I'll go first. When I read that it takes a photon over 100,000 years to exit the Sun as visible light, I was completely astounded. Curious what other insights from science people have learned that were completely unexpected to them.
Electrons in a copper wire do not travel at the speed of electricity. Not even close.
Electricity travels at nearly the speed of light.
Electrons themselves travel like molasses:
"In the case of a 12 gauge copper wire carrying 10 amperes of current (typical of home wiring), the individual electrons only move about 0.02 cm per sec or 1.2 inches per minute (in science this is called the drift velocity of the electrons.). If this is the situation in nature, why do the lights come on so quickly [when you flip the switch]? At this speed it would take the electrons hours to get to the lights."
This completely caught me by surprise, but it makes sense once it's pointed out. Imagine a pipe filled with solid balls that just fit in it, with little friction. If you push a ball in one end, a ball pops out the other almost immediately. But not the same ball! Even if you keep pushing balls in, that first one you pushed will take a while to get the other end.
Update: as rrobukef notes in a reply, this would be the case for direct current (DC). With the usual household alternating current (AC), the electrons barely move at all!
Science doesn't "prove" hypotheses - it disproves them.
For this to work, a hypothesis must be falsifiable. Most pseudoscience (and religion) makes non-falsifiable claims, meaning they are incompatible with scientific discourse.
This simple observation is a powerful tool in any bullshit-detection kit.
Once produced, a scientific hypothesis of any merit will be attacked vigorously with experiments until enough parties are convinced that disproof is sufficiently unlikely. The process isn't always pleasant for those making the falsifiable claims.
Sadly, this is not how science is taught in most schools. There, students are given the "truth" and, on a good day, asked to verify it experimentally. We are now living with the terrible consequences of generations of youth who think science is about "proving" the truth.
A compressed spring weighs more than the same spring uncompressed. The moon and earth weigh less together than if you weighed them separately and added the values together. Most of the weight of solid objects is due to the high speeds and binding energies of the elementary particles within them rather than the rest mass of the constituent particles. The number of particles that exist is relative to how fast you are accelerating. Everything that has energy (which is everything we know of) affects the gravitational field; this means that even photons are "attracted" to each other.
A non-relativistic quantum state will return arbitrarily close to its initial state an infinite number of times. There is such a thing as interaction-free measurements: you can take photos of things without ever letting light hit a detector and you can tell whether a bomb is "active" without actually interacting with the detonator.
Energy is just a number that is calculated as a function of the state of a closed system — that this number is a constant results from the time transitional invariance of the laws of physics. Similarly, conservation of momentum is due to the spatial invariance of the laws of physics, and conservation of angular momentum is due to rotational invariance. Also, conservation of energy does not hold under general relativity.
I already knew that "the universe is incomprehensibly large", but seeing how many entire galaxies there were in a random dark patch of sky was eye opening to me.
A 2016 poll of 1,500 scientists reported that 70% of them had failed to reproduce at least one other scientist's experiment (50% had failed to reproduce one of their own experiments).
OMG me too. I was having an eye exam. The technician had a black field with a bunch of lines. Holding a rod with a white dot, and told to let them know when it disappeared.
I laughed, "Well that will only happen if you put it behind your back."
They laughed, "Everyone has an astigmatism where the nerves enter the eye. We are looking for that or any other issues."
Holy shit... anyone reading that doesn't understand, follow that link and follow along. That was... terrifying when you think of the ramifications. What's more interesting with glasses, my blindspot is larger than without my glasses.
Wow... just... mind blown. I always read about it, but never experienced it... wow...
somewhat related, I was so glad when I found out the reason behind a dim bulb that's just turned off appearing brighter when _you look away_.
The answer is in the density of rod cells (which are photon receptors of the eye that specialize in low-light) are concentrated on the outer edges of the retina. So if you look straight at a dim bulb - the photons hit the cone cells, which aren't sensitive enough, but if you look away, the photons hit the rod cells and you can see the bulb!
It never fails to amuse me that any pressure or force that we intuitively feel is "pulled" by a vacuum, is only caused by air pressure on the other sides of an object.
When you see something hanging from a suction cup in your kitchen or bathroom, it's fun to imagine that the air around you is hammering the suction cup enough to keep it stuck there. With quite some force you'll notice, if you try to pull it straight out! But let some air in through a small gap, and it will help even things out.
A lack of air by itself does nothing. It's just about the net forces.
"The possibility that we are living in a false vacuum has never been a cheering one to contemplate. Vacuum decay is the ultimate ecological catastrophe; in the new vacuum there are new constants of nature; after vacuum decay, not only is life as we know it impossible, so is chemistry as we know it. However, one could always draw stoic comfort from the possibility that perhaps in the course of time the new vacuum would sustain, if not life as we know it, at least some structures capable of knowing joy. This possibility has now been eliminated."
I immediately went out and bought Greg Egan's "Schild's Ladder" after find out he'd used this as a plot device.
You should also read the Three Body Problem trilogy, specifically the last book, although I won't spoil it. It uses a plot device very similar to a false vacuum.
Not a fact per se, but: the sheer amount of living things that came before me, in the sense of my direct ancestors and their direct ancestors etc. etc – not only my human ancestors, but the whole of my ancestors all the way back to the origins of life itself – and I would not be here today if even one of them would have died before reproducing... that manages to blow my mind every single time I think about it.
Try counting the total number of your ancestors: you have 2 parents, they have 4 parents in total etc., i.e. 2^N where N is the number of generations. Going just 40 generations back (about 1000 years), you had 2^40 = 1,099,511,627,776 ancestors.
The sun orbits the center of the galaxy every 250 million years, so when the dinosaurs were around, they were on the other side of the galaxy, compared to where we are now.
Gravity travels at the speed of light (the speed of causality). If the sun suddenly disappeared, the earth would continue orbiting around where it used to be, for about 8 minutes.
Nothing can travel faster than light through space, in a vacuum. However, if you pick two points in space that are far enough apart (e.g. at opposite sides of the observable universe), these points will be moving apart faster than light, because space itself is expanding.
The expansion of space isn’t coming from a single point outward, like an explosion. It’s expanding by the same amount at every point in the universe. People analogize this in lower dimensions to stretching fabric or blowing up a balloon.
Let me add on. Your average big tree (oak, pine, maple, etc) after about 10 years of age, collect about 40 pounds of carbon dioxide every year. Again, averages, there are plenty of factors.
I use that as a way to visualize the problem with "a solution".
The dual slit experiment. Run the experiment with no one watching it, it produces result A. Run it again and watch it, it produces result B. Watching the experiment changes the result. WTF????
It's false information. It's debunked multiple times. "Watching" means "placing or turning on an additional detector", which ruins interference pattern. To develop intuition, look at double slit experiment made at macro scale using walking droplet.
The dual slit experiment produces different results? I must be thinking of something else - I thought that electrons passing through a dual slit always produce an interference pattern.
I absolutely cannot psychologically deal with the Monty Haul paradox. https://en.wikipedia.org/wiki/Monty_Hall_problem I've coded it multiple times in multiple programming languages as a cathartic exercise. Despite seeing the results obviously printed out in a console in front of me, I just can't handle it. I lose SAN just thinking about it.
The explanation that makes the most sense to me, from wiki:
Yet another insight is that your chance of winning by switching doors is directly related to your chance of choosing the winning door in the first place: if you choose the correct door on your first try, then switching loses; if you choose a wrong door on your first try, then switching wins; your chance of choosing the correct door on your first try is 1/3, and the chance of choosing a wrong door is 2/3.
The only explanation that 'felt' acceptable to me is to imagine that you're really playing two games instead of one. In the first game, you're right 1/3rd of the time. Then you get to play a new game where you're right half the time, but you can also choose to not play that game and stick with the results of the first game. Playing the second game (picking another door) is more obviously the right thing to do in this case.
If it makes you feel better, famous Hungarian mathematician Paul Erdös didn't understand it either. One of his colleagues had to write a computer program simulating it before he accepted it to be true.
That when we look up at distant stars, nebulas, & galaxies and the like...we are looking back in time. What we see could have been gone for decades, centuries, or longer.
“longer” is an understatement. The Andromeda galaxy, which is viewable by the naked eye, is 2.5 million lightyears away. And that’s the closest galaxy to us.
Growing up, I was taught that the main reason why it's bad to drink is because it kills brain cells and brain cells don't grow back. Apparently that is not the case anymore:
Not a science fact per se: Until recently I haven't realised the amount of damage inflicted by religion or in the name of religion if you will, to our species. Take Heliocentrism[^1] for example, it was alluded in the 5th century BC that the Earth revolves around the sun and that stars are other "suns". Then religion came along. Galileo nearly died for re-iterating a theory that was accepted by part of the scientific community nearly 2000 years before him.
In similar fashion, years ago while studying the circulatory system for the anatomy class I came across a wikipedia article. This particular part of the circulatory system was documented in detail by Egyptians in 200 BC. Knowledge came from the mummification process. The next breakthrough in this area was made in the 19th century.
Looks like our species could have a colony in Mars by now, if science were allowed to breakthrough linearly.
I'm not personally religious but I'd be very careful before assuming religion, an institution that's been with humans for thousands of years, was a net negative.
I think humans probably have some innate desire for institutions with religious-like properties. And as we've become more secular over the past 60 years, there's been an increase in people that seem to be making politics the replacement, which may end up being more destructive than theistic religion ever was.
Religion is an ambiguous term, which can be why arguments of this sort can get out of hand.
To some, religion = faith. And I think you'll find that most faith has little to say about science (and in the case of your example says nothing about the earth/sun relationship).
More commonly though, when referencing Religion you are really talking about Politics. Heliocentrasim, the crusades, Muslim terrorism, are all about politics, not faith.
When you make an argument using the word Religion in a political sense, but others read it as attacking their faith, then things get very ugly.
In other words you can be a devout Christian, and still consider the crusades to be awful. And you can be a good Muslim and consider 9/11 to be an act of war.
Most anytime someone talks about religion as being the cause of war and conflict, the root cause is politics, not faith.
[+] [-] Stratoscope|5 years ago|reply
Electricity travels at nearly the speed of light.
Electrons themselves travel like molasses:
"In the case of a 12 gauge copper wire carrying 10 amperes of current (typical of home wiring), the individual electrons only move about 0.02 cm per sec or 1.2 inches per minute (in science this is called the drift velocity of the electrons.). If this is the situation in nature, why do the lights come on so quickly [when you flip the switch]? At this speed it would take the electrons hours to get to the lights."
This completely caught me by surprise, but it makes sense once it's pointed out. Imagine a pipe filled with solid balls that just fit in it, with little friction. If you push a ball in one end, a ball pops out the other almost immediately. But not the same ball! Even if you keep pushing balls in, that first one you pushed will take a while to get the other end.
Update: as rrobukef notes in a reply, this would be the case for direct current (DC). With the usual household alternating current (AC), the electrons barely move at all!
https://www.uu.edu/dept/physics/scienceguys/2001Nov.cfm
https://wtamu.edu/~cbaird/sq/2014/02/19/what-is-the-speed-of...
[+] [-] rrobukef|5 years ago|reply
[+] [-] b0sk|5 years ago|reply
[+] [-] aazaa|5 years ago|reply
For this to work, a hypothesis must be falsifiable. Most pseudoscience (and religion) makes non-falsifiable claims, meaning they are incompatible with scientific discourse.
This simple observation is a powerful tool in any bullshit-detection kit.
Once produced, a scientific hypothesis of any merit will be attacked vigorously with experiments until enough parties are convinced that disproof is sufficiently unlikely. The process isn't always pleasant for those making the falsifiable claims.
Sadly, this is not how science is taught in most schools. There, students are given the "truth" and, on a good day, asked to verify it experimentally. We are now living with the terrible consequences of generations of youth who think science is about "proving" the truth.
[+] [-] Xcelerate|5 years ago|reply
A non-relativistic quantum state will return arbitrarily close to its initial state an infinite number of times. There is such a thing as interaction-free measurements: you can take photos of things without ever letting light hit a detector and you can tell whether a bomb is "active" without actually interacting with the detonator.
Energy is just a number that is calculated as a function of the state of a closed system — that this number is a constant results from the time transitional invariance of the laws of physics. Similarly, conservation of momentum is due to the spatial invariance of the laws of physics, and conservation of angular momentum is due to rotational invariance. Also, conservation of energy does not hold under general relativity.
[+] [-] cbsks|5 years ago|reply
https://hubblesite.org/contents/articles/hubble-deep-fields
I already knew that "the universe is incomprehensibly large", but seeing how many entire galaxies there were in a random dark patch of sky was eye opening to me.
[+] [-] perk|5 years ago|reply
[+] [-] cameldrv|5 years ago|reply
[+] [-] ffpip|5 years ago|reply
Thousands of similar questions on reddit for anyone interested- https://duckduckgo.com/?t=ffab&q=science+fact+site%3Areddit....
[+] [-] akmarinov|5 years ago|reply
[+] [-] pks016|5 years ago|reply
[+] [-] lazyjones|5 years ago|reply
[+] [-] Liquidity|5 years ago|reply
[+] [-] sloaken|5 years ago|reply
I laughed, "Well that will only happen if you put it behind your back."
They laughed, "Everyone has an astigmatism where the nerves enter the eye. We are looking for that or any other issues."
I was so shocked when the dot disappeared.
Also happy to hear it was the normal blind spot.
[+] [-] NoOneNew|5 years ago|reply
Wow... just... mind blown. I always read about it, but never experienced it... wow...
[+] [-] captn3m0|5 years ago|reply
The answer is in the density of rod cells (which are photon receptors of the eye that specialize in low-light) are concentrated on the outer edges of the retina. So if you look straight at a dim bulb - the photons hit the cone cells, which aren't sensitive enough, but if you look away, the photons hit the rod cells and you can see the bulb!
[+] [-] RaoulP|5 years ago|reply
When you see something hanging from a suction cup in your kitchen or bathroom, it's fun to imagine that the air around you is hammering the suction cup enough to keep it stuck there. With quite some force you'll notice, if you try to pull it straight out! But let some air in through a small gap, and it will help even things out.
A lack of air by itself does nothing. It's just about the net forces.
[+] [-] Corrado|5 years ago|reply
[+] [-] teh_klev|5 years ago|reply
https://en.wikipedia.org/wiki/False_vacuum
This quote blew my mind:
"The possibility that we are living in a false vacuum has never been a cheering one to contemplate. Vacuum decay is the ultimate ecological catastrophe; in the new vacuum there are new constants of nature; after vacuum decay, not only is life as we know it impossible, so is chemistry as we know it. However, one could always draw stoic comfort from the possibility that perhaps in the course of time the new vacuum would sustain, if not life as we know it, at least some structures capable of knowing joy. This possibility has now been eliminated."
I immediately went out and bought Greg Egan's "Schild's Ladder" after find out he'd used this as a plot device.
[+] [-] cercatrova|5 years ago|reply
[+] [-] ManuelKiessling|5 years ago|reply
[+] [-] tunesmith|5 years ago|reply
[+] [-] Geee|5 years ago|reply
[+] [-] akmarinov|5 years ago|reply
[+] [-] tashmahalic|5 years ago|reply
Nothing can travel faster than light through space, in a vacuum. However, if you pick two points in space that are far enough apart (e.g. at opposite sides of the observable universe), these points will be moving apart faster than light, because space itself is expanding.
The expansion of space isn’t coming from a single point outward, like an explosion. It’s expanding by the same amount at every point in the universe. People analogize this in lower dimensions to stretching fabric or blowing up a balloon.
[+] [-] masked_titan|5 years ago|reply
[+] [-] xlm1717|5 years ago|reply
[+] [-] rootbear|5 years ago|reply
[+] [-] m463|5 years ago|reply
[+] [-] tito|5 years ago|reply
So my trip to the grocery store could be adding as much carbon dioxide to the air as the groceries I pick up!
[+] [-] m463|5 years ago|reply
[+] [-] NoOneNew|5 years ago|reply
I use that as a way to visualize the problem with "a solution".
[+] [-] loandigger|5 years ago|reply
[+] [-] drran|5 years ago|reply
[+] [-] dilippkumar|5 years ago|reply
Anyone got a link?
[+] [-] JohnDeHope|5 years ago|reply
[+] [-] cbruns|5 years ago|reply
Yet another insight is that your chance of winning by switching doors is directly related to your chance of choosing the winning door in the first place: if you choose the correct door on your first try, then switching loses; if you choose a wrong door on your first try, then switching wins; your chance of choosing the correct door on your first try is 1/3, and the chance of choosing a wrong door is 2/3.
[+] [-] shaftway|5 years ago|reply
[+] [-] spurgu|5 years ago|reply
- If you happen to choose a door with a goat (⅔ of the time), the host has to choose a goat door, leaving "switch" a guaranteed win
- If you happen choose the door with the car (⅓ of the time), the host opens a random goat door and you have 50/50 between staying and switching
So always switching is the correct move - if you do that you'll win the ⅔ of the time (every time you open a goat door).
[+] [-] mercer|5 years ago|reply
[+] [-] bjourne|5 years ago|reply
[+] [-] kpwags|5 years ago|reply
[+] [-] perardi|5 years ago|reply
https://en.wikipedia.org/wiki/Andromeda_Galaxy
[+] [-] m463|5 years ago|reply
[+] [-] hbcondo714|5 years ago|reply
https://www.scientificamerican.com/article/the-adult-brain-d...
[+] [-] m463|5 years ago|reply
(the famous rat experiment with the "stimulating environment" and brain grown was later attributed to the exercise wheel)
[+] [-] adsjhdashkj|5 years ago|reply
[+] [-] atmosx|5 years ago|reply
In similar fashion, years ago while studying the circulatory system for the anatomy class I came across a wikipedia article. This particular part of the circulatory system was documented in detail by Egyptians in 200 BC. Knowledge came from the mummification process. The next breakthrough in this area was made in the 19th century.
Looks like our species could have a colony in Mars by now, if science were allowed to breakthrough linearly.
[^1]: https://en.wikipedia.org/wiki/Heliocentrism
[+] [-] DevX101|5 years ago|reply
I think humans probably have some innate desire for institutions with religious-like properties. And as we've become more secular over the past 60 years, there's been an increase in people that seem to be making politics the replacement, which may end up being more destructive than theistic religion ever was.
[+] [-] bruce511|5 years ago|reply
To some, religion = faith. And I think you'll find that most faith has little to say about science (and in the case of your example says nothing about the earth/sun relationship).
More commonly though, when referencing Religion you are really talking about Politics. Heliocentrasim, the crusades, Muslim terrorism, are all about politics, not faith.
When you make an argument using the word Religion in a political sense, but others read it as attacking their faith, then things get very ugly.
In other words you can be a devout Christian, and still consider the crusades to be awful. And you can be a good Muslim and consider 9/11 to be an act of war.
Most anytime someone talks about religion as being the cause of war and conflict, the root cause is politics, not faith.