I’m Michael Finkel and I wrote Nat Geo’s cover story about the science of sleep (and how most of us are not getting enough of it) AMA!

Is 5-6 hours of sleep in a pitch black room better than eight hours in a bright-ish room?

I like this question... mostly because I can't answer definitively answer. I'd like to poll some experts. That said, my sense is that 8 hours is better. While light can disturb sleep, once the body is fully launched into a good night's rest, one is usually unaware of the amount of ambient light.

Hi, what causes sleep paralysis and how can I prevent it from happening?

Hello. In general, according to the American Academy of Sleep Medicine, sleep paralysis -- during which a person in unable to move for a few seconds to a few minutes upon awaking -- can be triggered by mental stress, sleep deprivation, or irregular sleep-wake patterns. There may also be a hereditary factor. By the way -- fun fact -- many alien abduction stories have turned out to be cases of sleep paralysis. (Or at least that may be what the aliens want us to think.)

Let me give you a scenario. You're at like a beach cabana, and Brad Pitt approaches. Tries to lean in and kiss you. You would definitely resist, like at first. But if he was persistent, would you give in a little bit just to see what it felt like. Would you push him away? How hard? Like, what if he's really aggressive?

Brad Pitt? Sure, why not, I'd give him a smooch! My wife, I believe, would understand.

I find I don't require much sleep. On average 5 hours a night during work week and then about 8 on days off... sometimes. When I do get 8 hours plus I feel groggy and my muscles are tight and back hurts. But when I sleep about 5 I can wake up feeling refreshed and not in pain....why is this?

There is a range of "normal" sleep, and you are on the low end of it. I believe that a sleep doctor might point to your 8 hours of sleep on off days as an indication that you're not getting enough sleep during the work week -- many sleep scientists told me that big changes in sleep, like going from 5 hours to 8 hours, is the equivalent of shifting several time zones. This may be why you're feeling groggy -- your body literally feels like it's in the wrong time zone. I would consult with a sleep specialist.

My girlfriend needs the (very loud, very bright) TV to sleep... How does that even work and could she ever adapt to sleeping like a normal human?

As I mentioned to one other poster, perhaps you could find a decent compromise with a sound machine that helps your girlfriend and doesn't disturb you. Or is this wishful sleeping? Sleep is complex!

Didn’t a man/scumbag impersonate you after he’d murdered his wife and 3 children?

Yes.

It is very nice to meet you. I will enjoy reading your work. James Franco, sigh.

My question to you. Have you studied the effects of a rotating shift schedule on a body? I was Air Force for 20 years and we worked rotating shifts. Two days, two swings, two mids and four off.

Hello and thanks for your question. I won't repeat this too often, but I'm a journalist, not a sleep doctor. I have, however, immersed myself in the current state of the science. Shift work is notoriously destructive to healthy sleep patterns, which in turn leads to many other unfortunate health effects. There's even an official sleep disorder called Shift Work Disorder. But it sounds like you're no longer in the Air Force -- the body and brain tend to be rather forgiving, and if you're sleeping normally now, you should be fine. Though my advice to all is to check in with a sleep doctor. There are sleep labs throughout the country.

Have you heard of the sleep app Sleep Cycle? Is it helpful? Any apps for sleep you recommend?

Alas, I can't make any recommendations for sleep apps. I didn't test very many but in general, according to the majority of sleep scientists I interviewed, most sleep gadgets and apps are not great aids for sleep.

Why is it easier for me to fall asleep when taking a nap than when sleeping at night?

When napping, I can literally sleep on the floor. But when sleeping at night, it's hard to find the right position or I am just not that sleepy even if I didn't take a nap.

I know! I can be the same. Essentially you -- and me, and many others -- have a bit of a screwed up sleep cycle, and our internal clock is not well aligned with the actual clock. There's not time enough in this forum to go into specifics, but I would certainly consider consulting a sleep specialist. And perhaps try, as hard as it is, to avoid napping for a few days and see if that improves your nighttime sleep.

When someone is lucid dreaming, does their brain activity look different from normal dreaming?

Lucid dreaming -- in which the dreamer has some control over the dream -- is a fascinating side-subject that I did not have much time to dwell in. I'm not sure if there has been a thorough study of brain activity in lucid dreamers, but one leading sleep scientists told me that lucid dreaming was dangerous -- it's like the extreme sport of sleepers.

For the past few years, I've generally been able to build my schedule in such a way as to never need to use an alarm clock and just wake up when I wake up. It seems to work really well for me. Is there any research that illuminates why that might be? Also, I occasionally end up sleeping a little longer, and it seems to be associated with mild illness or fatigue, so I take it easy for a day or two. Have you seen anything that supports or contradicts that inference? Finally, are any of the smart sleep monitoring devices worth buying?

First, congrats. You are sleeping ideally! But with modern work schedules and kids and all that, it's very difficult for most of us to sleep without an alarm. You feel good because the body determines when it's best to wake up, not my dang cell phone. Illnesses do often require more rest -- again you're doing it right. I'm jealous. And I can't speak much about sleep monitoring devices, but the sleep experts I spoke with mostly seemed unimpressed with them.

Are you Einhorn?

Finkle is Einhorn. Einhorn is Finkle.

Truer words may have never been typed.

I'm looking for Ray Finkle... and a new pair of shorts

Let me know if you find Ray... or the shorts.

Hi. I just wanna ask, does sleeping late has a relationship with having pimples or acne?

I don't think so!

What's the best course of action regarding sleep for shift workers?

The best course of action, alas, may be an impossible one: stop working all-night shifts. I'd recommend seeing a sleep professional and working out a good sleep plan with him or her. Shift work is a complex (and very real) problem that can't, alas, be solved in the confines of an AMA.

Why is sleep absolutely necessary for all animals? In other words, why hasn't any animal evolved to not need sleep? It seems like such a potential evolutionary advantage to be active all the time that I imagine at least one or two species would have evolved not to sleep if it was physically possible, even if generally speaking sleep has benefits.

This is a huge topic but in general it just seems that no organic life can function full-speed 24 hours a day without rest. Everything needs down time to recover and repair.

Why is it that, when I (and my mother and sister) wake up, even after plenty of sleep, we feel terribly exhausted and physically crummy and unable to think, while others seem to wake up and just get going? How can I get in the habit of waking up and feeling ready and rested for the day?

I'd love to answer this question with some sort of definitive response but I can't, alas. You really should consider speaking with a sleep expert (the field is every growing, and most people don't live too far from a sleep center). In general, you may not be getting the "plenty of sleep" you desire -- it may be a disrupted sleep. Again, each case is different, and it sounds like you and your mom and sis could use a good consultation with an expert. I wish I could be of more help.

Two questions: 1) I don’t dream. There have been a few instances where I’d wake up aware that I did dream and was just forgetting it, but most often there’s just nothing.

2) I read once that the human sleep pattern before electricity was to go to sleep when the sun went down, wake up about four hours later, stay up and moving(such as do housework) for a few hours, then go back to sleep till the sun comes up. Is this recommended? Asking as a new mom with a similar broken sleep schedule.

Two answers:

1. You almost certainly do dream. You just don't remember them. Which, by the way, is the sign of a healthy sleeper. Much of our memory systems are shut down during dreaming.

2. That on and off sleep pattern did exist before electricity, but its prevalence is unknown, and in fact may have less to do with electricity than with the fact that houses long ago were much, much smaller, while families were much, much bigger, and in the middle of the night was the only time a couple could spend some actual couple time. Generally, sleep experts do not recommend messing with one long night's sleep. Sorry.

Do machines dream of electric sheep?

I think you'll have to ask Philip K. Dick that question.

Any cool or new facts/theories about dreams? I’d love to know more about the science behind dreams.

I’m the most skeptical person there is, but sometimes I have dreamed things out of the blue (as in, not about something that’s been weighing heavily on my mind or a current major issue in my life) and what happened in the dream happens the next day. I don’t believe in psychics or any of that woo-woo stuff but it was definitely unsettling.

Dreams are a huge subject but the latest thinking by some -- but by no means all! -- scientists is that... dreams are meaningless. Yes. Really. They're just random scraps of memories that aren't at all connected, and upon waking our brain quickly links them together into a story that never really existed.

How common is napping and how long do people nap for? Also how late is TO late to nap?

Napping is common throughout the world -- the problem is when a nap spills over into a mini-sleep, which can disrupt our real, essential nighttime sleep. One cool trick I learned while researching this story, one that has change my napping life: drink a cup of coffee immediately before you lay down to nap. Caffeine takes about 20 minutes to fully take effect, so you'll have a 20 minute nap -- an ideal length -- and wake up ready to go.

I get up like 2/3 times a night without fail (I’m under 30) and have for most of my life. I can’t sleep in and I feel tired every moment of my life. Do you have a good guess about what’s wrong with me?

Alas, sleep is so complex that I can't help much in this forum. Please consult a sleep doctor.

What's your opinion on polyphasic sleep?

Polyphasic sleep -- breaking a night sleep up into 2 or more parts -- is generally NOT recommended by sleep experts.

What are your thoughts on using melatonin as a sleep aid?

It's generally approved by sleep scientists -- it works and it's much much better than prescription pills. Take very low doses. (1 to 3 mm is fine -- don't buy the bigger doses!)

Is there a danger to getting too much sleep? Can consistently sleeping 10 or 12 hours a day be damaging to your health?

There is not thought to be a danger to long sleeping.

Is it better to go to bed later and wake up later or go to sleep earlier and wake up earlier (at least in terms of health)?

Consistency is key, and finding at least 7 hours a night. The specific hours don't matter so much.

Hi! How does the lack asleep affect athletes and people who work out? Does it affect muscle development and fat loss?

There are many studies on this, most preliminary. But there seems to be a direct link between proper sleep and good muscle development. The link between sleep deprivation and weight gain is pretty clear -- when we don't get enough sleep, the body overproduces a hormone called ghrelin, which causes us to eat more than we need.

You have an absolute dream career, how did you get into war reporting?

There are, of course, many downsides to the job (starting with the pay!) but overall I feel so lucky to be able to do the work I do. I got into war reporting the way many young journalists do -- I took myself, on my own dime (which I was later able to expense) into some war zones. Starting with Sarajevo, during the Bosnian Wars of the mid 1990s.

How much sleep should I must be having compulsorily? .

6 hours a night is considered the minimum for a healthy person, though there are many reports of people getting by on less it's possible that those people could be opening at a higher level with more sleep.

How much did the big pillow industry pay you to tell us we aren't getting enough sleep?

I'm awaiting my huge payment from them!

Do we actually know what sleep is for yet?

Yes, essentially: it's for many things, chief among them -- cellular restoration (for physical health) and memory consolidation (for brain function). The specific details of how we're restored physically and mentally is still an enormous scientific challenge.

Have you seen (or studied) a direct correlation between weight and amount of sleep? I have heard less sleep generally equals higher weight. Is this directly from lack of sleep, or more to do with how we behave while sleep deprived (eat more sugar to uplift us)?

People who are overweight do have more sleep issues, especially sleep apnea. But I don't believe there is any correlation between one's weight and one's need for sleep. In the animal kingdom, however, the animals who sleep the fewest number of hours tend to be very large (cows, elephants, horses) but this is theorized to be an evolutionary adaptation -- in general, the smaller an animal is, the more it faces predation, so the ability to sleep long periods out of harm's way may be a beneficial adaptation.

What story that youve covered did you have the most fun? Also which one did you learn the most from?

This one: https://on.natgeo.com/2zI0Dt8

Are there any good ways to avoid napping besides caffeine? I try to avoid caffeinated drinks but I hate needing to take a nap at 4 p.m. (which then makes it hard to sleep at a reasonable hour at night).

A better night's sleep is the best way to avoid napping, but I understand that it's difficult in this day and age to get a full, restful night's sleep.

If you could provide us with ONE tip to get better sleep, what would it be?

Go to bed at the same time every night. (I don't do this, but I wish I did.)

Why is it that when I wake up from some dreams it feels like what I was dreaming about actually happened?

The content of dreams -- as opposed to the science of what causes us to see images and apparently feel motion while we sleep -- is a very challenging subject, somewhat beyond the realm of science. Many (but by no means all) sleep scientists believe that the imagery in dreams is mostly random, and it's only after we're awake that the waking brian, forever seeking meaning and logical flow, sort of instantly knits together a story out of the random scraps. But it is certainly true that the imagery and sense of movement feels absolutely real, which is perhaps why you feel your dreams actually happened. I feel that too, and sometimes have apologized to my wife at breakfast for something I actually only did in a dream!

What are your thoughts on weighted blankets as a sleep aid?

I didn't read any research on this subject, but in general if weighted blankets (or any other harmless items like this) are helping you sleep better, then they are indeed a beneficial sleep aid.

Whats the best way to wake up? Also, why do i always have more trouble waking up mid dream even when the dream isnt important or interesting

The best way to wake up is without an alarm clock, with morning light rousing us and the body determining the right time to wake.

Do you think dreams have any significant meaning?

There is great debate about this, but I'd say more the half the scientists I spoke with would say dreams do NOT have significant meaning. Others would strongly disagree. The science is still in progress. It's a fascinating field.

How do you sleep at night?!

Also, since you have the reins of the /u/nationalgeographic user account, is there anything you'd like to say with the weight of that institution behind your voice?

Like most people -- sometimes I sleep well, but mostly I don't sleep quite enough.

And you're right, I have the reins of NG power at my fingertips, and right now all my Merry Prankster tendencies are tingling.

Shall I state that Darwin was totally wrong, and that humans were actually all delivered here in a giant spaceship?

Are you related to a Ray Finkel?

No, alas. But we're both saddled with that rather goofy surname.