The past, present, and future are not fundamental properties of Minkowski spacetime. It has been suggested that they are properties of a class of information gathering and utilizing systems (IGUSs). A human is a model IGUS robot. We provide a demonstration that what is perceived as past, present, and future is not uniquely determined from the laws of physics by constructing a robot that process information differently and therefore experience different “presents.” We construct a customized virtual reality (VR) system which allows an observer to switch between present and past moments. This “robot” (human with VR system) can experience immersion in the immediate past ad libitum. Being able to actually construct an IGUS that has the same “present” at two different coordinates along the worldline lends support to the IGUS approach for explaining the psychological nature of past/present/future.

1.
J. B.
Hartle
, “
The physics of now
,”
Am. J. Phys.
73
(
101
),
101
109
(
2005
).
2.
M.
Gell-Mann
and
J. B.
Hartle
, “
Decoherent histories quantum mechanics with one real fine-grained history
,”
Phys. Rev. A
85
,
062120
(
2012
).
3.
F.
Dowker
and
A.
Kent
, “
On the consistent histories approach to quantum mechanics
,”
J. Stat. Phys.
82
,
1575
1646
(
1996
).
4.

The target machine was running a capable CPU/GPU and at least 32 gigabytes of RAM. Unity video game engine was the core of the experience and provided the graphics engine, interface, and streaming tools necessary to receive the visual data from the camera, decode it, and display it to the observer as 180° video. The necessary changes required to also allow Unity to cache the visual data and replay it was made in C#, making use of the Graphics API provided. The cache was constructed as a buffer for textures and was made to hold as many frames as needed to display a certain timeframe to the observer during runtime when triggered.

5.
In the normal brain much of what the visual field information is exposed to is not sent to memory. Much depends upon what the observer attends to [
N.
Cowan
,
Attention and Memory: An Integrated Framework
(
Oxford U.P.
,
Oxford
,
2008
)]. Using the VR system with outriggers, the observer is experiencing the benefit of a powerful memory system for experiencing the “past” that he/she would not get otherwise with the less sophisticated biological memory system.
6.
G. C.
Burdea
and
P.
Coiffet
,
Virtual Reality Technology
(
John Wiley & Sons
,
London
,
2003
).
7.
D.
Friedman
,
R.
Pizarro
,
K.
Or-Berkers
,
S.
Neyret
,
P.
Zueni
, and
M.
Slater
, “
A method for generating an illusion of backwards time travel using immersive virtual reality—An exploratory study
,”
Front. Psychol.
5
,
943
(
2014
).
8.
P.
Davies
, “
That mysterious flow
,”
Sci. Am. Spec. Ed.
16
,
6
11
(
2006
).
9.
H.
Price
, “
The flow of time
,” in
The Oxford Handbook of the Philosophy of Time
, edited by
C.
Callender
(
Oxford U.P.
,
Oxford
,
2011
), pp.
276
311
.
10.
K.
Van Acoleyen
and
J.
Van Doorsselaere
, “
Captain Einstein: A VR experience of relativity
,” preprint arXiv:1806.11085 (
2018
), pp.
1
11
.
AAPT members receive access to the American Journal of Physics and The Physics Teacher as a member benefit. To learn more about this member benefit and becoming an AAPT member, visit the Joining AAPT page.