The Science Thread

Alrik Fassbauer said:

What about Zombies ?

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Personally I find the invention of zombies ridiculous. Totally unbelievable. The hype is beyond me.

Yes, I agree, but I thought what would happen to Zombies if they were eating fish brains in which antidepressants were found ? How would these antidepressants affect the Zombies which were eating them ?

I like pursuing this kind of questions.

Since zombies don't exist and their biochemistry and neurophysiology - if any, is unknown, it's impossible to say.

pibbur who maybe tries to destroy interesting questions with facts.

PS. Anyhow, the concentration of antidepressants in brain tissue would be much lower than the amount found in pills of said substances. So probably no effect anyhow. Unless the unexisting were hypersensitive to the drug. DS.

Today, 40 years ago, Voyager 1 launched.

From Wikipedia:
"At a distance of 139 AU (2.08×1010 km) from the Sun as of July 1, 2017,[3] it is the farthest spacecraft from Earth as well as the farthest man-made object. It is also the most distant object in the solar system whose location is known, even farther than Eris (96 AU) and V774104 (~103 AU)."

None of the other current leaving-the-solar-system-objects can overtake it.

We're still in touch with it btw, but signals take more than 19 hours to reach us.

pibbur who is impressed, really impressed.

pibbur who said:

Since zombies don't exist and their biochemistry and neurophysiology - if any, is unknown, it's impossible to say.

pibbur who maybe tries to destroy interesting questions with facts.

PS. Anyhow, the concentration of antidepressants in brain tissue would be much lower than the amount found in pills of said substances. So probably no effect anyhow. Unless the unexisting were hypersensitive to the drug. DS.

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However, the "rabies" version of zombies (28 Days Later style) could be plausible. Although they would probably attack each other too.

pibbur who said:

Today, 40 years ago, Voyager 1 launched.

From Wikipedia:
"At a distance of 139 AU (2.08×1010 km) from the Sun as of July 1, 2017,[3] it is the farthest spacecraft from Earth as well as the farthest man-made object. It is also the most distant object in the solar system whose location is known, even farther than Eris (96 AU) and V774104 (~103 AU)."

None of the other current leaving-the-solar-system-objects can overtake it.

We're still in touch with it btw, but signals take more than 19 hours to reach us.

pibbur who is impressed, really impressed.

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Pffff! It only takes me a minute to do the same distance in Eve Online.

pibbur who said:

Today, 40 years ago, Voyager 1 launched.

From Wikipedia:
"At a distance of 139 AU (2.08×1010 km) from the Sun as of July 1, 2017,[3] it is the farthest spacecraft from Earth as well as the farthest man-made object. It is also the most distant object in the solar system whose location is known, even farther than Eris (96 AU) and V774104 (~103 AU)."

None of the other current leaving-the-solar-system-objects can overtake it.

We're still in touch with it btw, but signals take more than 19 hours to reach us.

pibbur who is impressed, really impressed.

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I wonder considering the quantum transmission science i posted is available now, that if scientists will send a satellite with that functionality to follow it so we can get information quicker.

Damian said:

I wonder considering the quantum transmission science i posted is available now, that if scientists will send a satellite with that functionality to follow it so we can get information quicker.

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Unfortunately not. So-called quantum teleportation does not allow for faster-than-light communication, and if it did, things would start to get very strange indeed.

I thought that was the whole point of the technology - instantaneous communication across any distance. Can you link any article that validates your statement that it doesn't do this?

Ripper said:

Unfortunately not. So-called quantum teleportation does not allow for faster-than-light communication, and if it did, things would start to get very strange indeed.

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I think he's talking about this'n: https://www.sciencealert.com/scient...tual-quantum-communication-for-the-first-time

https://en.wikipedia.org/wiki/No-communication_theorem

Essentially, it goes back to the weirdness of quantum theory, which is often not conveyed very well in the popular articles. There is a fundamental difference, in quantum terms, between measuring the state of a particle, and forcing it into a chosen state.

Let's say a pair of quantum particles are entangled, and have only one property of being either 1 or 0. If you measure one particle, and find it to be in state 1, then you know that the other must be state 0, even if it's on the other side of the universe.

However, if I force my particle to be in state 1, then I break the entanglement, and the state of the other goes back to being a 50/50 chance of being in either state.

So, this ability is very useful for sending each other encrypted messages, but only if we can communicate and compare notes using a normal method of communication. If we can do that, we can detect if anyone has observed or interfered with the encryption key, and guarantee security.

But, it is completely useless for actually sending information using only the entanglement, because we can only know the state of the other particle if the state of mine was defined by a 50/50 chance. All we could "send" each other is random bits.

Ripper said:

https://en.wikipedia.org/wiki/No-communication_theorem

Essentially, it goes back to the weirdness of quantum theory, which is often not conveyed very well in the popular articles. There is a fundamental difference, in quantum terms, between measuring the state of a particle, and forcing it into a chosen state.

Let's say a pair of quantum particles are entangled, and have only one property of being either 1 or 0. If you measure one particle, and find it be be in state 1, then you know that the other must be state 0, even if it's on the other side of the universe.

However, if I force my particle to be in state 1, then I break the entanglement, and the state of the other goes back to being a 50/50 chance of being in either state.

So, this ability is very useful for sending each other encrypted messages, but only if we can communicate and compare notes using a normal method of communication. If we can do that, we can detect if anyone has observed or interfered with the encryption key, and guarantee security.

But, it is completely useless for actually sending information using only the entanglement, because we can only know the state of the other particle if the state of mine was defined by a 50/50 chance. All we could "send" each other is random bits.

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Ah, yes that is true. If we dont know what one is, knowing the other is useless. But I am pretty sure we will get that problem solved in the future. Is it true that quantum entanglement cannot send data faster than light?

Damian said:

Ah, yes that is true. If we dont know what one is, knowing the other is useless. But I am pretty sure we will get that problem solved in the future. Is it true that quantum entanglement cannot send data faster than light?

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Yes. Quantum theory, as we understand it, does not allow for FTL communication. It's not a problem to be solved - as far as we know, it's a law of nature. Although entanglement appears to allow for instantaneous action over any distance, the way it actually works prevents you from ever using it to send coherent information.

It's one of those rules that, if violated, would break down reality as we understand it, so if it ever happened, you could be sure it would be pretty earth shattering news. If you could transmit messages faster than light, you would then be able to send messages into the past. Then we wouldn't just have to worry about President Trump, but President Biff Tannen.

Ripper said:

Yes. Quantum theory, as we understand it, does not allow for FTL communication. It's not a problem to be solved - as far as we know, it's a law of nature. Although entanglement appears to allow for instantaneous action over any distance, the way it actually works prevents you from ever using it to send coherent information.

It's one of those rules that, if violated, would break down reality as we understand it, so if it ever happened, you could be sure it would be pretty earth shattering news. If you could transmit messages faster than light, you would then be able to send messages into the past. Then we wouldn't just have to worry about President Trump, but President Biff Tannen.

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Yeah from what i understood of it, it happens instantaneously, but to get the most of it you need to watch both at the same time. So what happens if a camera watches it and sends that data afterwards? Would it function as if a person watched it or if a person didnt watch it?

Although I am not sure if time travel is impossible, my physics teacher tried to teach me because of how light operates, that it was impossible to travel backwards in time, but that never made sense to me, it cause him a lot of frustration LOL. But I am pretty sure the amount of energy needed to send something back in time would be enormous such that even if Earth survives the next thousand years and a scientific breakthrough occurs such that we can send something back in time, at best it would be data that we could send back in time. But that is all speculation.

pibbur who said:

Today, 40 years ago, Voyager 1 launched.

From Wikipedia:
"At a distance of 139 AU (2.08×1010 km) from the Sun as of July 1, 2017,[3] it is the farthest spacecraft from Earth as well as the farthest man-made object. It is also the most distant object in the solar system whose location is known, even farther than Eris (96 AU) and V774104 (~103 AU)."

None of the other current leaving-the-solar-system-objects can overtake it.

We're still in touch with it btw, but signals take more than 19 hours to reach us.

pibbur who is impressed, really impressed.

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Yeah it's cool. I was similarly impressed a couple of weeks ago reading about how the Mars rover robots are still trundling around doing "stuff".

Here's the story, some great pics…

http://www.abc.net.au/news/2017-08-05/mars-curiosity-rover-five-year-anniversary/8750588

Damian said:

Although I am not sure if time travel is impossible, my physics teacher tried to teach me because of how light operates, that it was impossible to travel backwards in time, but that never made sense to me, it cause him a lot of frustration LOL. But I am pretty sure the amount of energy needed to send something back in time would be enormous such that even if Earth survives the next thousand years and a scientific breakthrough occurs such that we can send something back in time, at best it would be data that we could send back in time. But that is all speculation.

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Well, the amount of energy needed to send an object back in time by exceeding the speed of light is not enormous - it's infinite. That's why we can be pretty confident that it's not going to happen in that way.

There is a theoretical possibility that by creating a wormhole with ends at different points in time as well as space, you could travel into the past. That would require astronomical amounts of energy, but still finite. Until such time that the stars and black holes themselves are our playthings, that's not on the table.

Bear in mind though that there is no evidence that wormholes exist or can be created - it's just that the laws of physics don't necessarily appear to forbid them. Many scientists think that if we could create one, it would end up having properties that would again prevent us from doing what we hoped - that nature will not allow for us to break causality and create paradoxes by any means.

It can't be said enough (well, maybe it can, but that won't stop me): One should be very careful when trying to extrapolate the lore of the very small things (quantum mechanics) and the very massive, fast things (relativity) to the middle-sized world we live in.

pibbur who is happy that on the average his particles seem to agree with him whenever he chooses to do something.

Ripper said:

Yes. Quantum theory, as we understand it, does not allow for FTL communication. It's not a problem to be solved - as far as we know, it's a law of nature. Although entanglement appears to allow for instantaneous action over any distance, the way it actually works prevents you from ever using it to send coherent information.

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So what is the point of the ongoing experiments if it's useless?

Philistine said:

So what is the point of the ongoing experiments if it's useless?

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Well, for one reason, it's just research in fundamental science - to see if the tests match what theory predicts, and try to gain some more understanding of this fascinating phenomenon. You never know what you might find, and what applications might arise once you've made the discoveries.

We still don't really have any idea what entanglement is, in any kind of intuitive physical sense. Like a lot of quantum physics, it sort of exists only in the mathematics, without any sort of classical explanation. When particles are said to be entangled, there is no "tie" or link that you could explain in a physical sense. What's entangled is the probabilities of the properties of the system being one way or the other when measured. It makes a lot of sense to investigate these curious things, to see if it might lead to some deeper understanding.

The very practical use case they have in mind is the idea of encrypted security that is essentially guaranteed by the universe - a system of encryption that can be shown to be secure through mathematical proof and the fundamental nature of particles. One of the reasons they are interested in performing the "teleportation" from space, is that it would possibly allow for a future global satellite communication network, with, to the best of our knowledge, unbreakable encryption.

Ripper said:

Well, the amount of energy needed to send an object back in time by exceeding the speed of light is not enormous - it's infinite. That's why we can be pretty confident that it's not going to happen in that way.

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I dont understand why exceeding the speed of light suddenly lets you go back in time. But lets say that is true. The speed of light is a constant. Therefore exceeding the speed of light is a constant mark. By definition therefore energy needed to exceed that cannot be infinite(velocity =sqaure root of(Force x 2/mass)), unattainable maybe because it would literally rip matter apart at those speeds, but it wont be infinite.