. using grams or kilograms etc, meters per second or kilometer per second etc) or are all of the variables associated constant units? If it's constant, what is the correct unit to use for each variable?

For example, take a 5 kg object. Multiply by the speed of light (defined in this case as 299,792,458 m/s), squared, (8.987551787368e16 m/s), which gives us 4.493775893684e17. What unit is this number measured in?

What makes the speed of light relavent to measuring energy in objects with mass? If light is made up of photons, and photons have a mass of 0, that would make the energy of photons equal to 0 according to this equation. Wouldn't that mean light contains no energy, and therefore isn't a form of energy like we know it to be? If it's not a form of energy, why is light warm? How would solar panels work? How would photosynthesis work? How are lasers powerful enough to cut through metal? These are just examples to explain my thought process, not necessarily other questions that need to be answered.

Thanks y'all, I've tried googling (albeit not as hard as I could've) but I found nothing that answers these questions, and figured it would be easier to ask.

submitted by /u/tekno_trekker
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Why clouds don't form beyond a certain height?

Posted: 05 Jun 2020 07:09 AM PDT

OK, this might be dumb, but why do clouds don't form/rise above a certain height? What's the threshold to that height? Is it because water vapour doesn't rise above that height limit?

Thank you!

submitted by /u/waltzraghu
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Do all beans in a pod have the same exact genetic make up?

Posted: 05 Jun 2020 02:56 AM PDT

Like take edamame for example. Slice that open and you'll get yer self some beans. Are each one of those beans genetically independent? Y'know it's their own fruit, it's gonna do what it wants. Or are they all completely identical genetically. I'm making a character that gains different abilities based on the foods they've eaten. It made me curious as to the actual science behind it. I figured you guys could help me out. Or if anything I brought an odd chuckle to your feed. But so like for example. You've just eaten edamame and arise from the edaMAMA pod next to a healthy batch of bean bros. Are they going to be all identical, the same dna? And most importantly which one of them is gonna have the biggest dick? P.S. if you have any more cool sciencey food related ideas for this character message me.

submitted by /u/spraey_cheez
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Does surface texture/roughness have much impact on the solubility of a substance?

Posted: 05 Jun 2020 06:19 AM PDT

I'm thinking because a highly rough surface will technically have more surface area. I imagine this will only apply to the initial layer but that would still be of interest to me. If anyone has any links to any articles it would be greatly appreciated :)

submitted by /u/optiberry
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Southern California experienced an aftershock yesterday 11 months after the original one. How can this big of a delay happen?

Posted: 04 Jun 2020 08:37 AM PDT

Will a dream about a major physiological event trigger any relevant physiological reactions in the dreamer?

Posted: 04 Jun 2020 08:19 AM PDT

For example, if an individual dreams of something like childbirth, does that individual receive similar hormonal releases etc. be it in a lesser degree or otherwise as the real life event? I'm not sure how deep the science into the actual biology of dreaming is, but would be interested to know if their is any theories in this specific area.

submitted by /u/NotAshTaylor
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Does gravity work differently underground?

Posted: 04 Jun 2020 12:38 PM PDT

Does gravity get stronger, weaker or stay the same as it would be on the surface?

submitted by /u/the_fonzzz
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How can a Bi-elliptic transfer orbital maneuver be more efficient than a Hohmann transfer?

Posted: 04 Jun 2020 08:36 AM PDT

I know just enough about orbital mechanics to realize I know hardly anything, thank kerbal space program, and ran into this maneuver. I can't seem to wrap my head around how this could be a better plan. Any insight would be appreciated.

submitted by /u/Yorune
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How do mushrooms reproduce with other mushrooms?

Posted: 04 Jun 2020 12:37 PM PDT

I understand that they release spores through the mushroom but how do they share DNA?

submitted by /u/Inselaffen90
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Do freckles appear at the same spot every time or are they randomly placed?

Posted: 04 Jun 2020 01:46 AM PDT

was just looking myself in the mirror and noticed some new freckles. I get more freckles at summer and then all of them disappear at winter.

So my question is: Do freckles appear at the same spot every time or are they placed randomly?

(English is not my first language so sorry if there are any grammar or spelling mistakes)

submitted by /u/SingingVega
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Where is the line drawn between a language and a dialect?

Posted: 04 Jun 2020 10:19 AM PDT

For example, I am near fluent in French (Canadian) and can not understand Cajun French very well. But I can understand a little Italian, even though I have never studied Italian before. And it's not just between French dialects where this happens. Most English speakers say they can't understand Jamaican English, Arabic speakers say they can't understand people from Morocco, and I'm sure the list goes on with other major languages. What is making Italian almost easier to understand than Cajun French?

submitted by /u/Ninja-Snail
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What happens when radio waves collide, or multiple sources broadcast on the same frequency?

Posted: 04 Jun 2020 05:19 PM PDT

I know radio waves fall along the same spectrum as microwaves and visible light, and tuning into those frequencies with a device like a radio allows us to listen in on messages if you're within range of the source's broadcasting.

What happens when a device is tuned into a frequency that more than one source is broadcasting in? Would it mash the sounds together, or just result in audio static? Does that mean that someone could play a bunch of noise on all available frequencies in order to drown out whoever is using those frequencies in broadcasting range? Please note, i'm not attempting anything like this, just wondered if it was possible or what would happen haha

submitted by /u/EightiesHades
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How did plants survive the Ice Age?

Posted: 04 Jun 2020 06:09 AM PDT

If plants grow between temperatures of 32 F and 85 F, then how did they survive during the Ice Age, where temperatures were way colder.

Also, how did animals survive? What did they eat if there were barely any plants available?

submitted by /u/FutureAdi
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How to introduce $\Gamma(1\4)$ and $\Gamma(-ve integer)$?

Posted: 04 Jun 2020 12:10 PM PDT

When i wanted to prove that $\Gamma(-1)=\infty$ it turns to be $\inft over -1 $ which for me equal to $-\infty $ not $\infty$. When I draw $\Gamma(x)$ it's was singular at $x=-1$ where $lim_{x->-1+}=-\infty$ and $lim_{x->-1-}=\infty$..i need to know why $\Gamma(-ve integer)=\infty$ not $\Gamma(-ve integer)=+-\infty$?? ..Another question is $\Gamma(1\4)$ has an explicit value or not..like$\Gamma(1\2)=\sqrt(\pi)$? Or how can we introduce it?

submitted by /u/hassnataha
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