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David Blaine Freaks Jimmy Out

noims says...

Hang on, now, this is physics law.

Let's say it's a 1g nail and a 100g frog. In order to effect a 100-fold increase in relativistic mass (i.e. starting mass / sqrt( 1 - v^2/c^2) ) the velocity must be over 99% of the speed of light (it would be 99% if we didn't have to square them).

That's a hell of a lot more than 20 over, buddy. Is there a limit on that fine, or does it depend on the width of the ticket?

BSR said:

Yeah but it would roughly amount to a speeding ticket of 20 miles an hour over the speed limit. I doubt he'd fight it in court.

Color video of Albert Einstein actually explaining E=mc2

newtboy says...

Good, then I’m not just being dumb….But you don’t recall at what point it goes from KE= 1/2m V^2 to E= M C^2 …or the equation/function used to determine energy below the speed of light but above the 1/2 threshold?

Somewhere below C (speed of light) it gains up to 1/2 the total system energy, beyond simple kinetic energy…I’ve heard this alluded to as mass becoming energy, but never with any explanation how or even if that’s reality or just a mathematical “trick” to make the equations work…nor an equation describing the process. I only took year one physics….over 25 years ago.

noims said:

Actually, I think I can verify this. I remember in physics going through a derivation of why E=mc^2 and being very disappointed that it was just a specialised case of your second equation.

BSR (Member Profile)

The Big Misconception About Electricity

spawnflagger says...

In general I love the Ve channel, but I think this video does more to confuse people than to enlighten them.
Also, no mention of "holes" (even though that's more part of semiconductors).
Also, of the multiple-choice answers, there wasn't one corresponding to 80% speed of light which is the measured speed of electrical signal in copper (depends on the cable itself, frequency, and other factors).
And if all of the power actually travels through the air, then why does the ampacity of a cable matter at all? Tesla could be quick-charging with flimsy cat5 cable!

The Big Misconception About Electricity

bcglorf says...

Maybe I can illustrate better.

The 'answer' they give is less clear than it could be for illustrating that purpose. That is to say, the very small electric current that is transferred 'wirelessly', would work exactly the same if your wire were never connected to each other period. Making it a loop as the example, then ignoring the transmission of force on the electrons along that connected wire is unduly complicating the example. If you want to illustrate that current in a wire generates a mag field, and that mag field in turn can induce a current in another wire is much better done by pointing out the result is the same if the wires are not connected.

It also avoids re-inforcing the very common misconception people have about electricity in wire not being subject the the speed of light...

vil said:

Nah I dont see a bait and switch. I see people thinking electricity goes down wires while the underlying real world is fields propagating through space.

It really is a difference if you have the lightbulb 1 meter away or 1 light second away. We have a tendency to think abstractly of these situations, freely giving things ideal properties that they dont have and taking away the properties we dont like to use in our petty examples.

If you had enough voltage to overcome the drop in "ideal" 1 light second long cables they sure as hell would induce enough current in parallel cables 1 m away to light a bulb :-)

All that said people do under-appreciate how fast the speed of light is, just as they under appreciate how much a billion of anything, especially money, is.

The speed of light is getting to your destination instantly from your own point of view.

The Big Misconception About Electricity

vil says...

Nah I dont see a bait and switch. I see people thinking electricity goes down wires while the underlying real world is fields propagating through space.

It really is a difference if you have the lightbulb 1 meter away or 1 light second away. We have a tendency to think abstractly of these situations, freely giving things ideal properties that they dont have and taking away the properties we dont like to use in our petty examples.

If you had enough voltage to overcome the drop in "ideal" 1 light second long cables they sure as hell would induce enough current in parallel cables 1 m away to light a bulb :-)

All that said people do under-appreciate how fast the speed of light is, just as they under appreciate how much a billion of anything, especially money, is.

The speed of light is getting to your destination instantly from your own point of view.

The Big Misconception About Electricity

bcglorf says...

This is also a trick question, and in a way that I kinda dislike because it additionally confuses matters by the setup.

Specifically, any change to the electrical field in the wire triggered by something like flipping the switch IS always limited to propagating at the speed of light, and as such WILL take 1s to travel the ~300,000km through the wire.

There's a bait and switch here though, were if the wires are close enough, and the power on the wire is high enough, there is a strong enough magnetic field in the wire to reach across the 1m distance to the end of the wire by the light bulb. That magnetic field will induce a very small electric field on the wire as well. Calling that 'lighting' the bulb though is 100% a trick question though as no existing light bulbs are sensitive enough to light up from that little current unless the 'live' side of the wire is both in very close proximity and running very high voltage.

The part I dislike, is too many people believe that electricity running in a cable is 'faster' than light, and the trick here kinda re-inforces that rather than helping to clear that up for people.

Sci-Fi story from Many Worlds interpr. of Quantum Mechanics

vil says...

This is like travelling "faster than the speed of light". No idea what thats about either.

Nice SF story.

According to the currently most popular simplest many worlds theory the universe splits every time anything happens at the quantum level - good luck keeping up. Also good luck "communicating" without splitting more universes.

Also its just a theory.

Warp Speed Comparison

How The First Ever Telecoms Scam Worked

KrazyKat42 says...

For people who don't understand how this is relevant today, when the stock market opens everyday, the first traders get a huge jump on the others. The fastest trading networks are so fast, there have been several instances where the trade seemed faster than the speed of light. We are talking about internet speeds with less than 1 millisecond lag.

Space Engine 0.9.8.0 Trailer

jimnms says...

Obviously you haven't played with Space Engine. It's not much of a game, but I find myself lost in it for hours just exploring. The shots you see are made in-game, traveling at many thousand times the speed of light. Every star you see, you can literally travel to. It might have planets and moons in orbit which you can visit, or that "star" might even be an entirely new galaxy with billions more stars.

It does have a game mode with space ships, but I have never tried it. I just load it up from time to time, click a random star and go to it.

dannym3141 said:

Ah the obligatory zooming through space with large white blobs streaking past your face like what doesn't happen.

The limits of how far humanity can ever travel - Kurzgesagt

newtboy says...

What I can find said at 1g acceleration it will take just over 1 year (ship time, slightly longer to outside observers) to reach the speed of light.

That's 46 miles per second per megaparsec (roughly 3.2 million light years) not for the whole universe.

The local group is over 3 megaparsecs across....I can't find how far the nearest group is, but it's likely >thousands of megaparsecs away, meaning if it's just 1000 away, that's 46000mps (miles per second) added to a trip that would already take 3200000000years at the speed of light. 31,536,000 seconds per year X >46000mps= >14506560000000 extra miles per year X 3200000000years =>4.6420992e+21miles, or >789606940 light years, or >263 megaparsecs of expansion during the 1000 megaparsec trip (if I did the math right, and that's not compounded by the second as it should be, that would make those numbers far larger). This means if we only ever get to 1/4 light speed, expansion already is faster than we'll ever go, and every day there's more space to expand, so it's expanding faster.

Even if we somehow managed light speed and the excessively long trip, after well over 4 billion years at light speed, we would have long since ceased to be human and evolved into something else ....and that's the closest groups, farther away is already well out of reach even at full light speed.

EDIT: about the wormhole thing, 'could' means they haven't ruled it out yet, not that we do, or ever will have the ability, or even that physics allows it.

SDGundamX said:

If I'm doing the math correctly, the universe is expanding at around 46 miles per second, which is around 165,000 mph. Is there some reason why humans could not overcome this speed limit? It doesn't seem that exceptionally fast (no where near as fast as the speed of light), and if you accelerate slowly to it, like over several days or weeks, the g-forces involved wouldn't be that extreme, would they? The video didn't really explain why we could never go fast enough to overcome the expansion rate.

Also, I thought most theortical physicists like Stephen Hawking believe that in the future technology could advance enough to allow us bend space-time and hence travel "faster than the speed of light" without actually travelling faster than the speed of light, basically like folding a piece of paper and sticking a pin through both sides. When you lay the paper down flat, the two holes will seem quite far away from each other, but when you fold the paper, the holes are right next to each other. Our current understanding of physics doesn't rule out the possibility (at least from a mathematical perspective) although generating the energy necessary to perform such a feat would of course be problematic.

The limits of how far humanity can ever travel - Kurzgesagt

SDGundamX says...

If I'm doing the math correctly, the universe is expanding at around 46 miles per second, which is around 165,000 mph. Is there some reason why humans could not overcome this speed limit? It doesn't seem that exceptionally fast (no where near as fast as the speed of light), and if you accelerate slowly to it, like over several days or weeks, the g-forces involved wouldn't be that extreme, would they? The video didn't really explain why we could never go fast enough to overcome the expansion rate.

Also, I thought most theortical physicists like Stephen Hawking believe that in the future technology could advance enough to allow us bend space-time and hence travel "faster than the speed of light" without actually travelling faster than the speed of light, basically like folding a piece of paper and sticking a pin through both sides. When you lay the paper down flat, the two holes will seem quite far away from each other, but when you fold the paper, the holes are right next to each other. Our current understanding of physics doesn't rule out the possibility (at least from a mathematical perspective) although generating the energy necessary to perform such a feat would of course be problematic.

Going Interstellar - Photonic Propulsion

newtboy says...

I'm confused. They imply a 3 day trip to mars is possible, but is that at the maximum speed photonic propulsion can deliver, or do they include the acceleration and deceleration times? As I understood it, photonic propulsion can deliver extreme speeds, but only at a minimal acceleration. That means that maximum speed is much faster, but accelerating to that speed takes immensely longer, and the same goes for deceleration. Maybe they've invented a new method I've not heard of with much higher acceleration, but that's not really mentioned in the video.
They actually seem to imply they plan to use the same tech as cyclotrons, which means essentially a huge rail gun (and that's not photonic propulsion BTW, it's magnetic). Again, the amount of propulsion is miniscule, but the top speed is high with that method. Yes, you can expel matter at near speed of light, but only in tiny amounts and using huge amounts of energy.
Yes, it may take 10 minutes to achieve 30% the speed of light....with single molecules or atoms.
There are MANY reasons why we can't do this at macro sizes. Just look at the size of a cyclotron needed to accelerate an atom to those relativistic speeds. Now think about sizing that up to accelerate enough matter to move a spaceship instead of a single atom and it's likely near the size of the entire planet. We won't be building a cyclotron that size ever, nor will we likely ever shrink the accelerators to a size where they can fit inside a spaceship to shoot trillions of atoms out like a light speed gun. They are just too big and use too much power. Maybe once fusion is perfected and miniaturization also perfected it could work for interstellar travel, but never for local space travel, the acceleration levels are just too small.
Also, it seems solar sails give the same or better acceleration to the same top speeds without the impossible technology....but they don't work too well for stopping except at other stars.

China's gamified new system for keeping citizens in line

ChaosEngine says...

Yeah, this really is beyond horrifying.

"PC is more scary that open totalitarianism"? Nope, here's your real villain: stealth totalitarianism. Fuck over your fellow man in the name of a higher score.

"Chairman, oppressing the citizenry is hard work!"
"Fear not! I have a cunning plan to make them oppress each other"

And by god will it work.... put a number beside a name and people will do anything to make that number go up.

As an example: my wife got a new car recently that shows your average fuel consumption in l/100km. I didn't pay any attention to it until I was playing in the settings and found I could switch the units to km/l. A completely innocuous change, right? Except now it's a number that can go up, and I am obsessed with making it go up everything I drive her car.

I set cruise control at the speed limit and brake as little as possible.

A/C? Not unless I am actually melting!

Corners? You'd be amazed at how fast you can round them if you let a machine control your speed!

Red lights? Er, yeah, I suppose I should stop, but then I'll have to accelerate again!

And that number doesn't even matter! FSM only knows what I'd do if it affected my mortgage rate or something....



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