/sci/ - Science & Math

>>9521308
Nothing says we can't artificially surpass this limit.

>>9521320
so that "more speed means more mass" theory is only for particles?

>>9521320
And how would we do that, theoretically?

>>9521346
Alcubierre drive

>>9521308
Wormholes

>>9521353
Ah yes, of course. Then all we need is the mystic "exotic matter". Other "uses" of exotic mater: Time travel, infinite energy, and antigravity.

Sorry, but it can't and won't exist. It's a dumb mathematical anomaly of negative mass.

>>9521353
>>9521356
Where are all the alien civilization if such things are possible?

>measure speed of light again for shits and giggles
>dropped by about 100km/s since the last time
What are the implications, /sci/?

>>9521320
Since you use a "real" name (unlike most everybody else here), I can identify your posts.
Can I ask a question?
Have much physics have you studied (and leaned)?

Not trying to put you down, but you seem to have fallen for a number of sensationalistic pop-sci memes.

>>9521363
Universe is vast. Really vast.

>>9521330
its for all matter, but we do know that at a certain radius from us space is expanding away "faster than light"

so the concept exists

>>9521320
Since you use a "real" name (unlike most everybody else here), I can identify your posts.
Can I ask a question?
Have much physics have you studied (and learned)?

Not trying to put you down, but you seem to have fallen for a number of sensationalistic pop-sci memes.

>>9521361
he said theoretically
>>9521363
maybe it isnt, but if it was theres plenty of reasons why they might not. maybe they just really hate you

>>9521370
Fair point. But the Universe is also incredible old. Enough time has passed for alien civilizations to colonize giant swathes of space. Maybe they hide themselves but that's all speculation.

>>9521320
HAHAHAAHHA ALITTLE KIDDY BOY THINSK HE KNOWS HAHAHAHAHAHHAHAHAHAHHAHAHAHHA
HE HASNTE VEN HAVE HAD 2 YEARS OF DOING NOTHING BUT STUDY PHYSICS 8 HOURS A DAY

I ALREADY HAVE 25 YEARS OF THAT
AND THE PEOPLE WITH 40 OR 50 PLUS ALL AGREE WITH ME
CANT BEAT THE LIGHT SPEED
SO HAHA BUTT OBLITEEAREATED BOY WALK ON HOME DEFEATED LITTL EINFERIOR

>>9521376
>maybe they just really hate you
All the more reason to come down and deal with this non-zero risk.

>>9521368
Physics is not my field of study (i'm more a biology guy). I spit on the pop-sci BS.

>>9521364
Must be a glitch in the simulation.

>>9521364
the speed of light isnt a constant and everything we know is embarrassingly wrong. humanity would suicide

>>9521382
Fair enough.
FTL leads to really really serious problems with physics.
The Alcubierre drive and wormholes are genuine solutions to the Einstein equations.
No one is denying that.
But they all require "exotic matter", matter with a tensile strength greater than it's own mass. (It may seem dimensionally incorrect to compare "mass" and "tension" but that's the way it comes out in Einstein. There are conversion factors I'm glossing over here.)
Anyway, there are proofs that ANY superluminal scheme requires "exotic" matter.
And there are good reasons to believe it doesn't, and can't, exist. Most physicists would dismiss it out of hand, though they'd admit they can't prove it's so.

Steven Hawking has proposed a "chronology protection clause" which would absolutely ban FTL (as well as time machines and "naked" singularities) If created quantum fluctuations would instantly destroy the device before it could be used.

If you're interested in a non-mathematical (but definitely NOT pop-sci) introduction to the field, read Kip Thorne's book
>https://www.amazon.com/Black-Holes-Time-Warps-Commonwealth/dp/0393312763
Note this edition has "Nobel Prize Winner" stamped on the cover. That was for LIGO.

>>9521308
>You have to travel 10 years to nearest star
>blocks
t.brainlet

>>9521372
call back when you make a spaceship out of space

>>9521308
You can reach other stars without exceeding the speed of light, nearest stars are reachable within couple of decades with drives we can design even today.

>>9521364
something wrong with your method or data. ancient civilization measurements were very close to the modern one so it seems very unlikely to have shrunk that much in a few decades

>>9521499
>ancient civilization measurements
>of the speed of light

>>9521515
>>9521554

>>9521499
>ancient civilization
>a few decades

>>9521308
If you accelerate to at least 10% of G (Earth's Gravity 9.8 m/s^2), your ship will reach over half of c. Using this method you could reach Alpha Centauri within 12 years with minor relativistic effects.

>Bernard's Star - 14 years
>Sirius - 17 years
>Epsilon Eridani - 19 years
>61 Cygni - 20 years
>Tau Ceti - 20 years

>>9521353
>Alcubierre drive
>>9521356
>Wormholes
Both would violate causality if used for FTL (assuming either is possible).

>>9521353
>>9521356
neither of those surpass that limit. They completely obey it in every sense.

>>9521652

Depends on the type of courses you fly. You don't need to create a CTC with FTL unless you try.

It could be the case if you fly FTL, change your conventional velocity too much at the other end, then FTL back, which is what you do to create a CTC, you'll create an overload as soon as you try to go FTL and run into a wall of Hawking radiation.

>>9521308
>I'm blocked by something I can't even reach

>>9521619
>Bernard's Star - 14 years
>Sirius - 17 years
>Epsilon Eridani - 19 years
>61 Cygni - 20 years
>Tau Ceti - 20 years

Slowboating+Human life extension is the way.
Also we probably won't colonize any other planets, just create space habitats and travel to other stars to research life or astrophysical objects.

>>9521694
>just create space habitat
literally why though?

>>9521308
>unblocks it

>>9521720
>spend 20 years building space habitat with living space comparable to Argentina and controllable weather
>spend 500 years terraforming planet with wrong gravity so that it can resemble Russian Tundra
tough choice

>>9521694
>Slowboating
is this related to motorboating?

>>9521725
>living space comparable to Argentina
forget about it, if its anything like argentinta corrupt politicians will destroy it before it gets anywhere

>>9521730
so make it absolutely any other size
you can build them as big as you want, so long as your material choice has sufficient tensile strength

>>9521619
>travel at high % of c
>touch pebble
>ship is now slag and shrapnel
we need energy shields or heavy duty point defense lasers first, or we're going to get our shit kicked in record time by the interstellar medium

>>9521372

>>9521751
>travel at high % of c
>touch pebble
>ship is now slag and shrapnel
https://www.centauri-dreams.org/2009/04/03/shielding-the-starship/

Semyonov plots the radiation involved from encountering interstellar gas versus velocity and finds that at speeds much above a comparatively sedate 0.1 c, an astronaut could not be outside the hull without layers of shielding. Shielding the entire ship is problematic. A radiation-absorbing windscreen installed in front of the vehicle is possible, a titanium shield of 1-2 cm workable up to 0.3 c but becoming ‘dramatically thicker with acceleration.

>>9521725
>only 20 years to build a living space comparable to Argentina... in space
>terraforming is the only way to colonize planets
Your opinion has been discarded.

Just make something with imaginary mass.
infinite acceleration!

>>9521807
>>only 20 years to build a living space comparable to Argentina... in space
https://en.wikipedia.org/wiki/Bishop_Ring_(habitat)
>In the original proposal, the habitat would be approximately 1,000 km (620 mi) in radius and 500 km (310 mi) in width, containing 3 million square kilometers (1.2 million square miles) of living space,[3] comparable to the area of Argentina or India.
>>terraforming is the only way to colonize planets
Every planet you will encounter will be hostile to humans.Either by gravity, atmosphere or by biosphere(which is more valuable unspoiled for studying)

>>9521554
The coordinates are arbitrary, a modern add on, so it seems meaningless. but the speed of light can be found in two other places within the geometry of the great pyramid, when using the metre.

>>9521447
>If created quantum fluctuations would instantly destroy the device before it could be used.
Can you explain why to a brainlet? That seems pretty interesting

>>9521751
Would a magnetic shield work? Have the ship dilate interstellar dust by via an artificial magnetic shield? Realistic or science fiction?

>>9521781
Love Tim Urban's drawings

>>9521377
We could be the first

>>9521377
>Enough time has passed for alien civilizations to colonize giant swathes of space.
There is no reason for any civilization to extensively colonize after it reaches certain level of technological development.
>Maybe they hide themselves but that's all speculation.
We have several Dyson Sphere candidates already.

>>9521886
https://www.centauri-dreams.org/2009/02/09/dust-up-between-the-stars/
But there is another way to solve the problem. Magnetic shielding, using large current loops of superconducting wire to create a protective magnetic field, could reflect or deflect charged particles around the habitat. And the advantages of using the magnetic approach are considerable.

Get this: Although the mass of the magnetic shielding support structure is close to that of the hull shielding option we looked at above, the living quarters go from a space seven meters high and ten meters long (in three levels) to a habitat 200 meters in diameter with over 6000 cubic meters of usable volume. Foil bumpers are used to break down incoming dust into atoms and ionize the result, which can be then handled by the magnetic field.

>>9521782
that's just talking about interstellar gas and radiation, not the blunt force rape that rocks of decent size would be
it's speculated that there's more shit between the stars than around them, so we may very well hit something that the shield would be woefully inadequate to withstand

>>9521308
*blocks your Mars colonization*

>>9521308
the speed of light is so annoying because it's almost equal to 3*10^8

>>9521979
>make bowl
>spin it
>now have earth normal on the sides of the bowl
glory to engineering

>>9521985
If we crushed mars into a smaller ball then it would eventually have an acceleration of 9.8

>>9521995
We'll just send the astronauts up to mars with some mallets and tell them to crush it down a bit, then

>>9521995
doing that is a little finicky
you gotta get it perfect the first time or you're fucked

>>9521308
*Slows you down to 17 meters per second*

https://www.youtube.com/watch?v=EK6HxdUQm5s

>>9521995
>If we crushed mars into a smaller ball then it would eventually have an acceleration of 9.8 m/s^2

No. If you want Mars to have Earth-like gravity your going to have to make Mars dense enough to provide the same mass. What's your genius method for that?

>>9521308
Just increase the speed of light.

>>9521479
>nearest stars are reachable within couple of decades with drives we can design even today.
Nope.
The nearest stars are tens of thousands of years away with actual current technology, not "what-if" and "maybe" level stuff.
We'll have to invent something new to reach even the nearest stars in a reasonable time frame.

9522058
I see you've done everything you could to remain as uneducated as possible

>>9521694
>Human life extension is the way.
Maybe you could just give up your pipe-dream of personally walking on an alien world.
Generation ships are the way.

>>9522065
>giving up
this is why you fail at life

Simple solution
>AI piloted spacecraft
>Passengers in stasis
>Spacecraft accelerate at 1 mill-gee

>>9522050
Fnet = ma
Fg = (G* m1 * m2)/r^2
so if we set fg to fnet then we set m to m1 we would get
a = (G * m2)/r^2
so we can see that you can either increase the mass or decrease the radius. If we were to crush it then the mass would stay the same and the radius would go down so the force of gravity would go up.

>>9522071
>this is why you fail at life
When we do actually reach the stars, the goal won't be to put you personally on an alien world.

>>9521320
Why are there so many namefags on /sci/, that pretend to be educated and intelligent? Fuck off with your sci-fi/pop-sci shit and study something, cunts.

FTL travel is an anthrocentric fantasy because what most people seem to fall to grasp is that all those lovely planets and stars flew out there across the cosmos in the first place, on journeys over billions of years moving at a fraction of the speed of light.

>>9521320
>>9522098

>Nothing says we can't artificially surpass this limit.
TIL [math] \big( \text{Theory of Relativity} \big) = \big( \text{Nothing} \big) [/math]

t. namefag

>>9522345
Live from under an overpass

>>9522345
>TIL
Go back there.

>>9521308

>not fixing the meter such that c = 300,000,000 m/s

Why the meter was artificially ret-con-re-defined thus totally escapes me.

>>9521330
>>9521372
>relativistic mass
t. underaged
>>9521308
Just go fast, fucking length contraction will shorten the proper time of your journey without bound.

If you even did find an alien planet and land and you can breathe the air you would still probably die of a strange uncurable alien fungus

>>9521308
Not true Honkey, I can just create a stargate wormhole to anywhere in the galaxy by summoning a massive Black Power Hole, cracker

Only need 1g to travel around.

https://m.youtube.com/watch?v=GgpVe2G9ByE

>>9521363
They're here already.

>>9522592
what are the real life constant acceleration engines he's talking about?

>>9521554
>29°58'44" = 29.979246
gullible faggot

>>9521460
*blocks meaningful space exploration in your lifetime*

Better?

>>9522592
>e=mc^2

>>9522539
Thanks, Black Scientist Man.

>>9521364
It's slowing.

>>9522742
I will be happy to see interstellar probes in next 30-40 years, and prospect of manned travel in 100 years.
Cathedrals weren't built in a day or single lifespan either.

>>9521908
>There is no reason for any civilization to extensively colonize after it reaches certain level of technological development.
Fair enough, but I don't believe that every advanced civilization would go the same route. There should be at least some civilizations that colonized everything they could get their hands on. Is the Milky Way just too young for that and we are actually one of the first?
>We have several Dyson Sphere candidates already.
Interesting, but I can't find realible sources on that one.

>>9522798
Irrelevant. We will assimilate the Universe at 1/300th the speed of light until such a time that all things become one.

>>9521308
reading this thread has convinced me that /sci/ is possibly even more brain dead than /pol/
just replace jews for syfy memes

>>9522889
explain further

>>9522798
Interesting, but I can't find realible sources on that one.

https://home.fnal.gov/~carrigan/infrared_astronomy/infrared_astronomy_master.html

https://home.fnal.gov/~carrigan/infrared_astronomy/Other_searches.htm

>>9522800
>We will assimilate the Universe at 1/300th the speed of light until such a time that all things become one.
Actually with the speed of light you would be able to colonize only 25% or so of visible universe

>>9522058
>The nearest stars are tens of thousands of years away with actual current technology, not "what-if" and "maybe" level stuff.
We'll have to invent something new to reach even the nearest stars in a reasonable time frame.

Current technology allows us to construct drives capable of reaching nearest stars within 40-80 or so years. Quicker if we develop it more.
Speeds of 5-0% of light speed are withing our technological abilities today, it of course requires engineering but isn't anything that couldn't be done with an effort.
We can probably develop faster means of transportation that would require more breakthroughs and more dedicated resources like Project Starshot for probes where we could have vessels reaching other stars within decades

>>9522954
Who said anything about colonizing. Once the Universe collapses in on itself we will all be one once more. And then the cycle starts again.

>>9522965
pure cynical doubt is flowing from my attitude at your post
there's no way we're even close to 1% lightspeed or reaching anything further than Mars (with humans onboard) within the next century

>>9522974
Laser propulsion is perfectly doable and can send probes to other stars with 10% of light speed
https://en.wikipedia.org/wiki/Solar_sail

Honestly people. It's more realistic if we become immortal cyborgs first. Then we can worry about space travel and shit. At that point, time becomes irrelevant. We will assimilate the world. Planets turned into machines. All living this categorically organized and preserved in off-world habitats. Energy is the limit.

>>9522980
we're not gonna be a legit to communicate with them

>>9522984
Laser communication and Sun's gravity lensing by TAU relay probe

>>9522984
>We are not going to launch anything more fast than 1% of light speed
post shows it is certainly possible
>ok we won't be able to communicate
Changing the goalposts I see?

>>9522992
try it
I FUCKING DOUBT IT
but try it anyway
>>9522995
fucking suck my ass I didn't set any fucking goalposts cunt

>>9522889
>muh /pol/
Obsessed Ameriturds.

>>9522981
Cyborgs could just link up with utopian simulations. No point in going outwards if inwards is the easier method of ascending.

>>9523042
That would require literally everyone to not want to go out.
Even 0.001% of 10 billion is 100k people. Given enough time (and since they are imortal cyborgs they have time) they will amass resources needed to go to other solar system, where they can create their own culture based on exploration.
Plus no matter how advanced your civilization your resources will run out. So why not start gathering them asap.

>>9523042
>Cyborgs could just link up with utopian simulations
Meanwhile on /g/
>Wanting to become part of botnet
>FOSS community can't even write their own utopia. Lmao, the absolute state of FOSS.

>>9522605
Yea I'm an ayy AMA

>>9522889
It's true, no one in this thread seems to know anything about relativity except "muh speed of light."

>>9521363
Checking out all the interesting places in the universe, not visiting our backwater hillbilly system.

>>9524066
>chunks of rock, ice, and plasma are more interesting than an alien biosphere with tons of complex lifeforms

>>9522981
>It's more realistic if we become immortal cyborgs first.
>We will assimilate the world.
>Planets turned into machines.
>All living this categorically organized and preserved in off-world habitats.

We does this seem so familiar?

>>9522079
Like the Vaulters on ES2.

>>9522471
Wouldn't that be handy.

>>9522695
... RF resonance thrusters?

>>9522972
Evidence that it will?

And if true, I wonder if any previous space faring civilizations attempted to build a "seed ship" with their offspring in stasis, to accelerate away from the "crunch point"; then somehow ride out the impending explosion of radiation and subatomic particles moving at 99.99999%c..

>>9524073
>worn out brainlet meme
>implying that Earth is the only "complex biosphere"
>implying that Earth is near these other super-civilizations
>implying biospheres are the most interesting thing

>>9524083
If Borg would simply offer unlimited knowledge of all the races they encountered and virtual immortality in paradise for all they assimiliate Federation would fall within a year.

http://disc.yourwebapps.com/discussion.cgi?disc=159729;article=102431
Galactic Life Imager
Fri Jul 2, 2010 11:45pm
67.193.52.10

Mission - To image 1-meter-sized features including life, on planets up to 550 lightyears away. This volume of space contains an estimated 89,000 G-type stars like ours, and 1.8 million stars of all types. It would take many decades of operation to survey all of them.

Angular Resolution - To see 1-meter sized features at 550 lightyears requires a pair of telescopes positioned 415-AU apart (415-times the Earth-Sun distance). They can be launched in opposite directions to positions 208-AU from Earth.

Light Bucket - An earthlike planet may receive a similar amount of sunlight as Earth, about 1360 Watts per square meter. If we are viewing from a 90-deg angle, that radiation will be averaged over the 45-deg latitude zone of one hemisphere, giving an average 50 percent attenuation of reflected light. The above radiation muliplied by the surface area of one hemisphere, and reduced by the inverse square law over 550-lightyears distance, results in an exoplanet with a brightness of only 5.17E-22 Watts per square meter. If our videocamera is set up to detect 12 micron infrared light (1.66E-20 Joules per photon), with a 32x32 pixel single-photon avalanche diode (SPAD) detector running at 30 frames per second (that would be 30 photons per pixel per second) we would need a main reflecting mirror of 984,000 square meters area to collect a sufficient amount of light. This is equivalent to a circular mirror 1119-meters in diameter. Using shorter wavelength light, such as visible light versus infrared, increases the energy per photon and reduces the number of photons available per unit area, resulting in a larger main mirror to collect sufficient light, or alot of pixels not detecting any photons. Increasing the number of pixels in the camera and/or the frame rate has a similar negative effect.

>>9524205
Mirror Segments - A parabolic bowl with a 1000-meter focal length is very shallow having a surface area only 2 percent larger than a flat circular disk of the same diameter. If we construct the parabola out of equilateral triangular segments with 1.0392-meter edge length, which are then assembled into hexagonal mirrors 1.8-meters across the flats, then it would require 2,145,432 triangular segments. With a thickness of 7.5-centimeters the total mass of fused silica glass would be 167,805-tonnes. A 300-nanometer thick reflective aluminum coating would have a mass of 813-kg.

Manufacturing - Each factory would consist of a 19-meter diameter solar concentrator mirror focussing light on the interior of a metallized graphite crucible sheathed in zirconium orthosilicate. Inside the crucible the raw crushed silicate ore from an asteroid would be heated to 2273 deg Kelvin and melted to achieve a uniform composition, then stepped down to the softening temperature of 1956 deg Kelvin and extruded through a rectangular die. Four machines extruding a glass ribbon 0.9-meters wide x 0.075-meters thick at a rate of 11-centimeters per minute could manufacture all the required triangular glass blanks in under 60 months. After the glass ribbon is extruded it is stepped down to the annealing temperature of 1413 deg. Kelvin, where it is cut at angles of +60 and -60 degrees to produce triangular blanks. They are held at this temperature and annealed for 100 hrs to prevent shattering before cooling to room temperature. At a production rate of 12 blanks per hour per line, an annealing oven large enough to heat soak 4900 glass blanks would be needed. Once annealed the blanks are then polished to the diffraction limit (for 12 micron infrared radiation) and a 300-nm thick aluminum coating is applied to one surface. The mirrors are now externally reflective, the glass used merely as a geometric substrate for the reflective coating (glass is opaque to infrared).

>>9521378
>25 years
>real physics courses are only offered around second or third year of high school, the only thing close to college level being offered senior year
>16+25=41
A 41 year old man just sent a very heated message to another over the internet, with passion so it seems

>>9524140
>implying implications
You are speculating as much as anyone else here, yet you try to sound smarter. Just stop.

>>9521308
It doesn't, actually. By going very close to the speed of light, we can reach anywhere in (what would seem to us) as little time as we want.
the problem is reaching the speeds in the first place. not that we can't go faster.

>>9521377
>Enough time has passed for alien civilizations to colonize giant swathes of space
No. Space is a lot bigger than it is old. So big that, as far as alien life is concerned, you can ignore everything outside of our own galaxy.

>>9525986
I feel like this is basically time-travelling into the future more than anything else.

>>9521308
Who gives a fuck? It only takes twenty years to travel from star system to star system with tech we can almost build today. Now we only need to figure out a way to increase a person's lifespan by few hundred years - not nearly as impossible as breaking the speed of light - and there's nothing standing in the way of interstellar colonization.

>>9521619
>>9521694
>Tau Ceti - 20 years

if you accelerate at 1g you will get there in 5.2 years (by ship clock)