
Travel through wormholes is possible, but slow - lelf
https://phys.org/news/2019-04-wormholes.html
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noobermin
I'm not sure if this is the researchers' issue or is an issue with the
scientific press, but it would help if the "discoveries" theorists made with
their hitherto unestablished and untested theories like various string and QG
based theories were not touted as discoveries about the real world.

~~~
krastanov
"Discoveries" about the mathematical structure of these theories are actually
incredibly important even if no current day experiment can conceivably test
them. Special and general relativity were discoveries made in this way (at
least to an extent), and now general relativity is important for the proper
functioning of technology as "trivial and boring" as GPS. Even earlier in our
history, much of thermodynamics was developed in a similar fashion.

See the sibling comment for another version of this argument, but finding the
weird mathematical coincidences between the competing mathematical theories of
nature is very useful. In other words, there are mathematical and logical
tests that can be as important as experimental tests for the progress of our
understanding of nature.

~~~
ketralnis
They're incredibly important, but they shouldn't be touted as facts until
there's some consensus that they are facts

~~~
krastanov
Mathematical theorems (especially no-go theorems, one of the most powerful
tools in physics) are at least as much of a fact as an experimental
measurement. I can concede that a pop-sci outlet should be clear about what is
an experiment and what is a mathematical theorem, but was it really not clear
in this case?

This is a sincere question, and I care to hear your opinion: do you believe
that a reader of phys.org would need more than a glance at the article to know
this is a discovery about the mathematics of general relativity, not an
engineering breakthrough in the creation of a scifi-like hyperdrive?

~~~
naasking
> Mathematical theorems (especially no-go theorems, one of the most powerful
> tools in physics) are at least as much of a fact as an experimental
> measurement

That's an overstatement. Measurements are more important than theory. We
cannot form theories without measurements, and yes theories inform our
measurements, but science always begins and moves forward with measurements.

~~~
krastanov
General relativity, quantum computing, some parts of
thermodynamics/information theory/statistical physics, some parts of quantum
field theory, some parts of condensed matter physics are all things that
started as purely mathematical statements. I am not trying to diminish the
monumental importance of empirical measurements, but please do not diminish
the importance of logical consistency and mathematical constraints. We can say
a lot about our universe with great certainty even though in same cases making
direct measurements is orders of magnitude beyond our technology.

~~~
dbasedweeb
GR was amazing, but it wasn’t well known and accepted until the first
measurements confirmed it. Quantum Computing is still very much up in the air,
but it’s also weird to bring it up in this context, because QM is one of the
most tested theories of all time. QED In particular is tested to the most
decimal places of any prediction, ever. It’s also weird to act as though GR
and QM started out in a vacuum, instead of what they really were, which was
based on centuries of math, theory, and experiment.

Edit: Unrelated, but I see you’re a fellow Greg Egan fan, good to meet you!
Planck Dive has to be one of my all time favorites.

~~~
krastanov
We are talking past each other: It is a bit contradictory to say "quantum
computing is up in the air" and "QM is one of the most tested theories" as an
argument against what I am saying. Yes, both are statements are true, but they
are in no ways counterpoints to what I am saying, if anything they support it.
QM is a well established and empirically tested theory. Quantum Computing is a
purely mathematical construct that emerged from that well established theory
without any experimental evidence for it, and only now, 30 years later, we are
starting to have a chance to employ this purely mathematical construct in
practice.

Same with GR: it was a purely mathematical construct for a while until we
could test it, but there were too many theory clues that it must be right.

And this is not selection/survival bias: it is extremely rare for humanity to
find a robust mathematical construct for which we can have a high degree of
certainty that it describes the universe well. In the few cases where we have
had that certainty, due to mathematical proofs in seemingly disjoint fields,
we ended up being right.

To push it to stuff like super strings and quantum gravity: few respected
scientists would claim that their pet mathematical construct is correct, but
many of them will say "the vague commonalities between all these diverse and
seemingly unrelated mathematical constructs definitely point to an underlying
fundamental construct".

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SketchySeaBeast
Can someone point out where the article says why it's slower? I'm having
difficulty unpacking:

"The new theory was inspired when Jafferis began thinking about two black
holes that were entangled on a quantum level, as formulated in the ER=EPR
correspondence by Juan Maldacena from the Institute for Advanced Study and
Lenny Susskind from Stanford. Although this means the direct connection
between the black holes is shorter than the wormhole connection—and therefore
the wormhole travel is not a shortcut—the theory gives new insights into
quantum mechanics."

Why is the wormhole not a shortcut?

~~~
philipov
Based on the colloquia I watched by Lenny Susskind, the problem is that you
can put something into a wormhole, but to get it out the other end, you have
to carry the encoding you get to the other end of the wormhole to decode the
output. Because the distance to the singularity grows at the speed of light,
the length of the wormhole is essentially infinite. It is only the operator
you get from putting the object into the wormhole that lets it tunnel through
that infinity, so no shortcut.

EDIT: Here is the lecture I'm referring to:
[https://www.youtube.com/watch?v=nEDFh8ma9zM](https://www.youtube.com/watch?v=nEDFh8ma9zM)

~~~
logfromblammo
So...

Two entangled wormhole apertures function as Star Trek style transporter pads.
Feed mass into one hole, scanning it as it goes in. Transmit the pattern to
another aperture of the hole, using electromagnetic energy at the speed of
light, and when that end ejects a mass, apply the pattern to it, so it
resolves into an exact copy of what you put in.

The distance the mass travels may be shorter than the distance the energy
travels, but it can't resolve exiting mass as that object until the
information--that had to travel at the speed of light--arrives.

So you could potentially use a wormhole as a suicide machine that transports a
copy of you, that thinks it actually is you, to a distant location no faster
than the speed of light, in zero subjective time for the thing that will then
think it's you.

Is that a reasonable interpretation?

~~~
ben_w
I don’t think the suicide booth model of a teleporter fits a quantum
teleporter model, only the 3D printer teleporter model. From a quantum point
of view, all (e.g.) electrons are indistinguishable excitations in the same
field, and it’s the pattern that makes you “you”. If you’ll forgive a bit of
poetic licence, quantum teleportation seems more like Discworld magic, where
you have to exchange two identical sized lumps of matter.

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Abishek_Muthian
>To date, a major stumbling block in formulating traversable wormholes has
been the need for negative energy, which seemed to be inconsistent with
quantum gravity. However, Jafferis has overcome this using quantum field
theory tools, calculating quantum effects similar to the Casimir effect.

Prof. Stephen Hawking has explained the Casimir effect in hist last book
'Brief Answers to the Big Questions' in the chapter talking about Time Travel
with Wormholes.

"Imaging that you have two parallel metal plates a short distance apart. The
plates act like mirrors for the virtual particles and anti-particles. This
means that the region between the plates is a bit like an organ pipe and will
only admit light waves of certain resonant frequencies. The result is that
there are a slightly different number of vacuum fluctuations or virtual
particles between the plates than there are outside them, where vacuum
fluctuations can have any wavelength. The difference in number of virtual
particles between the plates compared with outside the plates means that they
don't exert much pressure on one side of the plates when compared with the
other. There is thus a slight force pushing the pates together. This force has
been measured experimentally. So, virtual particles actually exist and produce
real effects.

Because there are fewer virtual particles or vacuum fluctuations between
plates, they have a lower energy density than in the region outside. But the
energy density of empty space far away from the plates must be zero. Otherwise
it would warp space-time and the universe wouldn't be nearly flat. So the
energy density in the region between the plates must be negative"

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jaequery
When ever I think of traveling through a wormhole/blackhole, I imagine you
would be squished and crushed and come out the other end as pure vaporized
energy.

This makes me wonder, if there is the potential for our beings (or things) be
able to be vaporized and then recreated to original form.

If we are just mass and particles, this should be possible?

~~~
lupire
Uncertainty principle says...probably not. It's impossible to make a complete
copy of the pattern.

Even aside from that -- it's unlikely to be practical to scan something down
to the smallest level level of matter, because the tools we use to manipulate
things can't manipulate things smaller than their own finest details. So
there's a "glass wall" in that you can only replicate things less finely
detailed than the replicator. That works fine for macroscopic things (that's
why you can buy a 3D printer today), but is implausible for things that we
believe to be as finely detailed as our machines.

~~~
pontifier
That's what the "Heisinberg compensators" in star trek fix. I heard this
phrase in an episode once, and decided to figure out how that could even
work...

What I came up with was the idea that the scanning stage doesn't need to
gather exact data because it really doesn't matter. You just need to get
averages, and then build up a model that matches the statistics... (you don't
need to discover the exact energy and momentum of every particle, just measure
the temperature)

Basically you get teleporter jpeg compression... good enough to fool you, just
don't use it too many times without keeping the raw data:)

~~~
Zardoz84
"Heisinberg compensators" it's a clever lie that La Forge uses to fool
Moriarty on a chapter.

~~~
pontifier
They are mentioned several times, but no description is given for how they
might work.

[https://memory-alpha.fandom.com/wiki/Heisenberg_compensator](https://memory-
alpha.fandom.com/wiki/Heisenberg_compensator)

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readtheplaque
George R. R. Martin called it in 1974! :)
[https://scifi.stackexchange.com/questions/84453/scientist-
di...](https://scifi.stackexchange.com/questions/84453/scientist-discovers-
hyperspace-with-a-twist/84454#84454)

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vectorEQ
"To date, a major stumbling block in formulating traversable wormholes has
been the need for negative energy, which seemed to be inconsistent with
quantum gravity. "

it appears thus, most humans are inconsistent with quantum gravity :D:D

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krastanov
I would urge people interested in this topic to read the hard scifi work of
Greg Egan. In particularly, Diaspora. It is fascinating how much overlap is
between this mathematical work and his work of "mathematical fiction".

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philwelch
It seems to me that the speed of light, like conservation of energy, is just
one of those fundamental “no free lunch” rules of physics that we just plain
can’t cheat.

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drdeca
Why doesn’t this violate the topological censorship result?

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docode
It's possible.

